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mariadb ST_GeometryCollectionFromText ST\_GeometryCollectionFromText ============================== A synonym for [ST\_GeomCollFromText](../st_geomcollfromtext/index). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Progress Reporting Progress Reporting ================== MariaDB supports progress reporting for some long running commands. What is Progress Reporting? --------------------------- Progress reporting means that: * There is a `Progress` column in [SHOW PROCESSLIST](../show-processlist/index) which shows the total progress (0-100%) * [INFORMATION\_SCHEMA.PROCESSLIST](../information-schema-processlist-table/index) has three columns which allow you to see in which process stage we are and how much of that stage is completed: + `STAGE` + `MAX_STAGE` + `PROGRESS` (within current stage). * The client receives progress messages which it can display to the user to indicate how long the command will take. We have separate progress reporting for stages because different stages take different amounts of time. Supported Commands ------------------ Currently, the following commands can send progress report messages to the client: * [ALTER TABLE](../alter-table/index) * [CREATE INDEX](../create-index/index) * [DROP INDEX](../drop-index/index) * [LOAD DATA INFILE](../load-data-infile/index) (not `LOAD DATA LOCAL INFILE`, as in that case we don't know the size of the file). Some Aria storage engine operations also support progress messages: * [CHECK TABLE](../check-table/index) * [REPAIR TABLE](../repair-table/index) * [ANALYZE TABLE](../analyze-table/index) * [OPTIMIZE TABLE](../optimize-table/index) ### Limitations Although the above commands support progress reporting, there are some limitations to what progress is reported. To be specific, when executing one of these commands against an InnoDB table with [ALGORITHM=INPLACE](../innodb-online-ddl-operations-with-algorithminplace/index) (which is the default in [MariaDB 10.0](../what-is-mariadb-100/index)+), progress is only reported during the merge sort phase while reconstructing indexes. Enabling and Disabling Progress Reporting ----------------------------------------- `mysqld` (the MariaDB server) automatically sends progress report messages to clients that support the new protocol, using the value of the [progress\_report\_time](../server-system-variables/index#progress_report_time) variable. They are sent every max(`global.progress_report_time` , `progress_report_time`) seconds (by default 5). You can disable the sending of progress report messages to the client by setting either the local variable (affects only the current connection) or the global variable (affects all connections) to `0`. If the extra column in `SHOW PROCESSLIST` gives you a compatibility problem, you can disable it by starting `mysqld` with the `--old` flag. Clients Which Support Progress Reporting ---------------------------------------- * The [`mysql` command line client](../mysql-command-line-client/index) * The `mytop` that comes with MariaDB has a `'%'` column which shows the progress. Progress Reporting in the mysql Command Line Client --------------------------------------------------- Progress reporting is enabled by default in the [mysql client](../mysql-command-line-client/index). You can disable it with `--disable-progress-reports`. It is automatically disabled in batch mode. When enabled, for every supported command you get a progress report like: ``` ALTER TABLE my_mail ENGINE=aria; Stage: 1 of 2 'copy to tmp table' 5.37% of stage done ``` This is updated every [progress\_report\_time](../server-system-variables/index#progress_report_time) seconds (the default is 5). If the global `progress_report_time` is higher, this will be used. You can also disable error reporting by setting the variable to `0`. How to Add Support for Progress Peporting to a MySQL Client ----------------------------------------------------------- You need to use the [MariaDB 5.3](../what-is-mariadb-53/index) or later client library. You can check that the library supports progress reporting by doing: ``` #ifdef CLIENT_PROGRESS ``` To enable progress reporting to the client you need to add `CLIENT_PROGRESS` to the `connect_flag` in `mysql_real_connect()`: ``` mysql_real_connect(mysql, host, user, password, database, opt_mysql_port, opt_mysql_unix_port, connect_flag | CLIENT_PROGRESS); ``` Then you need to provide a callback function for progress reports: ``` static void report_progress(const MYSQL *mysql, uint stage, uint max_stage, double progress, const char *proc_info, uint proc_info_length); mysql_options(&mysql, MYSQL_PROGRESS_CALLBACK, (void*) report_progress); ``` The above `report_progress` function will be called for each progress message. This is the implementation used by `mysql.cc`: ``` uint last_progress_report_length; static void report_progress(const MYSQL *mysql, uint stage, uint max_stage, double progress, const char *proc_info, uint proc_info_length) { uint length= printf("Stage: %d of %d '%.*s' %6.3g%% of stage done", stage, max_stage, proc_info_length, proc_info, progress); if (length < last_progress_report_length) printf("%*s", last_progress_report_length - length, ""); putc('\r', stdout); fflush(stdout); last_progress_report_length= length; } ``` If you want only one number for the total progress, you can calculate it with: ``` double total_progress= ((stage -1) / (double) max_stage * 100.00 + progress / max_stage); ``` **Note:** `proc_info` is totally independent of stage. You can have many different `proc_info` values within a stage. The idea behind `proc_info` is to give the user more information about what the server is doing. How to Add Support for Progress Reporting to a Storage Engine ------------------------------------------------------------- The functions to use for progress reporting are: ``` void thd_progress_init(MYSQL_THD thd, unsigned int max_stage); ``` Initialize progress reporting with stages. This is mainly used for commands that are totally executed within the engine, like `CHECK TABLE`. You should not use this for operations that could be called by, for example, `ALTER TABLE` as this has already called the function. `max_stage` is the number of stages your storage engine will have. ``` void thd_progress_report(MYSQL_THD thd, unsigned long long progress, unsigned long long max_progress); ``` The above is used for reporting progress. * `progress` is how much of the file/rows/keys you have gone through. * `max_progress` is the max number of rows you will go through. You can call this with varying numbers, but normally the ratio `progress/max_progress` should be increasing. This function can be called even if you are not using stages, for example when enabling keys as part of `ALTER TABLE` or `ADD INDEX`. ``` void thd_progress_next_stage(MYSQL_THD thd); ``` To go to the next stage in a multi-stage process initiated by `thd_progress_init()`: ``` void thd_progress_end(MYSQL_THD thd); ``` End progress reporting; Sets 'Progress' back to 0 in `SHOW PROCESSLIST`. ``` const char *thd_proc_info(thd, 'stage name'); ``` This sets the name of the current status/stage that is displayed in `SHOW PROCESSLIST` and in the client. It's recommended that you call this between stages and thus before `thd_progress_report()` and `thd_progress_next_stage()`. This functions returns the last used `proc_info`. It's recommended that you restore `proc_info` to its original value when you are done processing. **Note:** `thd_proc_info()` is totally independent of stage. You can have many different `proc_info` values within a stage to give the user more information about what is going on. Examples to Look at in the MariaDB Source: ------------------------------------------ * `client/mysql.cc` for an example of how to use reporting. * `libmysql/client.c:cli_safe_read()` to see how progress packets are handled in client * `sql/protocol.cc::net_send_progress_packet()` for how progress packets are handled in server. Format of Progress Packets -------------------------- The progress packet is sent as an error packet with error number `65535`. It contains the following data (in addition to the error header): | Option | Number of bytes | Other info | | --- | --- | --- | | 1 | 1 | Number of strings. For future | | Stage | 1 | Stage from 1 - Max\_stage | | Max\_stage | 1 | Max number of stages | | Progress | 3 | Progress in `% * 1000` | | Status\_length | 1-2 | Packet length of string in `net_field_length()` format | | Status | Status\_length | Status / Stage name | See Also -------- * [What is MariaDB 5.3](../what-is-mariadb-53/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Information Schema INNODB_SYS_VIRTUAL Table Information Schema INNODB\_SYS\_VIRTUAL Table ============================================= **MariaDB starting with [10.2](../what-is-mariadb-102/index)**The `INNODB_SYS_VIRTUAL` table was added in [MariaDB 10.2](../what-is-mariadb-102/index). The [Information Schema](../information_schema/index) `INNODB_SYS_VIRTUAL` table contains information about base columns of [virtual columns](../generated-columns/index). The `PROCESS` [privilege](../grant/index) is required to view the table. It contains the following columns: | | | | | | | | --- | --- | --- | --- | --- | --- | | Field | Type | Null | Key | Default | Description | | TABLE\_ID | bigint(21) unsigned | NO | | 0 | | | POS | int(11) unsigned | NO | | 0 | | | BASE\_POS | int(11) unsigned | NO | | 0 | | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Concurrent Inserts Concurrent Inserts ================== The [MyISAM](../myisam/index) storage engine supports concurrent inserts. This feature allows [SELECT](../select/index) statements to be executed during [INSERT](../insert/index) operations, reducing contention. Whether concurrent inserts can be used or not depends on the value of the [concurrent\_insert](../server-system-variables/index#concurrent_insert) server system variable: * `NEVER` (0) disables concurrent inserts. * `AUTO` (1) allows concurrent inserts only when the target table has no free blocks (no data in the middle of the table has been deleted after the last [OPTIMIZE TABLE](../optimize-table/index)). This is the default. * `ALWAYS` (2) always enables concurrent inserts, in which case new rows are added at the end of a table if the table is being used by another thread. If the [binary log](../binary-log/index) is used, [CREATE TABLE ... SELECT](../create-table/index#create-table-select) and [INSERT ... SELECT](../insert-select/index) statements cannot use concurrent inserts. These statements acquire a read lock on the table, so concurrent inserts will need to wait. This way the log can be safely used to restore data. Concurrent inserts are not used by replicas with the row based [replication](../replication/index) (see [binary log formats](../binary-log-formats/index)). If an [INSERT](../insert/index) statement contain the [HIGH\_PRIORITY](../high_priority-and-low_priority-clauses/index) clause, concurrent inserts cannot be used. [INSERT ... DELAYED](../insert-delayed/index) is usually unneeded if concurrent inserts are enabled. [LOAD DATA INFILE](../load-data-infile/index) uses concurrent inserts if the `CONCURRENT` keyword is specified and [concurrent\_insert](../server-system-variables/index#concurrent_insert) is not `NEVER`. This makes the statement slower (even if no other sessions access the table) but reduces contention. [LOCK TABLES](../transactions-lock/index) allows non-conflicting concurrent inserts if a `READ LOCAL` lock is used. Concurrent inserts are not allowed if the `LOCAL` keyword is omitted. Notes ----- The decision to enable concurrent insert for a table is done when the table is opened. If you change the value of [concurrent\_insert](../server-system-variables/index#concurrent_insert) it will only affect new opened tables. If you want it to work for also for tables in use or cached, you should do [FLUSH TABLES](../flush/index) after setting the variable. See Also -------- * [INSERT](../insert/index) * [INSERT DELAYED](../insert-delayed/index) * [INSERT SELECT](../insert-select/index) * [HIGH\_PRIORITY and LOW\_PRIORITY](../high_priority-and-low_priority/index) * [INSERT - Default & Duplicate Values](../insert-default-duplicate-values/index) * [INSERT IGNORE](../insert-ignore/index) * [INSERT ON DUPLICATE KEY UPDATE](../insert-on-duplicate-key-update/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Database Design Example Phases 4-6: Testing, Operation and Maintenance Database Design Example Phases 4-6: Testing, Operation and Maintenance ====================================================================== This article follows on from [Database Design Example Phase 3: Implementation](../database-design-example-phase-3-implementation/index). Once the database is ready the application programs have been rolled out, it's time for the testing to begin. While the other phases of the database lifecycle can occur reasonably independently of the systems development process, part of the testing phase is how all the components run together. Load testing may indicate that MariaDB has not been set up to handle the expected 600 concurrent connections, and the configuration file needs to be changed. Other tests may indicate that in certain circumstances, duplicate key errors are received, as the locking mechanism is not uniformly implemented, and the application does not handle locking correctly. The application needs to be fixed. Backups also need to be tested, as well as the ability to smoothly restore from backup with a minimum of downtime. Testing is one of the most neglected and critical phases. A designer or manager who does not properly account for testing is simply incompetent. No matter how tiny your system, make sure you allocate time for thorough testing, and time for fixing the inevitable bugs. Once testing is complete, the system can be rolled out. You decide on a low-key rollout and give a few selected poets access to the website to upload their poems. You discover other problems. Some poets upload poems using [character sets](../data-types-character-sets-and-collations/index) you haven't catered for, and you need to make a few tweaks to ensure these are handled correctly. Soon enough, the system is rolled out completely. Maintenance, though, is a never-ending task, and with the immense popularity of the system, and with large numbers of updates and deletes, the system tends to become fragmented. The administrator regularly needs to take care of this, and, of course, the inevitable disk failure leads to an all-night restore session, and much thankfulness for the ease of use of [mysqldump](../mysqldump/index).. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Aria Storage Formats Aria Storage Formats ==================== The [Aria](../aria/index) storage engine supports three different table storage formats. These are FIXED, DYNAMIC and PAGE, and they can be set with the ROW FORMAT option in the [CREATE TABLE](../create-table/index) statement. PAGE is the default format, while FIXED and DYNAMIC are essentially the same as the [MyISAM formats](../myisam-storage-formats/index). The [SHOW TABLE STATUS](../show-table-status/index) statement can be used to see the storage format used by a table. Fixed-length ------------ Fixed-length (or static) tables contain records of a fixed-length. Each column is the same length for all records, regardless of the actual contents. It is the default format if a table has no BLOB, TEXT, VARCHAR or VARBINARY fields, and no ROW FORMAT is provided. You can also specify a fixed table with ROW\_FORMAT=FIXED in the table definition. Tables containing BLOB or TEXT fields cannot be FIXED, as by design these are both dynamic fields. Fixed-length tables have a number of characteristics * fast, since MariaDB will always know where a record begins * easy to cache * take up more space than dynamic tables, as the maximum amount of storage space will be allocated to each record. * reconstructing after a crash is uncomplicated due to the fixed positions * no fragmentation or need to re-organize, unless records have been deleted and you want to free the space up. Dynamic ------- Dynamic tables contain records of a variable length. It is the default format if a table has any BLOB, TEXT, VARCHAR or VARBINARY fields, and no ROW FORMAT is provided. You can also specify a DYNAMIC table with ROW\_FORMAT=DYNAMIC in the table definition. Dynamic tables have a number of characteristics * Each row contains a header indicating the length of the row. * Rows tend to become fragmented easily. UPDATING a record to be longer will likely ensure it is stored in different places on the disk. * All string columns with a length of four or more are dynamic. * They require much less space than fixed-length tables. * Restoring after a crash is more complicated than with FIXED tables. Page ---- Page format is the default format for Aria tables, and is the only format that can be used if TRANSACTIONAL=1. Page tables have a number of characteristics: * It's cached by the page cache, which gives better random performance as it uses fewer system calls. * Does not fragment as easily easily as the DYNAMIC format during UPDATES. The maximum number of fragments are very low. * Updates more quickly than dynamic tables. * Has a slight storage overhead, mainly notable on very small rows * Slower to perform a full table scan * Slower if there are multiple duplicated keys, as Aria will first write a row, then keys, and only then check for duplicates Transactional ------------- See [Aria Storage Engine](../aria-storage-engine/index) for the impact of the TRANSACTIONAL option on the row format. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb SHOW EVENTS SHOW EVENTS =========== Syntax ------ ``` SHOW EVENTS [{FROM | IN} schema_name] [LIKE 'pattern' | WHERE expr] ``` Description ----------- Shows information about Event Manager [events](../events/index) (created with `[CREATE EVENT](../create-event/index)`). Requires the `[EVENT](../grant/index#database-privileges)` privilege. Without any arguments, `SHOW EVENTS` lists all of the events in the current schema: ``` SELECT CURRENT_USER(), SCHEMA(); +----------------+----------+ | CURRENT_USER() | SCHEMA() | +----------------+----------+ | jon@ghidora | myschema | +----------------+----------+ SHOW EVENTS\G *************************** 1. row *************************** Db: myschema Name: e_daily Definer: jon@ghidora Time zone: SYSTEM Type: RECURRING Execute at: NULL Interval value: 10 Interval field: SECOND Starts: 2006-02-09 10:41:23 Ends: NULL Status: ENABLED Originator: 0 character_set_client: latin1 collation_connection: latin1_swedish_ci Database Collation: latin1_swedish_ci ``` To see the event action, use `[SHOW CREATE EVENT](../show-create-event/index)` instead, or look at the `[information\_schema.EVENTS](../information-schema-events-table/index)` table. To see events for a specific schema, use the `FROM` clause. For example, to see events for the test schema, use the following statement: ``` SHOW EVENTS FROM test; ``` The `LIKE` clause, if present, indicates which event names to match. The `WHERE` clause can be given to select rows using more general conditions, as discussed in [Extended Show](../extended-show/index). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb Upgrading from MariaDB 10.6 to MariaDB 10.7 Upgrading from MariaDB 10.6 to MariaDB 10.7 =========================================== ### How to Upgrade For Windows, see [Upgrading MariaDB on Windows](../upgrading-mariadb-on-windows/index). For MariaDB Galera Cluster, see [Upgrading from MariaDB 10.6 to MariaDB 10.7 with Galera Cluster](upgrading-from-mariadb-106-to-mariadb-107-with-galera-cluster) instead. Before you upgrade, it would be best to take a backup of your database. This is always a good idea to do before an upgrade. We would recommend [Mariabackup](../mariabackup/index). The suggested upgrade procedure is: 1. Modify the repository configuration, so the system's package manager installs [MariaDB 10.7](../what-is-mariadb-107/index). For example, * On Debian, Ubuntu, and other similar Linux distributions, see [Updating the MariaDB APT repository to a New Major Release](../installing-mariadb-deb-files/index#updating-the-mariadb-apt-repository-to-a-new-major-release) for more information. * On RHEL, CentOS, Fedora, and other similar Linux distributions, see [Updating the MariaDB YUM repository to a New Major Release](../yum/index#updating-the-mariadb-yum-repository-to-a-new-major-release) for more information. * On SLES, OpenSUSE, and other similar Linux distributions, see [Updating the MariaDB ZYpp repository to a New Major Release](../installing-mariadb-with-zypper/index#updating-the-mariadb-zypp-repository-to-a-new-major-release) for more information. 2. [Stop MariaDB](../starting-and-stopping-mariadb-automatically/index). 3. Uninstall the old version of MariaDB. * On Debian, Ubuntu, and other similar Linux distributions, execute the following: `sudo apt-get remove mariadb-server` * On RHEL, CentOS, Fedora, and other similar Linux distributions, execute the following: `sudo yum remove MariaDB-server` * On SLES, OpenSUSE, and other similar Linux distributions, execute the following: `sudo zypper remove MariaDB-server` 4. Install the new version of MariaDB. * On Debian, Ubuntu, and other similar Linux distributions, see [Installing MariaDB Packages with APT](../installing-mariadb-deb-files/index#installing-mariadb-packages-with-apt) for more information. * On RHEL, CentOS, Fedora, and other similar Linux distributions, see [Installing MariaDB Packages with YUM](../yum/index#installing-mariadb-packages-with-yum) for more information. * On SLES, OpenSUSE, and other similar Linux distributions, see [Installing MariaDB Packages with ZYpp](../installing-mariadb-with-zypper/index#installing-mariadb-packages-with-zypp) for more information. 5. Make any desired changes to configuration options in [option files](../configuring-mariadb-with-option-files/index), such as `my.cnf`. This includes removing any options that are no longer supported. 6. [Start MariaDB](../starting-and-stopping-mariadb-automatically/index). 7. Run [mariadb-upgrade](../mariadb-upgrade/index). * `mariadb-upgrade` does two things: 1. Ensures that the system tables in the [mysql](../the-mysql-database-tables/index) database are fully compatible with the new version. 2. Does a very quick check of all tables and marks them as compatible with the new version of MariaDB . ### Incompatible Changes Between 10.6 and 10.7 On most servers upgrading from 10.6 should be painless. However, there are some things that have changed which could affect an upgrade: #### Compression If a non-zlib compression algorithm was used in [InnoDB](../innodb/index) or [Mroonga](../mroonga/index) before upgrading to 10.7, those tables will be unreadable until the appropriate compression library is installed. See [Compression Plugins#Upgrading](../compression-plugins/index#upgrading). #### Options That Have Been Removed or Renamed The following options should be removed or renamed if you use them in your [option files](../configuring-mariadb-with-option-files/index): | Option | Reason | | --- | --- | | [wsrep\_replicate\_myisam](../galera-cluster-system-variables/index#wsrep_replicate_myisam) | Use [wsrep\_mode](../galera-cluster-system-variables/index#wsrep_mode) instead. | | [wsrep\_strict\_ddl](../galera-cluster-system-variables/index#wsrep_strict_ddl) | Use [wsrep\_mode](../galera-cluster-system-variables/index#wsrep_mode) instead. | ### See Also * [The features in MariaDB 10.7](../what-is-mariadb-107/index) * [Upgrading from MariaDB 10.6 to MariaDB 10.7 with Galera Cluster](upgrading-from-mariadb-106-to-mariadb-107-with-galera-cluster) * [Upgrading from MariaDB 10.5 to MariaDB 10.6](../upgrading-from-mariadb-105-to-mariadb-106/index) * [Upgrading from MariaDB 10.4 to MariaDB 10.5](../upgrading-from-mariadb-104-to-mariadb-105/index) * [Upgrading from MariaDB 10.3 to MariaDB 10.4](../upgrading-from-mariadb-103-to-mariadb-104/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Enhancements for START TRANSACTION WITH CONSISTENT SNAPSHOT Enhancements for START TRANSACTION WITH CONSISTENT SNAPSHOT =========================================================== With the introduction of [group commit](../group-commit-for-the-binary-log/index), MariaDB also introduced an enhanced storage engine API for COMMIT that allows engines to coordinate commit ordering and visibility with each other and with the [binary log](../binary-log/index). With these improvements, the `START TRANSACTION WITH CONSISTENT SNAPSHOT` statement was enhanced to ensure consistency between storage engines that support the new API. At the time of writing, the supporting engines are [XtraDB](../xtradb-and-innodb/index) and [PBXT](../pbxt-storage-engine/index). In addition, the binary log, while not a storage engine as such, also supports the new API and can provide a binlog position consistent with storage engine transaction snapshots. This means that with transaction isolation level at least [REPEATABLE READ](../set-transaction/index#repeatable-read), the `START TRANSACTION WITH CONSISTENT SNAPSHOT` statement can be used to ensure that queries will see a transaction-consistent view of the database also between storage engines. It is then not possible for a query to see the changes from some transaction T in XtraDB tables without also seeing the changes T makes to PBXT tables. (Within a single transactional storage engine like XtraDB or PBXT, consistency is always guaranteed even without using `START TRANSACTION WITH CONSISTENT SNAPSHOT`). For example, suppose the following two transactions run in parallel: Transaction T1: ``` BEGIN; SET @t = NOW(); UPDATE xtradb_table SET a= @t WHERE id = 5; UPDATE pbxt_table SET b= @t WHERE id = 5; COMMIT; ``` Transaction T2: ``` SET TRANSACTION ISOLATION LEVEL REPEATABLE READ; START TRANSACTION WITH CONSISTENT SNAPSHOT; SELECT t1.a, t2.b FROM xtradb_table t1 INNER JOIN pbxt_table t2 ON t1.id=t2.id WHERE t1.id = 5; ``` Then transaction T2 will always see the same value for `xtradb_table.a` and `pbxt_table.b`. (In [MariaDB 5.2](../what-is-mariadb-52/index) and earlier, and MySQL at least up to 5.5, `START TRANSACTION WITH CONSISTENT SNAPSHOT` did not give any guarantees of consistency between different storage engines. So it is possible, even with a "consistent" snapshot, to see the changes in a transaction only to InnoDB/XtraDB tables, not PBXT tables, for example.) Status Variables ---------------- Another use for these enhancements is to obtain a binary log position that is consistent with a particular transactional state of the storage engine(s) in the database. This is done with two status variables for the binary log: [binlog\_snapshot\_file](../replication-and-binary-log-status-variables/index#binlog_snapshot_file) and [binlog\_snapshot\_position](../replication-and-binary-log-status-variables/index#binlog_snapshot_position) These variables give the binary log file and position like `SHOW MASTER STATUS` does. But they can be queried in a transactionally consistent way. After starting a transaction using `START TRANSACTION WITH CONSISTENT SNAPSHOT`, the two variables will give the binlog position corresponding to the state of the database of the consistent snapshot so taken, irrespectively of which other transactions have been committed since the snapshot was taken (`SHOW MASTER STATUS` always shows the position of the last committed transaction). This works for MVCC storage engines that implement the commit ordering part of the storage engine API, which at the time of writing is XtraDB and PBXT. This is useful to obtain a logical dump/backup with a matching binlog position that can be used to provision a new slave with the original server as the master. First `START TRANSACTION WITH CONSISTENT SNAPSHOT` is executed. Then a consistent state of the database is obtained with queries, and the matching binlog position is obtained with `SHOW STATUS LIKE 'binlog_snapshot%'`. When this is loaded on a new slave server, the binlog position is used in a `CHANGE MASTER TO` statement to set the slave replicating from the correct position. With the variables binlog\_snapshot\_file and binlog\_snapshot\_position, such provisioning can be done fully non-blocking on the master. Without them, it is necessary to get the binlog position under `FLUSH TABLES WITH READ LOCK`; this can potentially stall the server for a long time, as it blocks new queries until all updates that have already started have finished. ### mysqldump The [mysqldump](../mysqldump/index) program was extended to use these status variables. This means that a backup suitable for provisioning a slave can be obtained as normal like this: ``` mysqldump --single-transaction --master-data ... ``` The dump will be fully non-blocking if both the mysqldump program and the queried server include the necessary feature (eg. both are from [MariaDB 5.2](../what-is-mariadb-52/index)-rpl, 5.3, or higher). In other cases, it will fall back to the old blocking method using `FLUSH TABLES WITH READ LOCK`. For more information on the design and implementation of this feature, see [MWL#136](http://askmonty.org/worklog/?tid=136). See Also -------- * [START TRANSACTION](../start-transaction/index) * [What is MariaDB 5.3](../what-is-mariadb-53/index) * [MyRocks and START TRANSACTION WITH CONSISTENT SNAPSHOT](../myrocks-and-start-transaction-with-consistent-snapshot/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb CEILING CEILING ======= Syntax ------ ``` CEILING(X) ``` Description ----------- Returns the smallest integer value not less than X. Examples -------- ``` SELECT CEILING(1.23); +---------------+ | CEILING(1.23) | +---------------+ | 2 | +---------------+ SELECT CEILING(-1.23); +----------------+ | CEILING(-1.23) | +----------------+ | -1 | +----------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Information Functions Information Functions ====================== General information functions, including BENCHMARK, CHARSET, DATABASE, USER, VERSION, etc. | Title | Description | | --- | --- | | [BENCHMARK](../benchmark/index) | Executes an expression repeatedly. | | [BINLOG\_GTID\_POS](../binlog_gtid_pos/index) | Returns a string representation of the corresponding GTID position. | | [CHARSET](../charset/index) | Returns the character set. | | [COERCIBILITY](../coercibility/index) | Returns the collation coercibility value. | | [COLLATION](../collation/index) | Collation of the string argument. | | [CONNECTION\_ID](../connection_id/index) | Connection thread ID. | | [CURRENT\_ROLE](../current_role/index) | Current role name. | | [CURRENT\_USER](../current_user/index) | Username/host that authenticated the current client. | | [DATABASE](../database/index) | Current default database. | | [DECODE\_HISTOGRAM](../decode_histogram/index) | Returns comma separated numerics corresponding to a probability distribution. | | [DEFAULT](../default/index) | Returns column default. | | [FOUND\_ROWS](../found_rows/index) | Number of (potentially) returned rows. | | [LAST\_INSERT\_ID](../last_insert_id/index) | Last inserted auto\_increment value. | | [LAST\_VALUE](../last_value/index) | Returns the last value in a list or set of values. | | [PROCEDURE ANALYSE](../procedure-analyse/index) | Suggests optimal data types for each column. | | [ROWNUM](../rownum/index) | Function that returns the number of accepted rows so far. | | [ROW\_COUNT](../row_count/index) | Number of rows affected by previous statement. | | [SCHEMA](../schema/index) | Synonym for DATABASE(). | | [SESSION\_USER](../session_user/index) | Synonym for USER(). | | [SYSTEM\_USER](../system_user/index) | Synonym for USER(). | | [USER](../user/index) | Current user/host. | | [VERSION](../version/index) | MariaDB server version. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb 10.1.25 Release Upgrade Tests 10.1.25 Release Upgrade Tests ============================= Upgrade from 10.0 ----------------- ### Tested revision da7604a2943f633df3b193e26ee20110bae9fa7a ### Test date 2017-07-04 18:46:27 ### Summary (PASS) All tests passed ### Details | # | type | pagesize | OLD version | file format | encrypted | compressed | | NEW version | file format | encrypted | compressed | readonly | result | notes | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | 1 | crash | 4 | 10.0.28 (inbuilt) | Antelope | - | - | => | 10.1.25 (inbuilt) | Antelope | - | - | - | OK | | | 2 | crash | 4 | 10.0.28 (inbuilt) | Barracuda | - | - | => | 10.1.25 (inbuilt) | Barracuda | - | - | - | OK | | | 3 | crash | 4 | 10.0.28 (inbuilt) | Antelope | - | - | => | 10.1.25 (inbuilt) | Antelope | on | - | - | OK | | | 4 | crash | 4 | 10.0.28 (inbuilt) | Barracuda | - | - | => | 10.1.25 (inbuilt) | Barracuda | on | - | - | OK | | | 5 | crash | 8 | 10.0.28 (inbuilt) | Antelope | - | - | => | 10.1.25 (inbuilt) | Antelope | on | - | - | OK | | | 6 | crash | 8 | 10.0.28 (inbuilt) | Barracuda | - | - | => | 10.1.25 (inbuilt) | Barracuda | on | - | - | OK | | | 7 | crash | 8 | 10.0.28 (inbuilt) | Barracuda | - | - | => | 10.1.25 (inbuilt) | Barracuda | - | - | - | OK | | | 8 | crash | 8 | 10.0.28 (inbuilt) | Antelope | - | - | => | 10.1.25 (inbuilt) | Antelope | - | - | - | OK | | | 9 | crash | 16 | 10.0.28 (inbuilt) | Antelope | - | - | => | 10.1.25 (inbuilt) | Antelope | - | - | - | OK | | | 10 | crash | 16 | 10.0.28 (inbuilt) | Barracuda | - | - | => | 10.1.25 (inbuilt) | Barracuda | - | - | - | OK | | | 11 | crash | 16 | 10.0.28 (inbuilt) | Antelope | - | - | => | 10.1.25 (inbuilt) | Antelope | on | - | - | OK | | | 12 | crash | 16 | 10.0.28 (inbuilt) | Barracuda | - | - | => | 10.1.25 (inbuilt) | Barracuda | on | - | - | OK | | | 13 | normal | 4 | 10.0.28 (inbuilt) | Barracuda | - | - | => | 10.1.25 (inbuilt) | Barracuda | on | - | - | OK | | | 14 | normal | 4 | 10.0.28 (inbuilt) | Antelope | - | - | => | 10.1.25 (inbuilt) | Antelope | on | - | - | OK | | | 15 | normal | 4 | 10.0.28 (inbuilt) | Barracuda | - | - | => | 10.1.25 (inbuilt) | Barracuda | - | - | - | OK | | | 16 | normal | 4 | 10.0.28 (inbuilt) | Antelope | - | - | => | 10.1.25 (inbuilt) | Antelope | - | - | - | OK | | | 17 | normal | 8 | 10.0.28 (inbuilt) | Barracuda | - | - | => | 10.1.25 (inbuilt) | Barracuda | - | - | - | OK | | | 18 | normal | 8 | 10.0.28 (inbuilt) | Antelope | - | - | => | 10.1.25 (inbuilt) | Antelope | - | - | - | OK | | | 19 | normal | 8 | 10.0.28 (inbuilt) | Barracuda | - | - | => | 10.1.25 (inbuilt) | Barracuda | on | - | - | OK | | | 20 | normal | 8 | 10.0.28 (inbuilt) | Antelope | - | - | => | 10.1.25 (inbuilt) | Antelope | on | - | - | OK | | | 21 | normal | 16 | 10.0.28 (inbuilt) | Antelope | - | - | => | 10.1.25 (inbuilt) | Antelope | on | - | - | OK | | | 22 | normal | 16 | 10.0.28 (inbuilt) | Barracuda | - | - | => | 10.1.25 (inbuilt) | Barracuda | on | - | - | OK | | | 23 | normal | 16 | 10.0.28 (inbuilt) | Antelope | - | - | => | 10.1.25 (inbuilt) | Antelope | - | - | - | OK | | | 24 | normal | 16 | 10.0.28 (inbuilt) | Barracuda | - | - | => | 10.1.25 (inbuilt) | Barracuda | - | - | - | OK | | Upgrade from 10.1 ----------------- ### Tested revision da7604a2943f633df3b193e26ee20110bae9fa7a ### Test date 2017-07-04 19:37:09 ### Summary (FAIL) [MDEV-13112](https://jira.mariadb.org/browse/MDEV-13112), [MDEV-13113](https://jira.mariadb.org/browse/MDEV-13113), one unknown failure ### Details | # | type | pagesize | OLD version | file format | encrypted | compressed | | NEW version | file format | encrypted | compressed | readonly | result | notes | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | 1 | crash | 64 | 10.1.20 (inbuilt) | Antelope | - | zlib | => | 10.1.25 (inbuilt) | Antelope | - | zlib | - | OK | | | 2 | crash | 64 | 10.1.20 (inbuilt) | Barracuda | - | zlib | => | 10.1.25 (inbuilt) | Barracuda | - | zlib | - | OK | | | 3 | crash | 64 | 10.1.20 (inbuilt) | Barracuda | on | zlib | => | 10.1.25 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | [MDEV-13112](https://jira.mariadb.org/browse/MDEV-13112)(31) | | 4 | crash | 64 | 10.1.20 (inbuilt) | Antelope | on | zlib | => | 10.1.25 (inbuilt) | Antelope | on | zlib | - | OK | | | 5 | crash | 64 | 10.1.20 (inbuilt) | Barracuda | - | - | => | 10.1.25 (inbuilt) | Barracuda | - | - | - | OK | | | 6 | crash | 64 | 10.1.20 (inbuilt) | Antelope | - | - | => | 10.1.25 (inbuilt) | Antelope | - | - | - | OK | | | 7 | crash | 64 | 10.1.20 (inbuilt) | Antelope | on | - | => | 10.1.25 (inbuilt) | Antelope | on | - | - | OK | | | 8 | crash | 64 | 10.1.20 (inbuilt) | Barracuda | on | - | => | 10.1.25 (inbuilt) | Barracuda | on | - | - | OK | | | 9 | crash | 8 | 10.1.20 (inbuilt) | Antelope | - | zlib | => | 10.1.25 (inbuilt) | Antelope | - | zlib | - | OK | | | 10 | crash | 8 | 10.1.20 (inbuilt) | Barracuda | - | zlib | => | 10.1.25 (inbuilt) | Barracuda | - | zlib | - | OK | | | 11 | crash | 8 | 10.1.20 (inbuilt) | Antelope | on | zlib | => | 10.1.25 (inbuilt) | Antelope | on | zlib | - | OK | | | 12 | crash | 8 | 10.1.20 (inbuilt) | Barracuda | on | zlib | => | 10.1.25 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | [MDEV-13112](https://jira.mariadb.org/browse/MDEV-13112)(14) | | 13 | crash | 8 | 10.1.20 (inbuilt) | Barracuda | on | - | => | 10.1.25 (inbuilt) | Barracuda | on | - | - | OK | | | 14 | crash | 8 | 10.1.20 (inbuilt) | Antelope | on | - | => | 10.1.25 (inbuilt) | Antelope | on | - | - | OK | | | 15 | crash | 8 | 10.1.20 (inbuilt) | Barracuda | - | - | => | 10.1.25 (inbuilt) | Barracuda | - | - | - | OK | | | 16 | crash | 8 | 10.1.20 (inbuilt) | Antelope | - | - | => | 10.1.25 (inbuilt) | Antelope | - | - | - | OK | | | 17 | crash | 16 | 10.1.20 (inbuilt) | Barracuda | - | zlib | => | 10.1.25 (inbuilt) | Barracuda | - | zlib | - | **FAIL** | [MDEV-13113](https://jira.mariadb.org/browse/MDEV-13113) | | 18 | crash | 16 | 10.1.20 (inbuilt) | Antelope | - | zlib | => | 10.1.25 (inbuilt) | Antelope | - | zlib | - | OK | | | 19 | crash | 16 | 10.1.20 (inbuilt) | Barracuda | on | zlib | => | 10.1.25 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | [MDEV-13113](https://jira.mariadb.org/browse/MDEV-13113) | | 20 | crash | 16 | 10.1.20 (inbuilt) | Antelope | on | zlib | => | 10.1.25 (inbuilt) | Antelope | on | zlib | - | OK | | | 21 | crash | 16 | 10.1.20 (inbuilt) | Antelope | on | - | => | 10.1.25 (inbuilt) | Antelope | on | - | - | OK | | | 22 | crash | 16 | 10.1.20 (inbuilt) | Barracuda | on | - | => | 10.1.25 (inbuilt) | Barracuda | on | - | - | **FAIL** | [MDEV-13113](https://jira.mariadb.org/browse/MDEV-13113) | | 23 | crash | 16 | 10.1.20 (inbuilt) | Antelope | - | - | => | 10.1.25 (inbuilt) | Antelope | - | - | - | OK | | | 24 | crash | 16 | 10.1.20 (inbuilt) | Barracuda | - | - | => | 10.1.25 (inbuilt) | Barracuda | - | - | - | **FAIL** | [MDEV-13113](https://jira.mariadb.org/browse/MDEV-13113) | | 25 | crash | 32 | 10.1.20 (inbuilt) | Barracuda | - | - | => | 10.1.25 (inbuilt) | Barracuda | - | - | - | OK | | | 26 | crash | 32 | 10.1.20 (inbuilt) | Antelope | - | - | => | 10.1.25 (inbuilt) | Antelope | - | - | - | OK | | | 27 | crash | 32 | 10.1.20 (inbuilt) | Barracuda | on | - | => | 10.1.25 (inbuilt) | Barracuda | on | - | - | OK | | | 28 | crash | 32 | 10.1.20 (inbuilt) | Antelope | on | - | => | 10.1.25 (inbuilt) | Antelope | on | - | - | OK | | | 29 | crash | 32 | 10.1.20 (inbuilt) | Barracuda | on | zlib | => | 10.1.25 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | [MDEV-13112](https://jira.mariadb.org/browse/MDEV-13112)(23) | | 30 | crash | 32 | 10.1.20 (inbuilt) | Antelope | on | zlib | => | 10.1.25 (inbuilt) | Antelope | on | zlib | - | OK | | | 31 | crash | 32 | 10.1.20 (inbuilt) | Barracuda | - | zlib | => | 10.1.25 (inbuilt) | Barracuda | - | zlib | - | OK | | | 32 | crash | 32 | 10.1.20 (inbuilt) | Antelope | - | zlib | => | 10.1.25 (inbuilt) | Antelope | - | zlib | - | OK | | | 33 | crash | 4 | 10.1.20 (inbuilt) | Barracuda | on | zlib | => | 10.1.25 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | [MDEV-13112](https://jira.mariadb.org/browse/MDEV-13112)(7) | | 34 | crash | 4 | 10.1.20 (inbuilt) | Antelope | on | zlib | => | 10.1.25 (inbuilt) | Antelope | on | zlib | - | OK | | | 35 | crash | 4 | 10.1.20 (inbuilt) | Barracuda | - | zlib | => | 10.1.25 (inbuilt) | Barracuda | - | zlib | - | **FAIL** | UPGRADE\_FAILURE | | 36 | crash | 4 | 10.1.20 (inbuilt) | Antelope | - | zlib | => | 10.1.25 (inbuilt) | Antelope | - | zlib | - | OK | | | 37 | crash | 4 | 10.1.20 (inbuilt) | Antelope | - | - | => | 10.1.25 (inbuilt) | Antelope | - | - | - | OK | | | 38 | crash | 4 | 10.1.20 (inbuilt) | Barracuda | - | - | => | 10.1.25 (inbuilt) | Barracuda | - | - | - | OK | | | 39 | crash | 4 | 10.1.20 (inbuilt) | Antelope | on | - | => | 10.1.25 (inbuilt) | Antelope | on | - | - | OK | | | 40 | crash | 4 | 10.1.20 (inbuilt) | Barracuda | on | - | => | 10.1.25 (inbuilt) | Barracuda | on | - | - | OK | | | 41 | normal | 8 | 10.1.20 (inbuilt) | Antelope | on | - | => | 10.1.25 (inbuilt) | Antelope | on | - | - | OK | | | 42 | normal | 8 | 10.1.20 (inbuilt) | Barracuda | on | - | => | 10.1.25 (inbuilt) | Barracuda | on | - | - | OK | | | 43 | normal | 8 | 10.1.20 (inbuilt) | Antelope | - | - | => | 10.1.25 (inbuilt) | Antelope | - | - | - | OK | | | 44 | normal | 8 | 10.1.20 (inbuilt) | Barracuda | - | - | => | 10.1.25 (inbuilt) | Barracuda | - | - | - | OK | | | 45 | normal | 8 | 10.1.20 (inbuilt) | Barracuda | - | zlib | => | 10.1.25 (inbuilt) | Barracuda | - | zlib | - | OK | | | 46 | normal | 8 | 10.1.20 (inbuilt) | Antelope | - | zlib | => | 10.1.25 (inbuilt) | Antelope | - | zlib | - | OK | | | 47 | normal | 8 | 10.1.20 (inbuilt) | Barracuda | on | zlib | => | 10.1.25 (inbuilt) | Barracuda | on | zlib | - | OK | | | 48 | normal | 8 | 10.1.20 (inbuilt) | Antelope | on | zlib | => | 10.1.25 (inbuilt) | Antelope | on | zlib | - | OK | | | 49 | normal | 64 | 10.1.20 (inbuilt) | Antelope | on | zlib | => | 10.1.25 (inbuilt) | Antelope | on | zlib | - | OK | | | 50 | normal | 64 | 10.1.20 (inbuilt) | Barracuda | on | zlib | => | 10.1.25 (inbuilt) | Barracuda | on | zlib | - | OK | | | 51 | normal | 64 | 10.1.20 (inbuilt) | Barracuda | - | zlib | => | 10.1.25 (inbuilt) | Barracuda | - | zlib | - | OK | | | 52 | normal | 64 | 10.1.20 (inbuilt) | Antelope | - | zlib | => | 10.1.25 (inbuilt) | Antelope | - | zlib | - | OK | | | 53 | normal | 64 | 10.1.20 (inbuilt) | Barracuda | on | - | => | 10.1.25 (inbuilt) | Barracuda | on | - | - | OK | | | 54 | normal | 64 | 10.1.20 (inbuilt) | Antelope | on | - | => | 10.1.25 (inbuilt) | Antelope | on | - | - | OK | | | 55 | normal | 64 | 10.1.20 (inbuilt) | Antelope | - | - | => | 10.1.25 (inbuilt) | Antelope | - | - | - | OK | | | 56 | normal | 64 | 10.1.20 (inbuilt) | Barracuda | - | - | => | 10.1.25 (inbuilt) | Barracuda | - | - | - | OK | | | 57 | normal | 32 | 10.1.20 (inbuilt) | Antelope | on | zlib | => | 10.1.25 (inbuilt) | Antelope | on | zlib | - | OK | | | 58 | normal | 32 | 10.1.20 (inbuilt) | Barracuda | on | zlib | => | 10.1.25 (inbuilt) | Barracuda | on | zlib | - | OK | | | 59 | normal | 32 | 10.1.20 (inbuilt) | Antelope | - | zlib | => | 10.1.25 (inbuilt) | Antelope | - | zlib | - | OK | | | 60 | normal | 32 | 10.1.20 (inbuilt) | Barracuda | - | zlib | => | 10.1.25 (inbuilt) | Barracuda | - | zlib | - | OK | | | 61 | normal | 32 | 10.1.20 (inbuilt) | Barracuda | on | - | => | 10.1.25 (inbuilt) | Barracuda | on | - | - | OK | | | 62 | normal | 32 | 10.1.20 (inbuilt) | Antelope | on | - | => | 10.1.25 (inbuilt) | Antelope | on | - | - | OK | | | 63 | normal | 32 | 10.1.20 (inbuilt) | Antelope | - | - | => | 10.1.25 (inbuilt) | Antelope | - | - | - | OK | | | 64 | normal | 32 | 10.1.20 (inbuilt) | Barracuda | - | - | => | 10.1.25 (inbuilt) | Barracuda | - | - | - | OK | | | 65 | normal | 16 | 10.1.20 (inbuilt) | Antelope | on | zlib | => | 10.1.25 (inbuilt) | Antelope | on | zlib | - | OK | | | 66 | normal | 16 | 10.1.20 (inbuilt) | Barracuda | on | zlib | => | 10.1.25 (inbuilt) | Barracuda | on | zlib | - | OK | | | 67 | normal | 16 | 10.1.20 (inbuilt) | Antelope | - | zlib | => | 10.1.25 (inbuilt) | Antelope | - | zlib | - | OK | | | 68 | normal | 16 | 10.1.20 (inbuilt) | Barracuda | - | zlib | => | 10.1.25 (inbuilt) | Barracuda | - | zlib | - | OK | | | 69 | normal | 16 | 10.1.20 (inbuilt) | Barracuda | - | - | => | 10.1.25 (inbuilt) | Barracuda | - | - | - | OK | | | 70 | normal | 16 | 10.1.20 (inbuilt) | Antelope | - | - | => | 10.1.25 (inbuilt) | Antelope | - | - | - | OK | | | 71 | normal | 16 | 10.1.20 (inbuilt) | Antelope | on | - | => | 10.1.25 (inbuilt) | Antelope | on | - | - | OK | | | 72 | normal | 16 | 10.1.20 (inbuilt) | Barracuda | on | - | => | 10.1.25 (inbuilt) | Barracuda | on | - | - | OK | | | 73 | normal | 4 | 10.1.20 (inbuilt) | Barracuda | on | - | => | 10.1.25 (inbuilt) | Barracuda | on | - | - | OK | | | 74 | normal | 4 | 10.1.20 (inbuilt) | Antelope | on | - | => | 10.1.25 (inbuilt) | Antelope | on | - | - | OK | | | 75 | normal | 4 | 10.1.20 (inbuilt) | Antelope | - | - | => | 10.1.25 (inbuilt) | Antelope | - | - | - | OK | | | 76 | normal | 4 | 10.1.20 (inbuilt) | Barracuda | - | - | => | 10.1.25 (inbuilt) | Barracuda | - | - | - | OK | | | 77 | normal | 4 | 10.1.20 (inbuilt) | Antelope | on | zlib | => | 10.1.25 (inbuilt) | Antelope | on | zlib | - | OK | | | 78 | normal | 4 | 10.1.20 (inbuilt) | Barracuda | on | zlib | => | 10.1.25 (inbuilt) | Barracuda | on | zlib | - | OK | | | 79 | normal | 4 | 10.1.20 (inbuilt) | Antelope | - | zlib | => | 10.1.25 (inbuilt) | Antelope | - | zlib | - | OK | | | 80 | normal | 4 | 10.1.20 (inbuilt) | Barracuda | - | zlib | => | 10.1.25 (inbuilt) | Barracuda | - | zlib | - | OK | | Upgrade from MySQL 5.6 ---------------------- ### Tested revision da7604a2943f633df3b193e26ee20110bae9fa7a ### Test date 2017-07-04 22:22:10 ### Summary (PASS) All tests passed ### Details | # | type | pagesize | OLD version | file format | encrypted | compressed | | NEW version | file format | encrypted | compressed | readonly | result | notes | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | 1 | normal | 16 | 5.6.35 (inbuilt) | Antelope | - | - | => | 10.1.25 (inbuilt) | Antelope | - | - | - | OK | | | 2 | normal | 16 | 5.6.35 (inbuilt) | Barracuda | - | - | => | 10.1.25 (inbuilt) | Barracuda | - | - | - | OK | | | 3 | normal | 16 | 5.6.35 (inbuilt) | Antelope | - | - | => | 10.1.25 (inbuilt) | Antelope | on | - | - | OK | | | 4 | normal | 16 | 5.6.35 (inbuilt) | Barracuda | - | - | => | 10.1.25 (inbuilt) | Barracuda | on | - | - | OK | | | 5 | normal | 4 | 5.6.35 (inbuilt) | Barracuda | - | - | => | 10.1.25 (inbuilt) | Barracuda | - | - | - | OK | | | 6 | normal | 4 | 5.6.35 (inbuilt) | Antelope | - | - | => | 10.1.25 (inbuilt) | Antelope | - | - | - | OK | | | 7 | normal | 4 | 5.6.35 (inbuilt) | Antelope | - | - | => | 10.1.25 (inbuilt) | Antelope | on | - | - | OK | | | 8 | normal | 4 | 5.6.35 (inbuilt) | Barracuda | - | - | => | 10.1.25 (inbuilt) | Barracuda | on | - | - | OK | | | 9 | normal | 8 | 5.6.35 (inbuilt) | Antelope | - | - | => | 10.1.25 (inbuilt) | Antelope | - | - | - | OK | | | 10 | normal | 8 | 5.6.35 (inbuilt) | Barracuda | - | - | => | 10.1.25 (inbuilt) | Barracuda | - | - | - | OK | | | 11 | normal | 8 | 5.6.35 (inbuilt) | Barracuda | - | - | => | 10.1.25 (inbuilt) | Barracuda | on | - | - | OK | | | 12 | normal | 8 | 5.6.35 (inbuilt) | Antelope | - | - | => | 10.1.25 (inbuilt) | Antelope | on | - | - | OK | | Crash recovery -------------- ### Tested revision da7604a2943f633df3b193e26ee20110bae9fa7a ### Test date 2017-07-04 22:47:13 ### Summary (FAIL) [MDEV-13112](https://jira.mariadb.org/browse/MDEV-13112) ### Details | # | type | pagesize | OLD version | file format | encrypted | compressed | | NEW version | file format | encrypted | compressed | readonly | result | notes | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | 1 | crash | 16 | 10.1.25 (inbuilt) | Antelope | on | - | => | 10.1.25 (inbuilt) | Antelope | on | - | - | OK | | | 2 | crash | 16 | 10.1.25 (inbuilt) | Barracuda | on | - | => | 10.1.25 (inbuilt) | Barracuda | on | - | - | OK | | | 3 | crash | 16 | 10.1.25 (inbuilt) | Antelope | - | - | => | 10.1.25 (inbuilt) | Antelope | - | - | - | OK | | | 4 | crash | 16 | 10.1.25 (inbuilt) | Barracuda | - | - | => | 10.1.25 (inbuilt) | Barracuda | - | - | - | OK | | | 5 | crash | 16 | 10.1.25 (inbuilt) | Antelope | on | zlib | => | 10.1.25 (inbuilt) | Antelope | on | zlib | - | OK | | | 6 | crash | 16 | 10.1.25 (inbuilt) | Barracuda | on | zlib | => | 10.1.25 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | [MDEV-13112](https://jira.mariadb.org/browse/MDEV-13112)(39) | | 7 | crash | 16 | 10.1.25 (inbuilt) | Antelope | - | zlib | => | 10.1.25 (inbuilt) | Antelope | - | zlib | - | OK | | | 8 | crash | 16 | 10.1.25 (inbuilt) | Barracuda | - | zlib | => | 10.1.25 (inbuilt) | Barracuda | - | zlib | - | OK | | | 9 | crash | 4 | 10.1.25 (inbuilt) | Antelope | on | - | => | 10.1.25 (inbuilt) | Antelope | on | - | - | OK | | | 10 | crash | 4 | 10.1.25 (inbuilt) | Barracuda | on | - | => | 10.1.25 (inbuilt) | Barracuda | on | - | - | OK | | | 11 | crash | 4 | 10.1.25 (inbuilt) | Barracuda | - | - | => | 10.1.25 (inbuilt) | Barracuda | - | - | - | OK | | | 12 | crash | 4 | 10.1.25 (inbuilt) | Antelope | - | - | => | 10.1.25 (inbuilt) | Antelope | - | - | - | OK | | | 13 | crash | 4 | 10.1.25 (inbuilt) | Barracuda | on | zlib | => | 10.1.25 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | [MDEV-13112](https://jira.mariadb.org/browse/MDEV-13112)(54) | | 14 | crash | 4 | 10.1.25 (inbuilt) | Antelope | on | zlib | => | 10.1.25 (inbuilt) | Antelope | on | zlib | - | OK | | | 15 | crash | 4 | 10.1.25 (inbuilt) | Antelope | - | zlib | => | 10.1.25 (inbuilt) | Antelope | - | zlib | - | OK | | | 16 | crash | 4 | 10.1.25 (inbuilt) | Barracuda | - | zlib | => | 10.1.25 (inbuilt) | Barracuda | - | zlib | - | OK | | | 17 | crash | 32 | 10.1.25 (inbuilt) | Antelope | on | zlib | => | 10.1.25 (inbuilt) | Antelope | on | zlib | - | OK | | | 18 | crash | 32 | 10.1.25 (inbuilt) | Barracuda | on | zlib | => | 10.1.25 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | [MDEV-13112](https://jira.mariadb.org/browse/MDEV-13112)(36) | | 19 | crash | 32 | 10.1.25 (inbuilt) | Antelope | - | zlib | => | 10.1.25 (inbuilt) | Antelope | - | zlib | - | OK | | | 20 | crash | 32 | 10.1.25 (inbuilt) | Barracuda | - | zlib | => | 10.1.25 (inbuilt) | Barracuda | - | zlib | - | OK | | | 21 | crash | 32 | 10.1.25 (inbuilt) | Barracuda | on | - | => | 10.1.25 (inbuilt) | Barracuda | on | - | - | OK | | | 22 | crash | 32 | 10.1.25 (inbuilt) | Antelope | on | - | => | 10.1.25 (inbuilt) | Antelope | on | - | - | OK | | | 23 | crash | 32 | 10.1.25 (inbuilt) | Barracuda | - | - | => | 10.1.25 (inbuilt) | Barracuda | - | - | - | OK | | | 24 | crash | 32 | 10.1.25 (inbuilt) | Antelope | - | - | => | 10.1.25 (inbuilt) | Antelope | - | - | - | OK | | | 25 | crash | 64 | 10.1.25 (inbuilt) | Antelope | - | - | => | 10.1.25 (inbuilt) | Antelope | - | - | - | OK | | | 26 | crash | 64 | 10.1.25 (inbuilt) | Barracuda | - | - | => | 10.1.25 (inbuilt) | Barracuda | - | - | - | OK | | | 27 | crash | 64 | 10.1.25 (inbuilt) | Barracuda | on | - | => | 10.1.25 (inbuilt) | Barracuda | on | - | - | OK | | | 28 | crash | 64 | 10.1.25 (inbuilt) | Antelope | on | - | => | 10.1.25 (inbuilt) | Antelope | on | - | - | OK | | | 29 | crash | 64 | 10.1.25 (inbuilt) | Barracuda | on | zlib | => | 10.1.25 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | [MDEV-13112](https://jira.mariadb.org/browse/MDEV-13112)(21) | | 30 | crash | 64 | 10.1.25 (inbuilt) | Antelope | on | zlib | => | 10.1.25 (inbuilt) | Antelope | on | zlib | - | OK | | | 31 | crash | 64 | 10.1.25 (inbuilt) | Barracuda | - | zlib | => | 10.1.25 (inbuilt) | Barracuda | - | zlib | - | OK | | | 32 | crash | 64 | 10.1.25 (inbuilt) | Antelope | - | zlib | => | 10.1.25 (inbuilt) | Antelope | - | zlib | - | OK | | | 33 | crash | 8 | 10.1.25 (inbuilt) | Barracuda | on | zlib | => | 10.1.25 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | [MDEV-13112](https://jira.mariadb.org/browse/MDEV-13112)(97) | | 34 | crash | 8 | 10.1.25 (inbuilt) | Antelope | on | zlib | => | 10.1.25 (inbuilt) | Antelope | on | zlib | - | OK | | | 35 | crash | 8 | 10.1.25 (inbuilt) | Antelope | - | zlib | => | 10.1.25 (inbuilt) | Antelope | - | zlib | - | OK | | | 36 | crash | 8 | 10.1.25 (inbuilt) | Barracuda | - | zlib | => | 10.1.25 (inbuilt) | Barracuda | - | zlib | - | OK | | | 37 | crash | 8 | 10.1.25 (inbuilt) | Antelope | on | - | => | 10.1.25 (inbuilt) | Antelope | on | - | - | OK | | | 38 | crash | 8 | 10.1.25 (inbuilt) | Barracuda | on | - | => | 10.1.25 (inbuilt) | Barracuda | on | - | - | OK | | | 39 | crash | 8 | 10.1.25 (inbuilt) | Barracuda | - | - | => | 10.1.25 (inbuilt) | Barracuda | - | - | - | OK | | | 40 | crash | 8 | 10.1.25 (inbuilt) | Antelope | - | - | => | 10.1.25 (inbuilt) | Antelope | - | - | - | OK | | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb DATE_ADD DATE\_ADD ========= Syntax ------ ``` DATE_ADD(date,INTERVAL expr unit) ``` Description ----------- Performs date arithmetic. The *date* argument specifies the starting date or datetime value. *expr* is an expression specifying the interval value to be added or subtracted from the starting date. *expr* is a string; it may start with a "`-`" for negative intervals. *unit* is a keyword indicating the units in which the expression should be interpreted. See [Date and Time Units](../date-and-time-units/index) for a complete list of permitted units. Examples -------- ``` SELECT '2008-12-31 23:59:59' + INTERVAL 1 SECOND; +-------------------------------------------+ | '2008-12-31 23:59:59' + INTERVAL 1 SECOND | +-------------------------------------------+ | 2009-01-01 00:00:00 | +-------------------------------------------+ ``` ``` SELECT INTERVAL 1 DAY + '2008-12-31'; +-------------------------------+ | INTERVAL 1 DAY + '2008-12-31' | +-------------------------------+ | 2009-01-01 | +-------------------------------+ ``` ``` SELECT '2005-01-01' - INTERVAL 1 SECOND; +----------------------------------+ | '2005-01-01' - INTERVAL 1 SECOND | +----------------------------------+ | 2004-12-31 23:59:59 | +----------------------------------+ ``` ``` SELECT DATE_ADD('2000-12-31 23:59:59', INTERVAL 1 SECOND); +----------------------------------------------------+ | DATE_ADD('2000-12-31 23:59:59', INTERVAL 1 SECOND) | +----------------------------------------------------+ | 2001-01-01 00:00:00 | +----------------------------------------------------+ ``` ``` SELECT DATE_ADD('2010-12-31 23:59:59', INTERVAL 1 DAY); +-------------------------------------------------+ | DATE_ADD('2010-12-31 23:59:59', INTERVAL 1 DAY) | +-------------------------------------------------+ | 2011-01-01 23:59:59 | +-------------------------------------------------+ ``` ``` SELECT DATE_ADD('2100-12-31 23:59:59', INTERVAL '1:1' MINUTE_SECOND); +---------------------------------------------------------------+ | DATE_ADD('2100-12-31 23:59:59', INTERVAL '1:1' MINUTE_SECOND) | +---------------------------------------------------------------+ | 2101-01-01 00:01:00 | +---------------------------------------------------------------+ ``` ``` SELECT DATE_ADD('1900-01-01 00:00:00', INTERVAL '-1 10' DAY_HOUR); +------------------------------------------------------------+ | DATE_ADD('1900-01-01 00:00:00', INTERVAL '-1 10' DAY_HOUR) | +------------------------------------------------------------+ | 1899-12-30 14:00:00 | +------------------------------------------------------------+ ``` ``` SELECT DATE_ADD('1992-12-31 23:59:59.000002', INTERVAL '1.999999' SECOND_MICROSECOND); +--------------------------------------------------------------------------------+ | DATE_ADD('1992-12-31 23:59:59.000002', INTERVAL '1.999999' SECOND_MICROSECOND) | +--------------------------------------------------------------------------------+ | 1993-01-01 00:00:01.000001 | +--------------------------------------------------------------------------------+ ``` See Also -------- * [DATE\_SUB](../date_sub/index) * [ADD\_MONTHS](../add_months/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb RELEASE_ALL_LOCKS RELEASE\_ALL\_LOCKS =================== **MariaDB until [10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/)**RELEASE\_ALL\_LOCKS was added in [MariaDB 10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/). Syntax ------ ``` RELEASE_ALL_LOCKS() ``` Description ----------- Releases all named locks held by the current session. Returns the number of locks released, or `0` if none were held. Statements using the `RELEASE_ALL_LOCKS` function are [not safe for statement-based replication](../unsafe-statements-for-statement-based-replication/index). Examples -------- ``` SELECT RELEASE_ALL_LOCKS(); +---------------------+ | RELEASE_ALL_LOCKS() | +---------------------+ | 0 | +---------------------+ SELECT GET_LOCK('lock1',10); +----------------------+ | GET_LOCK('lock1',10) | +----------------------+ | 1 | +----------------------+ SELECT RELEASE_ALL_LOCKS(); +---------------------+ | RELEASE_ALL_LOCKS() | +---------------------+ | 1 | +---------------------+ ``` See Also -------- * [GET\_LOCK](../get_lock/index) * [IS\_FREE\_LOCK](../is_free_lock/index) * [IS\_USED\_LOCK](../is_used_lock/index) * [RELEASE\_LOCK](../release_lock/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Creating a Debian Repository Creating a Debian Repository ============================ Below are instructions for creating your own Debian repository. The instructions are based on <http://www.debian.org/doc/manuals/repository-howto/repository-howto.en.html> ``` REPO_DIR={pick some location} mkdir $REPO_DIR mkdir $REPO_DIR/binary mkdir $REPO_DIR/source cp *.deb *.ddeb $REPO_DIR/binary cd $REPO_DIR dpkg-scanpackages binary /dev/null | gzip -9c > binary/Packages.gz dpkg-scansources source /dev/null | gzip -9c > source/Sources.gz ``` Using the Debian repository you just created -------------------------------------------- One needs to add a new file to the `/etc/apt/sources.list.d/` directory. For instance a new file called `mariadb.list` ``` # sergey's MariaDB repository # deb file:///home/psergey/testrepo binary/ deb-src file:///home/psergey/testrepo source/ ``` after which one can run ``` apt-get update # Let apt learn about the new repository apt-get install mariadb-server ``` and collect bugs :-). "apt-get install" will spray output of scripts and servers all over /var/log. It is also possible to set DEBIAN\_SCRIPT\_DEBUG=1 to get some (not all) of it to stdout. Cleaning up after failed installation ------------------------------------- Run ``` dpkg --get-selections | grep mariadb dpkg --get-selections | grep mysql ``` to see what is installed, and then ``` dpkg --purge <packages> ``` until the former produces empty output. Note: after some failures, /etc/mysql and /var/lib/mysql are not cleaned and still need to be removed manually. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb sysbench v0.5 - 3x 15 Minute Runs on perro with 5.2-wl86 b sysbench v0.5 - 3x 15 Minute Runs on perro with 5.2-wl86 b ========================================================== 3x 15 Minute Runs on perro with 5.2-wl86 key cache partitions off, 8, and 32 and key buffer size 75 MariDB sysbench benchmark comparison for key\_cache\_partitions in % with key\_buffer\_size = 75MB Each test was run 3 times for 15 minutes with 3 minutes warmup. ``` Number of threads 1 4 8 16 32 64 128 sysbench test oltp_complex_ro 8 / off 3.05 -0.10 0.57 1.00 -0.05 0.15 2.50 32 / off 3.04 -26.61* 0.89 -0.02 1.03 0.44 2.94 oltp_simple 8 / off -0.95 -1.10 -1.17 1.36 -2.65 -0.59 -1.01 32 / off 0.76 -0.02 0.66 2.75 1.96 3.05 -0.86 select 8 / off -1.45 -0.68 -2.31 -27.61* -0.52 -3.97 -0.24 32 / off -0.87 -1.63 -1.15 -2.10 0.44 1.12 1.39 update_index 8 / off -2.55 8.29* 3.14 4.16 1.13 1.95 1.29 32 / off -2.27 9.46* -0.12 2.64 0.69 -7.26* -0.24 ( 8/off*100)-100 (32/off*100)-100 * means unusually high STDEV off means key_cache_partitions off 8 means key_cache_partitions = 8 32 means key_cache_partitions = 32 ``` Benchmark was run on perro: Linux openSUSE 11.1 (x86\_64), single socket dual-core Intel 3.2GHz. with 1MB L2 cache, 2GB RAM, data\_dir on 2 disk software RAID 0 MariaDB and MySQL were compiled with ``` BUILD/compile-amd64-max ``` MariaDB revision was: ``` revno: 2742 committer: Igor Babaev <[email protected]> branch nick: maria-5.2-keycache timestamp: Tue 2010-02-16 08:41:11 -0800 message: WL#86: Partitioned key cache for MyISAM. This is the base patch for the task. ``` sysbench was run with the following parameters: ``` --oltp-table-size=20000000 \ # 20 million rows. --max-requests=0 \ --mysql-table-engine=MyISAM \ --mysql-user=root \ --mysql-engine-trx=no \ --myisam-max-rows=50000000 \ --rand-seed=303 ``` and the following variable parameters ``` --num-threads=$THREADS --test=${TEST_DIR}/${SYSBENCH_TEST} ``` Configuration used for MariDB: ``` --no-defaults \ --datadir=/mnt/data/sysbench/data \ --language=./sql/share/english \ --key_buffer_size=75M \ --key_cache_partitions=32 \ # Off | 8 | 32 --max_connections=256 \ --query_cache_size=0 \ --query_cache_type=0 \ --skip-grant-tables \ --socket=/tmp/mysql.sock \ --table_open_cache=512 \ --thread_cache=512 \ --tmpdir=/mnt/data/sysbench ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Cassandra Storage Engine Issues Cassandra Storage Engine Issues =============================== CassandraSE is no longer actively being developed and has been removed in [MariaDB 10.6](../what-is-mariadb-106/index). See [MDEV-23024](https://jira.mariadb.org/browse/MDEV-23024). This page lists difficulties and peculiarities of [Cassandra Storage Engine](../cassandra-storage-engine/index). I'm not putting them into bug tracker because it is not clear whether these properties should be considered bugs. No way to get E(#rows in column family) --------------------------------------- There seems to be no way to get even a rough estimate of how many different keys are present in a column family. I'm using an arbitrary value of 1000 now, which causes * EXPLAIN will always show rows=1000 for full table scans. In the future, this may cause poor query plans. * `DELETE FROM table` always prints "1000 rows affected", with no regards how many records were actually there in the table. ``` MariaDB [j1]> delete from t1; Query OK, 1000 rows affected (0.14 sec) ``` We could use the new [engine-independent-table-statistics](../engine-independent-table-statistics/index) feature to get some data statistics. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Creating the MariaDB Source Tarball Creating the MariaDB Source Tarball =================================== How to create a source tar.gz file. First [Setup your build environment](../linux_build_environment_setup/index). Then use automake/configure/make to generate the tar file: ``` BUILD/autorun.sh ./configure --with-plugin-xtradb make dist ``` This creates a source file with a name like `mysql-5.3.2-MariaDB-beta.tar.gz` See also [the generic build instructions](../generic-build-instructions/index). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb SQLTool Pro Database Editor SQLTool Pro Database Editor =========================== [SQLTool Pro](http://www.sqltoolpro.com/) is an Android client for MariaDB and several other databases. SQLTool Pro supports: * Interfaces optimized for both mobile and tablet devices * SSH tunneling with password and public key authentication * Exporting of data to CSV files * Customized queries using the query builder More information is available on the [SQLTool Pro Website](http://www.sqltoolpro.com/). SQLTool Pro phone interface: SQLTool Pro tablet interface: Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Getting Started with MariaDB Galera Cluster Getting Started with MariaDB Galera Cluster =========================================== The most recent release of [MariaDB 10.5](../what-is-mariadb-105/index) is: **[MariaDB 10.5.17](https://mariadb.com/kb/en/mariadb-10517-release-notes/)** Stable (GA) [DownloadNow](https://mariadb.com/downloads/) *[Alternate download from mariadb.org](https://mariadb.org/download/?tab=mariadb&release=10.5.17&product=mariadb)* The current [versions](../what-is-mariadb-galera-cluster/index#galera-versions) of the Galera wsrep provider library are 26.4.7 for [Galera](../galera/index) 4 and 25.3.32 for [Galera](../galera/index) 3. *For convenience, packages containing these libraries are included in the MariaDB [YUM and APT repositories](https://downloads.mariadb.org/mariadb/repositories/).* Currently, MariaDB Galera Cluster only supports the [InnoDB](../innodb/index) storage engine. A great resource for Galera users is the mailing list run by the developers at Codership. It can be found at [Codership on Google Groups](https://groups.google.com/forum/?fromgroups#!forum/codership-team). If you use Galera, then it is recommended you subscribe. Galera Cluster Support in MariaDB Server ---------------------------------------- MariaDB Galera Cluster is powered by: * MariaDB Server. * The [MySQL-wsrep](https://github.com/codership/mysql-wsrep) patch for MySQL Server and MariaDB Server developed by [Codership](http://www.codership.com). The patch currently supports only Unix-like operating systems. * The [Galera wsrep provider library](https://github.com/codership/galera/). In [MariaDB 10.1](../what-is-mariadb-101/index) and later, the [MySQL-wsrep](https://github.com/codership/mysql-wsrep) patch has been merged into MariaDB Server. This means that the functionality of MariaDB Galera Cluster can be obtained by installing the standard MariaDB Server packages and the [Galera wsrep provider library](https://github.com/codership/galera/) package. The following [Galera](../galera/index) version corresponds to each MariaDB Server version: * In [MariaDB 10.4](../what-is-mariadb-104/index) and later, MariaDB Galera Cluster uses [Galera](../galera/index) 4. This means that the [MySQL-wsrep](https://github.com/codership/mysql-wsrep) patch is version 26 and the [Galera wsrep provider library](https://github.com/codership/galera/) is version 4. * In [MariaDB 10.3](../what-is-mariadb-103/index) and before, MariaDB Galera Cluster uses [Galera](../galera/index) 3. This means that the [MySQL-wsrep](https://github.com/codership/mysql-wsrep) patch is version 25 and the [Galera wsrep provider library](https://github.com/codership/galera/) is version 3. See [Deciphering Galera Version Numbers](https://mariadb.com/resources/blog/deciphering-galera-version-numbers/) for more information about how to interpret these version numbers. See [What is MariaDB Galera Cluster?: Galera Versions](../what-is-mariadb-galera-cluster/index#galera-versions) for more information about which specific [Galera](../galera/index) version is included in each release of MariaDB Server. In supported builds, Galera Cluster functionality can be enabled by setting some configuration options that are mentioned below. Galera Cluster functionality is not enabled in a standard MariaDB Server installation unless explicitly enabled with these configuration options. Prerequisites ------------- ### Swap Size Requirements During normal operation a MariaDB Galera node does not consume much more memory than a regular MariaDB server. Additional memory is consumed for the certification index and uncommitted writesets, but normally this should not be noticeable in a typical application. There is one exception though: 1. **Writeset caching during state transfer.** When a node is receiving a state transfer it cannot process and apply incoming writesets because it has no state to apply them to yet. Depending on a state transfer mechanism (e.g. [mysqldump](../mysqldump/index)) the node that sends the state transfer may not be able to apply writesets as well. Thus they need to cache those writesets for a catch-up phase. Currently the writesets are cached in memory and, if the system runs out of memory either the state transfer will fail or the cluster will block waiting for the state transfer to end. To control memory usage for writeset caching, check the [Galera parameters](https://galeracluster.com/library/documentation/galera-parameters.html): `gcs.recv_q_hard_limit`, `gcs.recv_q_soft_limit`, and `gcs.max_throttle`. ### Limitations Before using MariaDB Galera Cluster, we would recommend reading through the [known limitations](../mariadb-galera-cluster-known-limitations/index), so you can be sure that it is appropriate for your application. Installing MariaDB Galera Cluster --------------------------------- To use MariaDB Galera Cluster, there are two primary packages that you need to install: 1. A MariaDB Server version that supports Galera Cluster. 2. The Galera wsrep provider library. As mentioned in the previous section, in [MariaDB 10.1](../what-is-mariadb-101/index) and above, Galera Cluster support is actually included in the standard MariaDB Server packages. That means that installing MariaDB Galera Cluster package is the same as installing standard MariaDB Server package in those versions. However, you will also have to install an additional package to obtain the Galera wsrep provider library. Some [SST](../introduction-to-state-snapshot-transfers-ssts/index) methods may also require additional packages to be installed. The `[mariabackup](../mariabackup-sst-method/index)` SST method is generally the best option for large clusters that expect a lot of load. ### Installing MariaDB Galera Cluster with a Package Manager MariaDB Galera Cluster can be installed via a package manager on Linux. In order to do so, your system needs to be configured to install from one of the MariaDB repositories. You can configure your package manager to install it from MariaDB Corporation's MariaDB Package Repository by using the [MariaDB Package Repository setup script](../mariadb-package-repository-setup-and-usage/index). You can also configure your package manager to install it from MariaDB Foundation's MariaDB Repository by using the [MariaDB Repository Configuration Tool](https://downloads.mariadb.org/mariadb/repositories/). #### Installing MariaDB Galera Cluster with yum/dnf On RHEL, CentOS, Fedora, and other similar Linux distributions, it is highly recommended to install the relevant [RPM packages](../rpm/index) from MariaDB's repository using `[yum](../yum/index)` or `[dnf](https://en.wikipedia.org/wiki/DNF_(software))`. Starting with RHEL 8 and Fedora 22, `yum` has been replaced by `dnf`, which is the next major version of `yum`. However, `yum` commands still work on many systems that use `dnf`. To install MariaDB Galera Cluster with `yum` or `dnf`, follow the instructions at [Installing MariaDB Galera Cluster with yum](../installing-mariadb-with-yum/index#installing-mariadb-galera-cluster-with-yum). #### Installing MariaDB Galera Cluster with apt-get On Debian, Ubuntu, and other similar Linux distributions, it is highly recommended to install the relevant [DEB packages](../installing-mariadb-deb-files/index) from MariaDB's repository using `[apt-get](https://wiki.debian.org/apt-get)`. To install MariaDB Galera Cluster with `apt-get`, follow the instructions at [Installing MariaDB Galera Cluster with apt-get](../installing-mariadb-deb-files/index#installing-mariadb-galera-cluster-with-apt). #### Installing MariaDB Galera Cluster with zypper On SLES, OpenSUSE, and other similar Linux distributions, it is highly recommended to install the relevant [RPM packages](../rpm/index) from MariaDB's repository using `[zypper](../installing-mariadb-with-zypper/index)`. To install MariaDB Galera Cluster with `zypper`, follow the instructions at [Installing MariaDB Galera Cluster with ZYpp](../installing-mariadb-with-zypper/index#installing-mariadb-galera-cluster-with-zypp). ### Installing MariaDB Galera Cluster with a Binary Tarball To install MariaDB Galera Cluster with a binary tarball, follow the instructions at [Installing MariaDB Binary Tarballs](../installing-mariadb-binary-tarballs/index). **MariaDB Galera Cluster starting with 10.0.24**To make the location of the `libgalera_smm.so` library in binary tarballs more similar to its location in other packages, the library is now found at `lib/galera/libgalera_smm.so` in the binary tarballs, and there is a symbolic link in the `lib` directory that points to it. ### Installing MariaDB Galera Cluster from Source To install MariaDB Galera Cluster by compiling it from source, you will have to compile both MariaDB Server and the Galera wsrep provider library. For some information on how to do this, see the pages at [Installing Galera From Source](../installing-galera-from-source/index). The pages at [Compiling MariaDB From Source](../compiling-mariadb-from-source/index) and [Galera Cluster Documentation: Building Galera Cluster for MySQL](https://galeracluster.com/library/documentation/install-mysql-src.html#building-galera-cluster-for-mysql) may also be helpful. When compiling [MariaDB 10.1](../what-is-mariadb-101/index) or earlier and you want to enable Galera Cluster support, be sure to set set `-DWITH_WSREP=ON` and `-DWITH_INNODB_DISALLOW_WRITES=ON` when running [cmake](../generic-build-instructions/index#using-cmake). When compiling [MariaDB 10.2](../what-is-mariadb-102/index) or later, it is enabled by default. Configuring MariaDB Galera Cluster ---------------------------------- A number of options need to be set in order for Galera Cluster to work when using MariaDB. See [Configuring MariaDB Galera Cluster](../configuring-mariadb-galera-cluster/index) for more information. Bootstrapping a New Cluster --------------------------- To first node of a new cluster needs to be bootstrapped by starting `[mysqld](../mysqld-options/index)` on that node with the option `[--wsrep-new-cluster](../mysqld-options/index#-wsrep-new-cluster)` option. This option tells the node that there is no existing cluster to connect to. The node will create a new UUID to identify the new cluster. Do not use the `[--wsrep-new-cluster](../mysqld-options/index#-wsrep-new-cluster)` option when connecting to an existing cluster. Restarting the node with this option set will cause the node to create new UUID to identify the cluster again, and the node won't reconnect to the old cluster. See the next section about how to reconnect to an existing cluster. For example, if you were manually starting `[mysqld](../mysqld-options/index)` on a node, then you could bootstrap it by executing the following: ``` $ mysqld --wsrep-new-cluster ``` However, keep in mind that most users are not going to be starting `[mysqld](../mysqld-options/index)` manually. Instead, most users will use a [service manager](../starting-and-stopping-mariadb-starting-and-stopping-mariadb/index) to start `[mysqld](../mysqld-options/index)`. See the following sections on how to bootstrap a node with the most common service managers. ### Systemd and Bootstrapping On operating systems that use [systemd](../systemd/index), a node can be bootstrapped in the following way: ``` $ galera_new_cluster ``` This wrapper uses [systemd](../systemd/index) to run `[mysqld](../mysqld-options/index)` with the `[--wsrep-new-cluster](../mysqld-options/index#-wsrep-new-cluster)` option. If you are using the [systemd](../systemd/index) service that supports the [systemd service's method for interacting with multiple MariaDB Server processes](../systemd/index#interacting-with-multiple-mariadb-server-processes), then you can bootstrap a specific instance by specifying the instance name as a suffix. For example: ``` $ galera_new_cluster mariadb@node1 ``` **MariaDB starting with [10.1.8](https://mariadb.com/kb/en/mariadb-1018-release-notes/)**Systemd support and the galera\_new\_cluster script were added in [MariaDB 10.1](../what-is-mariadb-101/index). ### SysVinit and Bootstrapping On operating systems that use [sysVinit](../sysvinit/index), a node can be bootstrapped in the following way: ``` $ service mysql bootstrap ``` This runs `[mysqld](../mysqld-options/index)` with the `[--wsrep-new-cluster](../mysqld-options/index#-wsrep-new-cluster)` option. Adding Another Node to a Cluster -------------------------------- Once you have a cluster running and you want to add/reconnect another node to it, you must supply an address of one or more of the existing cluster members in the `[wsrep\_cluster\_address](../galera-cluster-system-variables/index#wsrep_cluster_address)` option. For example, if the first node of the cluster has the address 192.168.0.1, then you could add a second node to the cluster by setting the following option in a server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index): ``` [mariadb] ... wsrep_cluster_address=gcomm://192.168.0.1 # DNS names work as well, IP is preferred for performance ``` The new node only needs to connect to one of the existing cluster nodes. Once it connects to one of the existing cluster nodes, it will be able to see all of the nodes in the cluster. However, it is generally better to list all nodes of the cluster in `[wsrep\_cluster\_address](../galera-cluster-system-variables/index#wsrep_cluster_address)`, so that any node can join a cluster by connecting to any of the other cluster nodes, even if one or more of the cluster nodes are down. It is even OK to list a node's own IP address in `[wsrep\_cluster\_address](../galera-cluster-system-variables/index#wsrep_cluster_address)`, since Galera Cluster is smart enough to ignore it. Once all members agree on the membership, the cluster's state will be exchanged. If the new node's state is different from that of the cluster, then it will request an IST or [SST](../introduction-to-state-snapshot-transfers-ssts/index) to make itself consistent with the other nodes. Restarting the Cluster ---------------------- If you shut down all nodes at the same time, then you have effectively terminated the cluster. Of course, the cluster's data still exists, but the running cluster no longer exists. When this happens, you'll need to bootstrap the cluster again. If the cluster is not bootstrapped and `[mysqld](../mysqld-options/index)` on the first node is just [started normally](../starting-and-stopping-mariadb-starting-and-stopping-mariadb/index), then the node willl try to connect to at least one of the nodes listed in the `[wsrep\_cluster\_address](../galera-cluster-system-variables/index#wsrep_cluster_address)` option. If no nodes are currently running, then this will fail. Bootstrapping the first node solves this problem. ### Determining the Most Advanced Node In some cases Galera will refuse to bootstrap a node if it detects that it might not be the most advanced node in the cluster. Galera makes this determination if the node was not the last one in the cluster to be shut down or if the node crashed. In those cases, manual intervention is needed. If you know for sure which node is the most advanced you can edit the `grastate.dat` file in the `[datadir](../server-system-variables/index#datadir)`. You can set `safe_to_bootstrap=1` on the most advanced node. You can determine which node is the most advanced by checking `grastate.dat` on each node and looking for the node with the highest `seqno`. If the node crashed and `seqno=-1`, then you can find the most advanced node by recovering the `seqno` on each node with the `[wsrep\_recover](../galera-cluster-system-variables/index#wsrep_recover)` option. For example: ``` $ mysqld --wsrep_recover ``` #### Systemd and Galera Recovery On operating systems that use `[systemd](../systemd/index)`, the position of a node can be recovered by running the `galera_recovery` script. For example: ``` $ galera_recovery ``` If you are using the `[systemd](../systemd/index)` service that supports the [systemd service's method for interacting with multiple MariaDB Server processes](../systemd/index#interacting-with-multiple-mariadb-server-processes), then you can recover the position of a specific instance by specifying the instance name as a suffix. For example: ``` $ galera_recovery mariadb@node1 ``` The `galera_recovery` script recovers the position of a node by running `[mysqld](../mysqld-options/index)` with the `[wsrep\_recover](../galera-cluster-system-variables/index#wsrep_recover)` option. When the `galera_recovery` script runs `[mysqld](../mysqld-options/index)`, it does not write to the [error log](../error-log/index). Instead, it redirects `[mysqld](../mysqld-options/index)` log output to a file named with the format `/tmp/wsrep_recovery.XXXXXX`, where `XXXXXX` is replaced with random characters. When Galera is enabled, MariaDB's `[systemd](../systemd/index)` service automatically runs the `galera_recovery` script prior to starting MariaDB, so that MariaDB starts with the proper Galera position. **MariaDB starting with [10.1.8](https://mariadb.com/kb/en/mariadb-1018-release-notes/)**Support for `[systemd](../systemd/index)` and the `galera_recovery` script were added in [MariaDB 10.1](../what-is-mariadb-101/index). State Snapshot Transfers (SSTs) ------------------------------- In a State Snapshot Transfer (SST), the cluster provisions nodes by transferring a full data copy from one node to another. When a new node joins the cluster, the new node initiates a State Snapshot Transfer to synchronize its data with a node that is already part of the cluster. See [Introduction to State Snapshot Transfers (SSTs)](../introduction-to-state-snapshot-transfers-ssts/index) for more information. Incremental State Transfers (ISTs) ---------------------------------- In an Incremental State Transfer (SST), the cluster provisions nodes by transferring a node's missing writesets from one node to another. When a new node joins the cluster, the new node initiates a Incremental State Transfer to synchronize its data with a node that is already part of the cluster. If a node has only been out of a cluster for a little while, then an IST is generally faster than an SST. Data at Rest Encryption ----------------------- In [MariaDB 10.1](../what-is-mariadb-101/index) and above, MariaDB Galera Cluster supports [Data at Rest Encryption](../data-at-rest-encryption/index). See [SSTs and Data at Rest Encryption](../introduction-to-state-snapshot-transfers-ssts/index#ssts-and-data-at-rest-encryption) for some disclaimers on how SSTs are affected when encryption is configured. Some data still cannot be encrypted: * The disk-based [Galera gcache](https://galeracluster.com/library/documentation/state-transfer.html#write-set-cache-gcache) is not encrypted ([MDEV-8072](https://jira.mariadb.org/browse/MDEV-8072)). Monitoring ---------- ### Status Variables [Galera Cluster's status variables](../mariadb-galera-cluster-status-variables/index) can be queried with the standard `[SHOW STATUS](../show-status/index)` command. For example: ``` SHOW GLOBAL STATUS LIKE 'wsrep_%'; ``` ### Cluster Change Notifications The cluster nodes can be configured to invoke a command when cluster membership or node status changes. This mechanism can also be used to communicate the event to some external monitoring agent. This is configured by setting `[wsrep\_notify\_cmd](../galera-cluster-system-variables/index#wsrep_notify_cmd)`. See [Galera Cluster documentation: Notification Command](https://galeracluster.com/library/documentation/notification-cmd.html) for more information. See Also -------- * [What is MariaDB Galera Cluster?](../what-is-mariadb-galera-cluster/index) * [About Galera Replication](../about-galera-replication/index) * [Galera Use Cases](../galera-use-cases/index) * [Codership on Google Groups](https://groups.google.com/forum/?fromgroups#!forum/codership-team) * [Galera Cluster documentation](https://galeracluster.com/library/documentation/) * [Galera Cluster documentation: Notification Command](http://galeracluster.com/documentation-webpages/notificationcmd.html) * [Introducing the “Safe-To-Bootstrap” feature in Galera Cluster](http://galeracluster.com/2016/11/introducing-the-safe-to-bootstrap-feature-in-galera-cluster/) * [Github - galera](https://github.com/codership/galera/) * [Github - mysql-wsrep](https://github.com/codership/mysql-wsrep/) Footnotes --------- Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb extract_table_from_file_name extract\_table\_from\_file\_name ================================ Syntax ------ ``` sys.extract_table_from_file_name(path) ``` Description ----------- `extract_table_from_file_name` is a [stored function](../stored-functions/index) available with the [Sys Schema](../sys-schema/index). Given a file path, it returns the table name. The function does not examine anything on disk. The return value, a VARCHAR(64), is determined solely from the provided path. Examples -------- ``` SELECT sys.extract_table_from_file_name('/usr/local/mysql/data/db/t1.ibd'); +---------------------------------------------------------------------+ | sys.extract_table_from_file_name('/usr/local/mysql/data/db/t1.ibd') | +---------------------------------------------------------------------+ | t1 | +---------------------------------------------------------------------+ ``` See also -------- * [extract\_schema\_from\_file\_name()](../extract_schema_from_file_name/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb mariadb-dumpslow mariadb-dumpslow ================ **MariaDB starting with [10.4.6](https://mariadb.com/kb/en/mariadb-1046-release-notes/)**From [MariaDB 10.4.6](https://mariadb.com/kb/en/mariadb-1046-release-notes/), `mariadb-dumpslow` is a symlink to `mysqldumpslow`, the tool for examining the [slow query log](../slow-query-log/index). **MariaDB starting with [10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/)**From [MariaDB 10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/), `mariadb-dumpslow` is the name of the tool, with `mysqldumpslow` a symlink . See [mysqldumpslow](../mysqldumpslow/index) for details. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb format_time format\_time ============ Syntax ------ ``` sys.format_time(picoseconds) ``` Description ----------- `format_time` is a [stored function](../stored-functions/index) available with the [Sys Schema](../sys-schema/index). Given a time in picoseconds, returns a human-readable time value and unit indicator. Unit can be: * ps - picoseconds * ns - nanoseconds * us - microseconds * ms - milliseconds * s - seconds * m - minutes * h - hours * d - days * w - weeks Examples -------- ``` SELECT sys.format_time(4321) AS ns, sys.format_time(43211234) AS us, sys.format_time(432112344321) AS ms, sys.format_time(43211234432123) AS s, sys.format_time(432112344321234) AS m, sys.format_time(4321123443212345) AS h, sys.format_time(432112344321234545) AS d, sys.format_time(43211234432123444543) AS w; +---------+----------+-----------+---------+--------+--------+--------+---------+ | ns | us | ms | s | m | h | d | w | +---------+----------+-----------+---------+--------+--------+--------+---------+ | 4.32 ns | 43.21 us | 432.11 ms | 43.21 s | 7.20 m | 1.20 h | 5.00 d | 71.45 w | +---------+----------+-----------+---------+--------+--------+--------+---------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb LineFromWKB LineFromWKB =========== A synonym for [ST\_LineFromWKB](../st_linefromwkb/index). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb CREATE FUNCTION CREATE FUNCTION =============== Syntax ------ ``` CREATE [OR REPLACE] [DEFINER = {user | CURRENT_USER | role | CURRENT_ROLE }] [AGGREGATE] FUNCTION [IF NOT EXISTS] func_name ([func_parameter[,...]]) RETURNS type [characteristic ...] RETURN func_body func_parameter: [ IN | OUT | INOUT | IN OUT ] param_name type type: Any valid MariaDB data type characteristic: LANGUAGE SQL | [NOT] DETERMINISTIC | { CONTAINS SQL | NO SQL | READS SQL DATA | MODIFIES SQL DATA } | SQL SECURITY { DEFINER | INVOKER } | COMMENT 'string' func_body: Valid SQL procedure statement ``` Description ----------- Use the `CREATE FUNCTION` statement to create a new [stored function](../stored-functions/index). You must have the [CREATE ROUTINE](../grant/index#database-privileges) database privilege to use `CREATE FUNCTION`. A function takes any number of arguments and returns a value from the function body. The function body can be any valid SQL expression as you would use, for example, in any select expression. If you have the appropriate privileges, you can call the function exactly as you would any built-in function. See [Security](#security) below for details on privileges. You can also use a variant of the `CREATE FUNCTION` statement to install a user-defined function (UDF) defined by a plugin. See [CREATE FUNCTION (UDF)](../create-function-udf/index) for details. You can use a [SELECT](../select/index) statement for the function body by enclosing it in parentheses, exactly as you would to use a subselect for any other expression. The `SELECT` statement must return a single value. If more than one column is returned when the function is called, error 1241 results. If more than one row is returned when the function is called, error 1242 results. Use a `LIMIT` clause to ensure only one row is returned. You can also replace the `RETURN` clause with a [BEGIN...END](../begin-end/index) compound statement. The compound statement must contain a `RETURN` statement. When the function is called, the `RETURN` statement immediately returns its result, and any statements after `RETURN` are effectively ignored. By default, a function is associated with the current database. To associate the function explicitly with a given database, specify the fully-qualified name as `*db\_name*.*func\_name*` when you create it. If the function name is the same as the name of a built-in function, you must use the fully qualified name when you call it. The parameter list enclosed within parentheses must always be present. If there are no parameters, an empty parameter list of () should be used. Parameter names are not case sensitive. Each parameter can be declared to use any valid data type, except that the COLLATE attribute cannot be used. For valid identifiers to use as function names, see [Identifier Names](../identifier-names/index). #### IN | OUT | INOUT | IN OUT **MariaDB starting with [10.8.0](https://mariadb.com/kb/en/mariadb-1080-release-notes/)**The function parameter qualifiers for `IN`, `OUT`, `INOUT`, and `IN OUT` were added in a 10.8.0 preview release. Prior to 10.8.0 quantifiers were supported only in procedures. `OUT`, `INOUT` and its equivalent `IN OUT`, are only valid if called from `SET` and not `SELECT`. These quantifiers are especially useful for creating functions with more than one return value. This allows functions to be more complex and nested. ``` DELIMITER $$ CREATE FUNCTION add_func3(IN a INT, IN b INT, OUT c INT) RETURNS INT BEGIN SET c = 100; RETURN a + b; END; $$ DELIMITER ; SET @a = 2; SET @b = 3; SET @c = 0; SET @res= add_func3(@a, @b, @c); SELECT add_func3(@a, @b, @c); ERROR 4186 (HY000): OUT or INOUT argument 3 for function add_func3 is not allowed here DELIMITER $$ CREATE FUNCTION add_func4(IN a INT, IN b INT, d INT) RETURNS INT BEGIN DECLARE c, res INT; SET res = add_func3(a, b, c) + d; if (c > 99) then return 3; else return res; end if; END; $$ DELIMITER ; SELECT add_func4(1,2,3); +------------------+ | add_func4(1,2,3) | +------------------+ | 3 | +------------------+ ``` #### AGGREGATE **MariaDB starting with [10.3.3](https://mariadb.com/kb/en/mariadb-1033-release-notes/)**From [MariaDB 10.3.3](https://mariadb.com/kb/en/mariadb-1033-release-notes/), it is possible to create stored aggregate functions as well. See [Stored Aggregate Functions](../stored-aggregate-functions/index) for details. #### RETURNS The `RETURNS` clause specifies the return type of the function. `NULL` values are permitted with all return types. What happens if the `RETURN` clause returns a value of a different type? It depends on the [SQL\_MODE](../sql-mode/index) in effect at the moment of the function creation. If the SQL\_MODE is strict (STRICT\_ALL\_TABLES or STRICT\_TRANS\_TABLES flags are specified), a 1366 error will be produced. Otherwise, the value is coerced to the proper type. For example, if a function specifies an `ENUM` or `SET` value in the `RETURNS` clause, but the `RETURN` clause returns an integer, the value returned from the function is the string for the corresponding `ENUM` member of set of `SET` members. MariaDB stores the SQL\_MODE system variable setting that is in effect at the time a routine is created, and always executes the routine with this setting in force, regardless of the server SQL mode in effect when the routine is invoked. #### LANGUAGE SQL `LANGUAGE SQL` is a standard SQL clause, and it can be used in MariaDB for portability. However that clause has no meaning, because SQL is the only supported language for stored functions. A function is deterministic if it can produce only one result for a given list of parameters. If the result may be affected by stored data, server variables, random numbers or any value that is not explicitly passed, then the function is not deterministic. Also, a function is non-deterministic if it uses non-deterministic functions like [NOW()](../now/index) or [CURRENT\_TIMESTAMP()](../current_user/index). The optimizer may choose a faster execution plan if it known that the function is deterministic. In such cases, you should declare the routine using the `DETERMINISTIC` keyword. If you want to explicitly state that the function is not deterministic (which is the default) you can use the `NOT DETERMINISTIC` keywords. If you declare a non-deterministic function as `DETERMINISTIC`, you may get incorrect results. If you declare a deterministic function as `NOT DETERMINISTIC`, in some cases the queries will be slower. #### OR REPLACE **MariaDB starting with [10.1.3](https://mariadb.com/kb/en/mariadb-1013-release-notes/)**If the optional `OR REPLACE` clause is used, it acts as a shortcut for: ``` DROP FUNCTION IF EXISTS function_name; CREATE FUNCTION function_name ...; ``` with the exception that any existing [privileges](../stored-routine-privileges/index) for the function are not dropped. #### IF NOT EXISTS **MariaDB starting with [10.1.3](https://mariadb.com/kb/en/mariadb-1013-release-notes/)**If the IF NOT EXISTS clause is used, MariaDB will return a warning instead of an error if the function already exists. Cannot be used together with OR REPLACE. #### [NOT] DETERMINISTIC The `[NOT] DETERMINISTIC` clause also affects [binary logging](../binary-log/index), because the `STATEMENT` format can not be used to store or replicate non-deterministic statements. `CONTAINS SQL`, `NO SQL`, `READS SQL DATA`, and `MODIFIES SQL DATA` are informative clauses that tell the server what the function does. MariaDB does not check in any way whether the specified clause is correct. If none of these clauses are specified, `CONTAINS SQL` is used by default. #### MODIFIES SQL DATA `MODIFIES SQL DATA` means that the function contains statements that may modify data stored in databases. This happens if the function contains statements like [DELETE](../delete/index), [UPDATE](../update/index), [INSERT](../insert/index), [REPLACE](../replace/index) or DDL. #### READS SQL DATA `READS SQL DATA` means that the function reads data stored in databases, but does not modify any data. This happens if [SELECT](../select/index) statements are used, but there no write operations are executed. #### CONTAINS SQL `CONTAINS SQL` means that the function contains at least one SQL statement, but it does not read or write any data stored in a database. Examples include [SET](../set/index) or [DO](../do/index). #### NO SQL `NO SQL` means nothing, because MariaDB does not currently support any language other than SQL. #### Oracle Mode **MariaDB starting with [10.3](../what-is-mariadb-103/index)**From [MariaDB 10.3](../what-is-mariadb-103/index), a subset of Oracle's PL/SQL language has been supported in addition to the traditional SQL/PSM-based MariaDB syntax. See [Oracle mode from MariaDB 10.3](../sql_modeoracle-from-mariadb-103/index#stored-procedures-and-stored-functions) for details on changes when running Oracle mode. Security -------- You must have the [EXECUTE](../grant/index#function-privileges) privilege on a function to call it. MariaDB automatically grants the `EXECUTE` and `ALTER ROUTINE` privileges to the account that called `CREATE FUNCTION`, even if the `DEFINER` clause was used. Each function has an account associated as the definer. By default, the definer is the account that created the function. Use the `DEFINER` clause to specify a different account as the definer. You must have the [SUPER](../grant/index#super) privilege, or, from [MariaDB 10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/), the [SET USER](../grant/index#set-user) privilege, to use the `DEFINER` clause. See [Account Names](../create-user/index#account-names) for details on specifying accounts. The `SQL SECURITY` clause specifies what privileges are used when a function is called. If `SQL SECURITY` is `INVOKER`, the function body will be evaluated using the privileges of the user calling the function. If `SQL SECURITY` is `DEFINER`, the function body is always evaluated using the privileges of the definer account. `DEFINER` is the default. This allows you to create functions that grant limited access to certain data. For example, say you have a table that stores some employee information, and that you've granted `SELECT` privileges [only on certain columns](../grant/index#column-privileges) to the user account `roger`. ``` CREATE TABLE employees (name TINYTEXT, dept TINYTEXT, salary INT); GRANT SELECT (name, dept) ON employees TO roger; ``` To allow the user the get the maximum salary for a department, define a function and grant the `EXECUTE` privilege: ``` CREATE FUNCTION max_salary (dept TINYTEXT) RETURNS INT RETURN (SELECT MAX(salary) FROM employees WHERE employees.dept = dept); GRANT EXECUTE ON FUNCTION max_salary TO roger; ``` Since `SQL SECURITY` defaults to `DEFINER`, whenever the user `roger` calls this function, the subselect will execute with your privileges. As long as you have privileges to select the salary of each employee, the caller of the function will be able to get the maximum salary for each department without being able to see individual salaries. Character sets and collations ----------------------------- Function return types can be declared to use any valid [character set and collation](../character-sets/index). If used, the COLLATE attribute needs to be preceded by a CHARACTER SET attribute. If the character set and collation are not specifically set in the statement, the database defaults at the time of creation will be used. If the database defaults change at a later stage, the stored function character set/collation will not be changed at the same time; the stored function needs to be dropped and recreated to ensure the same character set/collation as the database is used. Examples -------- The following example function takes a parameter, performs an operation using an SQL function, and returns the result. ``` CREATE FUNCTION hello (s CHAR(20)) RETURNS CHAR(50) DETERMINISTIC RETURN CONCAT('Hello, ',s,'!'); SELECT hello('world'); +----------------+ | hello('world') | +----------------+ | Hello, world! | +----------------+ ``` You can use a compound statement in a function to manipulate data with statements like `INSERT` and `UPDATE`. The following example creates a counter function that uses a temporary table to store the current value. Because the compound statement contains statements terminated with semicolons, you have to first change the statement delimiter with the `DELIMITER` statement to allow the semicolon to be used in the function body. See [Delimiters in the mysql client](../delimiters-in-the-mysql-client/index) for more. ``` CREATE TEMPORARY TABLE counter (c INT); INSERT INTO counter VALUES (0); DELIMITER // CREATE FUNCTION counter () RETURNS INT BEGIN UPDATE counter SET c = c + 1; RETURN (SELECT c FROM counter LIMIT 1); END // DELIMITER ; ``` Character set and collation: ``` CREATE FUNCTION hello2 (s CHAR(20)) RETURNS CHAR(50) CHARACTER SET 'utf8' COLLATE 'utf8_bin' DETERMINISTIC RETURN CONCAT('Hello, ',s,'!'); ``` See Also -------- * [Identifier Names](../identifier-names/index) * [Stored Aggregate Functions](../stored-aggregate-functions/index) * [CREATE FUNCTION (UDF)](../create-function-udf/index) * [SHOW CREATE FUNCTION](../show-create-function/index) * [ALTER FUNCTION](../alter-function/index) * [DROP FUNCTION](../drop-function/index) * [SHOW FUNCTION STATUS](../show-function-status/index) * [Stored Routine Privileges](../stored-routine-privileges/index) * [Information Schema ROUTINES Table](../information-schema-routines-table/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb EXPLAIN in the Slow Query Log EXPLAIN in the Slow Query Log ============================= Switching it On --------------- [EXPLAIN](../explain/index) output can be switched on by specifying the "`explain`" keyword in the [log\_slow\_verbosity](../server-system-variables/index#log_slow_verbosity) system variable. Alternatively, you can set with the `log-slow-verbosity` command line argument. ``` [mysqld] log-slow-verbosity=query_plan,explain ``` EXPLAIN output will only be recorded if the slow query log is written to a file (and not to a table - see [Writing logs into tables](../writing-logs-into-tables/index)). This limitation also applies to other extended statistics that are written into the slow query log. What it Looks Like ------------------ When explain recording is on, slow query log entries look like this: ``` # Time: 131112 17:03:32 # User@Host: root[root] @ localhost [] # Thread_id: 2 Schema: dbt3sf1 QC_hit: No # Query_time: 5.524103 Lock_time: 0.000337 Rows_sent: 1 Rows_examined: 65633 # # explain: id select_type table type possible_keys key key_len ref rows Extra # explain: 1 SIMPLE nation ref PRIMARY,n_name n_name 26 const 1 Using where; Using index # explain: 1 SIMPLE customer ref PRIMARY,i_c_nationkey i_c_nationkey 5 dbt3sf1.nation.n_nationkey 3145 Using index # explain: 1 SIMPLE orders ref i_o_custkey i_o_custkey 5 dbt3sf1.customer.c_custkey 7 Using index # SET timestamp=1384261412; select count(*) from customer, orders, nation where c_custkey=o_custkey and c_nationkey=n_nationkey and n_name='GERMANY'; ``` EXPLAIN lines start with `# explain:`. See Also -------- * [MDEV-407](https://jira.mariadb.org/browse/MDEV-407) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb Eperi Key Management Encryption Plugin Eperi Key Management Encryption Plugin ====================================== Eperi's Key Management Plugin Package no longer appears to be available. MariaDB's [data-at-rest encryption](../data-at-rest-encryption/index) requires the use of a [key management and encryption plugin](../encryption-key-management/index). These plugins are responsible both for the management of encryption keys and for the actual encryption and decryption of data. MariaDB supports the use of [multiple encryption keys](../encryption-key-management/index#using-multiple-encryption-keys). Each encryption key uses a 32-bit integer as a key identifier. If the specific plugin supports [key rotation](../encryption-key-management/index#rotating-keys), then encryption keys can also be rotated, which creates a new version of the encryption key. The Eperi Key Management plugin is a [key management and encryption plugin](../encryption-key-management/index) that integrates with [eperi Gateway for Databases](https://eperi.com/database-encryption/). Overview -------- The Eperi Key Management plugin is one of the [key management and encryption plugins](../encryption-key-management/index) that can be set up for users who want to use [data-at-rest encryption](../data-at-rest-encryption/index). Some of the plugin's primary features are: * It reads encryption keys from [eperi Gateway for Databases](https://eperi.com/database-encryption/). * It supports multiple encryption keys. * It supports key rotation. * It supports two different algorithms for encrypting data. The [eperi Gateway for Databases](https://eperi.com/database-encryption/) stores encryption keys on the key server outside of the database server itself, which provides an extra level of security. The [eperi Gateway for Databases](https://eperi.com/database-encryption/) also supports performing all data encryption operations on the key server as well, but this is optional. It also provides the following benefits: * Key management outside the database * No keys on database server hard disk * Graphical user interface for configuration * Encryption and decryption outside the database, supporting HSM's for maximum security. Support for MariaDB is provided in [eperi Gateway for Databases 3.4](https://eperi.com/eperi-gateway-for-databases-version-3-4-offers-native-mariadb-support/). Installing the Eperi Key Management Plugin's Package ---------------------------------------------------- For information on how to install the package, see Eperi's documentation at the [Eperi Customer Portal](https://customer.eperi.de/index.jsp). Installing the Plugin --------------------- Even after the package that contains the plugin's shared library is installed on the operating system, the plugin is not actually installed by MariaDB by default. The plugin can be installed by providing the `[--plugin-load](../mysqld-options/index#-plugin-load)` or the `[--plugin-load-add](../mysqld-options/index#-plugin-load-add)` options. This can be specified as a command-line argument to `[mysqld](../mysqld-options/index)` or it can be specified in a relevant server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index). For example: ``` [mariadb] ... plugin_load_add = eperi_key_management_plugin ``` Uninstalling the Plugin ----------------------- Before you uninstall the plugin, you should ensure that [data-at-rest encryption](../data-at-rest-encryption/index) is completely disabled, and that MariaDB no longer needs the plugin to decrypt tables or other files. You can uninstall the plugin dynamically by executing `[UNINSTALL SONAME](../uninstall-soname/index)` or `[UNINSTALL PLUGIN](../uninstall-plugin/index)`. For example: ``` UNINSTALL SONAME 'eperi_key_management_plugin'; ``` If you installed the plugin by providing the `[--plugin-load](../mysqld-options/index#-plugin-load)` or the `[--plugin-load-add](../mysqld-options/index#-plugin-load-add)` options in a relevant server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index), then those options should be removed to prevent the plugin from being loaded the next time the server is restarted. Configuring the Eperi Key Management Plugin ------------------------------------------- For information on how to configure the plugin, see Eperi's documentation at the [Eperi Customer Portal](https://customer.eperi.de/index.jsp). Using the Eperi Key Management Plugin ------------------------------------- Once the Eperi Key Management Plugin is enabled, you can use it by creating an encrypted table: ``` CREATE TABLE t (i int) ENGINE=InnoDB ENCRYPTED=YES ``` Now, table `t` will be encrypted using the encryption key from the key server. For more information on how to use encryption, see [Data at Rest Encryption](../data-at-rest-encryption/index). Using Multiple Encryption Keys ------------------------------ The Eperi Key Management Plugin supports [using multiple encryption keys](../encryption-key-management/index#using-multiple-encryption-keys). Each encryption key can be defined with a different 32-bit integer as a key identifier. When [encrypting InnoDB tables](../innodb-encryption/index), the key that is used to encrypt tables [can be changed](../innodb-xtradb-encryption-keys/index). When [encrypting Aria tables](../aria-encryption/index), the key that is used to encrypt tables [cannot currently be changed](../aria-encryption-keys/index). Key Rotation ------------ The Eperi Key Management plugin supports [key rotation](../encryption-key-management/index#key-rotation). Versions -------- | Version | Status | Introduced | | --- | --- | --- | | 1.0 | Unknown | [eperi Gateway for Databases](https://eperi.com/database-encryption/) 3.4.0 | System Variables ---------------- ### `eperi_key_management_plugin_databaseId` * **Description:** Determines the database ID which is processed in the eperi Gateway. * **Commandline:** `--eperi-key-management-plugin-databaseid=value` * **Scope:** Global * **Dynamic:** No * **Data Type:** `integer` * **Default Value:** `1` --- ### `eperi_key_management_plugin_encryption_algorithm` * **Description:** This system variable is used to determine which algorithm the plugin will use to encrypt data. + The recommended algorithm is `AES_CTR`, but this algorithm is only available when MariaDB is built with recent versions of [OpenSSL](https://www.openssl.org/). If the server is built with [wolfSSL](https://www.wolfssl.com/products/wolfssl/) or [yaSSL](https://www.wolfssl.com/products/yassl/), then this algorithm is not available. See [TLS and Cryptography Libraries Used by MariaDB](../tls-and-cryptography-libraries-used-by-mariadb/index) for more information about which libraries are used on which platforms. * **Commandline:** `--eperi-key-management-plugin-encryption-algorithm=value` * **Scope:** Global * **Dynamic:** No * **Data Type:** `enumerated` * **Default Value:** `AES_CBC` * **Valid Values:** `AES_CBC`, `AES_CTR` --- ### `eperi_key_management_plugin_encryption_mode` * **Description:** Encryption mode. * **Commandline:** `--eperi-key-management-plugin-encryption-mode=value` * **Scope:** Global * **Dynamic:** No * **Data Type:** `enumerated` * **Default Value:** `database` * **Valid Values:** `database`, `gateway` --- ### `eperi_key_management_plugin_osslmt` * **Description:** Determines, whether the plugin should register callback functions for OpenSSL thread support. * **Commandline:** `--eperi-key-management-plugin-osslmt=value` * **Scope:** Global * **Dynamic:** No * **Data Type:** `boolean` * **Default Value:** `0` (Linux), `1` (Windows) --- ### `eperi_key_management_plugin_port` * **Description:** Listener port for plugin. * **Commandline:** `--eperi-key-management-plugin-port=value` * **Scope:** Global * **Dynamic:** No * **Data Type:** `integer` * **Default Value:** `14332` --- ### `eperi_key_management_plugin_url` * **Description:** URL to key server. The expected format of the URL is <host>:<port>. The port number is optional, and the port number defaults to 14333 if it is not specified. * **Commandline:** `--eperi-key-management-plugin-url=value` * **Scope:** Global * **Dynamic:** No * **Data Type:** `string` * **Default Value:** `NULL` --- ### `eperi_key_management_plugin_url_check_disabled` * **Description:** Determines, whether the connection between plugin and eperi Gateway is tested at server startup. * **Commandline:** `--eperi-key-management-plugin-url-check-disabled=value` * **Scope:** Global * **Dynamic:** No * **Data Type:** `boolean` * **Default Value:** `1` --- Options ------- ### `eperi_key_management_plugin` * **Description:** Controls how the server should treat the plugin when the server starts up. + Valid values are: - `OFF` - Disables the plugin without removing it from the `[mysql.plugins](../mysqlplugin-table/index)` table. - `ON` - Enables the plugin. If the plugin cannot be initialized, then the server will still continue starting up, but the plugin will be disabled. - `FORCE` - Enables the plugin. If the plugin cannot be initialized, then the server will fail to start with an error. - `FORCE_PLUS_PERMANENT` - Enables the plugin. If the plugin cannot be initialized, then the server will fail to start with an error. In addition, the plugin cannot be uninstalled with `[UNINSTALL SONAME](../uninstall-soname/index)` or `[UNINSTALL PLUGIN](../uninstall-plugin/index)` while the server is running. + See [Plugin Overview: Configuring Plugin Activation at Server Startup](../plugin-overview/index#configuring-plugin-activation-at-server-startup) for more information. * **Commandline:** `--eperi-key-management-plugin=value` * **Data Type:** `enumerated` * **Default Value:** `ON` * **Valid Values:** `OFF`, `ON`, `FORCE`, `FORCE_PLUS_PERMANENT` --- See Also -------- * [Database Encryption - eperi](https://eperi.com/database-encryption/) * [eperi Gateway for Databases version 3.4 offers native MariaDB support](https://eperi.com/eperi-gateway-for-databases-version-3-4-offers-native-mariadb-support/) * [eperi Customer Portal](https://customer.eperi.de/index.jsp) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Buildbot Setup for Virtual Machines - Ubuntu 10.10 "maverick" Buildbot Setup for Virtual Machines - Ubuntu 10.10 "maverick" ============================================================= Base install ------------ ``` qemu-img create -f qcow2 vm-maverick-amd64-serial.qcow2 8G kvm -m 1024 -hda vm-maverick-amd64-serial.qcow2 -cdrom /kvm/ubuntu-10.10-server-amd64.iso -redir tcp:2246::22 -boot d -smp 2 -cpu qemu64 -net nic,model=virtio -net user # Install, picking default options mostly, only adding openssh server. kvm -m 1024 -hda vm-maverick-amd64-serial.qcow2 -cdrom /kvm/ubuntu-10.10-server-amd64.iso -redir tcp:2246::22 -boot c -smp 2 -cpu qemu64 -net nic,model=virtio -net user -nographic ssh -p 2246 localhost # edit /boot/grub/menu.lst and visudo, see below ssh -t -p 2246 localhost "mkdir .ssh; sudo addgroup $USER sudo" scp -P 2246 authorized_keys localhost:.ssh/ echo $'Buildbot\n\n\n\n\ny' | ssh -p 2246 localhost 'chmod -R go-rwx .ssh; sudo adduser --disabled-password buildbot; sudo addgroup buildbot sudo; sudo mkdir ~buildbot/.ssh; sudo cp .ssh/authorized_keys ~buildbot/.ssh/; sudo chown -R buildbot:buildbot ~buildbot/.ssh; sudo chmod -R go-rwx ~buildbot/.ssh' scp -P 2246 ttyS0.conf buildbot@localhost: ssh -p 2246 buildbot@localhost 'sudo cp ttyS0.conf /etc/init/; rm ttyS0.conf; sudo shutdown -h now' ``` ``` qemu-img create -f qcow2 vm-maverick-i386-serial.qcow2 8G kvm -m 1024 -hda vm-maverick-i386-serial.qcow2 -cdrom /kvm/ubuntu-10.10-server-i386.iso -redir tcp:2247::22 -boot d -smp 2 -cpu qemu32,-nx -net nic,model=virtio -net user # Install, picking default options mostly, only adding openssh server. kvm -m 1024 -hda vm-maverick-i386-serial.qcow2 -cdrom /kvm/ubuntu-10.10-server-i386.iso -redir tcp:2247::22 -boot c -smp 2 -cpu qemu32,-nx -net nic,model=virtio -net user -nographic ssh -p 2247 localhost # edit /boot/grub/menu.lst and visudo, see below ssh -t -p 2247 localhost "mkdir .ssh; sudo addgroup $USER sudo" scp -P 2247 authorized_keys localhost:.ssh/ echo $'Buildbot\n\n\n\n\ny' | ssh -p 2247 localhost 'chmod -R go-rwx .ssh; sudo adduser --disabled-password buildbot; sudo addgroup buildbot sudo; sudo mkdir ~buildbot/.ssh; sudo cp .ssh/authorized_keys ~buildbot/.ssh/; sudo chown -R buildbot:buildbot ~buildbot/.ssh; sudo chmod -R go-rwx ~buildbot/.ssh' scp -P 2247 ttyS0.conf buildbot@localhost: ssh -p 2247 buildbot@localhost 'sudo cp ttyS0.conf /etc/init/; rm ttyS0.conf; sudo shutdown -h now' ``` Enabling passwordless sudo: ``` sudo VISUAL=vi visudo # Add line at end: `%sudo ALL=NOPASSWD: ALL' ``` Editing /boot/grub/menu.lst: ``` sudo vi /etc/default/grub # Add/edit these entries: GRUB_CMDLINE_LINUX_DEFAULT="console=tty0 console=ttyS0,115200n8" GRUB_TERMINAL="serial" GRUB_SERIAL_COMMAND="serial --unit=0 --speed=115200 --word=8 --parity=no --stop=1" sudo update-grub ``` VMs for building .debs ---------------------- ``` for i in 'vm-maverick-amd64-serial.qcow2 2246 qemu64' 'vm-maverick-i386-serial.qcow2 2247 qemu32,-nx' ; do \ set $i; \ runvm --user=buildbot --logfile=kernel_$2.log --base-image=$1 --port=$2 --cpu=$3 "$(echo $1 | sed -e 's/serial/build/')" \ "sudo DEBIAN_FRONTEND=noninteractive apt-get update" \ "sudo DEBIAN_FRONTEND=noninteractive apt-get -y build-dep mysql-server-5.1" \ "sudo DEBIAN_FRONTEND=noninteractive apt-get install -y devscripts hardening-wrapper fakeroot doxygen texlive-latex-base ghostscript libevent-dev libssl-dev zlib1g-dev libreadline6-dev" ; \ done ``` VMs for install testing. ------------------------ See the [General Principles](../buildbot-setup-for-virtual-machines-general-principles/index) article for how to make the '`my.seed`' and '`sources.append`' files. ``` cat >sources.append <<END deb file:///home/buildbot/buildbot/debs binary/ deb-src file:///home/buildbot/buildbot/debs source/ END ``` ``` for i in 'vm-maverick-amd64-serial.qcow2 2246 qemu64' 'vm-maverick-i386-serial.qcow2 2247 qemu32,-nx' ; do \ set $i; \ runvm --user=buildbot --logfile=kernel_$2.log --base-image=$1 --port=$2 --cpu=$3 "$(echo $1 | sed -e 's/serial/install/')" \ "sudo DEBIAN_FRONTEND=noninteractive apt-get update" \ "sudo DEBIAN_FRONTEND=noninteractive apt-get install -y debconf-utils" \ "= scp -P $2 my.seed sources.append buildbot@localhost:/tmp/" \ "sudo debconf-set-selections /tmp/my.seed" \ "sudo sh -c 'cat /tmp/sources.append >> /etc/apt/sources.list'"; \ done ``` VMs for upgrade testing ----------------------- ``` for i in 'vm-maverick-amd64-install.qcow2 2246 qemu64' 'vm-maverick-i386-install.qcow2 2247 qemu32,-nx' ; do \ set $i; \ runvm --user=buildbot --logfile=kernel_$2.log --base-image=$1 --port=$2 --cpu=$3 "$(echo $1 | sed -e 's/install/upgrade/')" \ 'sudo DEBIAN_FRONTEND=noninteractive apt-get install -y mysql-server-5.1' \ 'mysql -uroot -prootpass -e "create database mytest; use mytest; create table t(a int primary key); insert into t values (1); select * from t"' ;\ done ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Disks Plugin Disks Plugin ============ **MariaDB starting with [10.2.14](https://mariadb.com/kb/en/mariadb-10214-release-notes/)**The `DISKS` plugin was first released in [MariaDB 10.3.6](https://mariadb.com/kb/en/mariadb-1036-release-notes/) and [MariaDB 10.2.14](https://mariadb.com/kb/en/mariadb-10214-release-notes/). The `DISKS` plugin creates the [DISKS](../information-schema-disks-table/index) table in the [INFORMATION\_SCHEMA](../information-schema/index) database. This table shows metadata about disks on the system. Before [MariaDB 10.4.7](https://mariadb.com/kb/en/mariadb-1047-release-notes/), [MariaDB 10.3.17](https://mariadb.com/kb/en/mariadb-10317-release-notes/) and [MariaDB 10.2.26](https://mariadb.com/kb/en/mariadb-10226-release-notes/), this plugin did **not** check [user privileges](../grant/index). When it is enabled, **any** user can query the `INFORMATION_SCHEMA.DISKS` table and see all the information it provides. Since [MariaDB 10.4.7](https://mariadb.com/kb/en/mariadb-1047-release-notes/), [MariaDB 10.3.17](https://mariadb.com/kb/en/mariadb-10317-release-notes/) and [MariaDB 10.2.26](https://mariadb.com/kb/en/mariadb-10226-release-notes/) , it required the [FILE privilege](../grant/index). The plugin only works on Linux. Installing the Plugin --------------------- Although the plugin's shared library is distributed with MariaDB by default, the plugin is not actually installed by MariaDB by default. There are two methods that can be used to install the plugin with MariaDB. The first method can be used to install the plugin without restarting the server. You can install the plugin dynamically by executing [INSTALL SONAME](../install-soname/index) or [INSTALL PLUGIN](../install-plugin/index). For example: ``` INSTALL SONAME 'disks'; ``` The second method can be used to tell the server to load the plugin when it starts up. The plugin can be installed this way by providing the [--plugin-load](../mysqld-options/index#-plugin-load) or the [--plugin-load-add](../mysqld-options/index#-plugin-load-add) options. This can be specified as a command-line argument to [mysqld](../mysqld-options/index) or it can be specified in a relevant server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index). For example: ``` [mariadb] ... plugin_load_add = disks ``` Uninstalling the Plugin ----------------------- You can uninstall the plugin dynamically by executing [UNINSTALL SONAME](../uninstall-soname/index) or [UNINSTALL PLUGIN](../uninstall-plugin/index). For example: ``` UNINSTALL SONAME 'disks'; ``` If you installed the plugin by providing the [--plugin-load](../mysqld-options/index#-plugin-load) or the [--plugin-load-add](../mysqld-options/index#-plugin-load-add) options in a relevant server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index), then those options should be removed to prevent the plugin from being loaded the next time the server is restarted. Example ------- ``` SELECT * FROM information_schema.DISKS; +-----------+-------+----------+---------+-----------+ | Disk | Path | Total | Used | Available | +-----------+-------+----------+---------+-----------+ | /dev/vda1 | / | 26203116 | 2178424 | 24024692 | | /dev/vda1 | /boot | 26203116 | 2178424 | 24024692 | | /dev/vda1 | /etc | 26203116 | 2178424 | 24024692 | +-----------+-------+----------+---------+-----------+ ``` Versions -------- | Version | Status | Introduced | | --- | --- | --- | | 1.1 | Stable | [MariaDB 10.4.7](https://mariadb.com/kb/en/mariadb-1047-release-notes/), [MariaDB 10.3.17](https://mariadb.com/kb/en/mariadb-10317-release-notes/), [MariaDB 10.2.26](https://mariadb.com/kb/en/mariadb-10226-release-notes/), [MariaDB 10.1.41](https://mariadb.com/kb/en/mariadb-10141-release-notes/) | | 1.0 | Beta | [MariaDB 10.3.6](https://mariadb.com/kb/en/mariadb-1036-release-notes/), [MariaDB 10.2.14](https://mariadb.com/kb/en/mariadb-10214-release-notes/), [MariaDB 10.1.32](https://mariadb.com/kb/en/mariadb-10132-release-notes/) | Options ------- ### `disks` * **Description:** Controls how the server should treat the plugin when the server starts up. + Valid values are: - `OFF` - Disables the plugin without removing it from the [mysql.plugins](../mysqlplugin-table/index) table. - `ON` - Enables the plugin. If the plugin cannot be initialized, then the server will still continue starting up, but the plugin will be disabled. - `FORCE` - Enables the plugin. If the plugin cannot be initialized, then the server will fail to start with an error. - `FORCE_PLUS_PERMANENT` - Enables the plugin. If the plugin cannot be initialized, then the server will fail to start with an error. In addition, the plugin cannot be uninstalled with [UNINSTALL SONAME](../uninstall-soname/index) or [UNINSTALL PLUGIN](../uninstall-plugin/index) while the server is running. + See [Plugin Overview: Configuring Plugin Activation at Server Startup](../plugin-overview/index#configuring-plugin-activation-at-server-startup) for more information. * **Commandline:** `--disks=value` * **Data Type:** `enumerated` * **Default Value:** `ON` * **Valid Values:** `OFF`, `ON`, `FORCE`, `FORCE_PLUS_PERMANENT` --- Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb Preparing and Installing MariaDB ColumnStore 1.1.x Preparing and Installing MariaDB ColumnStore 1.1.x =================================================== | Title | Description | | --- | --- | | [Preparing for ColumnStore Installation - 1.1.X](../preparing-for-columnstore-installation-11x/index) | Before installing MariaDB ColumnStore, there is some preparation necessary | | [MariaDB ColumnStore Cluster Test Tool](../mariadb-columnstore-cluster-test-tool/index) | Introduction MariaDB ColumnStore Cluster Test Tool is used to validate tha... | | [Installing and Configuring a Single Server ColumnStore System](../installing-and-configuring-mariadb-columnstore/index) | How to install ColumnStore on a single server system. | | [Installing and Configuring a Multi Server ColumnStore System - 1.1.X](../installing-and-configuring-a-multi-server-columnstore-system-11x/index) | How to install ColumnStore on a multi-server system | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Using and Maintaining the Binary Log Using and Maintaining the Binary Log ==================================== See [Overview of the Binary Log](../overview-of-the-binary-log/index) for a general overview of what the binary log is, and [Activating the Binary Log](../activating-the-binary-log/index) for how to make sure it's running on your system. For details on using the binary log for replication, see the [Replication](../replication/index) section. Purging Log Files ----------------- To delete all binary log files on the server, run the [RESET MASTER](../reset-master/index) command. To delete all binary logs before a certain datetime, or up to a certain number, use [PURGE BINARY LOGS](../sql-commands-purge-logs/index). If a replica is active but has yet to read from a binary log file you attempt to delete, the statement will fail with an error. However, if the replica is not connected and has yet to read from a log file you delete, the file will be deleted, but the replica will be unable to continue replicating once it connects again. Log files can also be removed automatically with the [expire\_logs\_days](../replication-and-binary-log-system-variables/index#expire_logs_days) system variable. This is set to 0 by default (no removal), but can be set to a time, in days, after which a binary log file will be automatically removed. Log files will only be checked for being older than [expire\_logs\_days](../replication-and-binary-log-system-variables/index#expire_logs_days) upon log rotation, so if your binary log only fills up slowly and does not reach [max\_binlog\_size](../replication-and-binary-log-system-variables/index#max_binlog_size) on a daily basis, you may see older log files still being kept. You can also force log rotation, and so expiry deletes, by running [FLUSH BINARY LOGS](../flush/index) on a regular basis. Always set [expire\_logs\_days](../replication-and-binary-log-system-variables/index#expire_logs_days) higher than any possible replica lag. From [MariaDB 10.6](../what-is-mariadb-106/index), the [binlog\_expire\_logs\_seconds](../replication-and-binary-log-system-variables/index#binlog_expire_logs_seconds) variable allows more precise control over binlog deletion, and takes precedence if both are non-zero. If the binary log index file has been removed, or incorrectly manually edited, all of the above forms of purging log files will fail. The .index file is a plain text file, and can be manually recreated or edited so that it lists only the binary log files that are present, in numeric/age order. ### Examples ``` PURGE BINARY LOGS TO 'mariadb-bin.000063'; ``` ``` PURGE BINARY LOGS BEFORE '2013-04-22 09:55:22'; ``` ### Safely Purging Binary Log Files While Replicating To be sure replication is not broken while deleting log files, perform the following steps: * Get a listing of binary log files on the primary by running [SHOW BINARY LOGS](../show-binary-logs/index). * Go to each replica server and run [SHOW SLAVE STATUS](../show-slave-status/index) to check which binary log file each replica is currently reading. * Find the earliest log file still being read by a replica. No log files before this one will be needed. * If you wish, make a backup of the log files to be deleted * Purge all log files before (not including) the file identified above. Binary Log Format ----------------- There are three formats for the binary log. The default is statement-based logging, while row-based logging and a mix of the two formats are also possible. See [Binary Log Formats](../binary-log-formats/index) for a full discussion. Selectively Logging to the Binary Log ------------------------------------- By default, all changes to data or data structure are logged. This behavior can be changed by starting the server with the `--binlog-ignore-db=database_name` or `--binlog-do-db=database_name` [options](../mysqld-options-full-list/index). `--binlog-ignore-db=database_name` specified a database to ignore for logging purposes, while `--binlog-do-db=database_name` will not log any statements unless they apply to the specified database. Neither option accepts comma-delimited lists of multiple databases as an option, since a database name can contain a comma. To apply to multiple databases, use the option multiple times. `--binlog-ignore-db=database_name` behaves differently depending on whether statement-based or row-based logging is used. For statement-based logging, the server will not log any statement where the *default database* is database\_name. The default database is set with the [USE](../use/index) statement. Similarly, `--binlog-do-db=database_name` also behaves differently depending on whether statement-based or row-based logging is used. For statement-based logging, the server will only log statement where the *default database* is database\_name. The default database is set with the [USE](../use/index) statement. For row-based logging, the server will log any updates to any tables in the named database/s, irrespective of the current database. ### Examples Assume the server has started with the option `--binlog-ignore-db=employees`. The following example *is* logged if statement-based logging is used, and *is not* logged with row-based logging. ``` USE customers; UPDATE employees.details SET bonus=bonus*1.2; ``` This is because statement-based logging examines the default database, in this case, `customers`. Since `customers` is not specified in the ignore list, the statement will be logged. If row-based logging is used, the example will not be logged as updates are written to the tables in the `employees` database. Assume instead the server started with the option `--binlog-do-db=employees`. The following example *is not* logged if statement-based logging is used, and *is* logged with row-based logging. ``` USE customers; UPDATE employees.details SET bonus=bonus*1.2; ``` This is again because statement-based logging examines the default database, in this case, `customers`. Since `customers` is not specified in the do list, the statement will not be logged. If row-based logging is used, the example will be logged as updates are written to the tables in the `employees` database. Effects of Full Disk Errors on Binary Logging --------------------------------------------- If MariaDB encounters a full disk error while trying to write to a binary log file, then it will keep retrying the write every 60 seconds. Log messages will get written to the error log every 600 seconds. For example: ``` 2018-11-27 2:46:46 140278181563136 [Warning] mysqld: Disk is full writing '/var/lib/mariadb-bin.00001' (Errcode: 28 "No space left on device"). Waiting for someone to free space... (Expect up to 60 secs delay for server to continue after freeing disk space) 2018-11-27 2:46:46 140278181563136 [Warning] mysqld: Retry in 60 secs. Message reprinted in 600 secs ``` However, if MariaDB encounters a full disk error while trying to open a new binary log file, then it will disable binary logging entirely. A log message like the following will be written to the error log: ``` 2018-11-27 3:30:49 140278181563136 [ERROR] Could not open '/var/lib/mariadb-bin.00002 for logging (error 28). Turning logging off for the whole duration of the MySQL server process. To turn it on again: fix the cause, shutdown the MySQL server and restart it. 2018-11-27 3:30:49 140278181563136 [ERROR] mysqld: Error writing file '(null)' (errno: 9 "Bad file descriptor") 2018-11-27 3:30:49 140278181563136 [ERROR] mysqld: Error writing file '(null)' (errno: 28 "No space left on device") ``` See Also -------- * [PURGE LOGS](../sql-commands-purge-logs/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Installing the Boost library needed for the OQGraph storage engine Installing the Boost library needed for the OQGraph storage engine ================================================================== The OQGraph storage engine needs a newer version of Boost that what is available on (most) distributions. The version installed is 1.42.0, available from <http://www.boost.org/>. The boost library is installed in all the builder virtual machine images with the following single command: ``` for i in "vm-hardy-amd64-build qemu64" "vm-hardy-i386-build qemu32,-nx" \ "vm-intrepid-amd64-build qemu64" "vm-intrepid-i386-build qemu32,-nx" \ "vm-karmic-amd64-build qemu64" "vm-karmic-i386-build qemu32,-nx" \ "vm-jaunty-amd64-build qemu64" "vm-jaunty-i386-deb-build qemu32,-nx" \ "vm-lucid-amd64-build qemu64" "vm-lucid-i386-build qemu32,-nx" \ "vm-maverick-amd64-build qemu64" "vm-maverick-i386-build qemu32,-nx" \ "vm-natty-amd64-build qemu64" "vm-natty-i386-build qemu64" \ "vm-oneiric-amd64-build qemu64" "vm-oneiric-i386-build qemu64" \ "vm-debian5-amd64-build qemu64" "vm-debian5-i386-build qemu32,-nx" \ "vm-debian4-amd64-build qemu64 --netdev=e1000" "vm-debian4-i386-build qemu32,-nx --netdev=e1000" \ "vm-centos5-i386-build qemu32,-nx" "vm-centos5-amd64-build qemu64" \ "vm-hardy-amd64-build qemu64" "vm-hardy-i386-build qemu32,-nx" \ "vm-jaunty-i386-deb-tarbake qemu32,-nx" ; do \ set $i; \ runvm -m 512 --smp=1 --port=2200 --user=buildbot --cpu=$2 $3 $1.qcow2 \ "= scp -P 2200 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no /kvm/boost_1_42_0.tar.gz buildbot@localhost:/dev/shm/" \ "sudo mkdir -p /usr/local/src /usr/local/include" \ "cd /usr/local/src && sudo tar zxf /dev/shm/boost_1_42_0.tar.gz" \ "cd /usr/local/include && sudo ln -s ../src/boost_1_42_0/boost ." ; \ done ``` Upgrade Boost to 1.49 --------------------- To upgrade boost on the VMs to 1.49 I performed the following steps: *I initially tried to upgrade the VMs using a script like the one at the top of the page which was used to install boost 1.42, but I ran into issues with getting it to work on all of the VMs (it worked on some, but not on others). So I ended up using the steps below.* 1. Copy the VM (keeping the original as a backup, in case something goes wrong): ``` oldvm="vm-debian6-i386-build.qcow2" newvm="vm-debian6-i386-build.upd.qcow2" cp -avi ${oldvm} ${newvm} ``` 2. Start the VM: ``` kvm -m 1024 -hda /kvm/vms/${newvm} -redir 'tcp:22775::22' -boot c -smp 1 -cpu qemu64 -net nic,model=virtio -net user -nographic ``` 3. Copy the boost tar.gz file over to the VM: ``` scp -i /kvm/vms/ssh-keys/id_dsa -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -P 22775 /kvm/boost_1_49_0.tar.gz buildbot@localhost:/dev/shm/ ``` 4. ssh into the VM: ``` ssh -i /kvm/vms/ssh-keys/id_dsa -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -p 22775 buildbot@localhost ``` 5. once inside the VM, perform the following steps: ``` cd /usr/local/src sudo tar zxf /dev/shm/boost_1_49_0.tar.gz cd /usr/local/include/ sudo rm boost sudo ln -s ../src/boost_1_49_0/boost . sudo /sbin/shutdown -h now ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Galera Functions Galera Functions ================= The following functions are for use with [Galera](../galera/index). | Title | Description | | --- | --- | | [WSREP\_LAST\_SEEN\_GTID](../wsrep_last_seen_gtid/index) | Returns the Global Transaction ID of the most recent write transaction observed by the client. | | [WSREP\_LAST\_WRITTEN\_GTID](../wsrep_last_written_gtid/index) | Returns the Global Transaction ID of the most recent write transaction performed by the client. | | [WSREP\_SYNC\_WAIT\_UPTO\_GTID](../wsrep_sync_wait_upto_gtid/index) | Blocks the client until the transaction specified by the given GTID is applied and committed. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb USE USE === Syntax ------ ``` USE db_name ``` Description ----------- The `'USE db_name'` statement tells MariaDB to use the `db_name` database as the default (current) database for subsequent statements. The database remains the default until the end of the session or another `USE` statement is issued: ``` USE db1; SELECT COUNT(*) FROM mytable; # selects from db1.mytable USE db2; SELECT COUNT(*) FROM mytable; # selects from db2.mytable ``` The [DATABASE()](../database/index) function ([SCHEMA()](../schema/index) is a synonym) returns the default database. Another way to set the default database is specifying its name at [mysql](../mysql-command-line-client/index) command line client startup. See Also -------- * [Identifier Qualifiers](../identifier-qualifiers/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb KILL [CONNECTION | QUERY] KILL [CONNECTION | QUERY] ========================= Syntax ------ ``` KILL [HARD | SOFT] { {CONNECTION|QUERY} thread_id | QUERY ID query_id | USER user_name } ``` Description ----------- Each connection to mysqld runs in a separate thread. You can see which threads are running with the `SHOW PROCESSLIST` statement and kill a thread with the `KILL thread_id` statement. `KILL` allows the optional `CONNECTION` or `QUERY` modifier: * `KILL CONNECTION` is the same as `KILL` with no modifier: It terminates the connection associated with the given thread or query id. * `KILL QUERY` terminates the statement that the connection thread\_id is currently executing, but leaves the connection itself intact. * `KILL QUERY ID` terminates the query by query\_id, leaving the connection intact. If a connection is terminated that has an active transaction, the transaction will be rolled back. If only a query is killed, the current transaction will stay active. See also [idle\_transaction\_timeout](../server-system-variables/index#idle_transaction_timeout). If you have the [PROCESS](../grant/index#process) privilege, you can see all threads. If you have the [SUPER](../grant/index#super) privilege, or, from [MariaDB 10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/), the [CONNECTION ADMIN](../grant/index#connection-admin) privilege, you can kill all threads and statements. Otherwise, you can see and kill only your own threads and statements. Killing queries that repair or create indexes on MyISAM and Aria tables may result in corrupted tables. Use the `SOFT` option to avoid this! The `HARD` option (default) kills a command as soon as possible. If you use `SOFT`, then critical operations that may leave a table in an inconsistent state will not be interrupted. Such operations include `REPAIR` and `INDEX` creation for [MyISAM](../myisam/index) and [Aria](../aria/index) tables ([REPAIR TABLE](../repair-table/index), [OPTIMIZE TABLE](../optimize-table/index)). `KILL ... USER username` will kill all connections/queries for a given user. `USER` can be specified one of the following ways: * username (Kill without regard to hostname) * username@hostname * [CURRENT\_USER](../current_user/index) or [CURRENT\_USER()](../current_user/index) If you specify a thread id and that thread does not exist, you get the following error: ``` ERROR 1094 (HY000): Unknown thread id: <thread_id> ``` If you specify a query id that doesn't exist, you get the following error: ``` ERROR 1957 (HY000): Unknown query id: <query_id> ``` However, if you specify a user name, no error is issued for non-connected (or even non-existing) users. To check if the connection/query has been killed, you can use the [ROW\_COUNT()](../row_count/index) function. A client whose connection is killed receives the following error: ``` ERROR 1317 (70100): Query execution was interrupted ``` To obtain a list of existing sessions, use the [SHOW PROCESSLIST](../show-processlist/index) statement or query the [Information Schema](../information-schema/index) [PROCESSLIST](../information-schema-processlist-table/index) table. **Note:** You cannot use `KILL` with the Embedded MySQL Server library because the embedded server merely runs inside the threads of the host application. It does not create any connection threads of its own. **Note:** You can also use `mysqladmin kill thread_id [,thread_id...]` to kill connections. To get a list of running queries, use `mysqladmin processlist`. See [mysqladmin](../mysqladmin/index). [Percona Toolkit](http://www.percona.com/doc/percona-toolkit/) contains a program, [pt-kill](http://www.percona.com/doc/percona-toolkit/pt-kill.html) that can be used to automatically kill connections that match certain criteria. For example, it can be used to terminate idle connections, or connections that have been busy for more than 60 seconds. See Also -------- * [Query limits and timeouts](../query-limits-and-timeouts/index) * [Aborting statements that exceed a certain time to execute](../aborting-statements/index) * [idle\_transaction\_timeout](../server-system-variables/index#idle_transaction_timeout) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb extract_schema_from_file_name extract\_schema\_from\_file\_name ================================= Syntax ------ ``` sys.extract_schema_from_file_name(path) ``` Description ----------- `extract_schema_from_file_name` is a [stored function](../stored-functions/index) available with the [Sys Schema](../sys-schema/index). Given a file path, it returns the schema (database) name. The file name is assumed to be within the schema directory, and therefore the function will not return the expected result with partitions, or when tables are defined using the DATA\_DIRECTORY table option. The function does not examine anything on disk. The return value, a VARCHAR(64), is determined solely from the provided path. Examples -------- ``` SELECT sys.extract_schema_from_file_name('/usr/local/mysql/data/db/t1.ibd'); +----------------------------------------------------------------------+ | sys.extract_schema_from_file_name('/usr/local/mysql/data/db/t1.ibd') | +----------------------------------------------------------------------+ | db | +----------------------------------------------------------------------+ ``` See also -------- * [extract\_table\_from\_file\_name()](../extract_table_from_file_name/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb HandlerSocket Configuration Options HandlerSocket Configuration Options =================================== The [HandlerSocket](../handlersocket/index) plugin has the following options. See also the [Full list of MariaDB options, system and status variables](../full-list-of-mariadb-options-system-and-status-variables/index). Add the options to the [mysqld] section of your my.cnf file. --- ### `handlersocket_accept_balance` * **Description:** When set to a value other than zero ('`0`'), handlersocket will try to balance accepted connections among threads. Default is `0` but if you use persistent connections (for example if you use client-side connection pooling) then a non-zero value is recommended. * **Commandline:** `--handlersocket-accept-balance="value"` * **Scope:** Global * **Dynamic:** No * **Type:** number * **Range:** `0` to `10000` * **Default Value:** `0` --- ### `handlersocket_address` * **Description:** Specify the IP address to bind to. * **Commandline:** `--handlersocket-address="value"` * **Scope:** Global * **Dynamic:** No * **Type:** IP Address * **Default Value:** Empty, previously `0.0.0.0` --- ### `handlersocket_backlog` * **Description:** Specify the listen backlog length. * **Commandline:** `--handlersocket-backlog="value"` * **Scope:** Global * **Dynamic:** No * **Type:** number * **Range:** `5` to `1000000` * **Default Value:** `32768` --- ### `handlersocket_epoll` * **Description:** Specify whether to use epoll for I/O multiplexing. * **Commandline:** `--handlersocket-epoll="value"` * **Scope:** Global * **Dynamic:** No * **Type:** number * **Valid values:** + **Min:** `0` + **Max:** `1` * **Default Value:** `1` --- ### `handlersocket_plain_secret` * **Description:** When set, enables plain-text authentication for the listener for read requests, with the value of the option specifying the secret authentication key. * **Commandline:** `--handlersocket-plain-secret="value"` * **Dynamic:** No * **Type:** string * **Default Value:** Empty --- ### `handlersocket_plain_secret_wr` * **Description:** When set, enables plain-text authentication for the listener for write requests, with the value of the option specifying the secret authentication key. * **Commandline:** `--handlersocket-plain-secret-wr="value"` * **Dynamic:** No * **Type:** string * **Default Value:** Empty --- ### `handlersocket_port` * **Description:** Specify the port to bind to for reads. An empty value disables the listener. * **Commandline:** `--handlersocket-port="value"` * **Scope:** Global * **Dynamic:** No * **Type:** number * **Default Value:** Empty, previously `9998` --- ### `handlersocket_port_wr` * **Description:** Specify the port to bind to for writes. An empty value disables the listener. * **Commandline:** `--handlersocket-port-wr="value"` * **Scope:** Global * **Dynamic:** No * **Type:** number * **Default Value:** Empty, previously `9999` --- ### `handlersocket_rcvbuf` * **Description:** Specify the maximum socket receive buffer (in bytes). If '0' then the system default is used. * **Commandline:** `--handlersocket-rcvbuf="value"` * **Scope:** Global * **Dynamic:** No * **Type:** number * **Range:** `0` to `1677216` * **Default Value:** `0` --- ### `handlersocket_readsize` * **Description:** Specify the minimum length of the request buffer. Larger values consume available memory but can make handlersocket faster for large requests. * **Commandline:** `--handlersocket-readsize="value"` * **Scope:** Global * **Dynamic:** No * **Type:** number * **Range:** `0` to `1677216` * **Default Value:** `0` (possibly `4096`) --- ### `handlersocket_sndbuf` * **Description:** Specify the maximum socket send buffer (in bytes). If '0' then the system default is used. * **Commandline:** `--handlersocket-sndbuf="value"` * **Scope:** Global * **Dynamic:** No * **Type:** number * **Range:** `0` to `1677216` * **Default Value:** `0` --- ### `handlersocket_threads` * **Description:** Specify the number of worker threads for reads. Recommended value = ((# CPU cores) \* 2). * **Commandline:** `--handlersocket-threads="value"` * **Scope:** Global * **Dynamic:** No * **Type:** number * **Range:** `1` to `3000` * **Default Value:** `16` --- ### `handlersocket_threads_wr` * **Description:** Specify the number of worker threads for writes. Recommended value = 1. * **Commandline:** `--handlersocket-threads-wr="value"` * **Scope:** Global * **Dynamic:** No * **Type:** number * **Range:** `1` to `3000` * **Default Value:** `1` --- ### `handlersocket_timeout` * **Description:** Specify the socket timeout in seconds. * **Commandline:** `--handlersocket-timeout="value"` * **Scope:** Global * **Dynamic:** No * **Type:** number * **Range:** `30` to `3600` * **Default Value:** `300` --- ### `handlersocket_verbose` * **Description:** Specify the logging verbosity. * **Commandline:** `--handlersocket-verbose="value"` * **Scope:** Global * **Dynamic:** No * **Type:** number * **Valid values:** + **Min:** `0` + **Max:** `10000` * **Default Value:** `10` --- ### `handlersocket_wrlock_timeout` * **Description:** The write lock timeout in seconds. When acting on write requests, handlersocket locks an advisory lock named 'handlersocket\_wr' and this option sets the timeout for it. * **Commandline:** `--handlersocket-wrlock-timeout="value"` * **Scope:** Global * **Dynamic:** No * **Type:** number * **Range:** `0` to `3600` --- Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb JSON_EXISTS JSON\_EXISTS ============ **MariaDB starting with [10.2.3](https://mariadb.com/kb/en/mariadb-1023-release-notes/)**JSON functions were added in [MariaDB 10.2.3](https://mariadb.com/kb/en/mariadb-1023-release-notes/). Syntax ------ Description ----------- Determines whether a specified JSON value exists in the given data. Returns `1` if found, `0` if not, or `NULL` if any of the inputs were NULL. Examples -------- ``` SELECT JSON_EXISTS('{"key1":"xxxx", "key2":[1, 2, 3]}', "$.key2"); +------------------------------------------------------------+ | JSON_EXISTS('{"key1":"xxxx", "key2":[1, 2, 3]}', "$.key2") | +------------------------------------------------------------+ | 1 | +------------------------------------------------------------+ SELECT JSON_EXISTS('{"key1":"xxxx", "key2":[1, 2, 3]}', "$.key3"); +------------------------------------------------------------+ | JSON_EXISTS('{"key1":"xxxx", "key2":[1, 2, 3]}', "$.key3") | +------------------------------------------------------------+ | 0 | +------------------------------------------------------------+ SELECT JSON_EXISTS('{"key1":"xxxx", "key2":[1, 2, 3]}', "$.key2[1]"); +---------------------------------------------------------------+ | JSON_EXISTS('{"key1":"xxxx", "key2":[1, 2, 3]}', "$.key2[1]") | +---------------------------------------------------------------+ | 1 | +---------------------------------------------------------------+ SELECT JSON_EXISTS('{"key1":"xxxx", "key2":[1, 2, 3]}', "$.key2[10]"); +----------------------------------------------------------------+ | JSON_EXISTS('{"key1":"xxxx", "key2":[1, 2, 3]}', "$.key2[10]") | +----------------------------------------------------------------+ | 0 | +----------------------------------------------------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb How to Quickly Insert Data Into MariaDB How to Quickly Insert Data Into MariaDB ======================================= This article describes different techniques for inserting data quickly into MariaDB. Background ---------- When inserting new data into MariaDB, the things that take time are: (in order of importance): * Syncing data to disk (as part of the end of transactions) * Adding new keys. The larger the index, the more time it takes to keep keys updated. * Checking against foreign keys (if they exist). * Adding rows to the storage engine. * Sending data to the server. The following describes the different techniques (again, in order of importance) you can use to quickly insert data into a table. Disabling Keys -------------- You can temporarily disable updating of non unique indexes. This is mostly useful when there are zero (or very few) rows in the table into which you are inserting data. ``` ALTER TABLE table_name DISABLE KEYS; BEGIN; ... inserting data with INSERT or LOAD DATA .... COMMIT; ALTER TABLE table_name ENABLE KEYS; ``` In many storage engines (at least MyISAM and Aria), `ENABLE KEYS` works by scanning through the row data and collecting keys, sorting them, and then creating the index blocks. This is an order of magnitude faster than creating the index one row at a time and it also uses less key buffer memory. **Note:** When you insert into an **empty table** with [INSERT](../insert/index) or [LOAD DATA](../load-data-infile/index), MariaDB **automatically** does an [DISABLE KEYS](../alter-table/index) before and an [ENABLE KEYS](../alter-table/index) afterwards. When inserting big amounts of data, integrity checks are sensibly time-consuming. It is possible to disable the `UNIQUE` indexes and the [foreign keys](../foreign-keys/index) checks using the [unique\_checks](../server-system-variables/index#unique_checks) and the [foreign\_key\_checks](../server-system-variables/index#foreign_key_checks) system variables: ``` SET @@session.unique_checks = 0; SET @@session.foreign_key_checks = 0; ``` For InnoDB tables, the [AUTO\_INCREMENT lock mode](../auto_increment-handling-in-innodb/index) can be temporarily set to 2, which is the fastest setting: ``` SET @@global.innodb_autoinc_lock_mode = 2; ``` Also, if the table has [INSERT triggers](../triggers/index) or [PERSISTENT](../virtual-columns/index) columns, you may want to drop them, insert all data, and recreate them. Loading Text Files ------------------ The **fastest way** to insert data into MariaDB is through the [LOAD DATA INFILE](../load-data-infile/index) command. The simplest form of the command is: ``` LOAD DATA INFILE 'file_name' INTO TABLE table_name; ``` You can also read a file locally on the machine where the client is running by using: ``` LOAD DATA LOCAL INFILE 'file_name' INTO TABLE table_name; ``` This is not as fast as reading the file on the server side, but the difference is not that big. `LOAD DATA INFILE` is very fast because: 1. there is no parsing of SQL. 2. data is read in big blocks. 3. if the table is empty at the beginning of the operation, all non unique indexes are disabled during the operation. 4. the engine is told to cache rows first and then insert them in big blocks (At least MyISAM and Aria support this). 5. for empty tables, some transactional engines (like Aria) do not log the inserted data in the transaction log because one can rollback the operation by just doing a [TRUNCATE](../truncate-table/index) on the table. Because of the above speed advantages there are many cases, when you need to insert **many** rows at a time, where it may be faster to create a file locally, add the rows there, and then use `LOAD DATA INFILE` to load them; compared to using `INSERT` to insert the rows. You will also get [progress reporting](../progress-reporting/index) for `LOAD DATA INFILE`. ### mariadb-import/mysqlimport You can import many files in parallel with [mariadb-import](../mysqlimport/index) (`mysqlimport` before [MariaDB 10.5](../what-is-mariadb-105/index)). For example: ``` mysqlimport --use-threads=10 database text-file-name [text-file-name...] ``` Internally [mariadb-import/mysqlimport](../mysqlimport/index) uses [LOAD DATA INFILE](../load-data-infile/index) to read in the data. Inserting Data with INSERT Statements ------------------------------------- ### Using Big Transactions When doing many inserts in a row, you should wrap them with `BEGIN / END` to avoid doing a full transaction (which includes a disk sync) for every row. For example, doing a begin/end every 1000 inserts will speed up your inserts by almost 1000 times. ``` BEGIN; INSERT ... INSERT ... END; BEGIN; INSERT ... INSERT ... END; ... ``` The reason why you may want to have many `BEGIN/END` statements instead of just one is that the former will use up less transaction log space. ### Multi-Value Inserts You can insert many rows at once with multi-value row inserts: ``` INSERT INTO table_name values(1,"row 1"),(2, "row 2"),...; ``` The limit for how much data you can have in one statement is controlled by the [max\_allowed\_packet](../server-system-variables/index#max_allowed_packet) server variable. Inserting Data Into Several Tables at Once ------------------------------------------ If you need to insert data into several tables at once, the best way to do so is to enable multi-row statements and send many inserts to the server at once: ``` INSERT INTO table_name_1 (auto_increment_key, data) VALUES (NULL,"row 1"); INSERT INTO table_name_2 (auto_increment, reference, data) values (NULL, LAST_INSERT_ID(), "row 2"); ``` [LAST\_INSERT\_ID()](../last_insert_id/index) is a function that returns the last `auto_increment` value inserted. By default, the command line `mysql` client will send the above as multiple statements. To test this in the `mysql` client you have to do: ``` delimiter ;; select 1; select 2;; delimiter ; ``` **Note:** for multi-query statements to work, your client must specify the `CLIENT_MULTI_STATEMENTS` flag to `mysql_real_connect()`. Server Variables That Can be Used to Tune Insert Speed ------------------------------------------------------ | Option | Description | | --- | --- | | [innodb\_buffer\_pool\_size](../innodb-system-variables/index#innodb_buffer_pool_size) | Increase this if you have many indexes in InnoDB/XtraDB tables | | [key\_buffer\_size](../myisam-system-variables/index#key_buffer_size) | Increase this if you have many indexes in MyISAM tables | | [max\_allowed\_packet](../server-system-variables/index#max_allowed_packet) | Increase this to allow bigger multi-insert statements | | [read\_buffer\_size](../server-system-variables/index#read_buffer_size) | Read block size when reading a file with `LOAD DATA` | See [Server System Variables](../server-system-variables/index) for the full list of server variables. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Information Schema INNODB_BUFFER_POOL_STATS Table Information Schema INNODB\_BUFFER\_POOL\_STATS Table ==================================================== The [Information Schema](../information_schema/index) `INNODB_BUFFER_POOL_STATS` table contains information about pages in the [buffer pool](../xtradbinnodb-memory-buffer/index), similar to what is returned with the `[SHOW ENGINE INNODB STATUS](../show-engine-innodb-status/index)` statement. The `PROCESS` [privilege](../grant/index) is required to view the table. It has the following columns: | Column | Description | | --- | --- | | `POOL_ID` | Buffer Pool identifier. From [MariaDB 10.5.1](https://mariadb.com/kb/en/mariadb-1051-release-notes/) returns a value of 0, since multiple InnoDB buffer pool instances has been removed. | | `POOL_SIZE` | Size in pages of the buffer pool. | | `FREE_BUFFERS` | Number of free pages in the buffer pool. | | `DATABASE_PAGES` | Total number of pages in the buffer pool. | | `OLD_DATABASE_PAGES` | Number of pages in the *old* sublist. | | `MODIFIED_DATABASE_PAGES` | Number of dirty pages. | | `PENDING_DECOMPRESS` | Number of pages pending decompression. | | `PENDING_READS` | Pending buffer pool level reads. | | `PENDING_FLUSH_LRU` | Number of pages in the LRU pending flush. | | `PENDING_FLUSH_LIST` | Number of pages in the flush list pending flush. | | `PAGES_MADE_YOUNG` | Pages moved from the *old* sublist to the *new* sublist. | | `PAGES_NOT_MADE_YOUNG` | Pages that have remained in the *old* sublist without moving to the *new* sublist. | | `PAGES_MADE_YOUNG_RATE` | Hits that cause blocks to move to the top of the *new* sublist. | | `PAGES_MADE_NOT_YOUNG_RATE` | Hits that do not cause blocks to move to the top of the *new* sublist due to the `[innodb\_old\_blocks](../xtradbinnodb-server-system-variables/index#innodb_old_blocks_time)` delay not being met. | | `NUMBER_PAGES_READ` | Number of pages read. | | `NUMBER_PAGES_CREATED` | Number of pages created. | | `NUMBER_PAGES_WRITTEN` | Number of pages written. | | `PAGES_READ_RATE` | Number of pages read since the last printout divided by the time elapsed, giving pages read per second. | | `PAGES_CREATE_RATE` | Number of pages created since the last printout divided by the time elapsed, giving pages created per second. | | `PAGES_WRITTEN_RATE` | Number of pages written since the last printout divided by the time elapsed, giving pages written per second. | | `NUMBER_PAGES_GET` | Number of logical read requests. | | `HIT_RATE` | Buffer pool hit rate. | | `YOUNG_MAKE_PER_THOUSAND_GETS` | For every 1000 gets, the number of pages made young. | | `NOT_YOUNG_MAKE_PER_THOUSAND_GETS` | For every 1000 gets, the number of pages not made young. | | `NUMBER_PAGES_READ_AHEAD` | Number of pages read ahead. | | `NUMBER_READ_AHEAD_EVICTED` | Number of pages read ahead by the read-ahead thread that were later evicted without being accessed by any queries. | | `READ_AHEAD_RATE` | Pages read ahead since the last printout divided by the time elapsed, giving read-ahead rate per second. | | `READ_AHEAD_EVICTED_RATE` | Read-ahead pages not accessed since the last printout divided by time elapsed, giving the number of read-ahead pages evicted without access per second. | | `LRU_IO_TOTAL` | Total least-recently used I/O. | | `LRU_IO_CURRENT` | Least-recently used I/O for the current interval. | | `UNCOMPRESS_TOTAL` | Total number of pages decompressed. | | `UNCOMPRESS_CURRENT` | Number of pages decompressed in the current interval | Examples -------- ``` DESC information_schema.innodb_buffer_pool_stats; +----------------------------------+---------------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +----------------------------------+---------------------+------+-----+---------+-------+ | POOL_ID | bigint(21) unsigned | NO | | 0 | | | POOL_SIZE | bigint(21) unsigned | NO | | 0 | | | FREE_BUFFERS | bigint(21) unsigned | NO | | 0 | | | DATABASE_PAGES | bigint(21) unsigned | NO | | 0 | | | OLD_DATABASE_PAGES | bigint(21) unsigned | NO | | 0 | | | MODIFIED_DATABASE_PAGES | bigint(21) unsigned | NO | | 0 | | | PENDING_DECOMPRESS | bigint(21) unsigned | NO | | 0 | | | PENDING_READS | bigint(21) unsigned | NO | | 0 | | | PENDING_FLUSH_LRU | bigint(21) unsigned | NO | | 0 | | | PENDING_FLUSH_LIST | bigint(21) unsigned | NO | | 0 | | | PAGES_MADE_YOUNG | bigint(21) unsigned | NO | | 0 | | | PAGES_NOT_MADE_YOUNG | bigint(21) unsigned | NO | | 0 | | | PAGES_MADE_YOUNG_RATE | double | NO | | 0 | | | PAGES_MADE_NOT_YOUNG_RATE | double | NO | | 0 | | | NUMBER_PAGES_READ | bigint(21) unsigned | NO | | 0 | | | NUMBER_PAGES_CREATED | bigint(21) unsigned | NO | | 0 | | | NUMBER_PAGES_WRITTEN | bigint(21) unsigned | NO | | 0 | | | PAGES_READ_RATE | double | NO | | 0 | | | PAGES_CREATE_RATE | double | NO | | 0 | | | PAGES_WRITTEN_RATE | double | NO | | 0 | | | NUMBER_PAGES_GET | bigint(21) unsigned | NO | | 0 | | | HIT_RATE | bigint(21) unsigned | NO | | 0 | | | YOUNG_MAKE_PER_THOUSAND_GETS | bigint(21) unsigned | NO | | 0 | | | NOT_YOUNG_MAKE_PER_THOUSAND_GETS | bigint(21) unsigned | NO | | 0 | | | NUMBER_PAGES_READ_AHEAD | bigint(21) unsigned | NO | | 0 | | | NUMBER_READ_AHEAD_EVICTED | bigint(21) unsigned | NO | | 0 | | | READ_AHEAD_RATE | double | NO | | 0 | | | READ_AHEAD_EVICTED_RATE | double | NO | | 0 | | | LRU_IO_TOTAL | bigint(21) unsigned | NO | | 0 | | | LRU_IO_CURRENT | bigint(21) unsigned | NO | | 0 | | | UNCOMPRESS_TOTAL | bigint(21) unsigned | NO | | 0 | | | UNCOMPRESS_CURRENT | bigint(21) unsigned | NO | | 0 | | +----------------------------------+---------------------+------+-----+---------+-------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb Improvements to ORDER BY Optimization Improvements to ORDER BY Optimization ===================================== **MariaDB starting with [10.1](../what-is-mariadb-101/index)**[MariaDB 10.1](../what-is-mariadb-101/index) includes several improvements to the [ORDER BY](../order-by/index) optimizer. The fixes were made as a response to complaints by MariaDB customers, so they fix real-world optimization problems. The fixes are a bit hard to describe (as the `ORDER BY` optimizer is complicated), but here's a short description: The [ORDER BY](../order-by/index) optimizer in [MariaDB 10.1](../what-is-mariadb-101/index): * Doesn’t make stupid choices when several multi-part keys and potential range accesses are present ([MDEV-6402](https://jira.mariadb.org/browse/MDEV-6402)). + This also fixes [MySQL Bug#12113](http://bugs.mysql.com/bug.php?id=12113). * Always uses “range” and (not full “index” scan) when it switches to an index to satisfy `ORDER BY … LIMIT` ([MDEV-6657](https://jira.mariadb.org/browse/MDEV-6657)). * Tries hard to be smart and use cost/number of records estimates from other parts of the optimizer ([MDEV-6384](https://jira.mariadb.org/browse/MDEV-6384), [MDEV-465](https://jira.mariadb.org/browse/MDEV-465)). + This change also fixes [MySQL Bug#36817](http://bugs.mysql.com/bug.php?id=36817). * Takes full advantage of InnoDB’s Extended Keys feature when checking if filesort() can be skipped ([MDEV-6796](https://jira.mariadb.org/browse/MDEV-6796)). Extra optimizations ------------------- Starting from [MariaDB 10.1.15](https://mariadb.com/kb/en/mariadb-10115-release-notes/) * The [ORDER BY](../order-by/index) optimizer takes multiple-equalities into account ([MDEV-8989](https://jira.mariadb.org/browse/MDEV-8989)). This optimization is not enabled by default in [MariaDB 10.1](../what-is-mariadb-101/index). You need to explicitly switch it ON by setting the [optimizer\_switch](../optimizer-switch/index) system variable, as follows: ``` optimizer_switch='orderby_uses_equalities=on' ``` Setting the switch ON is considered safe. It is off by default in [MariaDB 10.1](../what-is-mariadb-101/index) in order to avoid changing query plans in a stable release. It is on by default from [MariaDB 10.2](../what-is-mariadb-102/index) Comparison with MySQL 5.7 ------------------------- In [MySQL 5.7 changelog](http://mysqlserverteam.com/whats-new-in-mysql-5-7-generally-available/), one can find this passage: Make switching of index due to small limit cost-based ([WL#6986](http://askmonty.org/worklog/?tid=6986)) : We have made the decision in make\_join\_select() of whether to switch to a new index in order to support "ORDER BY ... LIMIT N" cost-based. This work fixes Bug#73837. MariaDB is not using Oracle's fix (we believe `make_join_select` is not the right place to do ORDER BY optimization), but the effect is the same: this case is covered by [MariaDB 10.1](../what-is-mariadb-101/index)'s optimizer. See Also -------- * Blog post [MariaDB 10.1: Better query optimization for ORDER BY … LIMIT](http://s.petrunia.net/blog/?p=103) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Performance Schema file_summary_by_event_name Table Performance Schema file\_summary\_by\_event\_name Table ======================================================= The [Performance Schema](../performance-schema/index) `file_summary_by_event_name` table contains file events summarized by event name. It contains the following columns: | Column | Description | | --- | --- | | `EVENT_NAME` | Event name. | | `COUNT_STAR` | Number of summarized events | | `SUM_TIMER_WAIT` | Total wait time of the summarized events that are timed. | | `MIN_TIMER_WAIT` | Minimum wait time of the summarized events that are timed. | | `AVG_TIMER_WAIT` | Average wait time of the summarized events that are timed. | | `MAX_TIMER_WAIT` | Maximum wait time of the summarized events that are timed. | | `COUNT_READ` | Number of all read operations, including `FGETS`, `FGETC`, `FREAD`, and `READ`. | | `SUM_TIMER_READ` | Total wait time of all read operations that are timed. | | `MIN_TIMER_READ` | Minimum wait time of all read operations that are timed. | | `AVG_TIMER_READ` | Average wait time of all read operations that are timed. | | `MAX_TIMER_READ` | Maximum wait time of all read operations that are timed. | | `SUM_NUMBER_OF_BYTES_READ` | Bytes read by read operations. | | `COUNT_WRITE` | Number of all write operations, including `FPUTS`, `FPUTC`, `FPRINTF`, `VFPRINTF`, `FWRITE`, and `PWRITE`. | | `SUM_TIMER_WRITE` | Total wait time of all write operations that are timed. | | `MIN_TIMER_WRITE` | Minimum wait time of all write operations that are timed. | | `AVG_TIMER_WRITE` | Average wait time of all write operations that are timed. | | `MAX_TIMER_WRITE` | Maximum wait time of all write operations that are timed. | | `SUM_NUMBER_OF_BYTES_WRITE` | Bytes written by write operations. | | `COUNT_MISC` | Number of all miscellaneous operations not counted above, including `CREATE`, `DELETE`, `OPEN`, `CLOSE`, `STREAM_OPEN`, `STREAM_CLOSE`, `SEEK`, `TELL`, `FLUSH`, `STAT`, `FSTAT`, `CHSIZE`, `RENAME`, and `SYNC`. | | `SUM_TIMER_MISC` | Total wait time of all miscellaneous operations that are timed. | | `MIN_TIMER_MISC` | Minimum wait time of all miscellaneous operations that are timed. | | `AVG_TIMER_MISC` | Average wait time of all miscellaneous operations that are timed. | | `MAX_TIMER_MISC` | Maximum wait time of all miscellaneous operations that are timed. | I/O operations can be avoided by caching, in which case they will not be recorded in this table. You can [TRUNCATE](../truncate-table/index) the table, which will reset all counters to zero. Example ------- ``` SELECT * FROM file_summary_by_event_name\G ... *************************** 49. row *************************** EVENT_NAME: wait/io/file/aria/MAD COUNT_STAR: 60 SUM_TIMER_WAIT: 397234368 MIN_TIMER_WAIT: 0 AVG_TIMER_WAIT: 6620224 MAX_TIMER_WAIT: 16808672 COUNT_READ: 0 SUM_TIMER_READ: 0 MIN_TIMER_READ: 0 AVG_TIMER_READ: 0 MAX_TIMER_READ: 0 SUM_NUMBER_OF_BYTES_READ: 0 COUNT_WRITE: 0 SUM_TIMER_WRITE: 0 MIN_TIMER_WRITE: 0 AVG_TIMER_WRITE: 0 MAX_TIMER_WRITE: 0 SUM_NUMBER_OF_BYTES_WRITE: 0 COUNT_MISC: 60 SUM_TIMER_MISC: 397234368 MIN_TIMER_MISC: 0 AVG_TIMER_MISC: 6620224 MAX_TIMER_MISC: 16808672 *************************** 50. row *************************** EVENT_NAME: wait/io/file/aria/control COUNT_STAR: 3 SUM_TIMER_WAIT: 24055778544 MIN_TIMER_WAIT: 0 AVG_TIMER_WAIT: 8018592848 MAX_TIMER_WAIT: 24027262400 COUNT_READ: 1 SUM_TIMER_READ: 24027262400 MIN_TIMER_READ: 0 AVG_TIMER_READ: 24027262400 MAX_TIMER_READ: 24027262400 SUM_NUMBER_OF_BYTES_READ: 52 COUNT_WRITE: 0 SUM_TIMER_WRITE: 0 MIN_TIMER_WRITE: 0 AVG_TIMER_WRITE: 0 MAX_TIMER_WRITE: 0 SUM_NUMBER_OF_BYTES_WRITE: 0 COUNT_MISC: 2 SUM_TIMER_MISC: 28516144 MIN_TIMER_MISC: 0 AVG_TIMER_MISC: 14258072 MAX_TIMER_MISC: 27262208 ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb MariaDB 5.3 - Asynchronous I/O on Windows with InnoDB MariaDB 5.3 - Asynchronous I/O on Windows with InnoDB ===================================================== Consider 2 pseudo-code implementation of event handling loop handling IO completion on Windows. * Using Windows events ``` void io_thread() { HANDLE handles = new HANDLE[32]; ... for (;;) { DWORD index = WaitForMultipleObjects(handles,32, FALSE); DWORD num_bytes; // Find file and overlapped structure for the index, GetOverlappedResult(file, overlapped, &num_bytes, TRUE); // handle io represented by overlapped } ``` * I/O Completion port based ``` void io_thread() { for (;;) { DWORD num_bytes; ULONG_PTR key; OVERLAPPED *overlapped; if (GetQueuedCompletionStatus(io_completion_port, &num_bytes, &key, &overlapped, INFINITE)) { // handle io represented by overlapped } } ``` Which one is more efficient ? The right answer is - I/O completion port based. This is because: 1. the number of outstanding events a thread can handle is not restricted by a constant like in the WaitForMultipleObject() case. 2. if there several io\_handler() threads running, they load-balance since every I/O can be "dequeued" by GetQueuedCompletionStatus in any io handler thread. With WaitForMultipleObjects(), the thread that will dequeue the I/O result is predetermined for each I/O. InnoDB has used asynchronous file I/O on Windows since the dawn of time, probably since NT3.1 . On some reason unknown to me (I can only speculate that Microsoft documentation was not good enough back then), InnoDB has always used method with events, and this lead to relatively complicated designs - if you're seeing "segment" mentioning in os0file.c or fil0fil.c , this is mostly due to the fact that number of events WaitForMultipleObjects() can handle is fixed. I changed async IO handling for XtraDB in MariaDB5.3 to use completion ports, rather than wait\_multiple technique. The results of a synthetic benchmark are good. The test that I run was sysbench 0.4 "update\_no\_key" ``` 4 16 64 256 1024 mariadb-5.2 17812 22378 23436 7882 6043 mariadb-5.2-fix 19217 24302 25499 25986 25925 mysql-5.5.13 12961 20445 16393 14407 5343 ``` I do understand, sysbench it does not resemble anything that real-life load, and I'm ready to admit cheating with durability for this specific benchmark, but this is an equal-opportunity cheating, all 3 versions ran with the same parameters. What do I refer to as durability cheating: 1. using [innodb\_flush\_log\_at\_trx\_commit=0](../xtradbinnodb-server-system-variables/index#innodb_flush_log_at_trx_commit) , which, for me , is ok for many scenarios 2. "Switch off Windows disk flushing" setting, which has the effect of not flushing data in the disk controller (file system caching is not used here anyway). This setting is only recommended for battery backed disks, my own desktop does not have it, of course. However, if I have not done the above, then I would be measuring the latency of a FlushFileBuffers() in my benchmark, which was not what I wanted. I wanted to stress the asynchronous IO. And here is the obligatory graph: Notes ----- This is taken from an original Facebook note from Vladislav Vaintroub, and it can be found: <https://www.facebook.com/note.php?note_id=238687382817625> It is also worth noting a note from Vlad about the graph: "The graph is given for 5.2, because I developed that patch for 5.2. I pushed it into 5.3 though :)" Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb SUBSTRING SUBSTRING ========= Syntax ------ ``` SUBSTRING(str,pos), SUBSTRING(str FROM pos), SUBSTRING(str,pos,len), SUBSTRING(str FROM pos FOR len) SUBSTR(str,pos), SUBSTR(str FROM pos), SUBSTR(str,pos,len), SUBSTR(str FROM pos FOR len) ``` Description ----------- The forms without a *`len`* argument return a substring from string *`str`* starting at position *`pos`*. The forms with a *`len`* argument return a substring *`len`* characters long from string *`str`*, starting at position *`pos`*. The forms that use *`FROM`* are standard SQL syntax. It is also possible to use a negative value for *`pos`*. In this case, the beginning of the substring is *`pos`* characters from the end of the string, rather than the beginning. A negative value may be used for *`pos`* in any of the forms of this function. By default, the position of the first character in the string from which the substring is to be extracted is reckoned as 1. For [Oracle-compatibility](../sql_modeoracle-from-mariadb-103/index), from [MariaDB 10.3.3](https://mariadb.com/kb/en/mariadb-1033-release-notes/), when sql\_mode is set to 'oracle', position zero is treated as position 1 (although the first character is still reckoned as 1). If any argument is `NULL`, returns `NULL`. Examples -------- ``` SELECT SUBSTRING('Knowledgebase',5); +------------------------------+ | SUBSTRING('Knowledgebase',5) | +------------------------------+ | ledgebase | +------------------------------+ SELECT SUBSTRING('MariaDB' FROM 6); +-----------------------------+ | SUBSTRING('MariaDB' FROM 6) | +-----------------------------+ | DB | +-----------------------------+ SELECT SUBSTRING('Knowledgebase',3,7); +--------------------------------+ | SUBSTRING('Knowledgebase',3,7) | +--------------------------------+ | owledge | +--------------------------------+ SELECT SUBSTRING('Knowledgebase', -4); +--------------------------------+ | SUBSTRING('Knowledgebase', -4) | +--------------------------------+ | base | +--------------------------------+ SELECT SUBSTRING('Knowledgebase', -8, 4); +-----------------------------------+ | SUBSTRING('Knowledgebase', -8, 4) | +-----------------------------------+ | edge | +-----------------------------------+ SELECT SUBSTRING('Knowledgebase' FROM -8 FOR 4); +------------------------------------------+ | SUBSTRING('Knowledgebase' FROM -8 FOR 4) | +------------------------------------------+ | edge | +------------------------------------------+ ``` [Oracle mode from MariaDB 10.3.3](../sql_modeoracle-from-mariadb-103/index): ``` SELECT SUBSTR('abc',0,3); +-------------------+ | SUBSTR('abc',0,3) | +-------------------+ | | +-------------------+ SELECT SUBSTR('abc',1,2); +-------------------+ | SUBSTR('abc',1,2) | +-------------------+ | ab | +-------------------+ SET sql_mode='oracle'; SELECT SUBSTR('abc',0,3); +-------------------+ | SUBSTR('abc',0,3) | +-------------------+ | abc | +-------------------+ SELECT SUBSTR('abc',1,2); +-------------------+ | SUBSTR('abc',1,2) | +-------------------+ | ab | +-------------------+ ``` See Also -------- * [INSTR()](../instr/index) - Returns the position of a string within a string * [LOCATE()](../locate/index) - Returns the position of a string within a string * [SUBSTRING\_INDEX()](../substring_index/index) - Returns a string based on substring Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Spider Server System Variables Spider Server System Variables ============================== The following variables are available when the [Spider](../spider/index) storage engine has been installed. See [Server System Variables](../server-system-variables/index) for a complete list of system variables and instructions on setting them. See also the [Full list of MariaDB options, system and status variables](../full-list-of-mariadb-options-system-and-status-variables/index). #### `spider_auto_increment_mode` * **Description:** The [auto increment](../auto_increment/index) mode. + `-1` Uses the [table parameter](../spider-table-parameters/index). + `0` Normal Mode. Uses a counter that Spider gets from the remote backend server with an exclusive lock for the auto-increment value. This mode is slow. Use Quick Mode (`2`), if you use Spider tables with the table partitioning feature and the auto-increment column is the first column of the index. Before [MariaDB 10.3](../what-is-mariadb-103/index), this value works as "1" for partitioned Spider tables. + `1` Quick Mode. Uses an internal Spider counter for the auto-increment value. This mode is fast, but it is possible for duplicates to occur when updating the same table from multiple Spider proxies. + `2` Set Zero Mode. The auto-increment value is given by the remote backend. Sets the column to `0`, even if you set the value to the auto-increment column in your statement. If you use the table with the table partitioning feature, it sets to zero after choosing an inserted partition. + `3` When the auto-increment column is set to `NULL`, the value is given by the remote backend server. If you set the auto-increment column to `0`,the value is given by the local server. Set [spider\_reset\_auto\_incremnet](#spider_reset_auto_increment) to `2` or `3` if you want to use an auto-increment column on the remote server. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Default Table Value:** `0` * **Range:** `-1` to `3` * **DSN Parameter Name:** `aim` --- #### `spider_bgs_first_read` * **Description:** Number of first read records to use when performing a concurrent background search. To start a range scan on the remote backend, the storage engine first needs to send the first record. Fetching a second record in the same query can save a network round trip stopping the plan if the backend has a single record. The first and second reads are used to warm up for background search. When not using [spider\_split\_read](#spider_split_read) and [spider\_semi\_split\_read](#spider_semi_split_read), the third read fetches the remaining data source in a single fetch. + `-1` Uses the [table parameter](../spider-table-parameters/index). + `0` Records are usually retrieved. + `1` and greater: Number of records. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Default Table Value:** `2` * **Range:** `-1` to `9223372036854775807` * **DSN Parameter Name:** `bfr` --- #### `spider_bgs_mode` * **Description:** Background search mode. This enables the use of a thread per data server connection if the query is not shard-based and must be distributed across shards. The partitioning plugin scans partitions one after the other to optimize memory usage. Because the shards are external, reading all shards can be performed in parallel when the plan prunes multiple partitions. + `-1` Uses the [table parameter](../spider-table-parameters/index). + `0` Disables background search. + `1` Uses background search when searching without locks + `2` Uses background search when searching without locks or with shared locks. + `3` Uses background search regardless of locks. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Default Table Value:** `0` * **Range:** `-1` to `3` * **DSN Parameter Name:** `bmd` --- #### `spider_bgs_second_read` * **Description:** Number of second read records on the backend server when using background search. When the first records are found from [spider\_bgs\_first\_read](#spider_bgs_first_read), the engine continues scanning a range adding a `LIMIT` of [spider\_bgs\_first\_read](#spider_bgs_first_read) and [spider\_bgs\_second\_read](#spider_bgs_second_read). + `-1` Uses the [table parameter](../spider-table-parameters/index). + `0` Records are usually retrieved. + `1` and greater: Number of records. * **Scope:** Global, Session * **Dynamic:** Yes * **Default Session Value:** `-1` * **Default Table Value:** `100` * **Range:** `-1` to `9223372036854775807` * **DSN Parameter Name:** `bsr` --- #### `spider_bka_engine` * **Description:** Storage engine used with temporary tables when the [spider\_bka\_mode](#spider_bka_mode) system variable is set to `1`. Defaults to the value of the [table parameter](../spider-table-parameters/index), which is [MEMORY](../memory-storage-engine/index) by default. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `string` * **Default Session Value:** `""` * **Default Table Value:** `Memory` * **DSN Parameter Name:** `bke` --- #### `spider_bka_mode` * **Description:** Internal action to perform when multi-split reads are disabled. If the [spider\_multi\_split\_read](#spider_multi_split_read) system variable is set to `0`, Spider uses this variable to determine how to handle statements when the optimizer resolves range retrieval to multiple conditions. + `-1` Uses the [table parameter](../spider-table-parameters/index). + `0` Uses "union all". + `1` Uses a temporary table, if it is judged acceptable. + `2` Uses a temporary table, if it is judged acceptable and avoids replication delay. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Default Table Value:** `1` * **Range:** `-1` to `2` * **DSN Parameter Name:** `bkm` --- #### `spider_bka_table_name_type` * **Description:** The type of temporary table name for bka. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Range:** `-1` to `1` * **Introduced:** [MariaDB 10.1.5](https://mariadb.com/kb/en/mariadb-1015-release-notes/) --- #### `spider_block_size` * **Description:** Size of memory block used in MariaDB. Can usually be left unchanged. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `16384` * **Range:** `0` to `4294967295` * **DSN Parameter Name:** `bsz` --- #### `spider_buffer_size` * **Description:** Buffer size. `-1`, the default, will use the [table parameter](../spider-table-parameters/index). * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Range:** `-1` to `2147483647` * **Introduced:** [MariaDB 10.5.4](https://mariadb.com/kb/en/mariadb-1054-release-notes/) --- #### `spider_bulk_size` * **Description:** Size in bytes of the buffer when multiple grouping multiple `INSERT` statements in a batch, (that is, bulk inserts). + `-1` The [table parameter](../spider-table-parameters/index) is adopted. + `0` or greater: Size of the buffer. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Default Table Value:** `16000` * **Range:** `-1` to `2147483647` * **DSN Parameter Name:** `bsz` --- #### `spider_bulk_update_mode` * **Description:** Bulk update and delete mode. Note: If you use a non-default value for the [spider\_bgs\_mode](#spider_bgs_mode) or [spider\_split\_read](#spider_split_read) system variables, Spider sets this variable to `2`. + `-1` Uses the [table parameter](../spider-table-parameters/index). + `0` Sends `UPDATE` and `DELETE` statements one by one. + `1` Collects multiple `UPDATE` and `DELETE` statements, then sends the collected statements one by one. + `2` Collects multiple `UPDATE` and `DELETE` statements and sends them together. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Default Table Value:** `0` * **Range:** `-1` to `2` * **DSN Parameter Name:** `bum` --- #### `spider_bulk_update_size` * **Description:** Size in bytes for `UPDATE` and `DELETE` queries when generating bulk updates. + `-1` The [table parameter](../spider-table-parameters/index) is adopted. + `0` or greater: Size of buffer. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Default Table Value:** `16000` * **Range:** `-1` to `2147483647` * **DSN Parameter Name:** `bus` --- #### `spider_casual_read` * **Description:** Casual Reads enables all isolation levels, (such as repeatable reads) to work with transactions on multiple backends. With auto-commit queries, you can relax read consistency and run on multiple connections to the backends. This enables parallel queries across partitions, even if multiple shards are stored on the same physical server. + `-1` Use [table parameter](../spider-table-parameters/index). + `0` Use casual read. + `1` Choose connection channel automatically. + `2` to `63` Number of connection channels. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Default Table Value:** `0` * **Range:** `-1` to `63` * **DSN Parameter Name:** `##` --- #### `spider_conn_recycle_mode` * **Description:** Connection recycle mode. + `0` Disconnect. + `1` Recycle by all sessions. + `2` Recycle in the same session. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Range:** `0` to `2` * **Default Session Value:** `0` --- #### `spider_conn_recycle_strict` * **Description:** Whether to force the creation of new connections. + `1` Don't force. + `0` Force new connection * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `0` * **Range:** `0` to `1` --- #### `spider_conn_wait_timeout` * **Description:** Max waiting time in seconds for Spider to get a remote connection. * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `10` * **Range:** `0` to `1000` * **Introduced:** [MariaDB 10.3.3](https://mariadb.com/kb/en/mariadb-1033-release-notes/) --- #### `spider_connect_error_interval` * **Description:** Return same error code until interval passes if connection is failed * **Scope:** Global, * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `1` * **Range:** `0` to `4294967295` --- #### `spider_connect_mutex` * **Description:** Whether to serialize remote servers connections (use mutex at connecting). Use this parameter if you get an error or slowdown due to too many connection processes. + `0` Not serialized. + `1` : Serialized. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Session Value:** `0` --- #### `spider_connect_retry_count` * **Description:** Number of times to retry connections that fail due to too many connection processes. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `1000` * **Range:** `0` to `2147483647` --- #### `spider_connect_retry_interval` * **Description:** Interval in microseconds for connection failure due to too many connection processes. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `1000` * **Range:** `-1` to `9223372036854775807` --- #### `spider_connect_timeout` * **Description:** Timeout in seconds to declare remote backend unresponsive when opening a connection. Change for high-latency networks. + `-1` The [table parameter](../spider-table-parameters/index) is adopted. + `0` Less than 1. + `1` and greater: Number of seconds. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Default Table Value:** `0` * **Range:** `-1` to `2147483647` * **DSN Parameter Name:** `cto` --- #### `spider_crd_bg_mode` * **Description:** Indexes cardinality statistics in the background. Disable when the [spider\_crd\_mode](#spider_crd_mode) system variable is set to `3` or when the [spider\_crd\_interval](#spider_crd_interval) variable is set to `0`. + `-1` Uses the [table parameter](../spider-table-parameters/index). + `0` Disables background confirmation. + `2` Enables background confirmation. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Default Table Value:** `1` * **Range:** `-1` to `2` * **DSN Parameter Name:** `cbm` --- #### `spider_crd_interval` * **Description:** Time interval in seconds of index cardinality statistics. Set to `0` to always get the latest information from remote servers. + `-1` The [table parameter](../spider-table-parameters/index) is adopted. + `1` or more: Interval in seconds table state confirmation. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Default Table Value:** `51` * **Range:** `-1` to `2147483647` * **DSN Parameter Name:** `civ` --- #### `spider_crd_mode` * **Description:** Mode for index cardinality statistics. By default, uses `SHOW` at the table-level. + `-1,0` Uses the [table parameter](../spider-table-parameters/index). + `1` Uses the `SHOW` command. + `2` Uses the Information Schema. + `3` Uses the `EXPLAIN` command. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Default Table Value:** `1` * **Range:** `-1` to `3` * **DSN Parameter Name:** `cmd` * **Deprecated:** [MariaDB 10.7.4](https://mariadb.com/kb/en/mariadb-1074-release-notes/), [MariaDB 10.8.3](https://mariadb.com/kb/en/mariadb-1083-release-notes/) --- #### `spider_crd_sync` * **Description:** Synchronize index cardinality statistics in partitioned tables. + `-1` Uses the [table parameter](../spider-table-parameters/index). + `0` Disables synchronization. + `1` Uses table state synchronization when opening a table, but afterwards performs no synchronization. + `2` Enables synchronization. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Default Table Value:** `0` * **Range:** `-1` to `2` * **DSN Parameter Name:** `csy` --- #### `spider_crd_type` * **Description:** Type of cardinality calculation. Only effective when the [spider\_crd\_mode](#spider_crd_mode) system variable is set to use `SHOW` (`1`) or to use the Information Schema (`2`). + `-1` Uses the [table parameter](../spider-table-parameters/index). + `0` Uses the value of the [spider\_crd\_weight](#spider_crd_weight) system variable, as a fixed value. + `1` Uses the value of the [spider\_crd\_weight](#spider_crd_weight) system variable, as an addition value. + `2` Uses the value of the [spider\_crd\_weight](#spider_crd_weight) system variable, as a multiplication value. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Default Table Value:** `2` * **Range:** `-1` to `2` * **DSN Parameter Name:** `ctp` * **Deprecated:** [MariaDB 10.7.4](https://mariadb.com/kb/en/mariadb-1074-release-notes/), [MariaDB 10.8.3](https://mariadb.com/kb/en/mariadb-1083-release-notes/) --- #### `spider_crd_weight` * **Description:** Weight coefficient used to calculate effectiveness of index from the cardinality of column. For more information, see the description for the [spider\_crd\_type](#spider_crd_type) system variable. + `-1` Uses the [table parameter](../spider-table-parameters/index). + `0` or greater: Weight. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Default Table Value:** `2` * **Range:** `-1` to `2147483647` * **DSN Parameter Name:** `cwg` * **Deprecated:** [MariaDB 10.7.4](https://mariadb.com/kb/en/mariadb-1074-release-notes/), [MariaDB 10.8.3](https://mariadb.com/kb/en/mariadb-1083-release-notes/) --- #### `spider_delete_all_rows_type` * **Description:** The type of delete\_all\_rows. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Range:** `-1` to `1` --- #### `spider_direct_dup_insert` * **Description:** Manages duplicate key check for [REPLACE](../replace/index), [INSERT IGNORE](../ignore/index) and [LOAD DATA LOCAL INFILE](../load-data-infile/index) to remote servers. This can save on network roundtrips if the key always maps to a single partition. For bulk operations, records are checked for duplicate key errors one by one on the remote server, unless you set it to avoid duplicate checks on local servers (`1`). + `-1` Uses the [table parameter](../spider-table-parameters/index). + `0` Performs duplicate checks on the local server. + `1` Avoids duplicate checks on the local server. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Default Table Value:** `0` * **Range:** `-1` to `1` * **DSN Parameter Name:** `ddi` --- #### `spider_direct_order_limit` * **Description:** Pushes `ORDER BY` and `LIMIT` operations to the remote server. + `-1` Uses the [table parameter](../spider-table-parameters/index). + `0` Uses local execution. + `1` Uses push down execution. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Default Table Value:** `0` * **Range:** `-1` to `9223372036854775807` * **DSN Parameter Name:** `dol` --- #### `spider_dry_access` * **Description:** Simulates an empty result-set. No queries are sent to the backend. Use for performance tuning. + `0` Normal access. + `1` All access from Spider to data node is suppressed. * **Scope:** Global * **Dynamic:** No * **Data Type:** `boolean` * **Default Value:** `OFF` --- #### `spider_error_read_mode` * **Description:** Sends an empty result-set when reading a backend server raises an error. Useful with applications that don't implement transaction replays. + `-1` Uses the [table parameter](../spider-table-parameters/index). + `0` Returns an error. + `1` Returns an empty result. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Default Table Value:** `0` * **Range:** `-1` to `1` * **DSN Parameter Name:** `erm` --- #### `spider_error_write_mode` * **Description:** Sends an empty result-set when writing to a backend server raises an error. Useful with applications that don't implement transaction replays. + `-1` Uses the [table parameter](../spider-table-parameters/index). + `0` Returns an error. + `1` Returns an empty result-set on error. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Default Table Value:** `0` * **Range:** `-1` to `1` * **DSN Parameter Name:** `ewm` --- #### `spider_first_read` * **Description:** Number of first read records to start a range scan on the backend server. Spider needs to send the first record. Fetching the second record saves network round-trips, stopping the plan if the backend has a single record. First read and second read are used to warm up for background searches, third reads without using the [spider\_split\_read](#spider_split_read) and [spider\_semi\_split\_read](#spider_semi_split_read) system variables fetches the remaining data source in a single last fetch. + `-1` Use the [table parameter](../spider-table-parameters/index). + `0` Usually retrieves records. + `1` and greater: Sets the number of first read records. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Default Table Value:** `2` * **Range:** `-1` to `9223372036854775807` * **DSN Parameter Name:** `frd` --- #### `spider_force_commit` * **Description:** Behavior when error occurs on `XA PREPARE`, `XA COMMIT`, and `XA ROLLBACK` statements. + `0` Returns the error. + `1` Returns the error when the `xid` doesn't exist, otherwise it continues processing the XA transaction. + `2` Continues processing the XA transaction, disregarding all errors. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `0` * **Range:** `0` to `2` --- #### `spider_general_log` * **Description:** Whether Spider logs all commands to the General Log. Spider logs error codes according to the [spider\_log\_result\_errors](#spider_log_result_errors) system variable. + `OFF` Logs no commands. + `ON` Logs commands to the General Log. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Session Value:** `OFF` --- #### `spider_index_hint_pushdown` * **Description:** Whether to use pushdown index hints, like `force_index`. + `0` Do not use pushdown hints + `1` Use pushdown hints * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Session Value:** `OFF` * **Introduced:** [MariaDB 10.3.3](https://mariadb.com/kb/en/mariadb-1033-release-notes/) --- #### `spider_init_sql_alloc_size` * **Description:** Initial size of the local SQL buffer. + `-1` Uses the [table parameter](../spider-table-parameters/index). + `0` or greater: Size of the buffer. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Default Table Value:** `1024` * **DSN Parameter Name:** `isa` * **Range:** `-1` to `2147483647` * **Deprecated:** [MariaDB 10.7.5](https://mariadb.com/kb/en/mariadb-1075-release-notes/), [MariaDB 10.8.4](https://mariadb.com/kb/en/mariadb-1084-release-notes/), [MariaDB 10.9.2](https://mariadb.com/kb/en/mariadb-1092-release-notes/) --- #### `spider_internal_limit` * **Description:** Limits the number of records when acquired from a remote server. + `-1` The [table parameter](../spider-table-parameters/index) is adopted. + `0` or greater: Records limit. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Default Table Value:** `9223372036854775807` * **Range:** `-1` to `9223372036854775807` * **DSN Parameter Name:** `ilm` * **Deprecated:** [MariaDB 10.7.4](https://mariadb.com/kb/en/mariadb-1074-release-notes/), [MariaDB 10.8.3](https://mariadb.com/kb/en/mariadb-1083-release-notes/) --- #### `spider_internal_offset` * **Description:** Skip records when acquired from the remote server. + `-1` Uses the [table parameter](../spider-table-parameters/index). + `0` or more : Number of records to skip. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Default Table Value:** `0` * **Range:** `-1` to `9223372036854775807` * **DSN Parameter Name:** `ios` * **Deprecated:** [MariaDB 10.7.4](https://mariadb.com/kb/en/mariadb-1074-release-notes/), [MariaDB 10.8.3](https://mariadb.com/kb/en/mariadb-1083-release-notes/) --- #### `spider_internal_optimize` * **Description:** Whether to perform push down operations for [OPTIMIZE TABLE](../optimize-table/index) statements. + `-1` Uses the [table parameter](../spider-table-parameters/index). + `0` Transmitted. + `1` Not transmitted. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Default Table Value:** `0` * **Range:** `-1` to `1` * **DSN Parameter Name:** `iom` --- #### `spider_internal_optimize_local` * **Description:** Whether to transmit to remote servers when [OPTIMIZE TABLE](optimize_table) statements are executed on the local server. + `-1` Uses the [table parameter](../spider-table-parameters/index). + `0` Not transmitted. + `1` Transmitted. * **Default Session Value:** `-1` * **Default Table Value:** `0` * **Range:** `-1` to `1` * **DSN Parameter Name:** `iol` --- #### `spider_internal_sql_log_off` * **Description:** Whether to log SQL statements sent to the remote server in the [General Query Log](../general-query-log/index). + Explicitly setting this system variable to either `ON` or `OFF` causes the Spider node to send a `SET sql_log_off` statement to each of the data nodes using the `SUPER` privilege. + `-1` Don't know or does not matter; don't send 'SET SQL\_LOG\_OFF' statement + `0` Send 'SET SQL\_LOG\_OFF 0' statement to data nodes (logs SQL statements to the remote server) + `1` Send 'SET SQL\_LOG\_OFF 1' statement to data nodes (doesn't log SQL statements to the remote server) * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` (previously `boolean`) * **Range:** `-1` to `1` * **Default Session Value:** `-1` (previously `ON`) --- #### `spider_internal_unlock` * **Description:** Whether to transmit unlock tables to the connection of the table used with `SELECT` statements. + `0` Not transmitted. + `1` Transmitted. * **Data Type:** `boolean` * **Default Session Value:** `0` --- #### `spider_internal_xa` * **Description:** Whether to implement XA at the server- or storage engine-level. When using the server-level, set different values for the [server\_id](../server-system-variables/index#server_id) system variable on all server instances to generate different `xid` values. + `OFF` Uses the storage engine protocol. + `ON` Uses the server protocol. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Session Value:** `OFF` --- #### `spider_internal_xa_id_type` * **Description:** The type of internal\_xa id. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `0` * **Range:** `-1` to `1` --- #### `spider_internal_xa_snapshot` * **Description:** Limitation for reading consistent data on all backend servers when using MariaDB's internal XA implementation and `START TRANSACTION WITH CONSISTENT SNAPSHOT`. + `0` Raise error when using a Spider table. + `1` Raise error when issued a `START TRANSACTION` statement. + `2` Takes a consistent snapshot on each backend, but loses global consistency. + `3` Starts transactions with XA, but removes `CONSISTENT SNAPSHOT`. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Range:** `0` to `3` * **Default Session Value:** `0` --- #### `spider_load_crd_at_startup` * **Description:** Whether to load CRD from the system table at startup. + `-1` Use [table parameter](../spider-table-parameters/index) + `0` Do not load + `1` Load * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `-1` * **Range:** `-1` to `1` * **Introduced:** [MariaDB 10.3.3](https://mariadb.com/kb/en/mariadb-1033-release-notes/) * **Deprecated:** [MariaDB 10.7.4](https://mariadb.com/kb/en/mariadb-1074-release-notes/), [MariaDB 10.8.3](https://mariadb.com/kb/en/mariadb-1083-release-notes/) --- #### `spider_load_sts_at_startup` * **Description:** Whether to load STS from the system table at startup. + `-1` Use [table parameter](../spider-table-parameters/index) + `0` Do not load + `1` Load * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `-1` * **Range:** `-1` to `1` * **Introduced:** [MariaDB 10.3.3](https://mariadb.com/kb/en/mariadb-1033-release-notes/) * **Deprecated:** [MariaDB 10.7.4](https://mariadb.com/kb/en/mariadb-1074-release-notes/), [MariaDB 10.8.3](https://mariadb.com/kb/en/mariadb-1083-release-notes/) --- #### `spider_local_lock_table` * **Description:** Whether to push [LOCK TABLES](../transactions-lock/index) statements down to the remote server. + `0` Transmitted. + `1` Not transmitted. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `0` --- #### `spider_lock_exchange` * **Description:** Whether to convert [SELECT... LOCK IN SHARE MODE](../lock-in-share-mode/index) and [SELECT... FOR UPDATE](../for-update/index) statements into a [LOCK TABLE](../lock/index) statement. + `0` Not converted. + `1` Converted. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `0` --- #### `spider_log_result_error_with_sql` * **Description:** How to log SQL statements with result errors. + `0` No log + `1` Log error + `2` Log warning summary + `3` Log warning + `4` Log info (Added in [MariaDB 10.5.4](https://mariadb.com/kb/en/mariadb-1054-release-notes/)) * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `0` * **Range:** `0` to `4` --- #### `spider_log_result_errors` * **Description:** Log results from data nodes to the Spider node in the [Error Log](../error-log/index). Performs no logging by default. + `0` : Logs no errors from data nodes. + `1` : Logs errors from data nodes. + `2` : Logs errors from data nodes, as well as warning summaries. + `3` : Logs errors from data nodes, as well as warning summaries and details. + `4` : Logs errors from data nodes, as well as warning summaries and details, and result summaries. * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `0` * **Range:** `0` to `4` --- #### `spider_low_mem_read` * **Description:** Whether to use low memory mode when executing queries issued internally to remote servers that return result-sets. + `-1` Uses the [table parameter](../spider-table-parameters/index). + `0` Doesn't use low memory mode. + `1` Uses low memory mode. * **Data Type:** `numeric` * **Default Value:** `-1` * **Default Table Value:** `1` * **Range:** `-1` to `1` --- #### `spider_max_connections` * **Description:** Maximum number of connections from Spider to a remote MariaDB servers. Defaults to `0`, which is no limit. * **Command-line:** `--spider-max-connections` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `0` * **Range:** `0` to `99999` * **Introduced:** [MariaDB 10.3.3](https://mariadb.com/kb/en/mariadb-1033-release-notes/) --- #### `spider_max_order` * **Description:** Maximum number of columns for `ORDER BY` operations. + `-1` The [table parameter](../spider-table-parameters/index) is adopted. + `0` and greater: Maximum number of columns. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Default Table Value:** `32767` * **Range:** `-1` to `32767` * **DSN Parameter Name:** `mod` --- #### `spider_multi_split_read` * **Description:** Whether to divide a statement into multiple SQL statements sent to the remote backend server when the optimizer resolves range retrievals to multiple conditions. + `-1` Uses the [table parameter](../spider-table-parameters/index). + `0` Doesn't divide statements. + `1` Divides statements. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Default Table Value:** `0` * **Range:** `-1` to `2147483647` * **DSN Parameter Name:** `msr` --- #### `spider_net_read_timeout` * **Description:** TCP timeout in seconds to declare remote backend servers unresponsive when reading from a connection. Change for high latency networks. + `-1` Uses the [table parameter](../spider-table-parameters/index). + `0` Less than 1 second timeout. + `1` and greater: Timeout in seconds. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Default Table Value:** `600` * **Range:** `-1` to `2147483647` * **DSN Parameter Name:** `nrt` --- #### `spider_net_write_timeout` * **Description:** TCP timeout in seconds to declare remote backend servers unresponsive when writing to a connection. Change for high latency networks. + `-1` The [table parameter](../spider-table-parameters/index) is adopted. + `0` Less than 1 second timeout. + `1` and more: Timeout in seconds. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Default Table Value:** `600` * **Range:** `-1` to `2147483647` * **DSN Parameter Name:** `nwt` --- #### `spider_ping_interval_at_trx_start` * **Description:** Resets the connection with keepalive timeout in seconds by sending a ping. + `0` At every transaction. + `1` and greater: Number of seconds. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `3600` * **Range:** `0` to `2147483647` --- #### `spider_quick_mode` * **Description:** Sets the backend query buffering to cache on the remote backend server or in the local buffer. + `-1` Uses the [table parameter](../spider-table-parameters/index). + `0` Local buffering, it acquires records collectively with `store_result`. + `1` Remote buffering, it acquires records one by one. Interrupts don't wait and recovery on context switch back. + `2` Remote buffering, it acquires records one by one. Interrupts wait to the end of the acquisition. + `3` Local buffering, uses a temporary table on disk when the result-set is greater than the value of the [spider\_quick\_page\_size](#spider_quick_page_size) system variable. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Default Table Value:** `0` * **Range:** `-1` to `3` * **DSN Parameter Name:** `qmd` --- #### `spider_quick_page_byte` * **Description:** Memory limit by size in bytes in a page when acquired record by record. + `-1` The [table parameter](../spider-table-parameters/index) is used. When quick\_mode is 1 or 2, Spider stores at least 1 record even if quick\_page\_byte is smaller than 1 record. When quick\_mode is 3, quick\_page\_byte is used for judging using temporary tables. That is given priority when spider\_quick\_page\_byte is set. + `0` or greater: Memory limit. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Range:** `-1` to `9223372036854775807` * **Introduced:** [MariaDB 10.4.3](https://mariadb.com/kb/en/mariadb-1043-release-notes/), [MariaDB 10.3.13](https://mariadb.com/kb/en/mariadb-10313-release-notes/) --- #### `spider_quick_page_size` * **Description:** Number of records in a page when acquired record by record. + `-1` The [table parameter](../spider-table-parameters/index) is adopted. + `0` or greater: Number of records. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Default Table Value:** `100` * **Range:** `-1` to `9223372036854775807` * **DSN Parameter Name:** `qps` --- #### `spider_read_only_mode` * **Description:** Whether to allow writes on Spider tables. + `-1` Uses the [table parameter](../spider-table-parameters/index). + `0` Allows writes to Spider tables. + `1` Makes tables read- only. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Default Table Value:** `0` * **Range:** `-1` to `1` * **DSN Parameter Name:** `rom` --- #### `spider_remote_access_charset` * **Description:** Forces the specified session [character set](../character-sets/index) when connecting to the backend server. This can improve connection time performance. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `string` * **Default Session Value:** `null` --- #### `spider_remote_autocommit` * **Description:** Sets the auto-commit mode when connecting to backend servers. This can improve connection time performance. + `-1` Doesn't change the auto-commit mode. + `0` Sets the auto-commit mode to `0`. + `1` Sets the auto-commit mode to `1`. * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Range:** `-1` to `1` --- #### `spider_remote_default_database` * **Description:** Sets the local default database when connecting to backend servers. This can improve connection time performance. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `string` * **Default Session Value:** Empty string --- #### `spider_remote_sql_log_off` * **Description:** Sets the [sql\_log\_off](../server-system-variables/index#sql_log_off) system variable to use when connecting to backend servers. + `-1` Doesn't set the value. + `0` Doesn't log Spider SQL statements to remote backend servers. + `1` Logs SQL statements on remote backend * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Range:** `-1` to `1` --- #### `spider_remote_time_zone` * **Description:** Forces the specified [time zone](../time-zones/index) setting when connecting to backend servers. This can improve connection performance when you know the time zone. * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `string` * **Default Session Value:** `null` --- #### `spider_remote_trx_isolation` * **Description:** Sets the [Transaction Isolation Level](../set-transaction/index#isolation-levels) when connecting to the backend server. + `-1` Doesn't set the Isolation Level. + `0` Sets to the `READ UNCOMMITTED` level. + `1` Sets to the `READ COMMITTED` level. + `2` Sets to the `REPEATABLE READ` level. + `3` Sets to the `SERIALIZABLE` level. * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Range:** `-1` to `3` --- #### `spider_remote_wait_timeout` * **Description:** Wait timeout in seconds on remote server. `-1` means not set. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `-1` * **Range:** `-1` to `2147483647` * **Introduced:** [MariaDB 10.4.5](https://mariadb.com/kb/en/mariadb-1045-release-notes/) --- #### `spider_reset_sql_alloc` * **Description:** Resets the per connection SQL buffer after an SQL statement executes. + `-1` Uses the [table parameter](../spider-table-parameters/index). + `0` Doesn't reset. + `1` Resets. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Default Table Value:** `1` * **Range:** `-1` to `1` * **DSN Parameter Name:** `rsa` --- #### `spider_same_server_link` * **Description:** Enables the linking of a table to the same local instance. + `0` Disables linking. + `1` Enables linking. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Session Value:** `OFF` --- #### `spider_second_read` * **Description:** Number of second read records on the backend server when the first records are found from the first read. Spider continues scanning a range, adding a `LIMIT` using the [spider\_first\_read](#spider_first_read) and [spider\_second\_read](#spider_second_read) variables. + `-1` Uses the [table parameter](../spider-table-parameters/index). + `0` Usually retrieves records. + `1` and greater: Number of records. * **Scope:** Global, Session * **Dynamic:** Yes * **Default Session Value:** `-1` * **Default Table Value:** `9223372036854775807` * **Range:** `-1` to `9223372036854775807` * **DSN Parameter Name:** `srd` --- #### `spider_select_column_mode` * **Description:** Mode for column retrieval from remote backend server. + `-1` Uses the [table parameter](../spider-table-parameters/index). + `0` Uses index columns when the `SELECT` statement can resolve with an index, otherwise uses all columns. + `1` Uses all columns judged necessary to resolve the query. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Default Table Value:** `1` * **Range:** `-1` to `1` * **DSN Parameter Name:** `scm` --- #### `spider_selupd_lock_mode` * **Description:** Local lock mode on `INSERT SELECT`. + `-1` Uses the [table parameter](../spider-table-parameters/index). + `0` Takes no locks. + `1` Takes shared locks. + `2` Takes exclusive locks. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Default Table Value:** `1` * **Range:** `-1` to `2` * **DSN Parameter Name:** `slm#` --- #### `spider_semi_split_read` * **Description:** Whether to use chunk retrieval with offset and limit parameters on SQL statements sent to the remote backend server when using the [spider\_split\_read](#spider_split_read) system variable. + `-1` Uses the [table parameter](../spider-table-parameters/index). + `0` Doesn't use chunk retrieval. + `1 or more` Uses chunk retrieval. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Default Table Value:** `0` * **Range:** `-1` to `2147483647` * **DSN Parameter Name:** `ssr#` --- #### `spider_semi_split_read_limit` * **Description:** Sets the limit value for the [spider\_semi\_split\_read](#spider_semi_split_read) system variable. + `-1` Uses the [table parameter](../spider-table-parameters/index). + `0` or more: The limit value. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Default Table Value:** `9223372036854775807` * **Range:** `-1` to `9223372036854775807` * **DSN Parameter Name:** `ssl#` --- #### `spider_semi_table_lock` * **Description:** Enables semi-table locking. This adds a [LOCK TABLES](../transactions-lock/index) statement to SQL executions sent to the remote backend server when using non-transactional storage engines to preserve consistency between roundtrips. + `0` Disables semi-table locking. + `1` Enables semi-table locking. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `1` * **Range:** `0` to `1` * **DSN Parameter Name:** `stl#` --- #### `spider_semi_table_lock_connection` * **Description:** Whether to use multiple connections with semi-table locking. To enable semi-table locking, use the [spider\_semi\_table\_lock](#spider_semi_table_lock) system variable. + `-1` Uses the [table parameter](../spider-table-parameters/index). + `0` Uses the same connection. + `1` Uses different connections. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Default Table Value:** `1` * **Range:** `-1` to `1` * **DSN Parameter Name:** `stc#` --- #### `spider_semi_trx` * **Description:** Enables semi-transactions. This controls transaction consistency when an SQL statement is split into multiple statements issued to the backend servers. You can preserve or relax consistency as need. Spider encapsulates auto-committed SQL statements within a transaction on the remote backend server. When using `READ COMMITTED` or `READ UNCOMMITTED` [transaction isolation levels](../set-transaction/index#isolation-levels) to force consistency, set the [spider\_semi\_trx\_isolation](#spider_semi_trx_isolation) system variable to `2`. + `0` Disables semi-transaction consistency. + `1` Enables semi-transaction consistency. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Session Value:** `ON` --- #### `spider_semi_trx_isolation` * **Description:** Set consistency during range SQL execution when [spider\_sync\_trx\_isolation](#spider_sync_trx_isolation) is 1 + `-1` OFF + `0` READ UNCOMMITTED + `1` READ COMMITTED + `2` REPEATABLE READ + `3` SERIALIZABLE * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Range:** `-1` to `3` --- #### `spider_skip_default_condition` * **Description:** Whether to compute condition push downs. + `-1` Uses the [table parameter](../spider-table-parameters/index). + `0` Computes condition push downs. + `1` Doesn't compute condition push downs. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Default Table Value:** `0` * **Range:** `-1` to `1` * **DSN Parameter Name:** `sdc` --- #### `spider_skip_parallel_search` * **Description:** Whether to skip parallel search by specific conditions. + `-1` :use [table parameter](../spider-table-parameters/index) + `0` :not skip + `1` :skip parallel search if query is not SELECT statement + `2` :skip parallel search if query has SQL\_NO\_CACHE + `3` :1+2 * **Commandline:** `--spider-skip-parallel-search=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Range:** `-1` to `3` * **Introduced:** [MariaDB 10.3.3](https://mariadb.com/kb/en/mariadb-1033-release-notes/) --- #### `spider_slave_trx_isolation` * **Description:** Transaction isolation level when Spider table is used by slave SQL thread. + `-1` off + `0` read uncommitted + `1` read committed + `2` repeatable read + `3` serializable * **Commandline:** `--spider-slave-trx-isolation=#` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Range:** `-1` to `3` * **Introduced:** [MariaDB 10.4.3](https://mariadb.com/kb/en/mariadb-1043-release-notes/), [MariaDB 10.3.13](https://mariadb.com/kb/en/mariadb-10313-release-notes/) --- #### `spider_split_read` * **Description:** Number of records in chunk to retry the result when a range query is sent to remote backend servers. + `-1` Uses the [table parameter](../spider-table-parameters/index). + `0` or more: Number of records. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Default Table Value:** `9223372036854775807` * **Range:** `-1` to `9223372036854775807` * **DSN Parameter Name:** `srd` --- #### `spider_store_last_crd` * **Description:** Whether to store last CRD result in the system table. + `-1` Use [table parameter](../spider-table-parameters/index). + `0` Do not store last CRD result in the system table. + `1` Store last CRD result in the system table. * **Commandline:** `--spider-store-last-crd=#` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Range:** `-1` to `1` * **Introduced:** [MariaDB 10.3.3](https://mariadb.com/kb/en/mariadb-1033-release-notes/) * **Deprecated:** [MariaDB 10.7.4](https://mariadb.com/kb/en/mariadb-1074-release-notes/), [MariaDB 10.8.3](https://mariadb.com/kb/en/mariadb-1083-release-notes/) --- #### `spider_store_last_sts` * **Description:** Whether to store last STS result in the system table. + `-1` Use [table parameter](../spider-table-parameters/index). + `0` Do not store last STS result in the system table. + `1` Store last STS result in the system table. * **Commandline:** `--spider-store-last-sts=#` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Range:** `-1` to `1` * **Introduced:** [MariaDB 10.3.3](https://mariadb.com/kb/en/mariadb-1033-release-notes/) * **Deprecated:** [MariaDB 10.7.4](https://mariadb.com/kb/en/mariadb-1074-release-notes/), [MariaDB 10.8.3](https://mariadb.com/kb/en/mariadb-1083-release-notes/) --- #### `spider_strict_group_by` * **Description:** Whether to use columns in select clause strictly for group by clause + `-1` Use the [table parameter](../spider-table-parameters/index). + `0` Do not strictly use columns in select clause for group by clause + `1` Use columns in select clause strictly for group by clause * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `-1` * **Range:** `-1` to `1` * **Introduced:** [MariaDB 10.5.4](https://mariadb.com/kb/en/mariadb-1054-release-notes/) --- #### `spider_sts_bg_mode` * **Description:** Enables background confirmation for table statistics. When background confirmation is enabled, Spider uses one thread per partition to maintain table status. Disable when the [spider\_sts\_interval](#spider_sts_interval) system variable is set to `0`, which causes Spider to always retrieve the latest information as need. It is effective, when the [spider\_sts\_interval](#spider_sts_interval) system variable is set to `10`. + `-1` Uses the [table parameter](../spider-table-parameters/index). + `0` Disables background confirmation. + `1` Enables background confirmation (create thread per table/partition). + `2` Enables background confirmation (use static threads). (from MariaDB 10.) * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Default Table Value:** `1` * **Range:** `-1` to `2` * **DSN Parameter Name:** `sbm` --- #### `spider_sts_interval` * **Description:** Time interval of table statistics from the remote backend servers. + `-1` Uses the [table parameter](../spider-table-parameters/index). + `0` Retrieves the latest table statistics on request. + `1` or more: Interval in seconds for table state confirmation. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Default Table Value:** `10` * **Range:** `-1` to `2147483647` * **DSN Parameter Name:** `siv` --- #### `spider_sts_mode` * **Description:** Table statistics mode. Mode for table statistics. The [SHOW](../show/index) command is used at the table level default. + `-1,0` Uses the [table parameter](../spider-table-parameters/index). + `1` Uses the `SHOW` command. + `2` Uses the Information Schema. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Default Table Value:** `1` * **Range:** `-1` to `2` * **DSN Parameter Name:** `smd` * **Deprecated:** [MariaDB 10.7.4](https://mariadb.com/kb/en/mariadb-1074-release-notes/), [MariaDB 10.8.3](https://mariadb.com/kb/en/mariadb-1083-release-notes/) --- #### `spider_sts_sync` * **Description:** Synchronizes table statistics in partitioned tables. + `-1` Uses the [table parameter](../spider-table-parameters/index). + `0` Doesn't synchronize table statistics in partitioned tables. + `1` Synchronizes table state when opening a table, doesn't synchronize after opening. + `2` Synchronizes table statistics. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Session Value:** `-1` * **Default Table Value:** `0` * **Range:** `-1` to `2` * **DSN Parameter Name:** `ssy` --- #### `spider_support_xa` * **Description:** XA Protocol for mirroring and for multi-shard transactions. + `1` Enables XA Protocol for these Spider operations. + `0` Disables XA Protocol for these Spider operations. * **Scope:** Global * **Dynamic:** No * **Data Type:** `boolean` * **Default Table Value:** `1` --- #### `spider_sync_autocommit` * **Description:** Whether to push down local auto-commits to remote backend servers. + `OFF` Pushes down local auto-commits. + `ON` Doesn't push down local auto-commits. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Session Value:** `ON` --- #### `spider_sync_sql_mode` * **Description:** Whether to sync [sql\_mode](../sql-mode/index). + `OFF` No sync + `ON` Sync * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `ON` * **Introduced:** [MariaDB 10.4.7](https://mariadb.com/kb/en/mariadb-1047-release-notes/) --- #### `spider_sync_time_zone` * **Description:** Whether to push the local time zone down to remote backend servers. + `OFF` Doesn't synchronize time zones. + `ON` Synchronize time zones. * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Session Value:** `OFF` * **Removed:** [MariaDB 10.3.9](https://mariadb.com/kb/en/mariadb-1039-release-notes/) --- #### `spider_sync_trx_isolation` * **Description:** Pushes local transaction isolation levels down to remote backend servers. + `OFF` Doesn't push down local isolation levels. + `ON` Pushes down local isolation levels. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Session Value:** `ON` --- #### `spider_table_crd_thread_count` * **Description:** Static thread count of table crd. * **Commandline:** `--spider-table-crd-thread-count=#` * **Scope:** Global * **Dynamic:** No * **Data Type:** `numeric` * **Default Value:** `10` * **Range:** `1` to `4294967295` * **Introduced:** [MariaDB 10.3.3](https://mariadb.com/kb/en/mariadb-1033-release-notes/) --- #### `spider_table_init_error_interval` * **Description:** Interval in seconds where the same error code is returned if table initialization fails. Use to protect against infinite loops in table links. * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `1` * **Range:** `0` to `4294967295` --- #### `spider_table_sts_thread_count` * **Description:** Static thread count of table sts. * **Commandline:** `--spider-table-sts-thread-count=#` * **Scope:** Global * **Dynamic:** No * **Data Type:** `numeric` * **Default Value:** `10` * **Range:** `1` to `4294967295` * **Introduced:** [MariaDB 10.3.3](https://mariadb.com/kb/en/mariadb-1033-release-notes/) --- #### `spider_udf_ct_bulk_insert_interval` * **Description:** Interval in milliseconds between bulk inserts at copying. For use with the UDF spider\_copy\_tables, which copies table data linked to a Spider table from the source server to destination server using bulk insert. If this interval is 0, it may cause higher write traffic. + `-1` Uses the UDF parameter. + `0` and more: Time in milliseconds. * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `-1` * **Default Table Value:** `2147483647` * **Range:** `-1` to `2147483647` * **Deprecated:** [MariaDB 10.7.4](https://mariadb.com/kb/en/mariadb-1074-release-notes/), [MariaDB 10.8.3](https://mariadb.com/kb/en/mariadb-1083-release-notes/) --- #### `spider_udf_ct_bulk_insert_rows` * **Description:** Number of rows to insert at a time when copying during bulk inserts. + `-1, 0`: Uses the [table parameter](../spider-table-parameters/index). + `1` and more: Number of rows * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `-1` * **Default Table Value:** `18446744073709551615` * **Range:** `-1` to `9223372036854775807` * **Deprecated:** [MariaDB 10.7.4](https://mariadb.com/kb/en/mariadb-1074-release-notes/), [MariaDB 10.8.3](https://mariadb.com/kb/en/mariadb-1083-release-notes/) --- #### `spider_udf_ds_bulk_insert_rows` * **Description:** Number of rows inserted at a time during bulk inserts when the result-set is stored in a temporary table on executing a UDF. + `-1, 0` Uses the UDF parameter. + `1` or more: Number of rows * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `-1` * **Default Table Value:** `9223372036854775807` * **Range:** `-1` to `9223372036854775807` * **Deprecated:** [MariaDB 10.7.4](https://mariadb.com/kb/en/mariadb-1074-release-notes/), [MariaDB 10.8.3](https://mariadb.com/kb/en/mariadb-1083-release-notes/) --- #### `spider_udf_ds_table_loop_mode` * **Description:** Whether to store the result-set in the same temporary table when the temporary table list count for UDF is less than the result-set count on UDF execution. + `-1` Uses the [table parameter](../spider-table-parameters/index). + `0` Drops records. + `1` Inserts the last table. + `2` Inserts the first table and loops again. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `-1` * **Range:** `-1` to `2` * **Deprecated:** [MariaDB 10.7.4](https://mariadb.com/kb/en/mariadb-1074-release-notes/), [MariaDB 10.8.3](https://mariadb.com/kb/en/mariadb-1083-release-notes/) --- #### `spider_udf_ds_use_real_table` * **Description:** Whether to use real table for temporary table list. + `-1` Use UDF parameter. + `0` Do not use real table. + `1` Use real table. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `-1` * **Range:** `-1` to `1` * **Deprecated:** [MariaDB 10.7.4](https://mariadb.com/kb/en/mariadb-1074-release-notes/), [MariaDB 10.8.3](https://mariadb.com/kb/en/mariadb-1083-release-notes/) --- #### `spider_udf_table_lock_mutex_count` * **Description:** Mutex count of table lock for Spider UDFs. * **Scope:** Global * **Dynamic:** No * **Data Type:** `numeric` * **Default Value:** `20` * **Range:** `1` to `4294967295` #### `spider_udf_table_mon_mutex_count` * **Description:** Mutex count of table mon for Spider UDFs. * **Scope:** Global * **Dynamic:** No * **Data Type:** `numeric` * **Default Value:** `20` * **Range:** `1` to `4294967295` --- #### `spider_use_all_conns_snapshot` * **Description:** Whether to pass `START TRANSACTION WITH SNAPSHOT` statements to all connections. + `OFF` Doesn't pass statement to all connections. + `ON` Passes statement to all connections. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Session Value:** `OFF` --- #### `spider_use_cond_other_than_pk_for_update` * **Description:** Whether to use all conditions even if condition has a primary key. + `0` Don't use all conditions + `1` Use all conditions * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `1` * **Range:** `0` to `1` * **Introduced:** [MariaDB 10.3.13](https://mariadb.com/kb/en/mariadb-10313-release-notes/), [MariaDB 10.4.3](https://mariadb.com/kb/en/mariadb-1043-release-notes/) --- #### `spider_use_consistent_snapshot` * **Description:** Whether to push a local `START TRANSACTION WITH CONSISTENT` statement down to remote backend servers. + `OFF` Doesn't push the local statement down. + `ON` Pushes the local statement down. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `OFF` --- #### `spider_use_default_database` * **Description:** Whether to use the default database. + `OFF` Doesn't use the default database. + `ON` Uses the default database. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `ON` --- #### `spider_use_flash_logs` * **Description:** Whether to push [FLUSH LOGS](flush-logs) statements down to remote backend servers. + `OFF` Doesn't push the statement down. + `ON` Pushes the statement down. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `OFF` --- #### `spider_use_handler` * **Description:** Converts [HANDLER](../handler/index) SQL statements. When the [spider\_sync\_trx\_isolation](#spider_sync_trx_isolation) system variable is set to `0`, Spider disables [HANDLER](../handler/index) conversions to prevent use of the statement on the [SERIALIZABLE](../set-transaction/index#serializable) isolation level. + `-1` Uses [table parameter](../spider-table-parameters/index). + `0` Converts [HANDLER](../handler/index) statements into [SELECT](../select/index) statements. + `1` Passes [HANDLER](../handler/index) to the remote backend server. + `2` Converts SQL statements to [HANDLER](../handler/index) statements. + `3` Converts SQL statements to [HANDLER](../handler/index) statements and [HANDLER](../handler/index) statements to SQL statements. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `-1` * **Default Table Value:** `0` * **Range:** `-1` to `3` * **DSN Parameter Name:** `uhd` * **Deprecated:** [MariaDB 10.7.4](https://mariadb.com/kb/en/mariadb-1074-release-notes/), [MariaDB 10.8.3](https://mariadb.com/kb/en/mariadb-1083-release-notes/) --- #### `spider_use_pushdown_udf` * **Description:** When using a UDF function in a condition and the [engine\_condition\_pushdown](../server-system-variables/index#engine_condition_pushdown) system variable is set to `1`, whether to execute the UDF function locally or push it down. + `-1` Uses the [table parameter](../spider-table-parameters/index). + `0` Doesn't transmit the UDF + `1` Transmits the UDF. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `-1` * **Default Table Value:** `1` * **Range:** `-1` to `1` * **DSN Parameter Name:** `upu` --- #### `spider_use_snapshot_with_flush_tables` * **Description:** Whether to encapsulate [FLUSH LOGS](flush-logs) and [UNLOCK TABLES](../lock-tables-and-unlock-tables/index) statements when `START TRANSACTION WITH CONSISTENT` and `FLUSH TABLE WITH READ LOCK` statements are sent to the remote backend servers. + `0` : No encapsulation. + `1` : Encapsulates, only when the [spider\_use\_all\_conns\_snapshot](#spider_use_all_conns_snapshot) system variable i set to `1`. + `2` : Synchronizes the snapshot using a [LOCK TABLES](../lock-tables-and-unlock-tables/index) statement and [flush|FLUSH TABLES]] at the XA transaction level. This is only effective when the [spider\_use\_all\_cons\_snapshot](#spider_use_all_cons_snapshot) system variable is set to `1`. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `0` * **Range:** `0` to `2` --- #### `spider_use_table_charset` * **Description:** Whether to use the local table [character set](../data-types-character-sets-and-collations/index) for the remote backend server connections. + `-1` Uses the [table parameter](../spider-table-parameters/index). + `0` Use `utf8`. + `1` Uses the table character set. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `-1` * **Default Table Value:** `1` * **Range:** `-1` to `1` * **DSN Parameter Name:** `utc` --- #### `spider_version` * **Description:** The current Spider version. Removed in [MariaDB 10.9.2](https://mariadb.com/kb/en/mariadb-1092-release-notes/) when the Spider version number was matched with the server version. * **Scope:** Global * **Dynamic:** No * **Data Type:** `string` * **Removed:** [MariaDB 10.9.2](https://mariadb.com/kb/en/mariadb-1092-release-notes/) --- #### `spider_wait_timeout` * **Description:** Wait timeout in seconds of setting to remote server. `-1` means not set. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `604800` * **Range:** `-1` to `2147483647` * **Introduced:** [MariaDB 10.4.5](https://mariadb.com/kb/en/mariadb-1045-release-notes/) --- #### `spider_xa_register_mode` * **Description:** Mode of XA transaction register into system table. + `0` Register all XA transactions + `1` Register only write XA transactions * **Command-line:** `--spider-xa-register-mode=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `1` * **Range:** `0` to `1` * **Introduced:** [MariaDB 10.3.3](https://mariadb.com/kb/en/mariadb-1033-release-notes/) * **Deprecated:** [MariaDB 10.7.4](https://mariadb.com/kb/en/mariadb-1074-release-notes/), [MariaDB 10.8.3](https://mariadb.com/kb/en/mariadb-1083-release-notes/) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb MyRocks in MariaDB 10.2 vs MariaDB 10.3 MyRocks in MariaDB 10.2 vs MariaDB 10.3 ======================================= MyRocks storage engine itself is identical in [MariaDB 10.2](../what-is-mariadb-102/index) and [MariaDB 10.3](../what-is-mariadb-103/index). [MariaDB 10.3](../what-is-mariadb-103/index) has a feature that should be interesting for MyRocks users. It is the [gtid\_pos\_auto\_engines](../gtid/index#gtid_pos_auto_engines) option ([MDEV-12179](https://jira.mariadb.org/browse/MDEV-12179)). This is a performance feature for replication slaves that use multiple transactional storage engines. For further information, see [mysql.gtid\_slave\_pos table](../mysqlgtid_slave_pos-table/index). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb SQRT SQRT ==== Syntax ------ ``` SQRT(X) ``` Description ----------- Returns the square root of X. If X is negative, NULL is returned. Examples -------- ``` SELECT SQRT(4); +---------+ | SQRT(4) | +---------+ | 2 | +---------+ SELECT SQRT(20); +------------------+ | SQRT(20) | +------------------+ | 4.47213595499958 | +------------------+ SELECT SQRT(-16); +-----------+ | SQRT(-16) | +-----------+ | NULL | +-----------+ SELECT SQRT(1764); +------------+ | SQRT(1764) | +------------+ | 42 | +------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb PBXT PBXT ===== PrimeBase XT (PBXT) is a general purpose transactional storage engine designed for high concurrency environments. PBXT is no longer maintained, and is not part of [MariaDB 5.5](../what-is-mariadb-55/index) or later. | Title | Description | | --- | --- | | [About PBXT](../about-pbxt/index) | A storage engine that was included by default until MariaDB 5.3. | | [Building PBXT](../building-pbxt/index) | The commands to use for building PBXT | | [File Organization in PBXT](../file-organization-in-pbxt/index) | How files are organized in PBXT | | [xtstat](../xtstat/index) | Used to monitor all internal activity of PBXT | | [Enhancements for START TRANSACTION WITH CONSISTENT SNAPSHOT](../enhancements-for-start-transaction-with-consistent-snapshot/index) | Enhancements for START TRANSACTION WITH CONSISTENT SNAPSHOT. | | [PBXT System Variables](../pbxt-system-variables/index) | PBXT System Variables | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb EQUALS EQUALS ====== Syntax ------ ``` Equals(g1,g2) ``` From [MariaDB 10.2.3](https://mariadb.com/kb/en/mariadb-1023-release-notes/): ``` MBREQUALS(g1,g2) ``` Description ----------- Returns `1` or `0` to indicate whether *`g1`* is spatially equal to *`g2`*. EQUALS() is based on the original MySQL implementation and uses object bounding rectangles, while [ST\_EQUALS()](index) uses object shapes. From [MariaDB 10.2.3](https://mariadb.com/kb/en/mariadb-1023-release-notes/), `MBREQUALS` is a synonym for `Equals`. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb dbForge Query Builder for MySQL & MariaDB dbForge Query Builder for MySQL & MariaDB ========================================= [**dbForge Query Builder**](https://www.devart.com/dbforge/mysql/querybuilder/) is a powerful visual tool that helps create any sort of MariaDB queries. Building a code has never been so easy – the query can be drawn on a diagram. dbForge Query Builder Key features: ----------------------------------- ### 1. Exporting Data Export your data to 14 popular formats Export data from several tables simultaneously Create templates for repeated operations ### 2. Database Explorer Work with multiple database connections Easy MariaDB query management with drag&drop functionality Quick script generation ![slider-database-explorer](https://mariadb.com/kb/en/dbforge-query-builder-for-mysql-mariadb/+image/slider-database-explorer "slider-database-explorer") ### 3. Visual Drag and Drop Query Builder Enjoy zooming and keyboard support in a sophisticated diagram Preview and print diagrams Add and edit sub-queries visually MariaDB JOINs generator ![slider-query-builder](https://mariadb.com/kb/en/dbforge-query-builder-for-mysql-mariadb/+image/slider-query-builder "slider-query-builder") ### 4. SQL Editing and Execution Check the syntax automatically Get quick information about schema objects Customize formatting profiles Execute scripts, statements and MariaDB fragments seamlessly ### 5. Query Profiler Compare the results of the query visually Review and evaluate a query plan shown in the tree view Get the detailed query information ### 6. Data Editor Enjoy advanced data filters Browse and edit large objects in Data Viewer and Editor windows Fetch asynchronous data ### 7. Data Reports Data Report wizard supports building Data Reports and customizing them with a rich set of controls. ### 8. Master-Detail Browser Allows users to view and analyze the data of several related database objects in a master-detail structured document. Edit data, build relationships, filter data based on specific criteria, sort data, etc. in the Design and Data views. ### 9. Pivot Tables Let the user manipulate the data visually, including sorting, grouping, or filtering fields, building charts, and calculating totals. Download a free 30-day trial of dbForge Query Builder for MariaDB and MySQL [here](https://www.devart.com/dbforge/mysql/querybuilder/download.html). [Documentation](https://docs.devart.com/querybuilder-for-mysql) | Version | Introduced | | --- | --- | | dbForge Query Builder 4.5 | [MariaDB 10.5](../what-is-mariadb-105/index) | | dbForge Query Builder 4.4 | [MariaDB 10.4](../what-is-mariadb-104/index) | | dbForge Query Builder 4.3 | [MariaDB 10.3](../what-is-mariadb-103/index) | | dbForge Query Builder 4.2 | [MariaDB 10.2](../what-is-mariadb-102/index), [MariaDB 10.1](../what-is-mariadb-101/index) | | dbForge Query Builder 3.1 | [MariaDB 10.0](../what-is-mariadb-100/index), [MariaDB 5.5](../what-is-mariadb-55/index) | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb SCHEMA SCHEMA ====== Syntax ------ ``` SCHEMA() ``` Description ----------- This function is a synonym for [DATABASE()](../database/index). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Engine-defined New Table/Field/Index Attributes Engine-defined New Table/Field/Index Attributes =============================================== In MariaDB, a storage engine can allow the user to specify additional attributes per index, field, or table. The engine needs to declare what attributes it introduces. API --- There are three new members in the `handlerton` structure, they can be set in the engine's initialization function as follows: ``` example_hton->table_options= example_table_option_array; example_hton->field_options= example_field_option_array; example_hton->index_options= example_index_option_array; ``` The arrays are declared statically, as in the following example: ``` static MYSQL_THDVAR_ULONG(varopt_default, PLUGIN_VAR_RQCMDARG, "default value of the VAROPT table option", NULL, NULL, 5, 0, 100, 0); struct ha_table_option_struct { char *strparam; ulonglong ullparam; uint enumparam; bool boolparam; ulonglong varparam; }; ha_create_table_option example_table_option_list[]= { HA_TOPTION_NUMBER("NUMBER", ullparam, UINT_MAX32, 0, UINT_MAX32, 10), HA_TOPTION_STRING("STR", strparam), HA_TOPTION_ENUM("ONE_OR_TWO", enumparam, "one,two", 0), HA_TOPTION_BOOL("YESNO", boolparam, 1), HA_TOPTION_SYSVAR("VAROPT", varopt, varparam), HA_TOPTION_END }; ``` The engine declares a structure `ha\_table\_option\_struct` that will hold values of these new attributes. And it describes these attributes to MySQL by creating an array of `HA\_TOPTION\_\*` macros. Note a detail: these macros expect a structure called `ha\_table\_option\_struct`, if the structure is called differently, a `#define` will be needed. There are five supported kinds of attributes: | macro name | attribure value type | correspondingCtype | additional parameters of a macro | | --- | --- | --- | --- | | `HA_TOPTION_NUMBER` | an integer number | `unsigned long long` | a default value, minimal allowed value, maximal allowed value, a factor, that any allowed should be a multiple of. | | `HA_TOPTION_STRING` | a string | `char *` | none. The default value is a null pointer. | | `HA_TOPTION_ENUM` | one value from a list of allowed values | `unsigned int` | a string with a comma-separated list of allowed values, and a default value as a number, starting from 0. | | `HA_TOPTION_BOOL` | a boolean | `bool` | a default value | | `HA_TOPTION_SYSVAR` | defined by the system variable | defined by the system variable | system variable name | *Do **not** use* `enum` *for your* `HA_TOPTION_ENUM` *C structure members, the size of the* `enum` *depends on the compiler, and even on the compilation options, and the plugin API uses only types with known storage sizes.* In all macros the first two parameters are name of the attribute as should be used in SQL in the `CREATE TABLE` statement, and the name of the corresponding member of the `ha_table_option_struct` structure. The `HA_TOPTION_SYSVAR` stands aside a bit. It does not specify the attribute type or the default value, instead it binds the attribute to a system variable. The attribute type and the range of allowed values will be the same as of the corresponding system variable. The attribute **default value** will be the **current value** of its system variable. And unlike other attribute types that are only stored in the `.frm` file if explicitly set in the `CREATE TABLE` statement, the `HA_TOPTION_SYSVAR` attributes are always stored. If the system variable value is changed, it will not affect existing tables. Note that for this very reason, if a table was created in the old version of a storage engine, and a new version has introduced a `HA_TOPTION_SYSVAR` attribute, the attribute value in the old tables will be the **default** value of the system variable, not its **current** value. The array ends with a `HA_TOPTION_END` macro. Field and index (key) attributes are declared similarly using `HA_FOPTION_*` and `HA_IOPTION_*` macros. When in a `CREATE TABLE` statement, the `::create()` handler method is called, the table attributes are available in the `table_arg->s->option_struct`, field attributes - in the `option_struct` member of the individual fields (objects of the `Field` class), index attributes - in the `option_struct` member of the individual keys (objects of the `KEY` class). Additionally, they are available in most other handler methods: the attributes are stored in the `.frm` file and on every open MySQL makes them available to the engine by filling the corresponding `option_struct` members of the table, fields, and keys. The `ALTER TABLE` needs a special support from the engine. MySQL compares old and new table definitions to decide whether it needs to rebuild the table or not. As the semantics of the engine declared attributes is unknown, MySQL cannot make this decision by analyzing attribute values - this is delegated to the engine. The `HA_CREATE_INFO` structure has three new members: ``` ha_table_option_struct *option_struct; ///< structure with parsed table options ha_field_option_struct **fields_option_struct; ///< array of field option structures ha_index_option_struct **indexes_option_struct; ///< array of index option structures ``` The engine (in the `::check_if_incompatible_data()` method) is responsible for comparing new values of the attributes from the `HA_CREATE_INFO` structure with the old values from the table and returning `COMPATIBLE_DATA_NO` if they were changed in such a way that requires the table to be rebuild. The example of declaring the attributes and comparing the values for the `ALTER TABLE` can be found in the EXAMPLE engine. SQL --- The engine declared attributes can be specified per field, index, or table in the `CREATE TABLE` or `ALTER TABLE`. The syntax is the conventional: ``` CREATE TABLE ... ( field ... [attribute=value [attribute=value ...]], ... index ... [attribute=value [attribute=value ...]], ... ) ... [attribute=value [attribute=value ...]] ``` All values must be specified as literals, not expressions. The value of a boolean option may be specified as one of YES, NO, ON, OFF, 1, or 0. A string value may be specified either quoted or not, as an identifier (if it is a valid identifier, of course). Compare with the old behavior: ``` CREATE TABLE ... ENGINE=FEDERATED CONNECTION='mysql://[email protected]'; ``` where the value of the ENGINE attribute is specified not quoted, while the value of the CONNECTION is quoted. When an attribute is set, it will be stored with the table definition and shown in the `SHOW CREATE TABLE;`. To remove an attribute from a table definition use `ALTER TABLE` to set its value to a `DEFAULT`. The values of unknown attributes or attributes with the illegal values cause an error by default. But with [ALTER TABLE](../alter-table/index) one can change the storage engine and some previously valid attributes may become unknown — to the new engine. They are not removed automatically, though, because the table might be altered back to the first engine, and these attributes will be valid again. Still [SHOW CREATE TABLE](../show-create-table/index) will comment these unknown attributes out in the output, otherwise they would make a generated [CREATE TABLE](../create-table/index) statement invalid. With the `IGNORE\_BAD\_TABLE\_OPTIONS` [sql mode](../sql_mode/index) this behavior changes. Unknown attributes do not cause an error, they only result in a warning. And [SHOW CREATE TABLE](../show-create-table/index) will not comment them out. This mode is implicitly enabled in the replication slave thread. See Also -------- * [Writing Plugins for MariaDB](../writing-plugins-for-mariadb/index) * [Storage Engines](../storage-engines/index) * [Storage Engine Development](../storage-engine-development/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb TO_BASE64 TO\_BASE64 ========== Syntax ------ ``` TO_BASE64(str) ``` Description ----------- Converts the string argument `str` to its base-64 encoded form, returning the result as a character string in the connection character set and collation. The argument `str` will be converted to string first if it is not a string. A NULL argument will return a NULL result. The reverse function, [FROM\_BASE64()](../from_base64/index), decodes an encoded base-64 string. There are a numerous different methods to base-64 encode a string. The following are used by MariaDB and MySQL: * Alphabet value 64 is encoded as '+'. * Alphabet value 63 is encoded as '/'. * Encoding output is made up of groups of four printable characters, with each three bytes of data encoded using four characters. If the final group is not complete, it is padded with '=' characters to make up a length of four. * To divide long output, a newline is added after every 76 characters. * Decoding will recognize and ignore newlines, carriage returns, tabs, and spaces. Examples -------- ``` SELECT TO_BASE64('Maria'); +--------------------+ | TO_BASE64('Maria') | +--------------------+ | TWFyaWE= | +--------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb ST_AsText ST\_AsText ========== Syntax ------ ``` ST_AsText(g) AsText(g) ST_AsWKT(g) AsWKT(g) ``` Description ----------- Converts a value in internal geometry format to its [WKT](../wkt-definition/index) representation and returns the string result. `ST_AsText()`, `AsText()`, `ST_AsWKT()` and `AsWKT()` are all synonyms. Examples -------- ``` SET @g = 'LineString(1 1,4 4,6 6)'; SELECT ST_AsText(ST_GeomFromText(@g)); +--------------------------------+ | ST_AsText(ST_GeomFromText(@g)) | +--------------------------------+ | LINESTRING(1 1,4 4,6 6) | +--------------------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Performance of MEMORY Tables Performance of MEMORY Tables ============================ Between [MariaDB 5.5.21](https://mariadb.com/kb/en/mariadb-5521-release-notes/) and 5.5.22 some work was done on how the hash index for a [MEMORY](../memory-storage-engine/index) table is created. This results in better performance when inserting rows into a memory table. The following benchmark compares MariaDB-5.5.21 and 5.5.25. Compiled with identical settings on the same machine. The operation was loading 50 million rows into a MEMORY table with LOAD DATA INFILE. Two different tables were tested: one with an indexed INT column and one with an indexed CHAR(20) column. The data files were pre-generated and located on a SSD. In order to make the effect visible, the cpu speed was set to minimum (core I5 @ 800Mhz) Result: | Table Type | MariaDB Version | rows per second | Percent | | --- | --- | --- | --- | | INT | 5.5.21 | 411022 | 100% | | | 5.5.25 | 510016 | 124% | | CHAR(20) | 5.5.21 | 259399 | 100% | | | 5.5.25 | 411535 | 159% | This is how the benchmark was run: ``` MariaDB [test]> tee 5.5.21.txt MariaDB [test]> set @instance="5.5.21"; MariaDB [test]> source bench.sql ``` The script used to generate the data files: ``` #!/usr/bin/perl -w $ROWS=50*1024*1024; open F, ">/tmp/hash1.txt" or die; for ($i=0; $i<$ROWS; $i++) { printf F "%d\n", int(rand($ROWS)); } close F or die; open F, ">/tmp/hash2.txt" or die; for ($i=0; $i<$ROWS; $i++) { $s=""; for (1..20) { $s .= chr(ord('a')+int(rand(26))); } print F $s, "\n"; } close F or die; ``` The benchmark SQL script bench.sql: ``` use test; -- need big heap tables set max_heap_table_size=4*1024*1024*1024; -- table to hold test results create table if not exists results ( id serial, operation char(32), opsize bigint unsigned, started datetime, ended datetime, instance char(20) ); -- dummy run with second data file drop table if exists t1; create table t1 (c1 char(20), index (c1)) engine memory; load data infile "/tmp/hash2.txt" into table t1; drop table t1; -- do total of 5 runs for each table -- run #1 create table t1 (c1 int, index (c1)) engine memory; select @t1:=now(); load data infile "/tmp/hash1.txt" into table t1; select @t2:=now(); select @rows:=count(*) from t1; insert into results (operation, opsize, started, ended, instance) values ("load into INT table", @rows, @t1, @t2, @instance); drop table t1; create table t1 (c1 char(20), index (c1)) engine memory; select @t1:=now(); load data infile "/tmp/hash2.txt" into table t1; select @t2:=now(); select @rows:=count(*) from t1; insert into results (operation, opsize, started, ended, instance) values ("load into CHAR(20) table", @rows, @t1, @t2, @instance); drop table t1; -- run #2 create table t1 (c1 int, index (c1)) engine memory; select @t1:=now(); load data infile "/tmp/hash1.txt" into table t1; select @t2:=now(); select @rows:=count(*) from t1; insert into results (operation, opsize, started, ended, instance) values ("load into INT table", @rows, @t1, @t2, @instance); drop table t1; create table t1 (c1 char(20), index (c1)) engine memory; select @t1:=now(); load data infile "/tmp/hash2.txt" into table t1; select @t2:=now(); select @rows:=count(*) from t1; insert into results (operation, opsize, started, ended, instance) values ("load into CHAR(20) table", @rows, @t1, @t2, @instance); drop table t1; -- run #3 create table t1 (c1 int, index (c1)) engine memory; select @t1:=now(); load data infile "/tmp/hash1.txt" into table t1; select @t2:=now(); select @rows:=count(*) from t1; insert into results (operation, opsize, started, ended, instance) values ("load into INT table", @rows, @t1, @t2, @instance); drop table t1; create table t1 (c1 char(20), index (c1)) engine memory; select @t1:=now(); load data infile "/tmp/hash2.txt" into table t1; select @t2:=now(); select @rows:=count(*) from t1; insert into results (operation, opsize, started, ended, instance) values ("load into CHAR(20) table", @rows, @t1, @t2, @instance); drop table t1; -- run #4 create table t1 (c1 int, index (c1)) engine memory; select @t1:=now(); load data infile "/tmp/hash1.txt" into table t1; select @t2:=now(); select @rows:=count(*) from t1; insert into results (operation, opsize, started, ended, instance) values ("load into INT table", @rows, @t1, @t2, @instance); drop table t1; create table t1 (c1 char(20), index (c1)) engine memory; select @t1:=now(); load data infile "/tmp/hash2.txt" into table t1; select @t2:=now(); select @rows:=count(*) from t1; insert into results (operation, opsize, started, ended, instance) values ("load into CHAR(20) table", @rows, @t1, @t2, @instance); drop table t1; -- run #5 create table t1 (c1 int, index (c1)) engine memory; select @t1:=now(); load data infile "/tmp/hash1.txt" into table t1; select @t2:=now(); select @rows:=count(*) from t1; insert into results (operation, opsize, started, ended, instance) values ("load into INT table", @rows, @t1, @t2, @instance); show table status like 't1'; drop table t1; create table t1 (c1 char(20), index (c1)) engine memory; select @t1:=now(); load data infile "/tmp/hash2.txt" into table t1; select @t2:=now(); select @rows:=count(*) from t1; insert into results (operation, opsize, started, ended, instance) values ("load into CHAR(20) table", @rows, @t1, @t2, @instance); show table status like 't1'; drop table t1; -- list all results select operation, instance, unix_timestamp(ended)-unix_timestamp(started) as duration, opsize/(unix_timestamp(ended)-unix_timestamp(started)) as ops_per_sec from results order by operation, instance, started; -- list average results select operation, instance, avg(opsize/(unix_timestamp(ended)-unix_timestamp(started))) as avg_ops_per_sec from results group by operation, instance; ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb The Aria Name The Aria Name ============= The [Aria](../aria/index) storage engine used to be called Maria. This page gives the history and background of how and why this name was changed to Aria. Backstory --------- When starting what became the MariaDB project, Monty and the initial developers only planned to work on a next generation [MyISAM](../myisam-storage-engine/index) storage engine replacement. This storage engine would be crash safe and eventually support transactions. Monty named the storage engine, and the project, after his daughter, Maria. Work began in earnest on the Maria storage engine but the plans quickly expanded and morphed and soon the developers were not just working on a storage engine, but on a complete branch of the MySQL database. Since the project was already called Maria, it made sense to call the whole database server MariaDB. Renaming Maria (the engine) --------------------------- So now there was the database, MariaDB, and the storage engine, Maria. To end the confusion this caused, the decision was made to rename the storage engine. Monty's first suggestion was to name it *Lucy*, after his dog, but few who heard it liked that idea. So the decision was made that the next best thing was for the community to suggest and vote on names. This was done by running a contest in 2009 through the end of May 2010. After that the best names were voted on by the community and Monty picked and [announced the winner](http://blogs.gnome.org/mneptok/2010/07/20/rename-maria-contest-winner/) (Aria) at OSCon 2010 in Portland. The winning entry was submitted by Chris Tooley. He received a Linux-powered [System 76](http://www.system76.com) Meerkat NetTop as his prize for suggesting the winning name from Monty Program. See Also -------- * [Why is the Software Called MariaDB?](../why-is-the-software-called-mariadb/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb MariaDB Features Not Available in SQL Server MariaDB Features Not Available in SQL Server ============================================ Some MariaDB features are not available in SQL Server. At first glance, it is not important to know about those features to migrate from SQL Server to MariaDB. However, this is not the case. Using MariaDB features that are not in SQL Server allows one to obtain more advantages from the migration, getting the most from MariaDB. This page has a list of MariaDB features that are not supported in SQL Server. The list is not exhaustive. Plugin Architecture ------------------- * [Storage engines](../storage-engines/index). * [Authentication plugins](../authentication-plugins/index). * [Encryption plugins](../key-management-and-encryption-plugins/index). * [ColumnStore](../mariadb-columnstore/index) is a columnar storage engine designed to scale horizontally. It runs on a specific edition of MariaDB, so currently it cannot be used in combination with other engines. SQL --- * The [sql\_mode](../sql-mode/index) variable determines in which cases an SQL statement should fail with an error, and in which cases it should succeed with a warning even if it is not entirely correct. For example, when a statement tries to insert a string in a column which is not big enough to contain it, it could fail, or it could insert a truncated string and emit a warning. It is a tradeoff between reliability and flexibility. + [SQL\_MODE=MSSQL](../sql_modemssql/index) allows one to use a small subset of SQL Server proprietary syntax. * The [`CREATE ... IF EXISTS`, `CREATE OR REPLACE`, `DROP ... IF NOT EXISTS`](../syntax-differences-between-mariadb-and-sql-server/index#if-exists-if-not-exists-or-replace) options are supported for most [DDL statements](../data-definition/index). * [SHOW](../syntax-differences-between-mariadb-and-sql-server/index#show-statements) statements. * [SHOW CREATE](../syntax-differences-between-mariadb-and-sql-server/index#show-create-statements) statements. * [SHOW PROCESSLIST](../show-processlist/index) and [PERFORMANCE\_SCHEMA THREAD table](../performance-schema-threads-table/index) provide much richer information, compared to SQL Server `sp_who()` and `sp_who2()` procedures. * [CHECKSUM TABLE](../checksum-table/index) statement. * [PL/SQL support](../sql_modeoracle-from-mariadb-103/index) (only for stored procedures and stored functions). * Row constructors. * `BEFORE` [triggers](../triggers/index). * [HANDLER](../handler-commands/index) statements, to scroll table rows ordered by an index or in their physical order. * [DO](../do/index) statement, to call functions without returning a result set. * [BENCHMARK()](../benchmark/index) function, to measure the speed of an SQL expression. See also [Syntax Differences between MariaDB and SQL Server](../syntax-differences-between-mariadb-and-sql-server/index). Types ----- * [Character sets and collations](../character-sets/index) don't depend on column type. They can be set globally, or at database, table or column level. * Columns may use non-constant expressions as the [DEFAULT](../create-table/index#default-column-option) value. [TIMESTAMP](../timestamp/index) columns may have a `DEFAULT` value. * [UNSIGNED](../numeric-data-type-overview/index#signed-unsigned-and-zerofill) numeric types. * [Dynamic columns](../dynamic-columns/index) (note that JSON is usually preferred to this feature). See also [SQL Server and MariaDB Types Comparison](../sql-server-and-mariadb-types-comparison/index). ### JSON For compatibility with some other database systems, MariaDB supports the [JSON](../json-data-type/index) pseudo-type. However, it is just an alias for: `LONGTEXT CHECK (JSON_VALID(column_name))` [JSON\_VALID()](../json_valid/index) is the MariaDB equivalent of SQL Server's `ISJSON()`. Features -------- * [Flashback](../flashback/index) functionality allows one to "undo" the changes that happened after a certain point in time. * [Partitioned tables](../partitioning-tables/index) support the following features: + Tables can be partitioned based on [multiple columns](../range-columns-and-list-columns-partitioning-types/index). + Several [partitioning types](../partitioning-overview/index#partitioning-types) are available. + Subpartitions. * [Progress reporting](../progress-reporting/index) for some typically expensive statements. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb ColumnStore Distributed Aggregate Functions ColumnStore Distributed Aggregate Functions =========================================== MariaDB ColumnStore supports the following aggregate functions, these can be used in the SELECT, HAVING, and ORDER BY clauses of the SQL statement. | Function | Description | | --- | --- | | AVG([DISTINCT] column) | Average value of a numeric (INT variations, NUMERIC, DECIMAL) column | | CORR(ColumnY, ColumnX) | The correlation coefficient for non-null pairs in a group. | | COUNT (\*, [DISTINCT] column) | The number of rows returned by a query or grouping. All datatypes are supported | | COVAR\_POP(ColumnY, ColumnX) | The population covariance for non-null pairs in a group. | | COVAR\_SAMP(ColumnY, ColumnX) | The sample covariance for non-null pairs in a group. | | MAX ([DISTINCT] column) | The maximum value of a column. All datatypes are supported. | | MIN ([DISTINCT] column) | The maximum value of a column. All datatypes are supported. | | REGR\_AVGX(ColumnY, ColumnX) | Average of the independent variable (sum(ColumnX)/N), where N is number of rows processed by the query | | REGR\_AVGY(ColumnY, ColumnX) | Average of the dependent variable (sum(ColumnY)/N), where N is number of rows processed by the query | | REGR\_COUNT(ColumnY, ColumnX) | The total number of input rows in which both column Y and column X are nonnull | | REGR\_INTERCEPT(ColumnY, ColumnX) | The y-intercept of the least-squares-fit linear equation determined by the (ColumnX, ColumnY) pairs | | REGR\_R2(ColumnY, ColumnX) | Square of the correlation coefficient. correlation coefficient is the regr\_intercept(ColumnY, ColumnX) for linear model | | REGR\_SLOPE(ColumnY, ColumnX) | The slope of the least-squares-fit linear equation determined by the (ColumnX, ColumnY) pairs | | REGR\_SXX(ColumnY, ColumnX) | REGR\_COUNT(y, x) \* VAR\_POP(x) for non-null pairs. | | REGR\_SXY(ColumnY, ColumnX) | REGR\_COUNT(y, x) \* COVAR\_POP(y, x) for non-null pairs. | | REGR\_SYY(ColumnY, ColumnX) | REGR\_COUNT(y, x) \* VAR\_POP(y) for non-null pairs. | | STD(), STDDEV(), STDDEV\_POP() | The population standard deviation of a numeric (INT variations, NUMERIC, DECIMAL) column | | STDDEV\_SAMP() | The sample standard deviation of a numeric (INT variations, NUMERIC, DECIMAL) column | | SUM([DISTINCT] column) | The sum of a numeric (INT variations, NUMERIC, DECIMAL) column | | VARIANCE(), VAR\_POP() | The population standard variance of a numeric (INT variations, NUMERIC, DECIMAL) column | | VAR\_SAMP() | The population standard variance of a numeric (INT variations, NUMERIC, DECIMAL) column | ### Note * Regression functions (REGR\_AVGX to REGR\_YY), CORR, COVAR\_POP and COVAR\_SAMP are supported for version 1.2.0 and higher ### Example An example group by query using aggregate functions is: ``` select year(o_orderdate) order_year, avg(o_totalprice) avg_totalprice, max(o_totalprice) max_totalprice, count(*) order_count from orders group by order_year order by order_year; ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb MyISAM Index Storage Space MyISAM Index Storage Space ========================== Regular [MyISAM](../myisam/index) tables make use of [B-tree indexes](../storage-engine-index-types/index#b-tree-indexes). String indexes are space-compressed, which reduces the size of [VARCHARs](../varchar/index) that don't use the full length, or a string that has trailing spaces. String indexes also make use of prefix-compression, where strings with identical prefixes are compressed. Numeric indexes can also be prefix-compressed compressed if the [PACK\_KEYS=1](../create-table/index#table-options) option is used. Regardless, the high byte is always stored first, which allows a reduced index size. In the worst case, with no strings being space-compressed, the total index storage space will be (index\_length+4)/0.67 per index. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb mariadb-admin mariadb-admin ============= **MariaDB starting with [10.4.6](https://mariadb.com/kb/en/mariadb-1046-release-notes/)**From [MariaDB 10.4.6](https://mariadb.com/kb/en/mariadb-1046-release-notes/), `mariadb-admin` is a symlink to `mysqladmin`, the administration program for the mysqld daemon. **MariaDB starting with [10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/)**From [MariaDB 10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/), `mariadb-admin` is the name of the administration program for the mysqld daemon, with `mysqladmin` a symlink . See [mysqladmin](../mysqladmin/index) for details. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Replication Filters Replication Filters =================== The terms *master* and *slave* have historically been used in replication, but the terms terms *primary* and *replica* are now preferred. The old terms are used still used in parts of the documentation, and in MariaDB commands, although [MariaDB 10.5](../what-is-mariadb-105/index) has begun the process of renaming. The documentation process is ongoing. See [MDEV-18777](https://jira.mariadb.org/browse/MDEV-18777) to follow progress on this effort. Replication filters allow users to configure [replication slaves](../replication-overview/index) to intentionally skip certain events. Binary Log Filters for Replication Masters ------------------------------------------ MariaDB provides options that can be used on a [replication master](../replication/index) to restrict local changes to specific databases from getting written to the [binary log](../binary-log/index), which also determines whether any replication slaves replicate those changes. ### Binary Log Filter Options The following options are available, and they are evaluated in the order that they are listed below. If there are conflicting settings, *binlog\_do\_db* prevails. #### `binlog_do_db` The [binlog\_do\_db](../mysqld-options/index#-binlog-do-db) option allows you to configure a [replication master](../replication/index) to write statements and transactions affecting databases that match a specified name into its [binary log](../binary-log/index). Since the filtered statements or transactions will not be present in the [binary log](../binary-log/index), its replication slaves will not be able to replicate them. This option will **not** work with cross-database updates with [statement-based logging](../binary-log-formats/index#statement-based-logging). See the [Statement-Based Logging](#statement-based-logging) section for more information. This option can **not** be set dynamically. When setting it on the command-line or in a server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index), the option does not accept a comma-separated list. If you would like to specify multiple filters, then you need to specify the option multiple times. For example: ``` [mariadb] ... binlog_do_db=db1 binlog_do_db=db2 ``` This will tell the master to do the following: * Write statements and transactions affecting the database named *db1* into the [binary log](../binary-log/index). * Write statements and transactions affecting the database named *db2* into the [binary log](../binary-log/index). * Don't write statements and transactions affecting any other databases into the [binary log](../binary-log/index). #### `binlog_ignore_db` The [binlog\_ignore\_db](../mysqld-options/index#-binlog-ignore-db) option allows you to configure a [replication master](../replication/index) to **not** write statements and transactions affecting databases that match a specified name into its [binary log](../binary-log/index). Since the filtered statements or transactions will not be present in the [binary log](../binary-log/index), its replication slaves will not be able to replicate them. This option will **not** work with cross-database updates with [statement-based logging](../binary-log-formats/index#statement-based-logging). See the [Statement-Based Logging](#statement-based-logging) section for more information. This option can **not** be set dynamically. When setting it on the command-line or in a server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index), the option does not accept a comma-separated list. If you would like to specify multiple filters, then you need to specify the option multiple times. For example: ``` [mariadb] ... binlog_ignore_db=db1 binlog_ignore_db=db2 ``` This will tell the master to do the following: * Don't write statements and transactions affecting the database named *db1* into the [binary log](../binary-log/index). * Don't write statements and transactions affecting the database named *db2* into the [binary log](../binary-log/index). * Write statements and transactions affecting any other databases into the [binary log](../binary-log/index). The [binlog\_ignore\_db](#binlog_ignore_db) option is effectively ignored if the [binlog\_do\_db](#binlog_do_db) option is set, so those two options should not be set together. Replication Filters for Replication Slaves ------------------------------------------ MariaDB provides options and system variables that can be used on used on a [replication slave](../replication/index) to filter events replicated in the [binary log](../binary-log/index). ### Replication Filter Options The following options and system variables are available, and they are evaluated in the order that they are listed below. If there are conflicting settings, the respective *replicate\_do\_* prevails. #### `replicate_rewrite_db` The [replicate\_rewrite\_db](../mysqld-options/index#-replicate-rewrite-db) option allows you to configure a [replication slave](../replication/index) to rewrite database names. It uses the format `master_database->slave_database`. If a slave encounters a [binary log](../binary-log/index) event in which the default database (i.e. the one selected by the [USE](../use/index) statement) is `master_database`, then the slave will apply the event in `slave_database` instead. This option will **not** work with cross-database updates with [statement-based logging](../binary-log-formats/index#statement-based-logging). See the [Statement-Based Logging](#statement-based-logging) section for more information. This option only affects statements that involve tables. This option does not affect statements involving the database itself, such as [CREATE DATABASE](../create-database/index), [ALTER DATABASE](../alter-database/index), and [DROP DATABASE](../drop-database/index). This option's rewrites are evaluated *before* any other replication filters configured by the `replicate_*` system variables. Statements that use table names qualified with database names do not work with other replication filters such as [replicate\_do\_table](#replicate_do_table). This option can **not** be set dynamically. When setting it on the command-line or in a server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index), the option does not accept a comma-separated list. If you would like to specify multiple filters, then you need to specify the option multiple times. For example: ``` [mariadb] ... replicate_rewrite_db=db1->db3 replicate_rewrite_db=db2->db4 ``` This will tell the slave to do the following: * If a [binary log](../binary-log/index) event is encountered in which the default database was *db1*, then apply the event in *db3* instead. * If a [binary log](../binary-log/index) event is encountered in which the default database was *db2*, then apply the event in *db4* instead. See [Configuring Replication Filter Options with Multi-Source Replication](#configuring-replication-filter-options-with-multi-source-replication) for how to configure this system variable with [multi-source replication](../multi-source-replication/index). #### `replicate_do_db` The [replicate\_do\_db](../replication-and-binary-log-server-system-variables/index#replicate_do_db) system variable allows you to configure a [replication slave](../replication/index) to apply statements and transactions affecting databases that match a specified name. This system variable will **not** work with cross-database updates with [statement-based logging](../binary-log-formats/index#statement-based-logging) or when using [mixed-based logging](../binary-log-formats/index#statement-based-logging) and the statement is logged statement based. For statement-based replication, only the default database (that is, the one selected by USE) is considered, not any explicitly mentioned tables in the query. See the [Statement-Based Logging](#statement-based-logging) section for more information. When setting it dynamically with [SET GLOBAL](../set/index#global-session), the system variable accepts a comma-separated list of filters. When setting it dynamically, it is not possible to specify database names that contain commas. If you need to specify database names that contain commas, then you will need to specify them by either providing the command-line options or configuring them in a server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index) when the server is [started](../starting-and-stopping-mariadb-starting-and-stopping-mariadb/index). When setting it dynamically, the [slave threads](../replication-threads/index#threads-on-the-slave) must be stopped. For example: ``` STOP SLAVE; SET GLOBAL replicate_do_db='db1,db2'; START SLAVE; ``` When setting it on the command-line or in a server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index), the system variable does not accept a comma-separated list. If you would like to specify multiple filters, then you need to specify the system variable multiple times. For example: ``` [mariadb] ... replicate_do_db=db1 replicate_do_db=db2 ``` This will tell the slave to do the following: * Replicate statements and transactions affecting the database named *db1*. * Replicate statements and transactions affecting the database named *db2*. * Ignore statements and transactions affecting any other databases. See [Configuring Replication Filter Options with Multi-Source Replication](#configuring-replication-filter-options-with-multi-source-replication) for how to configure this system variable with [multi-source replication](../multi-source-replication/index). #### `replicate_ignore_db` The [replicate\_ignore\_db](../replication-and-binary-log-server-system-variables/index#replicate_ignore_db) system variable allows you to configure a [replication slave](../replication/index) to ignore statements and transactions affecting databases that match a specified name. This system variable will **not** work with cross-database updates with [statement-based logging](../binary-log-formats/index#statement-based-logging) or when using [mixed-based logging](../binary-log-formats/index#statement-based-logging) and the statement is logged statement based. For statement-based replication, only the default database (that is, the one selected by USE) is considered, not any explicitly mentioned tables in the query. See the [Statement-Based Logging](#statement-based-logging) section for more information. When setting it dynamically with [SET GLOBAL](../set/index#global-session), the system variable accepts a comma-separated list of filters. When setting it dynamically, it is not possible to specify database names that contain commas. If you need to specify names or patterns that contain commas, then you will need to specify them by either providing the command-line options or configuring them in a server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index) when the server is [started](../starting-and-stopping-mariadb-starting-and-stopping-mariadb/index). When setting it dynamically, the [slave threads](../replication-threads/index#threads-on-the-slave) must be stopped. For example: ``` STOP SLAVE; SET GLOBAL replicate_ignore_db='db1,db2'; START SLAVE; ``` When setting it on the command-line or in a server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index), the system variable does not accept a comma-separated list. If you would like to specify multiple filters, then you need to specify the system variable multiple times. For example: ``` [mariadb] ... replicate_ignore_db=db1 replicate_ignore_db=db2 ``` This will tell the slave to do the following: * Ignore statements and transactions affecting databases named *db1*. * Ignore statements and transactions affecting databases named *db2*. * Replicate statements and transactions affecting any other databases. The [replicate\_ignore\_db](#replicate_ignore_db) system variable is effectively ignored if the [replicate\_do\_db](#replicate_do_db) system variable is set, so those two system variables should not be set together. See [Configuring Replication Filter Options with Multi-Source Replication](#configuring-replication-filter-options-with-multi-source-replication) for how to configure this system variable with [multi-source replication](../multi-source-replication/index). #### `replicate_do_table` The [replicate\_do\_table](../replication-and-binary-log-server-system-variables/index#replicate_do_table) system variable allows you to configure a [replication slave](../replication/index) to apply statements and transactions that affect tables that match a specified name. The table name is specified in the format: `dbname.tablename`. This system variable will **not** work with cross-database updates with [statement-based logging](../binary-log-formats/index#statement-based-logging). See the [Statement-Based Logging](#statement-based-logging) section for more information. This option only affects statements that involve tables. This option does not affect statements involving the database itself, such as [CREATE DATABASE](../create-database/index), [ALTER DATABASE](../alter-database/index), and [DROP DATABASE](../drop-database/index). When setting it dynamically with [SET GLOBAL](../set/index#global-session), the system variable accepts a comma-separated list of filters. When setting it dynamically, it is not possible to specify database or table names or patterns that contain commas. If you need to specify database or table names that contain commas, then you will need to specify them by either providing the command-line options or configuring them in a server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index) when the server is [started](../starting-and-stopping-mariadb-starting-and-stopping-mariadb/index). When setting it dynamically, the [slave threads](../replication-threads/index#threads-on-the-slave) must be stopped. For example: ``` STOP SLAVE; SET GLOBAL replicate_do_table='db1.tab,db2.tab'; START SLAVE; ``` When setting it on the command-line or in a server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index), the system variable does not accept a comma-separated list. If you would like to specify multiple filters, then you need to specify the system variable multiple times. For example: ``` [mariadb] ... replicate_do_table=db1.tab replicate_do_table=db2.tab ``` This will tell the slave to do the following: * Replicate statements and transactions affecting tables in databases named *db1* and which are named *tab*. * Replicate statements and transactions affecting tables in databases named *db2* and which are named *tab*. * Ignore statements and transactions affecting any other tables. See [Configuring Replication Filter Options with Multi-Source Replication](#configuring-replication-filter-options-with-multi-source-replication) for how to configure this system variable with [multi-source replication](../multi-source-replication/index). #### `replicate_ignore_table` The [replicate\_ignore\_table](../replication-and-binary-log-server-system-variables/index#replicate_ignore_table) system variable allows you to configure a [replication slave](../replication/index) to ignore statements and transactions that affect tables that match a specified name. The table name is specified in the format: `dbname.tablename`. This system variable will **not** work with cross-database updates with [statement-based logging](../binary-log-formats/index#statement-based-logging). See the [Statement-Based Logging](#statement-based-logging) section for more information. When setting it dynamically with [SET GLOBAL](../set/index#global-session), the system variable accepts a comma-separated list of filters. When setting it dynamically, it is not possible to specify database or table names that contain commas. If you need to specify database or table names that contain commas, then you will need to specify them by either providing the command-line options or configuring them in a server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index) when the server is [started](../starting-and-stopping-mariadb-starting-and-stopping-mariadb/index). When setting it dynamically, the [slave threads](../replication-threads/index#threads-on-the-slave) must be stopped. For example: ``` STOP SLAVE; SET GLOBAL replicate_ignore_table='db1.tab,db2.tab'; START SLAVE; ``` When setting it on the command-line or in a server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index), the system variable does not accept a comma-separated list. If you would like to specify multiple filters, then you need to specify the system variable multiple times. For example: ``` [mariadb] ... replicate_ignore_table=db1.tab replicate_ignore_table=db2.tab ``` This will tell the slave to do the following: * Ignore statements and transactions affecting tables in databases named *db1* and which are named *tab*. * Ignore statements and transactions affecting tables in databases named *db2* and which are named *tab*. * Replicate statements and transactions affecting any other tables. The [replicate\_ignore\_table](#replicate_ignore_table) system variable is effectively ignored if either the [replicate\_do\_table](#replicate_do_table) system variable or the [replicate\_wild\_do\_table](#replicate_wild_do_table) system variable is set, so the [replicate\_ignore\_table](#replicate_ignore_table) system variable should not be used with those two system variables. See [Configuring Replication Filter Options with Multi-Source Replication](#configuring-replication-filter-options-with-multi-source-replication) for how to configure this system variable with [multi-source replication](../multi-source-replication/index). #### `replicate_wild_do_table` The [replicate\_wild\_do\_table](../replication-and-binary-log-server-system-variables/index#replicate_wild_do_table) system variable allows you to configure a [replication slave](../replication/index) to apply statements and transactions that affect tables that match a specified wildcard pattern. The wildcard pattern uses the same semantics as the [LIKE](../like/index) operator. This means that the the following characters have a special meaning: * `_` - The `_` character matches any single character. * `%` - The `%` character matches zero or more characters. * `\` - The `\` character is used to escape the other special characters in cases where you need the literal character. This system variable will work with cross-database updates with [statement-based logging](../binary-log-formats/index#statement-based-logging). See the [Statement-Based Logging](#statement-based-logging) section for more information. The system variable does filter databases, tables, [views](../views/index) and [triggers](../triggers/index). The system variable does not filter [stored procedures](../stored-procedures/index), [stored functions](../stored-functions/index), and [events](../stored-programs-and-views-events/index). The [replicate\_do\_db](../replication-and-binary-log-server-system-variables/index#replicate_do_db) system variable will need to be used to filter those. If the table name pattern for a filter is just specified as `%`, then all tables in the database will be matched. In this case, the filter will also affect certain database-level statements, such as [CREATE DATABASE](../create-database/index), [ALTER DATABASE](../alter-database/index) and [DROP DATABASE](../drop-database/index). When setting it dynamically with [SET GLOBAL](../set/index#global-session), the system variable accepts a comma-separated list of filters. When setting it dynamically, it is not possible to specify database or table names or patterns that contain commas. If you need to specify database or table names or patterns that contain commas, then you will need to specify them by either providing the command-line options or configuring them in a server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index) when the server is [started](../starting-and-stopping-mariadb-starting-and-stopping-mariadb/index). When setting it dynamically, the [slave threads](../replication-threads/index#threads-on-the-slave) must be stopped. For example: ``` STOP SLAVE; SET GLOBAL replicate_wild_do_table='db%.tab%,app1.%'; START SLAVE; ``` When setting it on the command-line or in a server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index), the system variable does not accept a comma-separated list. If you would like to specify multiple filters, then you need to specify the system variable multiple times. For example: ``` [mariadb] ... replicate_wild_do_table=db%.tab% replicate_wild_do_table=app1.% ``` This will tell the slave to do the following: * Replicate statements and transactions affecting tables in databases that start with *db* and whose table names start with *tab*. * Replicate statements and transactions affecting the database named *app1*. * Ignore statements and transactions affecting any other tables and databases. See [Configuring Replication Filter Options with Multi-Source Replication](#configuring-replication-filter-options-with-multi-source-replication) for how to configure this system variable with [multi-source replication](../multi-source-replication/index). #### `replicate_wild_ignore_table` The [replicate\_wild\_ignore\_table](../replication-and-binary-log-server-system-variables/index#replicate_wild_ignore_table) system variable allows you to configure a [replication slave](../replication/index) to ignore statements and transactions that affect tables that match a specified wildcard pattern. The wildcard pattern uses the same semantics as the [LIKE](../like/index) operator. This means that the the following characters have a special meaning: * `_` - The `_` character matches any single character. * `%` - The `%` character matches zero or more characters. * `\` - The `\` character is used to escape the other special characters in cases where you need the literal character. This system variable will work with cross-database updates with [statement-based logging](../binary-log-formats/index#statement-based-logging). See the [Statement-Based Logging](#statement-based-logging) section for more information. The system variable does filter databases, tables, [views](../views/index) and [triggers](../triggers/index). The system variable does not filter [stored procedures](../stored-procedures/index), [stored functions](../stored-functions/index), and [events](../stored-programs-and-views-events/index). The [replicate\_ignore\_db](../replication-and-binary-log-server-system-variables/index#replicate_ignore_db) system variable will need to be used to filter those. If the table name pattern for a filter is just specified as `%`, then all tables in the database will be matched. In this case, the filter will also affect certain database-level statements, such as [CREATE DATABASE](../create-database/index), [ALTER DATABASE](../alter-database/index) and [DROP DATABASE](../drop-database/index). When setting it dynamically with [SET GLOBAL](../set/index#global-session), the system variable accepts a comma-separated list of filters. When setting it dynamically, it is not possible to specify database or table names or patterns that contain commas. If you need to specify database or table names or patterns that contain commas, then you will need to specify them by either providing the command-line options or configuring them in a server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index) when the server is [started](../starting-and-stopping-mariadb-starting-and-stopping-mariadb/index). When setting it dynamically, the [slave threads](../replication-threads/index#threads-on-the-slave) must be stopped. For example: ``` STOP SLAVE; SET GLOBAL replicate_wild_ignore_table='db%.tab%,app1.%'; START SLAVE; ``` When setting it on the command-line or in a server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index), the system variable does not accept a comma-separated list. If you would like to specify multiple filters, then you need to specify the system variable multiple times. For example: ``` [mariadb] ... replicate_wild_ignore_table=db%.tab% replicate_wild_ignore_table=app1.% ``` This will tell the slave to do the following: * Ignore statements and transactions affecting tables in databases that start with *db* and whose table names start with *tab*. * Ignore statements and transactions affecting all the tables in the database named *app1*. * Replicate statements and transactions affecting any other tables and databases. The [replicate\_ignore\_table](#replicate_wild_ignore_table) system variable is effectively ignored if either the [replicate\_do\_table](#replicate_do_table) system variable or the [replicate\_wild\_do\_table](#replicate_wild_do_table) system variable is set, so the [replicate\_ignore\_table](#replicate_wild_ignore_table) system variable should not be used with those two system variables. See [Configuring Replication Filter Options with Multi-Source Replication](#configuring-replication-filter-options-with-multi-source-replication) for how to configure this system variable with [multi-source replication](../multi-source-replication/index). #### Configuring Replication Filter Options with Multi-Source Replication How you configure replication filters with [multi-source replication](../multi-source-replication/index) depends on whether you are configuring them dynamically or whether you are configuring them in a server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index). ##### Setting Replication Filter Options Dynamically with Multi-Source Replication The usage of dynamic replication filters changes somewhat when [multi-source replication](../multi-source-replication/index) is in use. By default, the variables are addressed to the default connection, so in a multi-source environment, the required connection needs to be specified. There are two ways to do this. ###### Prefixing the Replication Filter Option with the Connection Name One way to change a replication filter for a multi-source connection is to explicitly specify the name when changing the filter. For example: ``` STOP SLAVE 'gandalf'; SET GLOBAL gandalf.replicate_do_table='database1.table1,database1.table2,database1.table3'; START SLAVE 'gandalf'; ``` ###### Changing the Default Connection Alternatively, the default connection can be changed by setting the [default\_master\_connection](../replication-and-binary-log-server-system-variables/index#default_master_connection) system variable, and then the replication filter can be changed in the usual fashion. For example: ``` SET default_master_connection = 'gandalf'; STOP SLAVE; SET GLOBAL replicate_do_table='database1.table1,database1.table2,database1.table3'; START SLAVE; ``` ##### Setting Replication Filter Options in Option Files with Multi-Source Replication If you are using [multi-source replication](../multi-source-replication/index) and if you would like to make this filter persist server restarts by adding it to a server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index), then the option file can also include the connection name that each filter would apply to. For example: ``` [mariadb] ... gandalf.replicate_do_db=database1 saruman.replicate_do_db=database2 ``` ### CHANGE MASTER Options The [CHANGE MASTER](../change-master-to/index) statement has a few options that can be used to filter certain types of [binary log](../binary-log/index) events. #### `IGNORE_SERVER_IDS` The [IGNORE\_SERVER\_IDS](../change-master-to/index#ignore_server_ids) option for `CHANGE MASTER` can be used to configure a [replication slave](../replication/index) to ignore [binary log](binary_log) events that originated from certain servers. Filtered [binary log](binary_log) events will not get logged to the slave’s [relay log](../relay-log/index), and they will not be applied by the slave. #### `DO_DOMAIN_IDS` The [DO\_DOMAIN\_IDS](../change-master-to/index#do_domain_ids) option for `CHANGE MASTER` can be used to configure a [replication slave](../replication/index) to only apply [binary log](binary_log) events if the transaction's [GTID](../global-transaction-id/index) is in a specific [gtid\_domain\_id](../gtid/index#gtid_domain_id) value. Filtered [binary log](binary_log) events will not get logged to the slave’s [relay log](../relay-log/index), and they will not be applied by the slave. #### `IGNORE_DOMAIN_IDS` The [IGNORE\_DOMAIN\_IDS](../change-master-to/index#ignore_domain_ids) option for `CHANGE MASTER` can be used to configure a [replication slave](../replication/index) to ignore [binary log](binary_log) events if the transaction's [GTID](../global-transaction-id/index) is in a specific [gtid\_domain\_id](../gtid/index#gtid_domain_id) value. Filtered [binary log](binary_log) events will not get logged to the slave’s [relay log](../relay-log/index), and they will not be applied by the slave. Replication Filters and Binary Log Formats ------------------------------------------ The way that a replication filter is interpreted can depend on the [binary log format](../binary-log-formats/index). ### Statement-Based Logging When an event is logged in its statement-based format, many replication filters that affect a database will test the filter against the default database (i.e. the one selected by the [USE](../use/index) statement). This applies to the following replication filters: * [binlog\_do\_db](#binlog_do_db) * [binlog\_ignore\_db](#binlog_ignore_db) * [replicate\_rewrite\_db](#replicate_rewrite_db) * [replicate\_do\_db](#replicate_do_db) * [replicate\_ignore\_db](#replicate_ignore_db) When an event is logged in its statement-based format, many replication filters that affect a table will test the filter against the table in the default database (i.e. the one selected by the [USE](../use/index) statement). This applies to the following replication filters: * [replicate\_do\_table](#replicate_do_table) * [replicate\_ignore\_table](#replicate_ignore_table) This means that cross-database updates **not** work with replication filters and statement-based binary logging. For example, if [replicate\_do\_table=db2.tab](replicate_do_table%3ddb2.tab) were set, then the following would not replicate with statement-based binary logging: ``` USE db1; INSERT INTO db2.tab VALUES (1); ``` If you need to be able to support cross-database updates with replication filters and statement-based binary logging, then you should use the following replication filters: * [replicate\_wild\_do\_table](#replicate_wild_do_table) * [replicate\_wild\_ignore\_table](#replicate_wild_ignore_table) ### Row-Based Logging When an event is logged in its row-based format, many replication filters that affect a database will test the filter against the database that is actually affected by the event. Similarly, when an event is logged in its row-based format, many replication filters that affect a table will test the filter against the table in the the database that is actually affected by the event. This means that cross-database updates work with replication filters and statement-based binary logging. Keep in mind that DDL statements are always logged to the [binary log](../binary-log/index) in statement-based format, even when the [binlog\_format](../replication-and-binary-log-system-variables/index#binlog_format) system variable is set to `ROW`. This means that the notes mentioned in [Statement-Based Logging](#statement-based-logging) always apply to DDL. Replication Filters and Galera Cluster -------------------------------------- When using Galera cluster, replication filters should be used with caution. See [Configuring MariaDB Galera Cluster: Replication Filters](../configuring-mariadb-galera-cluster/index#replication-filters) for more details. See Also -------- * [Dynamic replication filters — our wheel will be square!](https://mariadb.org/dynamic-replication-filters-our-wheel-will-be-square/) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
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mariadb CONNECT Table Types CONNECT Table Types ==================== The main feature of [CONNECT](../connect/index) is to give MariaDB the ability to handle tables from many sources, native files, other DBMS’s tables, or special “virtual” tables. Moreover, for all tables physically represented by data files, CONNECT recognizes many different file formats, described below but not limited in the future to this list, because more can be easily added to it on demand ([OEM tables](../connect-table-types-oem/index)). Note: You can download a [PDF version of the CONNECT documentation](https://mariadb.com/kb/en/connect-table-types/+attachment/connect_1_7_03) (1.7.0003). | Title | Description | | --- | --- | | [CONNECT Table Types Overview](../connect-table-types-overview/index) | CONNECT can handle many table formats. | | [Inward and Outward Tables](../inward-and-outward-tables/index) | The two broad categories of CONNECT tables. | | [CONNECT Table Types - Data Files](../connect-table-types-data-files/index) | CONNECT plain DOS or UNIX data files. | | [CONNECT Zipped File Tables](../connect-zipped-file-tables/index) | When the table file or files are compressed in one or several zip files. | | [CONNECT DOS and FIX Table Types](../connect-dos-and-fix-table-types/index) | CONNECT tables based on text files | | [CONNECT DBF Table Type](../connect-dbf-table-type/index) | CONNECT dBASE III or IV tables. | | [CONNECT BIN Table Type](../connect-bin-table-type/index) | CONNECT binary files in which each row is a logical record of fixed length | | [CONNECT VEC Table Type](../connect-vec-table-type/index) | CONNECT binary files organized in vectors | | [CONNECT CSV and FMT Table Types](../connect-csv-and-fmt-table-types/index) | Variable length CONNECT data files. | | [CONNECT - NoSQL Table Types](../connect-nosql-table-types/index) | Based on files that do not match the relational format but often represent hierarchical data. | | [CONNECT - Files Retrieved Using Rest Queries](../connect-files-retrieved-using-rest-queries/index) | JSON, XML and CSV data files can be retrieved as results from REST queries. | | [CONNECT JSON Table Type](../connect-json-table-type/index) | JSON (JavaScript Object Notation) is a widely-used lightweight data-interchange format. | | [CONNECT XML Table Type](../connect-xml-table-type/index) | CONNECT XML files | | [CONNECT INI Table Type](../connect-ini-table-type/index) | CONNECT INI Windows configuration or initialization files. | | [CONNECT - External Table Types](../connect-external-table-types/index) | Access tables belonging to the current or another server. | | [CONNECT ODBC Table Type: Accessing Tables From Another DBMS](../connect-odbc-table-type-accessing-tables-from-another-dbms/index) | CONNECT Table Types - ODBC Table Type: Accessing Tables from other DBMS | | [CONNECT JDBC Table Type: Accessing Tables from Another DBMS](../connect-jdbc-table-type-accessing-tables-from-another-dbms/index) | Using JDBC to access other tables. | | [CONNECT MONGO Table Type: Accessing Collections from MongoDB](../connect-mongo-table-type/index) | Used to directly access MongoDB collections as tables. | | [CONNECT MYSQL Table Type: Accessing MySQL/MariaDB Tables](../connect-mysql-table-type-accessing-mysqlmariadb-tables/index) | Accessing a MySQL or MariaDB table or view | | [CONNECT PROXY Table Type](../connect-proxy-table-type/index) | Tables that access and read the data of another table or view | | [CONNECT XCOL Table Type](../connect-xcol-table-type/index) | Based on another table/view, used when object tables have a column that contains a list of values | | [CONNECT OCCUR Table Type](../connect-occur-table-type/index) | Extension to the PROXY type when referring to a table/view having several c... | | [CONNECT PIVOT Table Type](../connect-pivot-table-type/index) | Transform the result of another table into another table along “pivot” and "fact" columns. | | [CONNECT TBL Table Type: Table List](../connect-tbl-table-type-table-list/index) | Define a table as a list of tables of any engine and type. | | [CONNECT - Using the TBL and MYSQL Table Types Together](../connect-using-the-tbl-and-mysql-table-types-together/index) | Used together, the TBL and MYSQL types lift all the limitations of the FEDERATED and MERGE engines | | [CONNECT Table Types - Special "Virtual" Tables](../connect-table-types-special-virtual-tables/index) | VIR, WMI and MAC special table types | | [CONNECT Table Types - VIR](../connect-table-types-vir/index) | VIR virtual type for CONNECT | | [CONNECT Table Types - OEM: Implemented in an External LIB](../connect-table-types-oem/index) | CONNECT OEM table types are implemented in an external library. | | [CONNECT Table Types - Catalog Tables](../connect-table-types-catalog-tables/index) | Catalog tables return information about another table or data source | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb MariaDB Transactions and Isolation Levels for SQL Server Users MariaDB Transactions and Isolation Levels for SQL Server Users ============================================================== This page explains how transactions work in MariaDB, and highlights the main differences between MariaDB and SQL Server transactions. Note that XA transactions are handled in a completely different way and are not covered in this page. See [XA Transactions](../xa-transactions/index). Missing Features ---------------- These SQL Server features are not available in MariaDB: * Autonomous transactions; * Distributed transactions. Transactions, Storage Engines and the Binary Log ------------------------------------------------ In MariaDB, transactions are optionally implemented by [storage engines](../storage-engines/index). The default storage engine, [InnoDB](../innodb/index), fully supports transactions. Other transactional storage engines include [MyRocks](../myrocks/index) and [TokuDB](../tokudb/index). Most storage engines are not transactional, therefore they should not considered general purpose engines. Most of the information in this page refers to generic MariaDB server behaviors or InnoDB. For [MyRocks](../myrocks/index) and [TokuDB](../tokudb/index) please check the proper KnowledgeBase sections. Writing into a non-transactional table in a transaction can still be useful. The reason is that a [metadata lock](../metadata-locking/index) is acquired on the table for the duration of the transaction, so that [ALTER TABLEs](../alter-table/index) are queued. It is possible to write into transactional and non-transactional tables within a single transaction. It is important to remember that non-transactional engines will have the following limitations: * In case of rollback, changes to non-transactional engines won't be undone. We will receive a warning `1196` which reminds us of this. * Data in transactional tables cannot be changed by other connections in the middle of a transaction, but data in non-transactional tables can. * In case of a crash, committed data written into a transactional table can always be recovered, but this is not necessarily true for non-transactional tables. If the [binary log](../binary-log/index) is enabled, writing into different transactional storage engines in a single transaction, or writing into transactional and non-transactional engines inside the same transaction, implies some extra work for MariaDB. It needs to perform a two-phase commit to be sure that changes to different tables are logged in the correct order. This affects the performance. Transaction Syntax ------------------ The first read or write to an InnoDB table starts a transaction. No data access is possible outside a transaction. By default [autocommit](../server-system-variables/index#autocommit) is on, which means that the transaction is committed automatically after each SQL statement. We can disable it, and manually commit transactions: ``` SET SESSION autocommit = 0; SELECT ... ; DELETE ... ; COMMIT; ``` Whether autocommit is enabled or not, we can start transactions explicitly, and they will not be automatically committed: ``` START TRANSACTION; SELECT ... ; DELETE ... ; COMMIT; ``` `BEGIN` can also be used to start a transaction, but does not work in stored procedures. Read-only transactions are also available using `START TRANSACTION READ ONLY`. This is a small performance optimization. MariaDB will issue an error when trying to write data in the middle of a read-only transaction. Only DML statements are transactional and can be rolled back. This may change in a future version, see [MDEV-17567](https://jira.mariadb.org/browse/MDEV-17567) - Atomic DDL and [MDEV-4259](https://jira.mariadb.org/browse/MDEV-4259) - transactional DDL. Changing autocommit and explicitly starting a transaction will implicitly commit the active transaction, if any. DDL statements, and several other statements, implicitly commit the active transaction. See [SQL statements That Cause an Implicit Commit](../sql-statements-that-cause-an-implicit-commit/index) for the complete list of these statements. A rollback can also be triggered implicitly, when certain errors occur. You can experiment with transactions to check in which cases they implicitly commit or rollback. The [in\_transaction](../server-system-variables/index#in_transaction) system variable can help: it is set to 1 when a transaction is in progress, or 0 when no transaction is in progress. This section only covers the basic syntax for transactions. Much more options are available. For more information, see [Transactions](../transactions/index). Constraint Checking ------------------- MariaDB supports the following [constraints](../constraint/index): * [Primary keys](../getting-started-with-indexes/index#primary-key) * [UNIQUE](../getting-started-with-indexes/index#unique-index) * [CHECK](../constraint/index#check-constraints) * [Foreign keys](../foreign-keys/index) In some databases, constraints can temporarily be violated during a transaction, and their enforcement can be deferred to the commit time. SQL Server does not support this, and always validates data against constraints at the end of each statement. MariaDB does something different: it always checks constraints after each row change. There are cases this policy makes some statements fail with an error, even if those statements would work on SQL Server. For example, suppose you have an `id` column that is the primary key, and you need to increase its value for some reason: ``` SELECT id FROM customer; +----+ | id | +----+ | 1 | | 2 | | 3 | | 4 | | 5 | +----+ UPDATE customer SET id = id + 1; ERROR 1062 (23000): Duplicate entry '2' for key 'PRIMARY' ``` The reason why this happens is that, as the first thing, MariaDB tries to change 1 to 2, but a value of 2 is already present in the primary key. A solution is to use this non-standard syntax: ``` UPDATE customer SET id = id + 1 ORDER BY id DESC; Query OK, 5 rows affected (0.00 sec) Rows matched: 5 Changed: 5 Warnings: 0 ``` Changing the ids in reversed order won't duplicate any value. Similar problems can happen with `CHECK` constraints and foreign keys. To solve them, we can use a different approach: ``` SET SESSION check_constraint_checks = 0; -- run some queries -- that temporarily violate a CHECK clause SET SESSION check_constraint_checks = 1; SET SESSION foreign_key_checks = 0; -- run some queries -- that temporarily violate a foreign key SET SESSION foreign_key_checks = 1; ``` The last solutions temporarily disable `CHECK` constraints and foreign keys. Note that, while this may solve practical problems, it is dangerous because: * This doesn't disable a single `CHECK` or foreign key, but also others, that you don't expect to violate. * This doesn't defer the constraint checks, but it simply disables them for a while. This means that, if you insert some invalid values, they will not be detected. See [check\_constraint\_checks](../server-system-variables/index#check_constraint_checks) and [foreign\_key\_checks](../server-system-variables/index#foreign_key_checks) system variables. Isolation Levels and Locks -------------------------- For more information about MariaDB isolation levels see [SET TRANSACTION](../set-transaction/index). ### Locking Reads In MariaDB, the locks acquired by a read do not depend on the isolation level (with one exception noted below). As a general rule: * Plain [SELECTs](../select/index) are not locking, they acquire snapshots instead. * To force a read to acquire a shared lock, use [SELECT ... LOCK IN SHARED MODE](../lock-in-share-mode/index). * To force a read to acquire an exclusive lock, use [SELECT ... FOR UPDATE](../for-update/index). ### Changing the Isolation Level The default, the isolation level in MariaDB is `REPEATABLE READ`. This can be changed with the [tx\_isolation](../server-system-variables/index#tx_isolation) system variable. Applications developed for SQL Server and later ported to MariaDB may run with `READ COMMITTED` without problems. Using a stricter level would reduce scalability. To use `READ COMMITTED` by default, add the following line to the MariaDB configuration file: ``` tx_isolation = 'READ COMMITTED' ``` It is also possible to change the default isolation level for the current session: ``` SET SESSION tx_isolation = 'read-committed'; ``` Or just for one transaction, by issuing the following statement before starting a transaction: ``` SET TRANSACTION ISOLATION LEVEL READ COMMITTED; ``` ### How Isolation Levels are Implemented in MariaDB MariaDB supports the following isolation levels: * `READ UNCOMMITTED` * `READ COMMITTED` * `REPEATABLE READ` * `SERIALIZABLE` MariaDB isolation levels differ from SQL Server in the following ways: * `REPEATABLE READ` does not acquire share locks on all read rows, nor a range lock on the missing values that match a `WHERE` clause. * It is not possible to change the isolation level in the middle of a transaction. * `SNAPSHOT` isolation level is not supported. Instead, you can use `START TRANSACTION WITH CONSISTENT SNAPSHOT` to acquire a snapshot at the beginning of the transaction. This is compatible with all isolation levels. Here is an example of `WITH CONSISTENT SNAPSHOT` usage: ``` -- session 1 SELECT * FROM t1; +----+ | id | +----+ | 1 | +----+ SELECT * FROM t2; +----+ | id | +----+ | 1 | +----+ START TRANSACTION WITH CONSISTENT SNAPSHOT; -- session 2 INSERT INTO t1 VALUES (2); -- session 1 SELECT * FROM t1; +----+ | id | +----+ | 1 | +----+ -- session 2 INSERT INTO t2 VALUES (2); -- session 1 SELECT * FROM t2; +----+ | id | +----+ | 1 | +----+ ``` As you can see, session 1 uses `WITH CONSISTENT SNAPSHOT`, thus it sees all tables as they were when the transaction begun. ### Avoiding Lock Waits When we try to read or modify a row that is exclusive-locked by another transaction, our transaction is queued until that lock is released. There could be more queued transactions waiting to acquire the same lock, in which case we will wait even more. There is a timeout for such waits, defined by the [innodb\_lock\_wait\_timeout](../innodb-system-variables/index#innodb_lock_wait_timeout) variable. If it is set to 0, statements that encounter a row lock will fail immediately. When the timeout is exceeded, MariaDB produces the following error: ``` ERROR 1205 (HY000): Lock wait timeout exceeded; try restarting transaction ``` It is important to note that this variable has two limitations (by design): * It only affects transactional statements, not statements like `ALTER TABLE` or `TRUNCATE TABLE`. * It only concerns row locks. It does not put a timeout on metadata locks, or table locks acquired - for example - with the [LOCK TABLES](../lock-tables/index) statement. Note however that [lock\_wait\_timeout](../server-system-variables/index#lock_wait_timeout) can be used for metadata locks. There is a special syntax that can be used with `SELECT` and some non-transactional statements including `ALTER TABLE`: the [WAIT and NOWAIT](../wait-and-nowait/index) clauses. This syntax puts a timeout in seconds for all lock types, including row locks, table locks, and metadata locks. For example: ``` Session 1: START TRANSACTION; -- let's acquire a metadata lock SELECT id FROM t WHERE 0; Session 2: DROP TABLE t WAIT 0; ERROR 1205 (HY000): Lock wait timeout exceeded; try restarting transaction ``` InnoDB Transactions ------------------- ### InnoDB Lock Types InnoDB locks are classified based on what exactly they lock, and which operations they lock. The first classification is the following: * Record Locks lock a row or, more precisely, an index entry. * Gap Locks lock an interval between two index entries. Note that indexes have virtual values of -Infinum and Infinum, so a gap lock can cover the gap before the first or after the last index entry. * Next-Key Locks lock an index entry and the gap between it and the next entry. They're a combination of record locks and gap locks. * Insert Intention Locks are gap locks acquired before inserting a new row. Lock modes are the following: * Exclusive Locks (X) are generally acquired on writes, e.g. immediately before deleting a row. Only one exclusive lock can be acquired on a resource simultaneously. * Shared Locks (S) can be acquired acquired on reads. Multiple shared locks can be acquired at the same time (because the rows are not supposed to change when shared-locked) but are incompatible with exclusive locks. * Intention locks (IS, XS) are acquired when it is not possible to acquire an exclusive lock or a shared lock. When a lock on a row or gap is released, the oldest intention lock on that resource (if any) is converted to an X or S lock. For more information see [InnoDB Lock Modes](../innodb-lock-modes/index). ### Information Schema Querying the [information\_schema](../information-schema/index) is the best way to see which transactions have acquired some locks and which transactions are waiting for some locks to be released. In particular, check the following tables: * [INNODB\_LOCKS](../information-schema-innodb_locks-table/index): requests for locks not yet fulfilled, or that are blocking another transaction. * [INNODB\_LOCK\_WAITS](../information-schema-innodb_lock_waits-table/index): queued requests to acquire a lock. * [INNODB\_TRX](../information-schema-innodb_trx-table/index): information about all currently executing InnoDB transactions, including SQL queries that are running. Here is an example of their usage. ``` -- session 1 START TRANSACTION; UPDATE t SET id = 15 WHERE id = 10; -- session 2 DELETE FROM t WHERE id = 10; -- session 1 USE information_schema; SELECT l.*, t.* FROM information_schema.INNODB_LOCKS l JOIN information_schema.INNODB_TRX t ON l.lock_trx_id = t.trx_id WHERE trx_state = 'LOCK WAIT' \G *************************** 1. row *************************** lock_id: 840:40:3:2 lock_trx_id: 840 lock_mode: X lock_type: RECORD lock_table: `test`.`t` lock_index: PRIMARY lock_space: 40 lock_page: 3 lock_rec: 2 lock_data: 10 trx_id: 840 trx_state: LOCK WAIT trx_started: 2019-12-23 18:43:46 trx_requested_lock_id: 840:40:3:2 trx_wait_started: 2019-12-23 18:43:46 trx_weight: 2 trx_mysql_thread_id: 46 trx_query: DELETE FROM t WHERE id = 10 trx_operation_state: starting index read trx_tables_in_use: 1 trx_tables_locked: 1 trx_lock_structs: 2 trx_lock_memory_bytes: 1136 trx_rows_locked: 1 trx_rows_modified: 0 trx_concurrency_tickets: 0 trx_isolation_level: REPEATABLE READ trx_unique_checks: 1 trx_foreign_key_checks: 1 trx_last_foreign_key_error: NULL trx_is_read_only: 0 trx_autocommit_non_locking: 0 ``` ### Deadlocks InnoDB detects deadlocks automatically. Since this consumes CPU time, some users prefer to disable this feature by setting the [innodb\_deadlock\_detect](../innodb-system-variables/index#innodb_deadlock_detect) variable to 0. If this is done, locked transactions will wait until the they exceed the [innodb\_lock\_wait\_timeout](../innodb-system-variables/index#innodb_lock_wait_timeout). Therefore it is important to set innodb\_lock\_wait\_timeout to a very low value, like 1. When InnoDB detects a deadlock, it kills the transaction that modified the least amount of data. The client will receive the following error: ``` ERROR 1213 (40001): Deadlock found when trying to get lock; try restarting transaction ``` The latest detected deadlock, and the killed transaction, can be viewed in the output of [SHOW ENGINE InnoDB STATUS](../show-engine-innodb-status/index). Here's an example: ``` ------------------------ LATEST DETECTED DEADLOCK ------------------------ 2019-12-23 18:55:18 0x7f51045e3700 *** (1) TRANSACTION: TRANSACTION 847, ACTIVE 10 sec starting index read mysql tables in use 1, locked 1 LOCK WAIT 4 lock struct(s), heap size 1136, 3 row lock(s), undo log entries 1 MySQL thread id 46, OS thread handle 139985942054656, query id 839 localhost root Updating delete from t where id = 10 *** (1) WAITING FOR THIS LOCK TO BE GRANTED: RECORD LOCKS space id 40 page no 3 n bits 80 index PRIMARY of table `test`.`t` trx id 847 lock_mode X locks rec but not gap waiting Record lock, heap no 2 PHYSICAL RECORD: n_fields 3; compact format; info bits 32 0: len 4; hex 8000000a; asc ;; 1: len 6; hex 00000000034e; asc N;; 2: len 7; hex 760000019c0495; asc v ;; *** (2) TRANSACTION: TRANSACTION 846, ACTIVE 25 sec starting index read mysql tables in use 1, locked 1 3 lock struct(s), heap size 1136, 2 row lock(s), undo log entries 1 MySQL thread id 39, OS thread handle 139985942361856, query id 840 localhost root Updating delete from t where id = 11 *** (2) HOLDS THE LOCK(S): RECORD LOCKS space id 40 page no 3 n bits 80 index PRIMARY of table `test`.`t` trx id 846 lock_mode X locks rec but not gap Record lock, heap no 2 PHYSICAL RECORD: n_fields 3; compact format; info bits 32 0: len 4; hex 8000000a; asc ;; 1: len 6; hex 00000000034e; asc N;; 2: len 7; hex 760000019c0495; asc v ;; *** (2) WAITING FOR THIS LOCK TO BE GRANTED: RECORD LOCKS space id 40 page no 3 n bits 80 index PRIMARY of table `test`.`t` trx id 846 lock_mode X locks rec but not gap waiting Record lock, heap no 3 PHYSICAL RECORD: n_fields 3; compact format; info bits 32 0: len 4; hex 8000000b; asc ;; 1: len 6; hex 00000000034f; asc O;; 2: len 7; hex 770000019d031d; asc w ;; *** WE ROLL BACK TRANSACTION (2) ``` The latest detected deadlock never disappears from the output of `SHOW ENGINE InnoDB STATUS`. If you cannot see any, MariaDB hasn't detected any InnoDB deadlocks since the last restart. Another way to monitor deadlocks is to set [innodb\_print\_all\_deadlocks](../innodb-system-variables/index#innodb_print_all_deadlocks) to 1 (0 is the default). InnoDB will log all detected deadlocks into the [error log](../error-log/index). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb IS_IPV4 IS\_IPV4 ======== Syntax ------ ``` IS_IPV4(expr) ``` Description ----------- If the expression is a valid IPv4 address, returns 1, otherwise returns 0. IS\_IPV4() is stricter than [INET\_ATON()](../inet_aton/index), but as strict as [INET6\_ATON()](../inet6_aton/index), in determining the validity of an IPv4 address. This implies that if IS\_IPV4 returns 1, the same expression will always return a non-NULL result when passed to INET\_ATON(), but that the reverse may not apply. Examples -------- ``` SELECT IS_IPV4('1110.0.1.1'); +-----------------------+ | IS_IPV4('1110.0.1.1') | +-----------------------+ | 0 | +-----------------------+ SELECT IS_IPV4('48f3::d432:1431:ba23:846f'); +--------------------------------------+ | IS_IPV4('48f3::d432:1431:ba23:846f') | +--------------------------------------+ | 0 | +--------------------------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb CREATE PACKAGE CREATE PACKAGE ============== **MariaDB starting with [10.3.5](https://mariadb.com/kb/en/mariadb-1035-release-notes/)**Oracle-style packages were introduced in [MariaDB 10.3.5](https://mariadb.com/kb/en/mariadb-1035-release-notes/). Syntax ------ ``` CREATE [ OR REPLACE] [DEFINER = { user | CURRENT_USER | role | CURRENT_ROLE }] PACKAGE [ IF NOT EXISTS ] [ db_name . ] package_name [ package_characteristic ... ] { AS | IS } [ package_specification_element ... ] END [ package_name ] package_characteristic: COMMENT 'string' | SQL SECURITY { DEFINER | INVOKER } package_specification_element: FUNCTION_SYM package_specification_function ; | PROCEDURE_SYM package_specification_procedure ; package_specification_function: func_name [ ( func_param [, func_param]... ) ] RETURNS func_return_type [ package_routine_characteristic... ] package_specification_procedure: proc_name [ ( proc_param [, proc_param]... ) ] [ package_routine_characteristic... ] func_return_type: type func_param: param_name [ IN | OUT | INOUT | IN OUT ] type proc_param: param_name [ IN | OUT | INOUT | IN OUT ] type type: Any valid MariaDB explicit or anchored data type package_routine_characteristic: COMMENT 'string' | LANGUAGE SQL | { CONTAINS SQL | NO SQL | READS SQL DATA | MODIFIES SQL DATA } | SQL SECURITY { DEFINER | INVOKER } ``` Description ----------- The `CREATE PACKAGE` statement can be used when [Oracle SQL\_MODE](../sql_modeoracle-from-mariadb-103/index) is set. The `CREATE PACKAGE` creates the specification for a stored package (a collection of logically related stored objects). A stored package specification declares public routines (procedures and functions) of the package, but does not implement these routines. A package whose specification was created by the `CREATE PACKAGE` statement, should later be implemented using the [CREATE PACKAGE BODY](../create-package-body/index) statement. Function parameter quantifiers IN | OUT | INOUT | IN OUT -------------------------------------------------------- **MariaDB starting with [10.8.0](https://mariadb.com/kb/en/mariadb-1080-release-notes/)**The function parameter quantifiers for `IN`, `OUT`, `INOUT`, and `IN OUT` where added in a 10.8.0 preview release. Prior to 10.8.0 quantifiers were supported only in procedures. `OUT`, `INOUT` and its equivalent `IN OUT`, are only valid if called from `SET` and not `SELECT`. These quantifiers are especially useful for creating functions and procedures with more than one return value. This allows functions and procedures to be more complex and nested. Examples -------- ``` SET sql_mode=ORACLE; DELIMITER $$ CREATE OR REPLACE PACKAGE employee_tools AS FUNCTION getSalary(eid INT) RETURN DECIMAL(10,2); PROCEDURE raiseSalary(eid INT, amount DECIMAL(10,2)); PROCEDURE raiseSalaryStd(eid INT); PROCEDURE hire(ename TEXT, esalary DECIMAL(10,2)); END; $$ DELIMITER ; ``` See Also -------- * [CREATE PACKAGE BODY](../create-package-body/index) * [SHOW CREATE PACKAGE](../show-create-package/index) * [DROP PACKAGE](../drop-package/index) * [Oracle SQL\_MODE](../sql_modeoracle-from-mariadb-103/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb RADIANS RADIANS ======= Syntax ------ ``` RADIANS(X) ``` Description ----------- Returns the argument *`X`*, converted from degrees to radians. Note that π radians equals 180 degrees. This is the converse of the [DEGREES()](../degrees/index) function. Examples -------- ``` SELECT RADIANS(45); +-------------------+ | RADIANS(45) | +-------------------+ | 0.785398163397448 | +-------------------+ SELECT RADIANS(90); +-----------------+ | RADIANS(90) | +-----------------+ | 1.5707963267949 | +-----------------+ SELECT RADIANS(PI()); +--------------------+ | RADIANS(PI()) | +--------------------+ | 0.0548311355616075 | +--------------------+ SELECT RADIANS(180); +------------------+ | RADIANS(180) | +------------------+ | 3.14159265358979 | +------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Building the best INDEX for a given SELECT Building the best INDEX for a given SELECT ========================================== The problem ----------- You have a SELECT and you want to build the best INDEX for it. This blog is a "cookbook" on how to do that task. * A short algorithm that works for many simpler SELECTs and helps in complex queries. * Examples of the algorithm, plus digressions into exceptions and variants * Finally a long list of "other cases". The hope is that a newbie can quickly get up to speed, and his/her INDEXes will no longer smack of "newbie". Many edge cases are explained, so even an expert may find something useful here. Algorithm --------- Here's the way to approach creating an INDEX, given a SELECT. Follow the steps below, gathering columns to put in the INDEX in order. When the steps give out, you usually have the 'perfect' index. 1. Given a WHERE with a bunch of expressions connected by AND: Include the columns (if any), in any order, that are compared to a constant and not hidden in a function. 2. You get one more chance to add to the INDEX; do the first of these that applies: * 2a. One column used in a 'range' -- BETWEEN, '>', LIKE w/o leading wildcard, etc. * 2b. All columns, in order, of the GROUP BY. * 2c. All columns, in order, of the ORDER BY if there is no mixing of ASC and DESC. Digression ---------- This blog assumes you know the basic idea behind having an INDEX. Here is a refresher on some of the key points. Virtually all INDEXes in MySQL are structured as BTrees BTrees allow very efficient for * Given a key, find the corresponding row(s); * "Range scans" -- That is start at one value for the key and repeatedly find the "next" (or "previous") row. A PRIMARY KEY is a UNIQUE KEY; a UNIQUE KEY is an INDEX. ("KEY" == "INDEX".) InnoDB "clusters" the PRIMARY KEY with the data. Hence, given the value of the PK ("PRIMARY KEY"), after drilling down the BTree to find the index entry, you have all the columns of the row when you get there. A "secondary key" (any UNIQUE or INDEX other than the PK) in InnoDB first drills down the BTree for the secondary index, where it finds a copy of the PK. Then it drills down the PK to find the row. Every InnoDB table has a PRIMARY KEY. While there is a default if you do not specify one, it is best to explicitly provide a PK. For completeness: MyISAM works differently. All indexes (including the PK) are in separate BTrees. The leaf node of such BTrees have a pointer (usually a byte offset) into the data file. All discussion here assumes InnoDB tables, however most statements apply to other Engines. First, some examples -------------------- Think of a list of names, sorted by last\_name, then first\_name. You have undoubtedly seen such lists, and they often have other information such as address and phone number. Suppose you wanted to look me up. If you remember my full name ('James' and 'Rick'), it is easy to find my entry. If you remembered only my last name ('James') and first initial ('R'). You would quickly zoom in on the Jameses and find the Rs in them. There, you might remember 'Rick' and ignore 'Ronald'. But, suppose you remembered my first name ('Rick') and only my last initial ('J'). Now you are in trouble. You would be scanning all the Js -- Jones, Rick; Johnson, Rick; Jamison, Rick; etc, etc. That's much less efficient. Those equate to ``` INDEX(last_name, first_name) -- the order of the list. WHERE last_name = 'James' AND first_name = 'Rick' -- best case WHERE last_name = 'James' AND first_name LIKE 'R%' -- pretty good WHERE last_name LIKE 'J%' AND first_name = 'Rick' -- pretty bad ``` Think about this example as I talk about "=" versus "range" in the Algorithm, below. Algorithm, step 1 (WHERE "column = const") ------------------------------------------ * `WHERE aaa = 123 AND ...` : an INDEX starting with aaa is good. * `WHERE aaa = 123 AND bbb = 456 AND ...` : an INDEX starting with aaa and bbb is good. In this case, it does not matter whether aaa or bbb comes first in the INDEX. * `xxx IS NULL` : this acts like "= const" for this discussion. * `WHERE t1.aa = 123 AND t2.bb = 456` -- You must only consider columns in the current table. Note that the expression must be of the form of `column\_name` = (constant). These do not apply to this step in the Algorithm: DATE(dt) = '...', LOWER(s) = '...', CAST(s ...) = '...', x='...' COLLATE... (If there are no "=" parts AND'd in the WHERE clause, move on to step 2 without any columns in your putative INDEX.) Algorithm, step 2 ----------------- Find the first of 2a / 2b / 2c that applies; use it; then quit. If none apply, then you are through gathering columns for the index. In some cases it is optimal to do step 1 (all equals) plus step 2c (ORDER BY). Algorithm, step 2a (one range) ------------------------------ A "range" shows up as * `aaa >= 123` -- any of <, <=, >=, >; but not <>, != * `aaa BETWEEN 22 AND 44` * `sss LIKE 'blah%'` -- but not `sss LIKE '%blah'` * `xxx IS NOT NULL` Add the column in the range to your putative INDEX. If there are more parts to the WHERE clause, you must stop now. Complete examples (assume nothing else comes after the snippet) * `WHERE aaa >= 123 AND bbb = 1 ⇒ INDEX(bbb, aaa)` (WHERE order does not matter; INDEX order does) * `WHERE aaa >= 123 ⇒ INDEX(aaa)` * `WHERE aaa >= 123 AND ccc > 'xyz' ⇒ INDEX(aaa) or INDEX(ccc)` (only one range) * `WHERE aaa >= 123 ORDER BY aaa ⇒ INDEX(aaa)` -- Bonus: The ORDER BY will use the INDEX. * `WHERE aaa >= 123 ORDER BY aaa ⇒ INDEX(aaa) DESC` -- Same Bonus. Algorithm, step 2b (GROUP BY) ----------------------------- If there is a GROUP BY, all the columns of the GROUP BY should now be added, in the specified order, to the INDEX you are building. (I do not know what happens if one of the columns is already in the INDEX.) If you are GROUPing BY an expression (including function calls), you cannot use the GROUP BY; stop. Complete examples (assume nothing else comes after the snippet) * `WHERE aaa = 123 AND bbb = 1 GROUP BY ccc ⇒ INDEX(bbb, aaa, ccc) or INDEX(aaa, bbb, ccc)` (='s first, in any order; then the GROUP BY) * `WHERE aaa >= 123 GROUP BY xxx ⇒ INDEX(aaa)` (You should have stopped with Step 2a) * `GROUP BY x,y ⇒ INDEX(x,y)` (no WHERE) * `WHERE aaa = 123 GROUP BY xxx, (a+b) ⇒ INDEX(aaa)` -- expression in GROUP BY, so no use including even xxx. Algorithm, step 2c (ORDER BY) ----------------------------- If there is a ORDER BY, all the columns of the ORDER BY should now be added, in the specified order, to the INDEX you are building. If there are multiple columns in the ORDER BY, and there is a mixture of ASC and DESC, do not add the ORDER BY columns; they won't help; stop. If you are ORDERing BY an expression (including function calls), you cannot use the ORDER BY; stop. Complete examples (assume nothing else comes after the snippet) * `WHERE aaa = 123 GROUP BY ccc ORDER BY ddd ⇒ INDEX(aaa, ccc)` -- should have stopped with Step 2b * `WHERE aaa = 123 GROUP BY ccc ORDER BY ccc ⇒ INDEX(aaa, ccc)` -- the ccc will be used for both GROUP BY and ORDER BY * `WHERE aaa = 123 ORDER BY xxx ASC, yyy DESC ⇒ INDEX(aaa)` -- mixture of ASC and DESC. The following are especially good. Normally a LIMIT cannot be applied until after lots of rows are gathered and then sorted according to the ORDER BY. But, if the INDEX gets all they way through the ORDER BY, only (OFFSET + LIMIT) rows need to be gathered. So, in these cases, you win the lottery with your new index: * `WHERE aaa = 123 GROUP BY ccc ORDER BY ccc LIMIT 10 ⇒ INDEX(aaa, ccc)` * `WHERE aaa = 123 ORDER BY ccc LIMIT 10 ⇒ INDEX(aaa, ccc)` * `ORDER BY ccc LIMIT 10 ⇒ INDEX(ccc)` * `WHERE ccc > 432 ORDER BY ccc LIMIT 10 ⇒ INDEX(ccc)` -- This "range" is compatible with ORDER BY (It does not make much sense to have a LIMIT without an ORDER BY, so I do not discuss that case.) Algorithm end ------------- You have collected a few columns; put them in INDEX and ADD that to the table. That will often produce a "good" index for the SELECT you have. Below are some other suggestions that may be relevant. An example of the Algorithm being 'wrong': ``` SELECT ... FROM t WHERE flag = true; ``` This would (according to the Algorithm) call for INDEX(flag). However, indexing a column that has two (or a small number of) values is almost always useless. This is called 'low cardinality'. The Optimizer would prefer to do a table scan than to bounce between the index BTree and the data. On the other hand, the Algorithm is 'right' with ``` SELECT ... FROM t WHERE flag = true AND date >= '2015-01-01'; ``` That would call for a compound index starting with a flag: INDEX(flag, date). Such an index is likely to be very beneficial. And it is likely to be more beneficial than INDEX(date). If your resulting INDEX include column(s) that are likely to be UPDATEd, note that the UPDATE will have extra work to remove a 'row' from one place in the INDEX's BTree and insert a 'row' back into the BTree. For example: ``` INDEX(x) UPDATE t SET x = ... WHERE ...; ``` There are too many variables to say whether it is better to keep the index or to toss it. In this case, shortening the index may may be beneficial: ``` INDEX(z, x) UPDATE t SET x = ... WHERE ...; ``` Changing to INDEX(z) would make for less work for the UPDATE, but might hurt some SELECT. It depends on the frequency of each, plus many more factors. Limitations ----------- (There are exceptions to some of these.) * You may not create an index bigger than 3KB. * You may not include a column that equates to bigger than some value (767 bytes -- VARCHAR(255) CHARACTER SET utf8). * You can deal with big fields using "prefix" indexing; but see below. * You should not have more than 5 columns in an index. (This is just a Rule of Thumb; nothing prevents having more.) * You should not have redundant indexes. (See below.) Flags and low cardinality ------------------------- `INDEX(flag)` is almost never useful if `flag` has very few values. More specifically, when you say WHERE flag = 1 and "1" occurs more than 20% of the time, such an index will be shunned. The Optimizer would prefer to scan the table instead of bouncing back and forth between the index and the data for more than 20% of the rows. ("20%" is really somewhere between 10% and 30%, depending on the phase of the moon.) "Covering" indexes ------------------ A "Covering" index is an index that contains all the columns in the SELECT. It is special in that the SELECT can be completed by looking only at the INDEX BTree. (Since InnoDB's PRIMARY KEY is clustered with the data, "covering" is of no benefit when considering at the PRIMARY KEY.) Mini-cookbook: 1. Gather the list of column(s) according to the "Algorithm", above. 2. Add to the end of the list the rest of the columns seen in the SELECT, in any order. Examples: * `SELECT x FROM t WHERE y = 5; ⇒ INDEX(y,x)` -- The algorithm said just INDEX(y) * `SELECT x,z FROM t WHERE y = 5 AND q = 7; ⇒ INDEX(y,q,x,z)` -- y and q in either order (Algorithm), then x and z in either order (covering). * `SELECT x FROM t WHERE y > 5 AND q > 7; ⇒ INDEX(y,q,x)` -- y or q first (that's as far as the Algorithm goes), then the other two fields afterwards. The speedup you get might be minor, or it might be spectacular; it is hard to predict. But... * It is not wise to build an index with lots of columns. Let's cut it off at 5 (Rule of Thumb). * Prefix indexes cannot 'cover', so don't use them anywhere in a 'covering' index. * There are limits (3KB?) on how 'wide' an index can be, so "covering" may not be possible. Redundant/excessive indexes --------------------------- INDEX(a,b) can find anything that INDEX(a) could find. So you don't need both. Get rid of the shorter one. If you have lots of SELECTs and they generate lots of INDEXes, this may cause a different problem. Each index must be updated (sooner or later) for each INSERT. More indexes ⇒ slower INSERTs. Limit the number of indexes on a table to about 6 (Rule of Thumb). Notice in the cookbook how it says "in any order" in a few places. If, for example, you have both of these (in different SELECTs): * `WHERE a=1 AND b=2` begs for either INDEX(a,b) or INDEX(b,a) * `WHERE a>1 AND b=2` begs only for INDEX(b,a) Include only INDEX(b,a) since it handles both cases with only one INDEX. Suppose you have a lot of indexes, including (a,b,c,dd) and (a,b,c,ee). Those are getting rather long. Consider either picking one of them, or having simply (a,b,c). Sometimes the selectivity of (a,b,c) is so good that tacking on 'dd' or 'ee' does make enough difference to matter. Optimizer picks ORDER BY ------------------------ The main cookbook skips over an important optimization that is sometimes used. The optimizer will sometimes ignore the WHERE and, instead, use an INDEX that matches the ORDER BY. This, of course, needs to be a perfect match -- all columns, in the same order. And all ASC or all DESC. This becomes especially beneficial if there is a LIMIT. But there is a problem. There could be two situations, and the Optimizer is sometimes not smart enough to see which case applies: * If the WHERE does very little filtering, fetching the rows in ORDER BY order avoids a sort and has little wasted effort (because of 'little filtering'). Using the INDEX matching the ORDER BY is better in this case. * If the WHERE does a lot of filtering, the ORDER BY is wasting a lot of time fetching rows only to filter them out. Using an INDEX matching the WHERE clause is better. What should you do? If you think the "little filtering" is likely, then create an index with the ORDER BY columns in order and hope that the Optimizer uses it when it should. OR -- Cases... * `WHERE a=1 OR a=2` -- This is turned into WHERE a IN (1,2) and optimized that way. * `WHERE a=1 OR b=2` usually cannot be optimized. * `WHERE x.a=1 OR y.b=2` This is even worse because of using two different tables. A workaround is to use UNION. Each part of the UNION is optimized separately. For the second case: ``` ( SELECT ... WHERE a=1 ) -- and have INDEX(a) UNION DISTINCT -- "DISTINCT" is assuming you need to get rid of dups ( SELECT ... WHERE b=2 ) -- and have INDEX(b) GROUP BY ... ORDER BY ... -- whatever you had at the end of the original query ``` Now the query can take good advantage of two different indexes. Note: "Index merge" might kick in on the original query, but it is not necessarily any faster than the UNION. Sister blog on compound indexes, including 'Index Merge' The third case (OR across 2 tables) is similar to the second. If you originally had a LIMIT, UNION gets complicated. If you started with ORDER BY z LIMIT 190, 10, then the UNION needs to be ``` ( SELECT ... LIMIT 200 ) -- Note: OFFSET 0, LIMIT 190+10 UNION DISTINCT -- (or ALL) ( SELECT ... LIMIT 200 ) LIMIT 190, 10 -- Same as originally ``` TEXT / BLOB ----------- You cannot directly index a TEXT or BLOB or large VARCHAR or large BINARY column. However, you can use a "prefix" index: INDEX(foo(20)). This says to index the first 20 characters of `foo`. But... It is rarely useful. Example of a prefix index: ``` INDEX(last_name(2), first_name) ``` The index for me would contain 'Ja', 'Rick'. That's not useful for distinguishing between 'Jamison', 'Jackson', 'James', etc., so the index is so close to useless that the optimizer often ignores it. Probably never do UNIQUE(foo(20)) because this applies a uniqueness constraint on the first 20 characters of the column, not the whole column! [More on prefix indexing](http://dev.mysql.com/doc/refman/5.6/en/create-index.html) Dates ----- DATE, DATETIME, etc. are tricky to compare against. Some tempting, but inefficient, techniques: `date_col LIKE '2016-01%'` -- must convert date\_col to a string, so acts like a function `LEFT(date_col, 4) = '2016-01'` -- hiding the column in function `DATE(date_col) = 2016` -- hiding the column in function All must do a full scan. (On the other hand, it can handy to use GROUP BY LEFT(date\_col, 7) for monthly grouping, but that is not an INDEX issue.) This is efficient, and can use an index: ``` date_col >= '2016-01-01' AND date_col < '2016-01-01' + INTERVAL 3 MONTH ``` This case works because both right-hand values are converted to constants, then it is a "range". I like the design pattern with INTERVAL because it avoids computing the last day of the month. And it avoids tacking on '23:59:59', which is wrong if you have microsecond times. (And other cases.) EXPLAIN Key\_len ---------------- Perform EXPLAIN SELECT... (and EXPLAIN FORMAT=JSON SELECT... if you have 5.6.5). Look at the Key that it chose, and the Key\_len. From those you can deduce how many columns of the index are being used for filtering. (JSON makes it easier to get the answer.) From that you can decide whether it is using as much of the INDEX as you thought. Caveat: Key\_len only covers the WHERE part of the action; the non-JSON output won't easily say whether GROUP BY or ORDER BY was handled by the index. IN -- `IN (1,99,3)` is sometimes optimized as efficiently as "=", but not always. Older versions of MySQL did not optimize it as well as newer versions. (5.6 is possibly the main turning point.) IN ( SELECT ... ) From version 4.1 through 5.5, IN ( SELECT ... ) was very poorly optimized. The SELECT was effectively re-evaluated every time. Often it can be transformed into a JOIN, which works much faster. Heres is a pattern to follow: ``` SELECT ... FROM a WHERE test_a AND x IN ( SELECT x FROM b WHERE test_b ); ⇒ SELECT ... FROM a JOIN b USING(x) WHERE test_a AND test_b; ``` The SELECT expressions will need "a." prefixing the column names. Alas, there are cases where the pattern is hard to follow. 5.6 does some optimizing, but probably not as good as the JOIN. If there is a JOIN or GROUP BY or ORDER BY LIMIT in the subquery, that complicates the JOIN in new format. So, it might be better to use this pattern: ``` SELECT ... FROM a WHERE test_a AND x IN ( SELECT x FROM ... ); ⇒ SELECT ... FROM a JOIN ( SELECT x FROM ... ) b USING(x) WHERE test_a; ``` Caveat: If you end up with two subqueries JOINed together, note that neither has any indexes, hence performance can be very bad. (5.6 improves on it by dynamically creating indexes for subqueries.) There is work going on in MariaDB and Oracle 5.7, in relation to "NOT IN", "NOT EXISTS", and "LEFT JOIN..IS NULL"; here is an old discussion on the topic So, what I say here may not be the final word. Explode/Implode --------------- When you have a JOIN and a GROUP BY, you may have the situation where the JOIN exploded more rows than the original query (due to many:many), but you wanted only one row from the original table, so you added the GROUP BY to implode back to the desired set of rows. This explode + implode, itself, is costly. It would be better to avoid them if possible. Sometimes the following will work. Using DISTINCT or GROUP BY to counteract the explosion ``` SELECT DISTINCT a.*, b.y FROM a JOIN b ⇒ SELECT a.*, ( SELECT GROUP_CONCAT(b.y) FROM b WHERE b.x = a.x ) AS ys FROM a ``` When using second table just to check for existence: ``` SELECT a.* FROM a JOIN b ON b.x = a.x GROUP BY a.id ⇒ SELECT a.*, FROM a WHERE EXISTS ( SELECT * FROM b WHERE b.x = a.x ) ``` [Another variant](http://dba.stackexchange.com/questions/115059/mysql-query-causing-high-cpu-and-taking-forever-to-execute/115120#115120) Many-to-many mapping table -------------------------- Do it this way. ``` CREATE TABLE XtoY ( # No surrogate id for this table x_id MEDIUMINT UNSIGNED NOT NULL, -- For JOINing to one table y_id MEDIUMINT UNSIGNED NOT NULL, -- For JOINing to the other table # Include other fields specific to the 'relation' PRIMARY KEY(x_id, y_id), -- When starting with X INDEX (y_id, x_id) -- When starting with Y ) ENGINE=InnoDB; ``` Notes: * Lack of an AUTO\_INCREMENT id for this table -- The PK given is the 'natural' PK; there is no good reason for a surrogate. * "MEDIUMINT" -- This is a reminder that all INTs should be made as small as is safe (smaller ⇒ faster). Of course the declaration here must match the definition in the table being linked to. * "UNSIGNED" -- Nearly all INTs may as well be declared non-negative * "NOT NULL" -- Well, that's true, isn't it? * "InnoDB" -- More effecient than MyISAM because of the way the PRIMARY KEY is clustered with the data in InnoDB. * "INDEX(y\_id, x\_id)" -- The PRIMARY KEY makes it efficient to go one direction; this index makes the other direction efficient. No need to say UNIQUE; that would be extra effort on INSERTs. * In the secondary index, saying justINDEX(y\_id) would work because it would implicit include x\_id. But I would rather make it more obvious that I am hoping for a 'covering' index. To conditionally INSERT new links, use [IODKU](http://dev.mysql.com/doc/refman/5.6/en/insert-on-duplicate.html) Note that if you had an AUTO\_INCREMENT in this table, IODKU would "burn" ids quite rapidly. Subqueries and UNIONs --------------------- Each subquery SELECT and each SELECT in a UNION can be considered separately for finding the optimal INDEX. Exception: In a "correlated" ("dependent") subquery, the part of the WHERE that depends on the outside table is not easily factored into the INDEX generation. (Cop out!) JOINs ----- The first step is to decide what order the optimizer will go through the tables. If you cannot figure it out, then you may need to be pessimistic and create two indexes for each table -- one assuming the table will be used first, one assiming that it will come later in the table order. The optimizer usually starts with one table and extracts the data needed from it. As it finds a useful (that is, matches the WHERE clause, if any) row, it reaches into the 'next' table. This is called NLJ ("Nested Loop Join"). The process of filtering and reaching to the next table continues through the rest of the tables. The optimizer usually picks the "first" table based on these hints: * STRAIGHT\_JOIN forces the the table order. * The WHERE clause limits which rows needed (whether indexed or not). * The table to the "left" in a LEFT JOIN usually comes before the "right" table. (By looking at the table definitions, the optimizer may decide that "LEFT" is irrelevant.) * The current INDEXes will encourage an order. * etc. Running EXPLAIN tells you the table order that the Optimizer is very likely to use today. After adding a new INDEX, the optimizer may pick a different table order. You should anticipate the order changing, guess at what order makes the most sense, and build the INDEXes accordingly. Then rerun EXPLAIN to see if the Optimizer's brain was on the same wavelength you were on. You should build the INDEX for the "first" table based on any parts of the WHERE, GROUP BY, and ORDER BY clauses that are relevant to it. If a GROUP/ORDER BY mentions a different table, you should ignore that clause. The second (and subsequent) table will be reached into based on the ON clause. (Instead of using commajoin, please write JOINs with the JOIN keyword and ON clause!) In addition, there could be parts of the WHERE clause that are relevant. GROUP/ORDER BY are not to be considered in writing the optimal INDEX for subsequent tables. PARTITIONing ------------ PARTITIONing is rarely a substitute for a good INDEX. PARTITION BY RANGE is a technique that is sometimes useful when indexing fails to be good enough. In a two-dimensional situation such as nearness in a geographical sense, one dimension can partially be handled by partition pruning; then the other dimension can be handled by a regular index (preferrably the PRIMARY KEY). This goes into more detail: [Find nearest 10 pizza parlors](../mariadb/partition-maintenance/index). FULLTEXT -------- FULLTEXT is now implemented in InnoDB as well as MyISAM. It provides a way to search for "words" in TEXT columns. This is much faster (when it is applicable) than col LIKE '%word%'. ``` WHERE x = 1 AND MATCH (...) AGAINST (...) ``` always(?) uses the FULLTEXT index first. That is, the whole Algorithm is invalidated when one of the ANDs is a MATCH. Signs of a Newbie ----------------- * No "compound" (aka "composite") indexes * No PRIMARY KEY * Redundant indexes (especially blatant is PRIMARY KEY(id), KEY(id)) * Most or all columns individually indexes ("But I indexed everything") * "Commajoin" -- That is `FROM a, b WHERE a.x=b.x` instead of `FROM a JOIN b ON a.x=b.x` Speeding up wp\_postmeta ------------------------ The published table (see Wikipedia) is ``` CREATE TABLE wp_postmeta ( meta_id bigint(20) unsigned NOT NULL AUTO_INCREMENT, post_id bigint(20) unsigned NOT NULL DEFAULT '0', meta_key varchar(255) DEFAULT NULL, meta_value longtext, PRIMARY KEY (meta_id), KEY post_id (post_id), KEY meta_key (meta_key) ) ENGINE=InnoDB DEFAULT CHARSET=utf8; ``` The problems: * The AUTO\_INCREMENT provides no benefit; in fact it slows down most queries and clutters disk. * Much better is PRIMARY KEY(post\_id, meta\_key) -- clustered, handles both parts of usual JOIN. * BIGINT is overkill, but that can't be fixed without changing other tables. * VARCHAR(255) can be a problem in 5.6 with utf8mb4; see workarounds below. * When would `meta\_key` or `meta\_value` ever be NULL? The solutions: ``` CREATE TABLE wp_postmeta ( post_id BIGINT UNSIGNED NOT NULL, meta_key VARCHAR(255) NOT NULL, meta_value LONGTEXT NOT NULL, PRIMARY KEY(post_id, meta_key), INDEX(meta_key) ) ENGINE=InnoDB; ``` Postlog ------- Initial posting: March, 2015; Refreshed Feb, 2016; Add DATE June, 2016; Add WP example May, 2017. The tips in this document apply to MySQL, MariaDB, and Percona. See also -------- * [Percona 2015 Tutorial Slides](http://mysql.rjweb.org/slides/IndexCookbook.pdf) * Some info in the MySQL manual: [ORDER BY Optimization](http://dev.mysql.com/doc/refman/5.6/en/order-by-optimization.html) * A short, but complicated, [example](http://stackoverflow.com/questions/28974572/mysql-index-for-order-by-with-date-range-in-where) * [MySQL manual page on range accesses in composite indexes](http://dev.mysql.com/doc/refman/5.7/en/range-optimization.html#range-access-multi-part) * [Some discussion of JOIN](http://dba.stackexchange.com/questions/120551/very-slow-query-not-sure-if-mysql-index-is-being-used) * [Indexing 101: Optimizing MySQL queries on a single table](https://www.percona.com/blog/2015/04/27/indexing-101-optimizing-mysql-queries-on-a-single-table/) (Stephane Combaudon - Percona) * [A complex query, well explained.](http://stackoverflow.com/a/37024870/1766831) This blog is the consolidation of a Percona tutorial I gave in 2013, plus many years of experience in fixing thousands of slow queries on hundreds of systems. I apologize that this does not tell you how create INDEXes for all SELECTs. Some are just too complex. Rick James graciously allowed us to use this article in the Knowledge Base. [Rick James' site](http://mysql.rjweb.org/) has other useful tips, how-tos, optimizations, and debugging tips. Original source: <http://mysql.rjweb.org/doc.php/random> Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb Thread Pool System and Status Variables Thread Pool System and Status Variables ======================================= This article describes the system and status variables used by the MariaDB thread pool. For a full description, see [Thread Pool in MariaDB](../thread-pool-in-mariadb/index). System variables ---------------- #### `extra_max_connections` * **Description:** The number of connections on the `[extra\_port](#extra_port)`. + See [Thread Pool in MariaDB: Configuring the Extra Port](../thread-pool-in-mariadb/index#configuring-the-extra-port) for more information. * **Commandline:** `--extra-max-connections=#` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `1` * **Range:** `1` to `100000` --- #### `extra_port` * **Description:** Extra port number to use for TCP connections in a `one-thread-per-connection` manner. If set to `0`, then no extra port is used. + See [Thread Pool in MariaDB: Configuring the Extra Port](../thread-pool-in-mariadb/index#configuring-the-extra-port) for more information. * **Commandline:** `--extra-port=#` * **Scope:** Global * **Dynamic:** No * **Data Type:** `numeric` * **Default Value:** `0` --- #### `thread_handling` * **Description:** Determines how the server handles threads for client connections. In addition to threads for client connections, this also applies to certain internal server threads, such as [Galera slave threads](../about-galera-replication/index#galera-slave-threads). + When the default `one-thread-per-connection` mode is enabled, the server uses one thread to handle each client connection. + When the `pool-of-threads` mode is enabled, the server uses the [thread pool](../thread-pool-in-mariadb/index) for client connections. + When the `no-threads` mode is enabled, the server uses a single thread for all client connections, which is really only usable for debugging. * **Commandline:** `--thread-handling=name` * **Scope:** Global * **Dynamic:** No * **Data Type:** `enumeration` * **Default Value:** `one-thread-per-connection` * **Valid Values:** `no-threads`, `one-thread-per-connection`, `pool-of-threads`. * **Documentation:** [Using the thread pool](../thread-pool-in-mariadb/index). * **Notes:** In MySQL the thread pool is only available in MySQL enterprise 5.5.16 and above. In MariaDB it's available in all versions. --- #### `thread_pool_dedicated_listener` * **Description:** If set to 1, then each group will have its own dedicated listener, and the listener thread will not pick up work items. As a result, the queueing time in the [Information Schema Threadpool\_Queues](../information-schema-threadpool_queues-table/index) and the actual queue size in the [Information Schema Threadpool\_Groups](../information-schema-threadpool_groups-table/index) table will be more exact, since IO requests are immediately dequeued from poll, without delay. + This system variable is only meaningful on **Unix**. * **Commandline:** `thread-pool-dedicated-listener={0|1}` * **Scope:** * **Dynamic:** * **Data Type:** `boolean` * **Default Value:** `0` * **Introduced:** [MariaDB 10.5.0](https://mariadb.com/kb/en/mariadb-1050-release-notes/) --- #### `thread_pool_exact_stats` * **Description:** If set to 1, provides better queueing time statistics by using a high precision timestamp, at a small performance cost, for the time when the connection was added to the queue. This timestamp helps calculate the queuing time shown in the [Information Schema Threadpool\_Queues](../information-schema-threadpool_queues-table/index) table. + This system variable is only meaningful on **Unix**. * **Commandline:** `thread-pool-exact-stats={0|1}` * **Scope:** * **Dynamic:** * **Data Type:** `boolean` * **Default Value:** `0` * **Introduced:** [MariaDB 10.5.0](https://mariadb.com/kb/en/mariadb-1050-release-notes/) --- #### `thread_pool_idle_timeout` * **Description:** The number of seconds before an idle worker thread exits. The default value is `60`. If there is currently no work to do, how long should an idle thread wait before exiting? + This system variable is only meaningful on **Unix**. + The `[thread\_pool\_min\_threads](#thread_pool_min_threads)` system variable is comparable for Windows. * **Commandline:** `thread-pool-idle-timeout=#` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `60` * **Documentation:** [Using the thread pool](../thread-pool-in-mariadb/index). --- #### `thread_pool_max_threads` * **Description:** The maximum number of threads in the [thread pool](../thread-pool-in-mariadb/index). Once this limit is reached, no new threads will be created in most cases. + On Unix, in rare cases, the actual number of threads can slightly exceed this, because each [thread group](../thread-groups-in-the-unix-implementation-of-the-thread-pool/index) needs at least two threads (i.e. at least one worker thread and at least one listener thread) to prevent deadlocks. * **Scope:** * **Commandline:** `thread-pool-max-threads=#` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** + `65536` (>= [MariaDB 10.2.4](https://mariadb.com/kb/en/mariadb-1024-release-notes/)) + `1000` (<= [MariaDB 10.2.3](https://mariadb.com/kb/en/mariadb-1023-release-notes/), >= [MariaDB 10.1](../what-is-mariadb-101/index)) + `500` (<= [MariaDB 10.0](../what-is-mariadb-100/index)) * **Range:** `1` to `65536` * **Documentation:** [Using the thread pool](../thread-pool-in-mariadb/index). --- #### `thread_pool_min_threads` * **Description:** Minimum number of threads in the [thread pool](../thread-pool-in-mariadb/index). In bursty environments, after a period of inactivity, threads would normally be retired. When the next burst arrives, it would take time to reach the optimal level. Setting this value higher than the default would prevent thread retirement even if inactive. + This system variable is only meaningful on **Windows**. + The `[thread\_pool\_idle\_timeout](#thread_pool_idle_timeout)` system variable is comparable for Unix. * **Commandline:** `thread-pool-min-threads=#` * **Data Type:** `numeric` * **Default Value:** `1` * **Documentation:** [Using the thread pool](../thread-pool-in-mariadb/index). --- #### `thread_pool_oversubscribe` * **Description:** Determines how many worker threads in a thread group can remain active at the same time once a thread group is oversubscribed due to stalls. The default value is `3`. Usually, a thread group only has one active worker thread at a time. However, the timer thread can add more active worker threads to a thread group if it detects a stall. There are trade-offs to consider when deciding whether to allow **only one** thread per CPU to run at a time, or whether to allow **more than one** thread per CPU to run at a time. Allowing only one thread per CPU means that the thread can have unrestricted access to the CPU while its running, but it also means that there is additional overhead from putting threads to sleep or waking them up more frequently. Allowing more than one thread per CPU means that the threads have to share the CPU, but it also means that there is less overhead from putting threads to sleep or waking them up. + See [Thread Groups in the Unix Implementation of the Thread Pool: Thread Group Oversubscription](../thread-groups-in-the-unix-implementation-of-the-thread-pool/index#thread-group-oversubscription) for more information. + This is primarily for **internal** use, and it is **not** meant to be changed for most users. + This system variable is only meaningful on **Unix**. * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `3` * **Range:** `1` to `65536` * **Documentation:** [Using the thread pool](../thread-pool-in-mariadb/index). --- #### `thread_pool_prio_kickup_timer` * **Description:** Time in milliseconds before a dequeued low-priority statement is moved to the high-priority queue. + This system variable is only meaningful on **Unix**. * **Commandline:** `thread-pool-kickup-timer=#` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `1000` * **Range:** `0` to `4294967295` * **Introduced:** [MariaDB 10.2.2](https://mariadb.com/kb/en/mariadb-1022-release-notes/) * **Documentation:** [Using the thread pool](../thread-pool-in-mariadb/index). --- #### `thread_pool_priority` * **Description:** [Thread pool](../thread-pool-in-mariadb/index) priority. High-priority connections usually start executing earlier than low-priority. If set to 'auto' (the default), the actual priority (low or high) is determined by whether or not the connection is inside a transaction. * **Commandline:** `--thread-pool-priority=#` * **Scope:** Global,Connection * **Data Type:** `enum` * **Default Value:** `auto` * **Valid Values:** `high`, `low`, `auto`. * **Introduced:** [MariaDB 10.2.2](https://mariadb.com/kb/en/mariadb-1022-release-notes/) * **Documentation:** [Using the thread pool](../thread-pool-in-mariadb/index). --- #### `thread_pool_size` * **Description:** The number of [thread groups](../thread-groups-in-the-unix-implementation-of-the-thread-pool/index) in the [thread pool](../thread-pool-in-mariadb/index), which determines how many statements can execute simultaneously. The default value is the number of CPUs on the system. When setting this system variable's value at system startup, the max value is 100000. However, it is not a good idea to set it that high. When setting this system variable's value dynamically, the max value is either 128 or the value that was set at system startup--whichever value is higher. + See [Thread Groups in the Unix Implementation of the Thread Pool](../thread-groups-in-the-unix-implementation-of-the-thread-pool/index) for more information. + This system variable is only meaningful on **Unix**. * **Commandline:** `--thread-pool-size=#` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** Based on the number of processors (but see [MDEV-7806](https://jira.mariadb.org/browse/MDEV-7806)). * **Range:** `1` to `128` (< [MariaDB 5.5.37](https://mariadb.com/kb/en/mariadb-5537-release-notes/), [MariaDB 10.0.11](https://mariadb.com/kb/en/mariadb-10011-release-notes/)), `1` to `100000` (>= [MariaDB 5.5.37](https://mariadb.com/kb/en/mariadb-5537-release-notes/), [MariaDB 10.0.11](https://mariadb.com/kb/en/mariadb-10011-release-notes/)) * **Documentation:** [Using the thread pool](../thread-pool-in-mariadb/index). --- #### `thread_pool_stall_limit` * **Description:** The number of milliseconds between each stall check performed by the timer thread. The default value is `500`. Stall detection is used to prevent a single client connection from monopolizing a thread group. When the timer thread detects that a thread group is stalled, it wakes up a sleeping worker thread in the thread group, if one is available. If there isn't one, then it creates a new worker thread in the thread group. This temporarily allows several client connections in the thread group to run in parallel. However, note that the timer thread will not create a new worker thread if the number of threads in the thread pool is already greater than or equal to the maximum defined by the `[thread\_pool\_max\_threads](#thread_pool_max_threads)` variable, unless the thread group does not already have a listener thread. + See [Thread Groups in the Unix Implementation of the Thread Pool: Thread Group Stalls](../thread-groups-in-the-unix-implementation-of-the-thread-pool/index#thread-group-stalls) for more information. + This system variable is only meaningful on **Unix**. + Note that if you are migrating from the MySQL Enterprise thread pool plugin, then the unit used in their implementation is 10ms, not 1ms. * **Commandline:** `--thread-pool-stall-limit=#` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `500` * **Range:** `10` to `4294967295` (< [MariaDB 10.5](../what-is-mariadb-105/index)), `1` to `4294967295` (>= [MariaDB 10.5](../what-is-mariadb-105/index)) * **Documentation:** [Using the thread pool](../thread-pool-in-mariadb/index). --- Status variables ---------------- #### `Threadpool_idle_threads` * **Description:** Number of inactive threads in the [thread pool](../thread-pool-in-mariadb/index). Threads become inactive for various reasons, such as by waiting for new work. However, an inactive thread is not necessarily one that has not been assigned work. Threads are also considered inactive if they are being blocked while waiting on disk I/O, or while waiting on a lock, etc. + This status variable is only meaningful on **Unix**. * **Scope:** Global, Session * **Data Type:** `numeric` --- #### `Threadpool_threads` * **Description:** Number of threads in the [thread pool](../thread-pool-in-mariadb/index). In rare cases, this can be slightly higher than `[thread\_pool\_max\_threads](#thread_pool_max_threads)`, because each thread group needs at least two threads (i.e. at least one worker thread and at least one listener thread) to prevent deadlocks. * **Scope:** Global, Session * **Data Type:** `numeric` --- See Also -------- * [Thread Pool in MariaDB](../thread-pool-in-mariadb/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb SET TRANSACTION SET TRANSACTION =============== Syntax ------ ``` SET [GLOBAL | SESSION] TRANSACTION transaction_property [, transaction_property] ... transaction_property: ISOLATION LEVEL level | READ WRITE | READ ONLY level: REPEATABLE READ | READ COMMITTED | READ UNCOMMITTED | SERIALIZABLE ``` Description ----------- This statement sets the transaction isolation level or the transaction access mode globally, for the current session, or for the next transaction: * With the `GLOBAL` keyword, the statement sets the default transaction level globally for all subsequent sessions. Existing sessions are unaffected. * With the `SESSION` keyword, the statement sets the default transaction level for all subsequent transactions performed within the current session. * Without any `SESSION` or `GLOBAL` keyword, the statement sets the isolation level for the next (not started) transaction performed within the current session. A change to the global default isolation level requires the `[SUPER](../grant/index)` privilege. Any session is free to change its session isolation level (even in the middle of a transaction), or the isolation level for its next transaction. ### Isolation Level To set the global default isolation level at server startup, use the `[--transaction-isolation=level](../server-system-variables/index#tx_isolation)` option on the command line or in an option file. Values of level for this option use dashes rather than spaces, so the allowable values are `READ-UNCOMMITTED`, `READ-COMMITTED`, `REPEATABLE-READ`, or `SERIALIZABLE`. For example, to set the default isolation level to `REPEATABLE READ`, use these lines in the `[mysqld]` section of an option file: ``` [mysqld] transaction-isolation = REPEATABLE-READ ``` To determine the global and session transaction isolation levels at runtime, check the value of the `[tx\_isolation](../server-system-variables/index#tx_isolation)` system variable: ``` SELECT @@GLOBAL.tx_isolation, @@tx_isolation; ``` InnoDB supports each of the translation isolation levels described here using different locking strategies. The default level is `REPEATABLE READ`. For additional information about InnoDB record-level locks and how it uses them to execute various types of statements, see [InnoDB Lock Modes](../innodb-lock-modes/index), and <http://dev.mysql.com/doc/refman/en/innodb-locks-set.html>. ### Isolation Levels The following sections describe how MariaDB supports the different transaction levels. #### READ UNCOMMITTED `SELECT` statements are performed in a non-locking fashion, but a possible earlier version of a row might be used. Thus, using this isolation level, such reads are not consistent. This is also called a "dirty read." Otherwise, this isolation level works like `READ COMMITTED`. #### READ COMMITTED A somewhat Oracle-like isolation level with respect to consistent (non-locking) reads: Each consistent read, even within the same transaction, sets and reads its own fresh snapshot. See <http://dev.mysql.com/doc/refman/en/innodb-consistent-read.html>. For locking reads (`SELECT` with `FOR UPDATE` or `LOCK IN SHARE MODE`), InnoDB locks only index records, not the gaps before them, and thus allows the free insertion of new records next to locked records. For `UPDATE` and `DELETE` statements, locking depends on whether the statement uses a unique index with a unique search condition (such as `WHERE id = 100`), or a range-type search condition (such as `WHERE id > 100`). For a unique index with a unique search condition, InnoDB locks only the index record found, not the gap before it. For range-type searches, InnoDB locks the index range scanned, using gap locks or next-key (gap plus index-record) locks to block insertions by other sessions into the gaps covered by the range. This is necessary because "phantom rows" must be blocked for MySQL replication and recovery to work. **Note:** If the `READ COMMITTED` isolation level is used or the [innodb\_locks\_unsafe\_for\_binlog](../innodb-system-variables/index#innodb_locks_unsafe_for_binlog) system variable is enabled, there is no InnoDB gap locking except for [foreign-key](../foreign-keys/index) constraint checking and duplicate-key checking. Also, record locks for non-matching rows are released after MariaDB has evaluated the `WHERE` condition.If you use `READ COMMITTED` or enable innodb\_locks\_unsafe\_for\_binlog, you must use row-based binary logging. #### REPEATABLE READ This is the default isolation level for InnoDB. For consistent reads, there is an important difference from the `READ COMMITTED` isolation level: All consistent reads within the same transaction read the snapshot established by the first read. This convention means that if you issue several plain (non-locking) `SELECT` statements within the same transaction, these `SELECT` statements are consistent also with respect to each other. See <http://dev.mysql.com/doc/refman/en/innodb-consistent-read.html>. For locking reads (SELECT with FOR UPDATE or LOCK IN SHARE MODE), UPDATE, and DELETE statements, locking depends on whether the statement uses a unique index with a unique search condition, or a range-type search condition. For a unique index with a unique search condition, InnoDB locks only the index record found, not the gap before it. For other search conditions, InnoDB locks the index range scanned, using gap locks or next-key (gap plus index-record) locks to block insertions by other sessions into the gaps covered by the range. This is the minimum isolation level for non-distributed [XA transactions](../xa-transactions/index). #### SERIALIZABLE This level is like REPEATABLE READ, but InnoDB implicitly converts all plain SELECT statements to `[SELECT ... LOCK IN SHARE MODE](../select/index#lock-in-share-mode-and-for-update-clauses)` if `[autocommit](../server-system-variables/index#autocommit)` is disabled. If autocommit is enabled, the SELECT is its own transaction. It therefore is known to be read only and can be serialized if performed as a consistent (non-locking) read and need not block for other transactions. (This means that to force a plain SELECT to block if other transactions have modified the selected rows, you should disable autocommit.) Distributed [XA transactions](../xa-transactions/index) should always use this isolation level. ### Access Mode The access mode specifies whether the transaction is allowed to write data or not. By default, transactions are in `READ WRITE` mode (see the [tx\_read\_only](../server-system-variables/index#tx_read_only) system variable). `READ ONLY` mode allows the storage engine to apply optimizations that cannot be used for transactions which write data. The only exception to this rule is that read only transactions can perform DDL statements on temporary tables. It is not permitted to specify both `READ WRITE` and `READ ONLY` in the same statement. `READ WRITE` and `READ ONLY` can also be specified in the `[START TRANSACTION](../start-transaction/index)` statement, in which case the specified mode is only valid for one transaction. Examples -------- ``` SET GLOBAL TRANSACTION ISOLATION LEVEL SERIALIZABLE; ``` Attempting to set the isolation level within an existing transaction without specifying `GLOBAL` or `SESSION`. ``` START TRANSACTION; SET TRANSACTION ISOLATION LEVEL SERIALIZABLE; ERROR 1568 (25001): Transaction characteristics can't be changed while a transaction is in progress ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb DECODE DECODE ====== Syntax ------ ``` DECODE(crypt_str,pass_str) ``` In [Oracle mode](../sql_modeoracle/index) from [MariaDB 10.3.2](https://mariadb.com/kb/en/mariadb-1032-release-notes/): ``` DECODE(expr, search_expr, result_expr [, search_expr2, result_expr2 ...] [default_expr]) ``` In all modes from [MariaDB 10.3.2](https://mariadb.com/kb/en/mariadb-1032-release-notes/): ``` DECODE_ORACLE(expr, search_expr, result_expr [, search_expr2, result_expr2 ...] [default_expr]) ``` Description ----------- In the default mode, `DECODE` decrypts the encrypted string *crypt\_str* using *pass\_str* as the password. *crypt\_str* should be a string returned from [ENCODE()](../encode/index). The resulting string will be the original string only if *pass\_str* is the same. In [Oracle mode](../sql_modeoracle/index) from [MariaDB 10.3.2](https://mariadb.com/kb/en/mariadb-1032-release-notes/), `DECODE` compares *expr* to the search expressions, in order. If it finds a match, the corresponding result expression is returned. If no matches are found, the default expression is returned, or NULL if no default is provided. NULLs are treated as equivalent. `DECODE_ORACLE` is a synonym for the Oracle-mode version of the function, and is available in all modes. Examples -------- From [MariaDB 10.3.2](https://mariadb.com/kb/en/mariadb-1032-release-notes/): ``` SELECT DECODE_ORACLE(2+1,3*1,'found1',3*2,'found2','default'); +--------------------------------------------------------+ | DECODE_ORACLE(2+1,3*1,'found1',3*2,'found2','default') | +--------------------------------------------------------+ | found1 | +--------------------------------------------------------+ SELECT DECODE_ORACLE(2+4,3*1,'found1',3*2,'found2','default'); +--------------------------------------------------------+ | DECODE_ORACLE(2+4,3*1,'found1',3*2,'found2','default') | +--------------------------------------------------------+ | found2 | +--------------------------------------------------------+ SELECT DECODE_ORACLE(2+2,3*1,'found1',3*2,'found2','default'); +--------------------------------------------------------+ | DECODE_ORACLE(2+2,3*1,'found1',3*2,'found2','default') | +--------------------------------------------------------+ | default | +--------------------------------------------------------+ ``` Nulls are treated as equivalent: ``` SELECT DECODE_ORACLE(NULL,NULL,'Nulls are equivalent','Nulls are not equivalent'); +----------------------------------------------------------------------------+ | DECODE_ORACLE(NULL,NULL,'Nulls are equivalent','Nulls are not equivalent') | +----------------------------------------------------------------------------+ | Nulls are equivalent | +----------------------------------------------------------------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb MariaDB ColumnStore Backup and Restore MariaDB ColumnStore Backup and Restore ======================================= | Title | Description | | --- | --- | | [Backup and Restore for MariaDB ColumnStore 1.0.x](../backup-and-restore-for-mariadb-columnstore-10x/index) | Backup/Restore Process for MariaDB ColumnStore 1.0.x Backup Overview The h... | | [Backup and Restore for MariaDB ColumnStore 1.1.0 onwards](../backup-and-restore-for-mariadb-columnstore-110-onwards/index) | Backup and Restore package The Backup and Restore is part of the MariaDB C... | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb HandlerSocket Client Libraries HandlerSocket Client Libraries ============================== In order to make use of the [HandlerSocket](../handlersocket/index) plugin in your applications, you will need to use the appropriate client library. The following client libraries are available: * C++ + [libhsclient](https://github.com/ahiguti/HandlerSocket-Plugin-for-MySQL) *(included with the HandlerSocket plugin source)* * Perl + [perl-Net-HandlerSocket](https://github.com/ahiguti/HandlerSocket-Plugin-for-MySQL) *(included with the HandlerSocket plugin source)* * PHP + [Net\_HandlerSocket](https://github.com/openpear/Net_HandlerSocket) + [HSPHP](http://github.com/tz-lom/HSPHP) + [php-ext-handlersocketi](https://github.com/kjdev/php-ext-handlersocketi) * Java + [hs4j](http://code.google.com/p/hs4j/) + [handlersocketforjava](http://code.google.com/p/handlersocketforjava/) * Python + [python-handler-socket](http://pypi.python.org/pypi/python-handler-socket) + [pyhandlersocket](https://code.launchpad.net/~songofacandy/+junk/pyhandlersocket) * Ruby + [ruby-handlersocket](https://github.com/winebarrel/ruby-handlersocket) + [handlersocket](https://github.com/miyucy/handlersocket) * JavaScript + [node-handlersocket](https://github.com/koichik/node-handlersocket) * Scala + [hs2client](https://github.com/fujohnwang/hs2client) * Haskell + <https://github.com/wuxb45/HandlerSocket-Haskell-Client> Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb InnoDB Online DDL Operations with the INPLACE Alter Algorithm InnoDB Online DDL Operations with the INPLACE Alter Algorithm ============================================================= Supported Operations by Inheritance ----------------------------------- When the [ALGORITHM](../alter-table/index#algorithm) clause is set to `INPLACE`, the supported operations are a superset of the operations that are supported when the [ALGORITHM](../alter-table/index#algorithm) clause is set to `NOCOPY`. Similarly, when the [ALGORITHM](../alter-table/index#algorithm) clause is set to `NOCOPY`, the supported operations are a superset of the operations that are supported when the [ALGORITHM](../alter-table/index#algorithm) clause is set to `INSTANT`. Therefore, when the [ALGORITHM](../alter-table/index#algorithm) clause is set to `INPLACE`, some operations are supported by inheritance. See the following additional pages for more information about these supported operations: * [InnoDB Online DDL Operations with ALGORITHM=NOCOPY](../innodb-online-ddl-operations-with-algorithmnocopy/index) * [InnoDB Online DDL Operations with ALGORITHM=INSTANT](../innodb-online-ddl-operations-with-algorithminstant/index) Column Operations ----------------- ### `ALTER TABLE ... ADD COLUMN` InnoDB supports adding columns to a table with [ALGORITHM](../alter-table/index#algorithm) set to `INPLACE`. The table is rebuilt, which means that all of the data is reorganized substantially, and the indexes are rebuilt. As a result, the operation is quite expensive. With the exception of adding an [auto-increment](../auto_increment/index) column, this operation supports the non-locking strategy. This strategy can be explicitly chosen by setting the [LOCK](../alter-table/index#lock) clause to `NONE`. When this strategy is used, all concurrent DML is permitted. For example: ``` CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50) ); SET SESSION alter_algorithm='INPLACE'; ALTER TABLE tab ADD COLUMN c varchar(50); Query OK, 0 rows affected (0.006 sec) ``` This applies to [ALTER TABLE ... ADD COLUMN](../alter-table/index#add-column) for [InnoDB](../innodb/index) tables. ### `ALTER TABLE ... DROP COLUMN` InnoDB supports dropping columns from a table with [ALGORITHM](../alter-table/index#algorithm) set to `INPLACE`. The table is rebuilt, which means that all of the data is reorganized substantially, and the indexes are rebuilt. As a result, the operation is quite expensive. This operation supports the non-locking strategy. This strategy can be explicitly chosen by setting the [LOCK](../alter-table/index#lock) clause to `NONE`. When this strategy is used, all concurrent DML is permitted. For example: ``` CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50), c varchar(50) ); SET SESSION alter_algorithm='INPLACE'; ALTER TABLE tab DROP COLUMN c; Query OK, 0 rows affected (0.021 sec) ``` This applies to [ALTER TABLE ... DROP COLUMN](../alter-table/index#drop-column) for [InnoDB](../innodb/index) tables. ### `ALTER TABLE ... MODIFY COLUMN` This applies to [ALTER TABLE ... MODIFY COLUMN](../alter-table/index#modify-column) for [InnoDB](../innodb/index) tables. #### Reordering Columns InnoDB supports reordering columns within a table with [ALGORITHM](../alter-table/index#algorithm) set to `INPLACE`. The table is rebuilt, which means that all of the data is reorganized substantially, and the indexes are rebuilt. As a result, the operation is quite expensive. This operation supports the non-locking strategy. This strategy can be explicitly chosen by setting the [LOCK](../alter-table/index#lock) clause to `NONE`. When this strategy is used, all concurrent DML is permitted. For example: ``` CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50), c varchar(50) ); SET SESSION alter_algorithm='INPLACE'; ALTER TABLE tab MODIFY COLUMN c varchar(50) AFTER a; Query OK, 0 rows affected (0.022 sec) ``` #### Changing the Data Type of a Column InnoDB does **not** support modifying a column's data type with [ALGORITHM](../alter-table/index#algorithm) set to `INPLACE` in most cases. There are some exceptions: * In [MariaDB 10.2.2](https://mariadb.com/kb/en/mariadb-1022-release-notes/) and later, InnoDB supports increasing the length of `VARCHAR` columns with [ALGORITHM](../alter-table/index#algorithm) set to `INPLACE`, unless it would require changing the number of bytes requires to represent the column's length. A `VARCHAR` column that is between 0 and 255 bytes in size requires 1 byte to represent its length, while a `VARCHAR` column that is 256 bytes or longer requires 2 bytes to represent its length. This means that the length of a column cannot be increased with [ALGORITHM](../alter-table/index#algorithm) set to `INPLACE` if the original length was less than 256 bytes, and the new length is 256 bytes or more. * In [MariaDB 10.4.3](https://mariadb.com/kb/en/mariadb-1043-release-notes/) and later, InnoDB supports increasing the length of `VARCHAR` columns with [ALGORITHM](../alter-table/index#algorithm) set to `INPLACE` in the cases where the operation supports having the [ALGORITHM](../alter-table/index#algorithm) clause set to `INSTANT`. See [InnoDB Online DDL Operations with ALGORITHM=INSTANT: Changing the Data Type of a Column](../innodb-online-ddl-operations-with-algorithminstant/index#changing-the-data-type-of-a-column) for more information. For example, this fails: ``` CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50), c varchar(50) ); SET SESSION alter_algorithm='INPLACE'; ALTER TABLE tab MODIFY COLUMN c int; ERROR 1846 (0A000): ALGORITHM=INPLACE is not supported. Reason: Cannot change column type INPLACE. Try ALGORITHM=COPY ``` But this succeeds in [MariaDB 10.2.2](https://mariadb.com/kb/en/mariadb-1022-release-notes/) and later, because the original length of the column is less than 256 bytes, and the new length is still less than 256 bytes: ``` CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50), c varchar(50) ) CHARACTER SET=latin1; SET SESSION alter_algorithm='INPLACE'; ALTER TABLE tab MODIFY COLUMN c varchar(100); Query OK, 0 rows affected (0.005 sec) ``` But this fails in [MariaDB 10.2.2](https://mariadb.com/kb/en/mariadb-1022-release-notes/) and later, because the original length of the column is less than 256 bytes, and the new length is greater than 256 bytes: ``` CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50), c varchar(255) ) CHARACTER SET=latin1; SET SESSION alter_algorithm='INPLACE'; ALTER TABLE tab MODIFY COLUMN c varchar(256); ERROR 1846 (0A000): ALGORITHM=INPLACE is not supported. Reason: Cannot change column type INPLACE. Try ALGORITHM=COPY ``` #### Changing a Column to NULL InnoDB supports modifying a column to allow [NULL](../create-table/index#null-and-not-null) values with [ALGORITHM](../alter-table/index#algorithm) set to `INPLACE`. The table is rebuilt, which means that all of the data is reorganized substantially, and the indexes are rebuilt. As a result, the operation is quite expensive. This operation supports the non-locking strategy. This strategy can be explicitly chosen by setting the [LOCK](../alter-table/index#lock) clause to `NONE`. When this strategy is used, all concurrent DML is permitted. For example: ``` CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50), c varchar(50) NOT NULL ); SET SESSION alter_algorithm='INPLACE'; ALTER TABLE tab MODIFY COLUMN c varchar(50) NULL; Query OK, 0 rows affected (0.021 sec) ``` #### Changing a Column to NOT NULL InnoDB supports modifying a column to **not** allow [NULL](../create-table/index#null-and-not-null) values with [ALGORITHM](../alter-table/index#algorithm) set to `INPLACE`. It is required for [strict mode](../sql-mode/index#strict-mode) to be enabled in [SQL\_MODE](../sql-mode/index). The operation will fail if the column contains any `NULL` values. Changes that would interfere with referential integrity are also not permitted. The table is rebuilt, which means that all of the data is reorganized substantially, and the indexes are rebuilt. As a result, the operation is quite expensive. This operation supports the non-locking strategy. This strategy can be explicitly chosen by setting the [LOCK](../alter-table/index#lock) clause to `NONE`. When this strategy is used, all concurrent DML is permitted. For example: ``` CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50), c varchar(50) ); SET SESSION alter_algorithm='INPLACE'; ALTER TABLE tab MODIFY COLUMN c varchar(50) NOT NULL; Query OK, 0 rows affected (0.021 sec) ``` #### Adding a New `ENUM` Option InnoDB supports adding a new [ENUM](../enum/index) option to a column with [ALGORITHM](../alter-table/index#algorithm) set to `INPLACE`. In order to add a new [ENUM](../enum/index) option with [ALGORITHM](../alter-table/index#algorithm) set to `INPLACE`, the following requirements must be met: * It must be added to the end of the list. * The storage requirements must not change. This operation only changes the table's metadata, so the table does not have to be rebuilt.. This operation supports the non-locking strategy. This strategy can be explicitly chosen by setting the [LOCK](../alter-table/index#lock) clause to `NONE`. When this strategy is used, all concurrent DML is permitted. For example, this succeeds: ``` CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50), c ENUM('red', 'green') ); SET SESSION alter_algorithm='INPLACE'; ALTER TABLE tab MODIFY COLUMN c ENUM('red', 'green', 'blue'); Query OK, 0 rows affected (0.004 sec) ``` But this fails: ``` CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50), c ENUM('red', 'green') ); SET SESSION alter_algorithm='INPLACE'; ALTER TABLE tab MODIFY COLUMN c ENUM('red', 'blue', 'green'); ERROR 1846 (0A000): ALGORITHM=INPLACE is not supported. Reason: Cannot change column type INPLACE. Try ALGORITHM=COPY ``` #### Adding a New `SET` Option InnoDB supports adding a new [SET](../set-data-type/index) option to a column with [ALGORITHM](../alter-table/index#algorithm) set to `INPLACE`. In order to add a new [SET](../set-data-type/index) option with [ALGORITHM](../alter-table/index#algorithm) set to `INPLACE`, the following requirements must be met: * It must be added to the end of the list. * The storage requirements must not change. This operation only changes the table's metadata, so the table does not have to be rebuilt.. This operation supports the non-locking strategy. This strategy can be explicitly chosen by setting the [LOCK](../alter-table/index#lock) clause to `NONE`. When this strategy is used, all concurrent DML is permitted. For example, this succeeds: ``` CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50), c SET('red', 'green') ); SET SESSION alter_algorithm='INPLACE'; ALTER TABLE tab MODIFY COLUMN c SET('red', 'green', 'blue'); Query OK, 0 rows affected (0.004 sec) ``` But this fails: ``` CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50), c SET('red', 'green') ); SET SESSION alter_algorithm='INPLACE'; ALTER TABLE tab MODIFY COLUMN c SET('red', 'blue', 'green'); ERROR 1846 (0A000): ALGORITHM=INPLACE is not supported. Reason: Cannot change column type INPLACE. Try ALGORITHM=COPY ``` #### Removing System Versioning from a Column In [MariaDB 10.3.8](https://mariadb.com/kb/en/mariadb-1038-release-notes/) and later, InnoDB supports removing [system versioning](../system-versioned-tables/index) from a column with [ALGORITHM](../alter-table/index#algorithm) set to `INPLACE`. In order for this to work, the [system\_versioning\_alter\_history](../system-versioned-tables/index#system_versioning_alter_history) system variable must be set to `KEEP`. See [MDEV-16330](https://jira.mariadb.org/browse/MDEV-16330) for more information. This operation supports the non-locking strategy. This strategy can be explicitly chosen by setting the [LOCK](../alter-table/index#lock) clause to `NONE`. When this strategy is used, all concurrent DML is permitted. For example: ``` CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50), c varchar(50) WITH SYSTEM VERSIONING ); SET SESSION system_versioning_alter_history='KEEP'; SET SESSION alter_algorithm='INPLACE'; ALTER TABLE tab MODIFY COLUMN c varchar(50) WITHOUT SYSTEM VERSIONING; Query OK, 0 rows affected (0.005 sec) ``` ### `ALTER TABLE ... ALTER COLUMN` This applies to [ALTER TABLE ... ALTER COLUMN](../alter-table/index#alter-column) for [InnoDB](../innodb/index) tables. #### Setting a Column's Default Value InnoDB supports modifying a column's [DEFAULT](../create-table/index#default-column-option) value with [ALGORITHM](../alter-table/index#algorithm) set to `INPLACE`. This operation only changes the table's metadata, so the table does not have to be rebuilt. This operation supports the non-locking strategy. This strategy can be explicitly chosen by setting the [LOCK](../alter-table/index#lock) clause to `NONE`. When this strategy is used, all concurrent DML is permitted. For example: ``` CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50), c varchar(50) ); SET SESSION alter_algorithm='INPLACE'; ALTER TABLE tab ALTER COLUMN c SET DEFAULT 'No value explicitly provided.'; Query OK, 0 rows affected (0.005 sec) ``` #### Removing a Column's Default Value InnoDB supports removing a column's [DEFAULT](../create-table/index#default-column-option) value with [ALGORITHM](../alter-table/index#algorithm) set to `INPLACE`. This operation only changes the table's metadata, so the table does not have to be rebuilt. This operation supports the non-locking strategy. This strategy can be explicitly chosen by setting the [LOCK](../alter-table/index#lock) clause to `NONE`. When this strategy is used, all concurrent DML is permitted. For example: ``` CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50), c varchar(50) DEFAULT 'No value explicitly provided.' ); SET SESSION alter_algorithm='INPLACE'; ALTER TABLE tab ALTER COLUMN c DROP DEFAULT; Query OK, 0 rows affected (0.005 sec) ``` ### `ALTER TABLE ... CHANGE COLUMN` InnoDB supports renaming a column with [ALGORITHM](../alter-table/index#algorithm) set to `INPLACE`, unless the column's data type or attributes changed in addition to the name. This operation only changes the table's metadata, so the table does not have to be rebuilt. This operation supports the non-locking strategy. This strategy can be explicitly chosen by setting the [LOCK](../alter-table/index#lock) clause to `NONE`. When this strategy is used, all concurrent DML is permitted. For example, this succeeds: ``` CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50), c varchar(50) ); SET SESSION alter_algorithm='INPLACE'; ALTER TABLE tab CHANGE COLUMN c str varchar(50); Query OK, 0 rows affected (0.006 sec) ``` But this fails: ``` CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50), c varchar(50) ); SET SESSION alter_algorithm='INPLACE'; ALTER TABLE tab CHANGE COLUMN c num int; ERROR 1846 (0A000): ALGORITHM=INPLACE is not supported. Reason: Cannot change column type INPLACE. Try ALGORITHM=COPY ``` This applies to [ALTER TABLE ... CHANGE COLUMN](../alter-table/index#change-column) for [InnoDB](../innodb/index) tables. Index Operations ---------------- ### `ALTER TABLE ... ADD PRIMARY KEY` InnoDB supports adding a primary key to a table with [ALGORITHM](../alter-table/index#algorithm) set to `INPLACE`. If the new primary key column is not defined as [NOT NULL](../create-table/index#null-and-not-null), then it is highly recommended for [strict mode](../sql-mode/index#strict-mode) to be enabled in [SQL\_MODE](../sql-mode/index). Otherwise, `NULL` values will be silently converted to the default value for the given data type, which is probably not the desired behavior in this scenario. The table is rebuilt, which means that all of the data is reorganized substantially, and the indexes are rebuilt. As a result, the operation is quite expensive. This operation supports the non-locking strategy. This strategy can be explicitly chosen by setting the [LOCK](../alter-table/index#lock) clause to `NONE`. When this strategy is used, all concurrent DML is permitted. For example, this succeeds: ``` CREATE OR REPLACE TABLE tab ( a int, b varchar(50), c varchar(50) ); SET SESSION sql_mode='STRICT_TRANS_TABLES'; SET SESSION alter_algorithm='INPLACE'; ALTER TABLE tab ADD PRIMARY KEY (a); Query OK, 0 rows affected (0.021 sec) ``` But this fails: ``` CREATE OR REPLACE TABLE tab ( a int, b varchar(50), c varchar(50) ); INSERT INTO tab VALUES (NULL, NULL, NULL); SET SESSION sql_mode='STRICT_TRANS_TABLES'; SET SESSION alter_algorithm='INPLACE'; ALTER TABLE tab ADD PRIMARY KEY (a); ERROR 1265 (01000): Data truncated for column 'a' at row 1 ``` And this fails: ``` CREATE OR REPLACE TABLE tab ( a int, b varchar(50), c varchar(50) ); INSERT INTO tab VALUES (1, NULL, NULL); INSERT INTO tab VALUES (1, NULL, NULL); SET SESSION sql_mode='STRICT_TRANS_TABLES'; SET SESSION alter_algorithm='INPLACE'; ALTER TABLE tab ADD PRIMARY KEY (a); ERROR 1062 (23000): Duplicate entry '1' for key 'PRIMARY' ``` This applies to [ALTER TABLE ... ADD PRIMARY KEY](../alter-table/index#add-primary-key) for [InnoDB](../innodb/index) tables. ### `ALTER TABLE ... DROP PRIMARY KEY` InnoDB does **not** support dropping a primary key with [ALGORITHM](../alter-table/index#algorithm) set to `INPLACE` in most cases. If you try to do so, then you will see an error. InnoDB only supports this operation with [ALGORITHM](../alter-table/index#algorithm) set to `COPY`. Concurrent DML is \*not\* permitted. However, there is an exception. If you are dropping a primary key, and adding a new one at the same time, then that operation can be performed with [ALGORITHM](../alter-table/index#algorithm) set to `INPLACE`. This operation supports the non-locking strategy. This strategy can be explicitly chosen by setting the [LOCK](../alter-table/index#lock) clause to `NONE`. When this strategy is used, all concurrent DML is permitted. For example, this fails: ``` CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50), c varchar(50) ); SET SESSION alter_algorithm='INPLACE'; ALTER TABLE tab DROP PRIMARY KEY; ERROR 1846 (0A000): ALGORITHM=INPLACE is not supported. Reason: Dropping a primary key is not allowed without also adding a new primary key. Try ALGORITHM=COPY ``` But this succeeds: ``` CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50), c varchar(50) ); SET SESSION sql_mode='STRICT_TRANS_TABLES'; SET SESSION alter_algorithm='INPLACE'; ALTER TABLE tab DROP PRIMARY KEY, ADD PRIMARY KEY (b); Query OK, 0 rows affected (0.020 sec) ``` This applies to [ALTER TABLE ... DROP PRIMARY KEY](../alter-table/index#drop-primary-key) for [InnoDB](../innodb/index) tables. ### `ALTER TABLE ... ADD INDEX` and `CREATE INDEX` This applies to [ALTER TABLE ... ADD INDEX](../alter-table/index#add-index) and [CREATE INDEX](../create-index/index) for [InnoDB](../innodb/index) tables. #### Adding a Plain Index InnoDB supports adding a plain index to a table with [ALGORITHM](../alter-table/index#algorithm) set to `INPLACE`. The table is not rebuilt. This operation supports the non-locking strategy. This strategy can be explicitly chosen by setting the [LOCK](../alter-table/index#lock) clause to `NONE`. When this strategy is used, all concurrent DML is permitted. For example, this succeeds: ``` CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50), c varchar(50) ); SET SESSION alter_algorithm='INPLACE'; ALTER TABLE tab ADD INDEX b_index (b); Query OK, 0 rows affected (0.010 sec) ``` And this succeeds: ``` CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50), c varchar(50) ); SET SESSION alter_algorithm='INPLACE'; CREATE INDEX b_index ON tab (b); Query OK, 0 rows affected (0.011 sec) ``` #### Adding a Fulltext Index InnoDB supports adding a [FULLTEXT](../full-text-indexes/index) index to a table with [ALGORITHM](../alter-table/index#algorithm) set to `INPLACE`. The table is not rebuilt in some cases. However, there are some limitations, such as: * Adding a [FULLTEXT](../full-text-indexes/index) index to a table that does not have a user-defined `FTS_DOC_ID` column will require the table to be rebuilt once. When the table is rebuilt, the system adds a hidden `FTS_DOC_ID` column. From that point forward, adding additional [FULLTEXT](../full-text-indexes/index) indexes to the same table will not require the table to be rebuilt when [ALGORITHM](../alter-table/index#algorithm) is set to `INPLACE`. * Only one [FULLTEXT](../full-text-indexes/index) index may be added at a time when [ALGORITHM](../alter-table/index#algorithm) is set to `INPLACE`. * If a table has more than one [FULLTEXT](../full-text-indexes/index) index, then it cannot be rebuilt by any [ALTER TABLE](../alter-table/index) operations when [ALGORITHM](../alter-table/index#algorithm) is set to `INPLACE`. * If a table has a [FULLTEXT](../full-text-indexes/index) index, then it cannot be rebuilt by any [ALTER TABLE](../alter-table/index) operations when the [LOCK](../alter-table/index#lock) clause is set to `NONE`. This operation supports a read-only locking strategy. This strategy can be explicitly chosen by setting the [LOCK](../alter-table/index#lock) clause to `SHARED`. When this strategy is used, read-only concurrent DML is permitted. For example, this succeeds, but requires the table to be rebuilt, so that the hidden `FTS_DOC_ID` column can be added: ``` CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50), c varchar(50) ); SET SESSION alter_algorithm='INPLACE'; ALTER TABLE tab ADD FULLTEXT INDEX b_index (b); Query OK, 0 rows affected (0.055 sec) ``` And this succeeds in the same way as above: ``` CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50), c varchar(50) ); SET SESSION alter_algorithm='INPLACE'; CREATE FULLTEXT INDEX b_index ON tab (b); Query OK, 0 rows affected (0.041 sec) ``` And this succeeds, and the second command does not require the table to be rebuilt: ``` CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50), c varchar(50) ); SET SESSION alter_algorithm='INPLACE'; ALTER TABLE tab ADD FULLTEXT INDEX b_index (b); Query OK, 0 rows affected (0.043 sec) ALTER TABLE tab ADD FULLTEXT INDEX c_index (c); Query OK, 0 rows affected (0.017 sec) ``` But this second command fails, because only one [FULLTEXT](../full-text-indexes/index) index can be added at a time: ``` CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50), c varchar(50), d varchar(50) ); SET SESSION alter_algorithm='INPLACE'; ALTER TABLE tab ADD FULLTEXT INDEX b_index (b); Query OK, 0 rows affected (0.041 sec) ALTER TABLE tab ADD FULLTEXT INDEX c_index (c), ADD FULLTEXT INDEX d_index (d); ERROR 1846 (0A000): ALGORITHM=INPLACE is not supported. Reason: InnoDB presently supports one FULLTEXT index creation at a time. Try ALGORITHM=COPY ``` And this third command fails, because a table cannot be rebuilt when it has more than one [FULLTEXT](../full-text-indexes/index) index: ``` CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50), c varchar(50) ); SET SESSION alter_algorithm='INPLACE'; ALTER TABLE tab ADD FULLTEXT INDEX b_index (b); Query OK, 0 rows affected (0.040 sec) ALTER TABLE tab ADD FULLTEXT INDEX c_index (c); Query OK, 0 rows affected (0.015 sec) ALTER TABLE tab FORCE; ERROR 1846 (0A000): ALGORITHM=INPLACE is not supported. Reason: InnoDB presently supports one FULLTEXT index creation at a time. Try ALGORITHM=COPY ``` #### Adding a Spatial Index InnoDB supports adding a [SPATIAL](../spatial-index/index) index to a table with [ALGORITHM](../alter-table/index#algorithm) set to `INPLACE`. However, there are some limitations, such as: * If a table has a [SPATIAL](../spatial-index/index) index, then it cannot be rebuilt by any [ALTER TABLE](../alter-table/index) operations when the [LOCK](../alter-table/index#lock) clause is set to `NONE`. This operation supports a read-only locking strategy. This strategy can be explicitly chosen by setting the [LOCK](../alter-table/index#lock) clause to `SHARED`. When this strategy is used, read-only concurrent DML is permitted. For example, this succeeds: ``` CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50), c GEOMETRY NOT NULL ); SET SESSION alter_algorithm='INPLACE'; ALTER TABLE tab ADD SPATIAL INDEX c_index (c); Query OK, 0 rows affected (0.006 sec) ``` And this succeeds in the same way as above: ``` CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50), c GEOMETRY NOT NULL ); SET SESSION alter_algorithm='INPLACE'; CREATE SPATIAL INDEX c_index ON tab (c); Query OK, 0 rows affected (0.006 sec) ``` ### `ALTER TABLE ... DROP INDEX` and `DROP INDEX` InnoDB supports dropping indexes from a table with [ALGORITHM](../alter-table/index#algorithm) set to `INPLACE`. This operation only changes the table's metadata, so the table does not have to be rebuilt. This operation supports the non-locking strategy. This strategy can be explicitly chosen by setting the [LOCK](../alter-table/index#lock) clause to `NONE`. When this strategy is used, all concurrent DML is permitted. For example, this succeeds: ``` CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50), c varchar(50), INDEX b_index (b) ); SET SESSION alter_algorithm='INPLACE'; ALTER TABLE tab DROP INDEX b_index; ``` And this succeeds: ``` CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50), c varchar(50), INDEX b_index (b) ); SET SESSION alter_algorithm='INPLACE'; DROP INDEX b_index ON tab; ``` This applies to [ALTER TABLE ... DROP INDEX](../alter-table/index#drop-index) and [DROP INDEX](../drop-index/index) for [InnoDB](../innodb/index) tables. ### `ALTER TABLE ... ADD FOREIGN KEY` InnoDB supports adding foreign key constraints to a table with [ALGORITHM](../alter-table/index#algorithm) set to `INPLACE`. In order to add a new foreign key constraint to a table with [ALGORITHM](../alter-table/index#algorithm) set to `INPLACE`, the [foreign\_key\_checks](../server-system-variables/index#foreign_key_checks) system variable needs to be set to `OFF`. If it is set to `ON`, then `ALGORITHM=COPY` is required. This operation only changes the table's metadata, so the table does not have to be rebuilt. This operation supports the non-locking strategy. This strategy can be explicitly chosen by setting the [LOCK](../alter-table/index#lock) clause to `NONE`. When this strategy is used, all concurrent DML is permitted. For example, this fails: ``` CREATE OR REPLACE TABLE tab1 ( a int PRIMARY KEY, b varchar(50), c varchar(50), d int ); CREATE OR REPLACE TABLE tab2 ( a int PRIMARY KEY, b varchar(50) ); SET SESSION alter_algorithm='INPLACE'; ALTER TABLE tab1 ADD FOREIGN KEY tab2_fk (d) REFERENCES tab2 (a); ERROR 1846 (0A000): ALGORITHM=INPLACE is not supported. Reason: Adding foreign keys needs foreign_key_checks=OFF. Try ALGORITHM=COPY ``` But this succeeds: ``` CREATE OR REPLACE TABLE tab1 ( a int PRIMARY KEY, b varchar(50), c varchar(50), d int ); CREATE OR REPLACE TABLE tab2 ( a int PRIMARY KEY, b varchar(50) ); SET SESSION foreign_key_checks=OFF; SET SESSION alter_algorithm='INPLACE'; ALTER TABLE tab1 ADD FOREIGN KEY tab2_fk (d) REFERENCES tab2 (a); Query OK, 0 rows affected (0.011 sec) ``` This applies to [ALTER TABLE ... ADD FOREIGN KEY](../alter-table/index#add-foreign-key) for [InnoDB](../innodb/index) tables. ### `ALTER TABLE ... DROP FOREIGN KEY` InnoDB supports dropping foreign key constraints from a table with [ALGORITHM](../alter-table/index#algorithm) set to `INPLACE`. This operation only changes the table's metadata, so the table does not have to be rebuilt. This operation supports the non-locking strategy. This strategy can be explicitly chosen by setting the [LOCK](../alter-table/index#lock) clause to `NONE`. When this strategy is used, all concurrent DML is permitted. For example: ``` CREATE OR REPLACE TABLE tab2 ( a int PRIMARY KEY, b varchar(50) ); CREATE OR REPLACE TABLE tab1 ( a int PRIMARY KEY, b varchar(50), c varchar(50), d int, FOREIGN KEY tab2_fk (d) REFERENCES tab2 (a) ); SET SESSION alter_algorithm='INPLACE'; ALTER TABLE tab1 DROP FOREIGN KEY tab2_fk; Query OK, 0 rows affected (0.005 sec) ``` This applies to [ALTER TABLE ... DROP FOREIGN KEY](../alter-table/index#drop-foreign-key) for [InnoDB](../innodb/index) tables. Table Operations ---------------- ### `ALTER TABLE ... AUTO_INCREMENT=...` InnoDB supports changing a table's [AUTO\_INCREMENT](../auto_increment/index) value with [ALGORITHM](../alter-table/index#algorithm) set to `INPLACE`. This operation should finish instantly. The table is not rebuilt. This operation supports the non-locking strategy. This strategy can be explicitly chosen by setting the [LOCK](../alter-table/index#lock) clause to `NONE`. When this strategy is used, all concurrent DML is permitted. For example: ``` CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50), c varchar(50) ); SET SESSION alter_algorithm='INPLACE'; ALTER TABLE tab AUTO_INCREMENT=100; Query OK, 0 rows affected (0.004 sec) ``` This applies to [ALTER TABLE ... AUTO\_INCREMENT=...](../create-table/index#auto_increment) for [InnoDB](../innodb/index) tables. ### `ALTER TABLE ... ROW_FORMAT=...` InnoDB supports changing a table's [row format](../innodb-storage-formats/index) with [ALGORITHM](../alter-table/index#algorithm) set to `INPLACE`. The table is rebuilt, which means that all of the data is reorganized substantially, and the indexes are rebuilt. As a result, the operation is quite expensive. This operation supports the non-locking strategy. This strategy can be explicitly chosen by setting the [LOCK](../alter-table/index#lock) clause to `NONE`. When this strategy is used, all concurrent DML is permitted. For example: ``` CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50), c varchar(50) ) ROW_FORMAT=DYNAMIC; SET SESSION alter_algorithm='INPLACE'; ALTER TABLE tab ROW_FORMAT=COMPRESSED; Query OK, 0 rows affected (0.025 sec) ``` This applies to [ALTER TABLE ... ROW\_FORMAT=...](../create-table/index#row_format) for [InnoDB](../innodb/index) tables. ### `ALTER TABLE ... KEY_BLOCK_SIZE=...` InnoDB supports changing a table's [KEY\_BLOCK\_SIZE](../innodb-storage-formats/index#using-the-compressed-row-format) with [ALGORITHM](../alter-table/index#algorithm) set to `INPLACE`. The table is rebuilt, which means that all of the data is reorganized substantially, and the indexes are rebuilt. As a result, the operation is quite expensive. This operation supports the non-locking strategy. This strategy can be explicitly chosen by setting the [LOCK](../alter-table/index#lock) clause to `NONE`. When this strategy is used, all concurrent DML is permitted. For example: ``` CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50), c varchar(50) ) ROW_FORMAT=COMPRESSED KEY_BLOCK_SIZE=4; SET SESSION alter_algorithm='INPLACE'; ALTER TABLE tab KEY_BLOCK_SIZE=2; Query OK, 0 rows affected (0.021 sec) ``` This applies to [KEY\_BLOCK\_SIZE=...](../create-table/index#key_block_size) for [InnoDB](../innodb/index) tables. ### `ALTER TABLE ... PAGE_COMPRESSED=...` and `ALTER TABLE ... PAGE_COMPRESSION_LEVEL=...` In [MariaDB 10.3.10](https://mariadb.com/kb/en/mariadb-10310-release-notes/) and later, InnoDB supports setting a table's [PAGE\_COMPRESSED](../create-table/index#page_compressed) value to `1` with [ALGORITHM](../alter-table/index#algorithm) set to `INPLACE`. InnoDB also supports changing a table's [PAGE\_COMPRESSED](../create-table/index#page_compressed) value from `1` to `0` with [ALGORITHM](../alter-table/index#algorithm) set to `INPLACE`. In these versions, InnoDB also supports changing a table's [PAGE\_COMPRESSION\_LEVEL](../create-table/index#page_compression_level) value with [ALGORITHM](../alter-table/index#algorithm) set to `INPLACE`. This operation supports the non-locking strategy. This strategy can be explicitly chosen by setting the [LOCK](../alter-table/index#lock) clause to `NONE`. When this strategy is used, all concurrent DML is permitted. See [MDEV-16328](https://jira.mariadb.org/browse/MDEV-16328) for more information. For example, this succeeds: ``` CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50), c varchar(50) ); SET SESSION alter_algorithm='INPLACE'; ALTER TABLE tab PAGE_COMPRESSED=1; Query OK, 0 rows affected (0.006 sec) ``` And this succeeds: ``` CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50), c varchar(50) ) PAGE_COMPRESSED=1; SET SESSION alter_algorithm='INPLACE'; ALTER TABLE tab PAGE_COMPRESSED=0; Query OK, 0 rows affected (0.020 sec) ``` And this succeeds: ``` CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50), c varchar(50) ) PAGE_COMPRESSED=1 PAGE_COMPRESSION_LEVEL=5; SET SESSION alter_algorithm='INPLACE'; ALTER TABLE tab PAGE_COMPRESSION_LEVEL=4; Query OK, 0 rows affected (0.006 sec) ``` This applies to [PAGE\_COMPRESSED=...](../create-table/index#page_compressed) and [PAGE\_COMPRESSION\_LEVEL=...](../create-table/index#page_compression_level) for [InnoDB](../innodb/index) tables. ### `ALTER TABLE ... DROP SYSTEM VERSIONING` InnoDB supports dropping [system versioning](../system-versioned-tables/index) from a table with [ALGORITHM](../alter-table/index#algorithm) set to `INPLACE`. This operation supports the read-only locking strategy. This strategy can be explicitly chosen by setting the [LOCK](../alter-table/index#lock) clause to `SHARED`. When this strategy is used, read-only concurrent DML is permitted. For example: ``` CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50), c varchar(50) ) WITH SYSTEM VERSIONING; SET SESSION alter_algorithm='INPLACE'; ALTER TABLE tab DROP SYSTEM VERSIONING; ``` This applies to [ALTER TABLE ... DROP SYSTEM VERSIONING](../alter-table/index#drop-system-versioning) for [InnoDB](../innodb/index) tables. ### `ALTER TABLE ... DROP CONSTRAINT` In [MariaDB 10.3.6](https://mariadb.com/kb/en/mariadb-1036-release-notes/) and later, InnoDB supports dropping a [CHECK](../constraint/index#check-constraints) constraint from a table with [ALGORITHM](../alter-table/index#algorithm) set to `INPLACE`. See [MDEV-16331](https://jira.mariadb.org/browse/MDEV-16331) for more information. This operation supports the non-locking strategy. This strategy can be explicitly chosen by setting the [LOCK](../alter-table/index#lock) clause to `NONE`. When this strategy is used, all concurrent DML is permitted. For example: ``` CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50), c varchar(50), CONSTRAINT b_not_empty CHECK (b != '') ); SET SESSION alter_algorithm='INPLACE'; ALTER TABLE tab DROP CONSTRAINT b_not_empty; Query OK, 0 rows affected (0.004 sec) ``` This applies to [ALTER TABLE ... DROP CONSTRAINT](../alter-table/index#drop-constraint) for [InnoDB](../innodb/index) tables. ### `ALTER TABLE ... FORCE` InnoDB supports forcing a table rebuild with [ALGORITHM](../alter-table/index#algorithm) set to `INPLACE`. The table is rebuilt, which means that all of the data is reorganized substantially, and the indexes are rebuilt. As a result, the operation is quite expensive. This operation supports the non-locking strategy. This strategy can be explicitly chosen by setting the [LOCK](../alter-table/index#lock) clause to `NONE`. When this strategy is used, all concurrent DML is permitted. For example: ``` CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50), c varchar(50) ); SET SESSION alter_algorithm='INPLACE'; ALTER TABLE tab FORCE; Query OK, 0 rows affected (0.022 sec) ``` This applies to [ALTER TABLE ... FORCE](../alter-table/index#force) for [InnoDB](../innodb/index) tables. ### `ALTER TABLE ... ENGINE=InnoDB` InnoDB supports forcing a table rebuild with [ALGORITHM](../alter-table/index#algorithm) set to `INPLACE`. The table is rebuilt, which means that all of the data is reorganized substantially, and the indexes are rebuilt. As a result, the operation is quite expensive. This operation supports the non-locking strategy. This strategy can be explicitly chosen by setting the [LOCK](../alter-table/index#lock) clause to `NONE`. When this strategy is used, all concurrent DML is permitted. For example: ``` CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50), c varchar(50) ); SET SESSION alter_algorithm='INPLACE'; ALTER TABLE tab ENGINE=InnoDB; Query OK, 0 rows affected (0.022 sec) ``` This applies to [ALTER TABLE ... ENGINE=InnoDB](../create-table/index#storage-engine) for [InnoDB](../innodb/index) tables. ### `OPTIMIZE TABLE ...` InnoDB supports optimizing a table with [ALGORITHM](../alter-table/index#algorithm) set to `INPLACE`. If the [innodb\_defragment](../innodb-system-variables/index#innodb_defragment) system variable is set to `OFF`, and if the [innodb\_optimize\_fulltext\_only](../innodb-system-variables/index#innodb_optimize_fulltext_only) system variable is also set to `OFF`, then `OPTIMIZE TABLE` will be equivalent to `ALTER TABLE … FORCE`. The table is rebuilt, which means that all of the data is reorganized substantially, and the indexes are rebuilt. As a result, the operation is quite expensive. If either of the previously mentioned system variables is set to `ON`, then `OPTIMIZE TABLE` will optimize some data without rebuilding the table. However, the file size will not be reduced. For example, this succeeds: ``` CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50), c varchar(50) ); SHOW GLOBAL VARIABLES WHERE Variable_name IN('innodb_defragment', 'innodb_optimize_fulltext_only'); +-------------------------------+-------+ | Variable_name | Value | +-------------------------------+-------+ | innodb_defragment | OFF | | innodb_optimize_fulltext_only | OFF | +-------------------------------+-------+ SET SESSION alter_algorithm='INPLACE'; OPTIMIZE TABLE tab; +---------+----------+----------+-------------------------------------------------------------------+ | Table | Op | Msg_type | Msg_text | +---------+----------+----------+-------------------------------------------------------------------+ | db1.tab | optimize | note | Table does not support optimize, doing recreate + analyze instead | | db1.tab | optimize | status | OK | +---------+----------+----------+-------------------------------------------------------------------+ 2 rows in set (0.026 sec) ``` And this succeeds, but the table is not rebuilt: ``` CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50), c varchar(50) ); SET GLOBAL innodb_defragment=ON; SHOW GLOBAL VARIABLES WHERE Variable_name IN('innodb_defragment', 'innodb_optimize_fulltext_only'); +-------------------------------+-------+ | Variable_name | Value | +-------------------------------+-------+ | innodb_defragment | ON | | innodb_optimize_fulltext_only | OFF | +-------------------------------+-------+ SET SESSION alter_algorithm='INPLACE'; OPTIMIZE TABLE tab; +---------+----------+----------+----------+ | Table | Op | Msg_type | Msg_text | +---------+----------+----------+----------+ | db1.tab | optimize | status | OK | +---------+----------+----------+----------+ 1 row in set (0.004 sec) ``` This applies to [OPTIMIZE TABLE](../optimize-table/index) for [InnoDB](../innodb/index) tables. ### `ALTER TABLE ... RENAME TO` and `RENAME TABLE ...` InnoDB supports renaming a table with [ALGORITHM](../alter-table/index#algorithm) set to `INPLACE`. This operation only changes the table's metadata, so the table does not have to be rebuilt. This operation supports the exclusive locking strategy. This strategy can be explicitly chosen by setting the [LOCK](../alter-table/index#lock) clause to `EXCLUSIVE`. When this strategy is used, concurrent DML is **not** permitted. For example, this succeeds: ``` CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50), c varchar(50) ); SET SESSION alter_algorithm='INPLACE'; ALTER TABLE tab RENAME TO old_tab; Query OK, 0 rows affected (0.011 sec) ``` And this succeeds: ``` CREATE OR REPLACE TABLE tab ( a int PRIMARY KEY, b varchar(50), c varchar(50) ); SET SESSION alter_algorithm='INPLACE'; RENAME TABLE tab TO old_tab; ``` This applies to [ALTER TABLE ... RENAME TO](../alter-table/index#rename-to) and [RENAME TABLE](../rename-table/index) for [InnoDB](../innodb/index) tables. Limitations ----------- ### Limitations Related to Fulltext Indexes * If a table has more than one [FULLTEXT](../full-text-indexes/index) index, then it cannot be rebuilt by any [ALTER TABLE](../alter-table/index) operations when [ALGORITHM](../alter-table/index#algorithm) is set to `INPLACE`. * If a table has a [FULLTEXT](../full-text-indexes/index) index, then it cannot be rebuilt by any [ALTER TABLE](../alter-table/index) operations when the [LOCK](../alter-table/index#lock) clause is set to `NONE`. ### Limitations Related to Spatial Indexes * If a table has a [SPATIAL](../spatial-index/index) index, then it cannot be rebuilt by any [ALTER TABLE](../alter-table/index) operations when the [LOCK](../alter-table/index#lock) clause is set to `NONE`. ### Limitations Related to Generated (Virtual and Persistent/Stored) Columns [Generated columns](../generated-columns/index) do not currently support online DDL for all of the same operations that are supported for "real" columns. See [Generated (Virtual and Persistent/Stored) Columns: Statement Support](../generated-columns/index#statement-support) for more information on the limitations. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb ST_ENVELOPE ST\_ENVELOPE ============ Syntax ------ ``` ST_ENVELOPE(g) ENVELOPE(g) ``` Description ----------- Returns the Minimum Bounding Rectangle (MBR) for the geometry value `g`. The result is returned as a Polygon value. The polygon is defined by the corner points of the bounding box: ``` POLYGON((MINX MINY, MAXX MINY, MAXX MAXY, MINX MAXY, MINX MINY)) ``` `ST_ENVELOPE()` and `ENVELOPE()` are synonyms. Examples -------- ``` SELECT AsText(ST_ENVELOPE(GeomFromText('LineString(1 1,4 4)'))); +----------------------------------------------------------+ | AsText(ST_ENVELOPE(GeomFromText('LineString(1 1,4 4)'))) | +----------------------------------------------------------+ | POLYGON((1 1,4 1,4 4,1 4,1 1)) | +----------------------------------------------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb mysql.spider_xa_failed_log Table mysql.spider\_xa\_failed\_log Table =================================== The `mysql.spider_xa_failed_log` table is installed by the [Spider storage engine](../spider/index). **MariaDB starting with [10.4](../what-is-mariadb-104/index)**In [MariaDB 10.4](../what-is-mariadb-104/index) and later, this table uses the [Aria](../aria/index) storage engine. **MariaDB until [10.3](../what-is-mariadb-103/index)**In [MariaDB 10.3](../what-is-mariadb-103/index) and before, this table uses the [MyISAM](../myisam-storage-engine/index) storage engine. It contains the following fields: | Field | Type | Null | Key | Default | Description | | --- | --- | --- | --- | --- | --- | | format\_id | int(11) | NO | | 0 | | | gtrid\_length | int(11) | NO | | 0 | | | bqual\_length | int(11) | NO | | 0 | | | data | binary(128) | NO | MUL | | | | scheme | char(64) | NO | | | | | host | char(64) | NO | | | | | port | char(5) | NO | | | | | socket | text | NO | | NULL | | | username | char(64) | NO | | | | | password | char(64) | NO | | | | | ssl\_ca | text | YES | | NULL | | | ssl\_capath | text | YES | | NULL | | | ssl\_cert | text | YES | | NULL | | | ssl\_cipher | char(64) | YES | | NULL | | | ssl\_key | text | YES | | NULL | | | ssl\_verify\_server\_cert | tinyint(4) | NO | | 0 | | | default\_file | text | YES | | NULL | | | default\_group | char(64) | YES | | NULL | | | dsn | char(64) | YES | | NULL | | | filedsn | text | YES | | NULL | | | driver | char(64) | YES | | NULL | | | thread\_id | int(11) | YES | | NULL | | | status | char(8) | NO | | | | | failed\_time | timestamp | NO | | current\_timestamp() | | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb mysqlaccess mysqlaccess =========== **MariaDB starting with [10.4.6](https://mariadb.com/kb/en/mariadb-1046-release-notes/)**From [MariaDB 10.4.6](https://mariadb.com/kb/en/mariadb-1046-release-notes/), `mariadb-access` is a symlink to `mysqlaccess`. **MariaDB starting with [10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/)**From [MariaDB 10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/), `mariadb-access` is the name of the tool, with `mysqlaccess` a symlink . `mysqlaccess` is a tool for checking access privileges, developed by Yves Carlier. It checks the access privileges for a host name, user name, and database combination. Note that mysqlaccess checks access using only the [user](../mysqluser-table/index), [db](../mysqldb-table/index), and host tables. It does not check table, column, or routine privileges specified in the [tables\_priv](../mysqltables_priv-table/index), [columns\_priv](../mysqlcolumns_priv-table/index), or [procs\_priv](../mysqlprocs_priv-table/index) tables. Usage ----- ``` mysqlaccess [host [user [db]]] OPTIONS ``` If your MariaDB distribution is installed in some non-standard location, you must change the location where *mysqlaccess* expects to find the mysql client. Edit the *mysqlaccess* script at approximately line 18. Search for a line that looks like this: <<code> $MYSQL = ´/usr/local/bin/mysql´; # path to mysql executable <</code>> Change the path to reflect the location where *mysql* actually is stored on your system. If you do not do this, a *Broken pipe error* will occur when you run *mysqlaccess*. Options ------- | Option | Description | | --- | --- | | `-?`, `--help` | Displayhelp and exit. | | `-v`, `--version` | Display version. | | `-u username`, `--user=username` | Username for logging in to the db. | | `-p[password]`, `--password[=password]` | Password to use for user. If ommitted, `mysqlaccess` prompts for one. | | `-h hostname`, `--host=hostname` | Name or IP of the host. | | `-d dbname`, `--db=dbname` | Name of the database. | | `-U username`, `--superuser=username` | Connect as superuser. | | `-P password`, `--spassword=password` | Password for superuser. | | `-H server`, `--rhost=server` | Remote server to connect to. | | `--old_server` | Connect to a very old MySQL servers (before version 3.21) that does not know how to handle full WHERE clauses. | | `-b`, `--brief` | Single-line tabular report. | | `-t`, `--table` | Report in table-format. | | `--relnotes` | Print release-notes. | | `--plan` | Print suggestions/ideas for future releases. | | `--howto` | Some examples of how to run `mysqlaccess'. | | `--debug=N` | Enter debug level N (0..3). | | `--copy` | Reload temporary grant-tables from original ones. | | `--preview` | Show differences in privileges after making changes in (temporary) grant-tables. | | `--commit` | Copy grant-rules from temporary tables to grant-tables (the grant tables must be flushed after, for example with `[mysqladmin reload](../mysqladmin/index)`). | | `--rollback` | Undo the last changes to the grant-tables. | Note ---- At least the user (`-u`) and the database (`-d`) must be given, even with wildcards. If no host is provided, `localhost' is assumed. Wildcards (\*,?,%,\_) are allowed for *host*, *user* and *db*, but be sure to escape them from your shell!! (ie type \\* or '\*') Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb InnoDB Purge InnoDB Purge ============ When a transaction updates a row in an InnoDB table, InnoDB's MVCC implementation keeps old versions of the row in the [InnoDB undo log](../innodb-undo-log/index). The old versions are kept at least until all transactions older than the transaction that updated the row are no longer open. At that point, the old versions can be deleted. InnoDB has purge process that is used to delete these old versions. Optimizing Purge Performance ---------------------------- ### Configuring the Purge Threads The number of purge threads can be set by configuring the `[innodb\_purge\_threads](../innodb-system-variables/index#innodb_purge_threads)` system variable. This system variable can be specified as a command-line argument to `[mysqld](../mysqld-options/index)` or it can be specified in a relevant server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index). For example: ``` [mariadb] ... innodb_purge_threads = 6 ``` ### Configuring the Purge Batch Size The purge batch size is defined as the number of [InnoDB redo log](../innodb-redo-log/index) records that must be written before triggering purge. The purge batch size can be set by configuring the `[innodb\_purge\_batch\_size](../innodb-system-variables/index#innodb_purge_batch_size)` system variable. This system variable can be specified as a command-line argument to `[mysqld](../mysqld-options/index)` or it can be specified in a relevant server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index). For example: ``` [mariadb] ... innodb_purge_batch_size = 50 ``` ### Configuring the Max Purge Lag If purge operations are lagging on a busy server, then this can be a tough situation to recover from. As a solution, InnoDB allows you to set the max purge lag. The max purge lag is defined as the maximum number of [InnoDB undo log](../innodb-undo-log/index) that can be waiting to be purged from the history until InnoDB begins delaying DML statements. The max purge lag can be set by configuring the `[innodb\_max\_purge\_lag](../innodb-system-variables/index#innodb_max_purge_lag)` system variable. This system variable can be changed dynamically with `[SET GLOBAL](../set/index#global-session)`. For example: ``` SET GLOBAL innodb_max_purge_lag=1000; ``` This system variable can also be specified as a command-line argument to `[mysqld](../mysqld-options/index)` or it can be specified in a relevant server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index). For example: ``` [mariadb] ... innodb_max_purge_lag = 1000 ``` The maximum delay can be set by configuring the `[innodb\_max\_purge\_lag\_delay](../innodb-system-variables/index#innodb_max_purge_lag_delay)` system variable. This system variable can be changed dynamically with `[SET GLOBAL](../set/index#global-session)`. For example: ``` SET GLOBAL innodb_max_purge_lag_delay=100; ``` This system variable can also be specified as a command-line argument to `[mysqld](../mysqld-options/index)` or it can be specified in a relevant server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index). For example: ``` [mariadb] ... innodb_max_purge_lag_delay = 100 ``` ### Configuring the Purge Rollback Segment Truncation Frequency **MariaDB starting with [10.2.2](https://mariadb.com/kb/en/mariadb-1022-release-notes/)**The `[innodb\_purge\_rseg\_truncate\_frequency](../innodb-system-variables/index#innodb_purge_rseg_truncate_frequency)` system variable was first added in [MariaDB 10.2.2](https://mariadb.com/kb/en/mariadb-1022-release-notes/). The purge rollback segment truncation frequency is defined as the number of purge loops that are run before unnecessary rollback segments are truncated. The purge rollback segment truncation frequency can be set by configuring the `[innodb\_purge\_rseg\_truncate\_frequency](../innodb-system-variables/index#innodb_purge_rseg_truncate_frequency)` system variable. This system variable can be changed dynamically with `[SET GLOBAL](../set/index#global-session)`. For example: ``` SET GLOBAL innodb_purge_rseg_truncate_frequency=64; ``` This system variable can also be specified as a command-line argument to `[mysqld](../mysqld-options/index)` or it can be specified in a relevant server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index). For example: ``` [mariadb] ... innodb_purge_rseg_truncate_frequency = 64 ``` ### Configuring the Purge Undo Log Truncation **MariaDB starting with [10.2.2](https://mariadb.com/kb/en/mariadb-1022-release-notes/)**The `[innodb\_undo\_log\_truncate](../innodb-system-variables/index#innodb_undo_log_truncate)` and `[innodb\_max\_undo\_log\_size](../innodb-system-variables/index#innodb_max_undo_log_size)` system variables were first added in [MariaDB 10.2.2](https://mariadb.com/kb/en/mariadb-1022-release-notes/). Purge undo log truncation occurs when InnoDB truncates an entire [InnoDB undo log](../innodb-undo-log/index) tablespace, rather than deleting individual [InnoDB undo log](../innodb-undo-log/index) records. Purge undo log truncation can be enabled by configuring the `[innodb\_undo\_log\_truncate](../innodb-system-variables/index#innodb_undo_log_truncate)` system variable. This system variable can be changed dynamically with `[SET GLOBAL](../set/index#global-session)`. For example: ``` SET GLOBAL innodb_undo_log_truncate=ON; ``` This system variable can also be specified as a command-line argument to `[mysqld](../mysqld-options/index)` or it can be specified in a relevant server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index). For example: ``` [mariadb] ... innodb_undo_log_truncate = ON ``` An [InnoDB undo log](../innodb-undo-log/index) tablespace is truncated when it exceeds the maximum size that is configured for [InnoDB undo log](../innodb-undo-log/index) tablespaces. The maximum size can be set by configuring the `[innodb\_max\_undo\_log\_size](../innodb-system-variables/index#innodb_max_undo_log_size)` system variable. This system variable can be changed dynamically with `[SET GLOBAL](../set/index#global-session)`. For example: ``` SET GLOBAL innodb_max_undo_log_size='64M'; ``` This system variable can also be specified as a command-line argument to `[mysqld](../mysqld-options/index)` or it can be specified in a relevant server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index). For example: ``` [mariadb] ... innodb_max_undo_log_size = 64M ``` Purge's Effect on Row Metadata ------------------------------ An InnoDB table's clustered index has three hidden system columns that are automatically generated. These hidden system columns are: * `DB_ROW_ID` - If the table has no other `PRIMARY KEY` or no other `UNIQUE KEY` defined as `NOT NULL` that can be promoted to the table's `PRIMARY KEY`, then InnoDB will use a hidden system column called `DB_ROW_ID`. InnoDB will automatically generated the value for the column from a global InnoDB-wide 48-bit sequence (instead of being table-local). * `DB_TRX_ID` - The transaction ID of either the transaction that last changed the row or the transaction that currently has the row locked. * `DB_ROLL_PTR` - A pointer to the [InnoDB undo log](../innodb-undo-log/index) that contains the row's previous record. The value of `DB_ROLL_PTR` is only valid if `DB_TRX_ID` belongs to the current read view. The oldest valid read view is the purge view. If a row's last [InnoDB undo log](../innodb-undo-log/index) record is purged, this can obviously effect the value of the row's `DB_ROLL_PTR` column, because there would no longer be any [InnoDB undo log](../innodb-undo-log/index) record for the pointer to reference. In [MariaDB 10.2](../what-is-mariadb-102/index) and before, the purge process wouldn't touch the value of the row's `DB_TRX_ID` column. However, in [MariaDB 10.3](../what-is-mariadb-103/index) and later, the purge process will set a row's `DB_TRX_ID` column to `0` after all of the row's associated [InnoDB undo log](../innodb-undo-log/index) records have been deleted. This change allows InnoDB to perform an optimization: if a query wants to read a row, and if the row's `DB_TRX_ID` column is set to `0`, then it knows that no other transaction has the row locked. Usually, InnoDB needs to lock the transaction system's mutex in order to safely check whether a row is locked, but this optimization allows InnoDB to confirm that the row can be safely read without any heavy internal locking. This optimization can speed up reads, but it come at a noticeable cost at other times. For example, it can cause the purge process to use more I/O after inserting a lot of rows, since the value of each row's `DB_TRX_ID` column will have to be reset. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Performance Schema events_waits_summary_global_by_event_name Table Performance Schema events\_waits\_summary\_global\_by\_event\_name Table ======================================================================== The [Performance Schema](../performance-schema/index) `events_waits_summary_global_by_event_name` table contains wait events summarized by event name. It contains the following columns: | Column | Description | | --- | --- | | `EVENT_NAME` | Event name. | | `COUNT_STAR` | Number of summarized events | | `SUM_TIMER_WAIT` | Total wait time of the summarized events that are timed. | | `MIN_TIMER_WAIT` | Minimum wait time of the summarized events that are timed. | | `AVG_TIMER_WAIT` | Average wait time of the summarized events that are timed. | | `MAX_TIMER_WAIT` | Maximum wait time of the summarized events that are timed. | The `*_TIMER_WAIT` columns only calculate results for timed events, as non-timed events have a `NULL` wait time. Example ------- ``` SELECT * FROM events_waits_summary_global_by_event_name\G ... *************************** 303. row *************************** EVENT_NAME: wait/io/socket/sql/server_tcpip_socket COUNT_STAR: 0 SUM_TIMER_WAIT: 0 MIN_TIMER_WAIT: 0 AVG_TIMER_WAIT: 0 MAX_TIMER_WAIT: 0 *************************** 304. row *************************** EVENT_NAME: wait/io/socket/sql/server_unix_socket COUNT_STAR: 0 SUM_TIMER_WAIT: 0 MIN_TIMER_WAIT: 0 AVG_TIMER_WAIT: 0 MAX_TIMER_WAIT: 0 *************************** 305. row *************************** EVENT_NAME: wait/io/socket/sql/client_connection COUNT_STAR: 0 SUM_TIMER_WAIT: 0 MIN_TIMER_WAIT: 0 AVG_TIMER_WAIT: 0 MAX_TIMER_WAIT: 0 *************************** 306. row *************************** EVENT_NAME: idle COUNT_STAR: 265 SUM_TIMER_WAIT: 46861125181000000 MIN_TIMER_WAIT: 1000000 AVG_TIMER_WAIT: 176834434000000 MAX_TIMER_WAIT: 4912417573000000 ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb PI PI == Syntax ------ ``` PI() ``` Description ----------- Returns the value of π (pi). The default number of decimal places displayed is six, but MariaDB uses the full double-precision value internally. Examples -------- ``` SELECT PI(); +----------+ | PI() | +----------+ | 3.141593 | +----------+ SELECT PI()+0.0000000000000000000000; +-------------------------------+ | PI()+0.0000000000000000000000 | +-------------------------------+ | 3.1415926535897931159980 | +-------------------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Hashicorp Key Management Plugin Hashicorp Key Management Plugin =============================== **MariaDB starting with [10.9](../what-is-mariadb-109/index)**The Hashicorp Key Management Plugin is used to implement encryption using keys stored in the Hashicorp Vault KMS. The current version of this plugin implements the following features: * Authentication is done using the Hashicorp Vault's token authentication method; * If additional client authentication is required, then the path to the CA authentication bundle file may be passed as a plugin parameter; * The creation of the keys and their management is carried out using the Hashicorp Vault KMS and their tools; * The plugin uses libcurl (https) as an interface to the HashiCorp Vault server; * JSON parsing is performed through the JSON service (through the include/mysql/service\_json.h); * HashiCorp Vault 1.2.4 was used for development and testing. Since we require support for key versioning, the key-value storage must be configured in Hashicorp Vault as a key-value storage that uses the interface of the second version. For example, you can create it as follows: ``` ~$ vault secrets enable -path /test -version=2 kv ``` Key names must correspond to their numerical identifiers. Key identifiers itself, their possible values and rules of use are described in more detail in the MariaDB main documentation. From the point of view of the key-value storage (in terms of Hashicorp Vault), the key is a secret containing one key-value pair with the name "data" and a value representing a binary string containing the key value, for example: ``` ~$ vault kv get /test/1 ====== Metadata ====== Key Value --- ----- created_time 2019-12-14T14:19:19.42432951Z deletion_time n/a destroyed false version 1 ==== Data ==== Key Value --- ----- data 0123456789ABCDEF0123456789ABCDEF ``` Keys values are strings containing binary data. MariaDB currently uses the AES algorithm with 256-bit keys as the default encryption method. In this case, the keys that will be stored in the Hashicorp Vault should be 32-byte strings. Most likely you will use some utilities for creating and administering keys designed to work with Hashicorp Vault. But in the simplest case, keys can be created from the command line through the vault utility, for example, as follows: ``` ~$ vault kv put /test/1 data="0123456789ABCDEF0123456789ABCDEF" ``` If you use default encryption (AES), you should ensure that the key length is 32 bytes, otherwise it may fail to use InnoDB as a data storage. The plugin currently does not unseal Hashicorp Vault on its own, you must do this in advance and on your own. To use Hashicorp Vault KMS, the plugin must be preloaded and activated on the server. Most of its parameters should not be changed during plugin operation and therefore must be preconfigured as part of the server configuration through configuration file or command line options: ``` --plugin-load-add=hashicorp_key_management.so --loose-hashicorp-key-management --loose-hashicorp-key-management-vault-url="$VAULT_ADDR/v1/test" --loose-hashicorp-key-management-token="$VAULT_TOKEN" ``` ### Options The plugin supports the following parameters, which must be set in advance and cannot be changed during server operation: #### `hashicorp-key-management-vault-url` * **Description:** HTTP[s] URL that is used to connect to the Hashicorp Vault server. It must include the name of the scheme (https: *for a secure connection) and, according to the API rules for storages of the key-value type in Hashicorp Vault, after the server address, the path must begin with the "/v1/" string (as prefix), for example: `[https://127.0.0.1:8200/v1/my\_secrets##](#). By default, the path is not set, therefore you must replace with the correct path to your secrets.`* * **Commandline:** `--[loose-]hashicorp-key-management-vault-url="<url>"` #### `hashicorp-key-management-token` * **Description:** Authentication token that passed to the Hashicorp Vault in the request header. By default, this parameter contains an empty string, so you must specify the correct value for it, otherwise the Hashicorp Vault server will refuse authorization. * **Commandline:** `--[loose-]hashicorp-key-management-token="<token>"` #### `hashicorp-key-management-vault-ca` * **Description:** Path to the Certificate Authority (CA) bundle (is a file that contains root and intermediate certificates). By default, this parameter contains an empty string, which means no CA bundle. * **Commandline:** `--[loose-]hashicorp-key-management-vault-ca="<path>"` #### `hashicorp-key-management-timeout` * **Description:** Set the duration (in seconds) for the Hashicorp Vault server connection timeout. The default value is 15 seconds. The allowed range is from 1 to 86400 seconds. The user can also specify a zero value, which means the default timeout value set by the libcurl library (currently 300 seconds). * **Commandline:** `--[loose-]hashicorp-key-management-timeout=<timeout>` #### `hashicorp-key-management-retries` * **Description:** Number of server request retries in case of timeout. Default is three retries. * **Commandline:** `----[loose-]hashicorp-key-management-retries=<retries>` #### `hashicorp-key-management-caching-enabled` * **Description:** Enable key caching (storing key values received from the Hashicorp Vault server in the local memory). By default caching is enabled. * **Commandline:** `--[loose-]hashicorp-key-management-caching-enabled="on"|"off"` #### `hashicorp-key-management-use-cache-on-timeout` * **Description:** This parameter instructs the plugin to use the key values or version numbers taken from the cache in the event of a timeout when accessing the vault server. By default this option is disabled. Please note that key values or version numbers will be read from the cache when the timeout expires only after the number of attempts to read them from the storage server that specified by the --[loose-]hashicorp-key-management-retries parameter has been exhausted. * **Commandline:** `--[loose-]hashicorp-key-management-use-cache-on-timeout="on"|"off"` #### `hashicorp-key-management-cache-timeout` * **Description:** The time (in milliseconds) after which the value of the key stored in the cache becomes invalid and an attempt to read this data causes a new request send to the vault server. By default, cache entries become invalid after 60,000 milliseconds (after one minute). If the value of this parameter is zero, then the keys will always be considered invalid, but they still can be used if the vault server is unavailable and the corresponding cache operating mode (--[loose-]hashicorp-key-management-use-cache-on-timeout="on") is enabled. * **Commandline:** `--[loose-]hashicorp-key-management-cache-timeout=<timeout>` #### `hashicorp-key-management-cache-version-timeout` * **Description:** The time (in milliseconds) after which the information about latest version number of the key (which stored in the cache) becomes invalid and an attempt to read this information causes a new request send to the vault server. If the value of this parameter is zero, then information about latest key version numbers always considered invalid, unless there is no communication with the vault server and use of the cache is allowed when the server is unavailable. By default, this parameter is zero, that is, the latest version numbers for the keys stored in the cache are considered always invalid, except when the vault server is unavailable and use of the cache is allowed on server failures. * **Commandline:** `--[loose-]hashicorp-key-management-cache-version-timeout=<timeout>` #### `hashicorp-key-management-check-kv-version` * **Description:** This parameter enables ("on", this is the default value) or disables ("off") checking the kv storage version during plugin initialization. The plugin requires storage to be version 2 or older in order for it to work properly. * **Commandline:** `--[loose-]hashicorp-key-management-check-kv-version="on"|"off"` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb INT INT === Syntax ------ ``` INT[(M)] [SIGNED | UNSIGNED | ZEROFILL] INTEGER[(M)] [SIGNED | UNSIGNED | ZEROFILL] ``` Description ----------- A normal-size integer. When marked UNSIGNED, it ranges from 0 to 4294967295, otherwise its range is -2147483648 to 2147483647 (SIGNED is the default). If a column has been set to ZEROFILL, all values will be prepended by zeros so that the INT value contains a number of M digits. INTEGER is a synonym for INT. **Note:** If the ZEROFILL attribute has been specified, the column will automatically become UNSIGNED. `INT4` is a synonym for `INT`. For details on the attributes, see [Numeric Data Type Overview](../numeric-data-type-overview/index). Examples -------- ``` CREATE TABLE ints (a INT,b INT UNSIGNED,c INT ZEROFILL); ``` With [strict\_mode](../sql-mode/index#strict-mode) set, the default from [MariaDB 10.2.4](https://mariadb.com/kb/en/mariadb-1024-release-notes/): ``` INSERT INTO ints VALUES (-10,-10,-10); ERROR 1264 (22003): Out of range value for column 'b' at row 1 INSERT INTO ints VALUES (-10,10,-10); ERROR 1264 (22003): Out of range value for column 'c' at row 1 INSERT INTO ints VALUES (-10,10,10); INSERT INTO ints VALUES (2147483648,2147483648,2147483648); ERROR 1264 (22003): Out of range value for column 'a' at row 1 INSERT INTO ints VALUES (2147483647,2147483648,2147483648); SELECT * FROM ints; +------------+------------+------------+ | a | b | c | +------------+------------+------------+ | -10 | 10 | 0000000010 | | 2147483647 | 2147483648 | 2147483648 | +------------+------------+------------+ ``` With [strict\_mode](../sql-mode/index#strict-mode) unset, the default until [MariaDB 10.2.3](https://mariadb.com/kb/en/mariadb-1023-release-notes/): ``` INSERT INTO ints VALUES (-10,-10,-10); Query OK, 1 row affected, 2 warnings (0.10 sec) Warning (Code 1264): Out of range value for column 'b' at row 1 Warning (Code 1264): Out of range value for column 'c' at row 1 INSERT INTO ints VALUES (-10,10,-10); Query OK, 1 row affected, 1 warning (0.08 sec) Warning (Code 1264): Out of range value for column 'c' at row 1 INSERT INTO ints VALUES (-10,10,10); INSERT INTO ints VALUES (2147483648,2147483648,2147483648); Query OK, 1 row affected, 1 warning (0.07 sec) Warning (Code 1264): Out of range value for column 'a' at row 1 INSERT INTO ints VALUES (2147483647,2147483648,2147483648); SELECT * FROM ints; +------------+------------+------------+ | a | b | c | +------------+------------+------------+ | -10 | 0 | 0000000000 | | -10 | 10 | 0000000000 | | -10 | 10 | 0000000010 | | 2147483647 | 2147483648 | 2147483648 | | 2147483647 | 2147483648 | 2147483648 | +------------+------------+------------+ ``` See Also -------- * [Numeric Data Type Overview](../numeric-data-type-overview/index) * [TINYINT](../tinyint/index) * [SMALLINT](../smallint/index) * [MEDIUMINT](../mediumint/index) * [BIGINT](../bigint/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Backup, Restore and Import Clients Backup, Restore and Import Clients =================================== Clients for taking backups or importing/restoring data | Title | Description | | --- | --- | | [Backup/Restore + Data Export/Import via dbForge Studio](../backup-restore-and-import-clients-backuprestore-data-exportimport-via-dbfor/index) | The fastest and easiest way to perform these operations with MariaDB databases. | | [Mariabackup](../mariabackup/index) | Physical backups, supports Data-at-Rest and InnoDB compression. | | [Percona XtraBackup](../backing-up-and-restoring-databases-percona-xtrabackup/index) | Open source tool for performing hot backups of MariaDB, MySQL and Percona Server databases. | | [mariadb-dump](../mariadb-dump/index) | Symlink or new name for mysqldump. | | [mariadb-dump/mysqldump](../mariadb-dumpmysqldump/index) | Dump a database or a collection of databases in a portable format. | | [mariadb-hotcopy](../mariadb-hotcopy/index) | Symlink or new name for mysqlhotcopy. | | [mariadb-import](../mariadb-import/index) | Symlink or new name for mysqlimport. | | [mysqlhotcopy](../mysqlhotcopy/index) | Fast backup program on local machine. Deprecated. | | [mysqlimport](../mysqlimport/index) | Loads tables from text files in various formats. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Information Schema Information Schema =================== Articles about the Information Schema | Title | Description | | --- | --- | | [Information Schema Tables](../information-schema-tables/index) | Tables in the Information\_Schema database | | [Extended Show](../extended-show/index) | Extended SHOW with WHERE and LIKE. | | [TIME\_MS column in INFORMATION\_SCHEMA.PROCESSLIST](../time_ms-column-in-information_schemaprocesslist/index) | Microseconds in the INFORMATION\_SCHEMA.PROCESSLIST table | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb CURDATE CURDATE ======= Syntax ------ ``` CURDATE() CURRENT_DATE CURRENT_DATE() ``` Description ----------- `CURDATE` returns the current date as a value in 'YYYY-MM-DD' or YYYYMMDD format, depending on whether the function is used in a string or numeric context. `CURRENT_DATE` and `CURRENT_DATE()` are synonyms. Examples -------- ``` SELECT CURDATE(); +------------+ | CURDATE() | +------------+ | 2019-03-05 | +------------+ ``` In a numeric context (note this is not performing date calculations): ``` SELECT CURDATE() +0; +--------------+ | CURDATE() +0 | +--------------+ | 20190305 | +--------------+ ``` Data calculation: ``` SELECT CURDATE() - INTERVAL 5 DAY; +----------------------------+ | CURDATE() - INTERVAL 5 DAY | +----------------------------+ | 2019-02-28 | +----------------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb CREATE PACKAGE BODY CREATE PACKAGE BODY =================== **MariaDB starting with [10.3.5](https://mariadb.com/kb/en/mariadb-1035-release-notes/)**Oracle-style packages were introduced in [MariaDB 10.3.5](https://mariadb.com/kb/en/mariadb-1035-release-notes/). Syntax ------ ``` CREATE [ OR REPLACE ] [DEFINER = { user | CURRENT_USER | role | CURRENT_ROLE }] PACKAGE BODY [ IF NOT EXISTS ] [ db_name . ] package_name [ package_characteristic... ] { AS | IS } package_implementation_declare_section package_implementation_executable_section END [ package_name] package_implementation_declare_section: package_implementation_item_declaration [ package_implementation_item_declaration... ] [ package_implementation_routine_definition... ] | package_implementation_routine_definition [ package_implementation_routine_definition...] package_implementation_item_declaration: variable_declaration ; variable_declaration: variable_name[,...] type [:= expr ] package_implementation_routine_definition: FUNCTION package_specification_function [ package_implementation_function_body ] ; | PROCEDURE package_specification_procedure [ package_implementation_procedure_body ] ; package_implementation_function_body: { AS | IS } package_routine_body [func_name] package_implementation_procedure_body: { AS | IS } package_routine_body [proc_name] package_routine_body: [ package_routine_declarations ] BEGIN statements [ EXCEPTION exception_handlers ] END package_routine_declarations: package_routine_declaration ';' [package_routine_declaration ';']... package_routine_declaration: variable_declaration | condition_name CONDITION FOR condition_value | user_exception_name EXCEPTION | CURSOR_SYM cursor_name [ ( cursor_formal_parameters ) ] IS select_statement ; package_implementation_executable_section: END | BEGIN statement ; [statement ; ]... [EXCEPTION exception_handlers] END exception_handlers: exception_handler [exception_handler...] exception_handler: WHEN_SYM condition_value [, condition_value]... THEN_SYM statement ; [statement ;]... condition_value: condition_name | user_exception_name | SQLWARNING | SQLEXCEPTION | NOT FOUND | OTHERS_SYM | SQLSTATE [VALUE] sqlstate_value | mariadb_error_code ``` Description ----------- The `CREATE PACKAGE BODY` statement can be used when [Oracle SQL\_MODE](../sql_modeoracle-from-mariadb-103/index) is set. The `CREATE PACKAGE BODY` statement creates the package body for a stored package. The package specification must be previously created using the [CREATE PACKAGE](../create-package/index) statement. A package body provides implementations of the package public routines and can optionally have: * package-wide private variables * package private routines * forward declarations for private routines * an executable initialization section Examples -------- ``` SET sql_mode=ORACLE; DELIMITER $$ CREATE OR REPLACE PACKAGE employee_tools AS FUNCTION getSalary(eid INT) RETURN DECIMAL(10,2); PROCEDURE raiseSalary(eid INT, amount DECIMAL(10,2)); PROCEDURE raiseSalaryStd(eid INT); PROCEDURE hire(ename TEXT, esalary DECIMAL(10,2)); END; $$ CREATE PACKAGE BODY employee_tools AS -- package body variables stdRaiseAmount DECIMAL(10,2):=500; -- private routines PROCEDURE log (eid INT, ecmnt TEXT) AS BEGIN INSERT INTO employee_log (id, cmnt) VALUES (eid, ecmnt); END; -- public routines PROCEDURE hire(ename TEXT, esalary DECIMAL(10,2)) AS eid INT; BEGIN INSERT INTO employee (name, salary) VALUES (ename, esalary); eid:= last_insert_id(); log(eid, 'hire ' || ename); END; FUNCTION getSalary(eid INT) RETURN DECIMAL(10,2) AS nSalary DECIMAL(10,2); BEGIN SELECT salary INTO nSalary FROM employee WHERE id=eid; log(eid, 'getSalary id=' || eid || ' salary=' || nSalary); RETURN nSalary; END; PROCEDURE raiseSalary(eid INT, amount DECIMAL(10,2)) AS BEGIN UPDATE employee SET salary=salary+amount WHERE id=eid; log(eid, 'raiseSalary id=' || eid || ' amount=' || amount); END; PROCEDURE raiseSalaryStd(eid INT) AS BEGIN raiseSalary(eid, stdRaiseAmount); log(eid, 'raiseSalaryStd id=' || eid); END; BEGIN -- This code is executed when the current session -- accesses any of the package routines for the first time log(0, 'Session ' || connection_id() || ' ' || current_user || ' started'); END; $$ DELIMITER ; ``` See Also -------- * [CREATE PACKAGE](../create-package/index) * [SHOW CREATE PACKAGE BODY](../show-create-package-body/index) * [DROP PACKAGE BODY](../drop-package-body/index) * [Oracle SQL\_MODE](../sql_modeoracle-from-mariadb-103/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Prepared Statements Prepared Statements ==================== In addition to using prepared statements from the libmysqld, you can also do prepared statements from any client by using the text based prepared statement interface. You first prepare the statement with [PREPARE](../prepare-statement/index), execute with [EXECUTE](../execute-statement/index), and release it with [DEALLOCATE](../deallocate-drop-prepared-statement/index). | Title | Description | | --- | --- | | [PREPARE Statement](../prepare-statement/index) | Define a prepare statement. | | [Out Parameters in PREPARE](../out-parameters-in-prepare/index) | Using question mark placeholders for out-parameters in the PREPARE statement | | [EXECUTE Statement](../execute-statement/index) | Executes a previously PREPAREd statement | | [DEALLOCATE / DROP PREPARE](../deallocate-drop-prepare/index) | Deallocates a prepared statement. | | [EXECUTE IMMEDIATE](../execute-immediate/index) | Immediately execute a dynamic SQL statement | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb FETCH FETCH ===== Syntax ------ ``` FETCH cursor_name INTO var_name [, var_name] ... ``` Description ----------- This statement fetches the next row (if a row exists) using the specified [open](../open/index) [cursor](../programmatic-and-compound-statements-cursors/index), and advances the cursor pointer. `var_name` can be a [local variable](../declare-variable/index), but *not* a [user-defined variable](../user-defined-variables/index). If no more rows are available, a No Data condition occurs with `SQLSTATE` value `02000`. To detect this condition, you can set up a handler for it (or for a `NOT FOUND` condition). See [Cursor Overview](../cursor-overview/index) for an example. See Also -------- * [Cursor Overview](../cursor-overview/index) * [DECLARE CURSOR](../declare-cursor/index) * [OPEN cursor\_name](../open/index) * [CLOSE cursor\_name](../close/index) * [Cursors in Oracle mode](../sql_modeoracle-from-mariadb-103/index#cursors) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb InnoDB Change Buffering InnoDB Change Buffering ======================= The change buffer has been disabled by default from [MariaDB 10.5.15](https://mariadb.com/kb/en/mariadb-10515-release-notes/), [MariaDB 10.6.7](https://mariadb.com/kb/en/mariadb-1067-release-notes/), [MariaDB 10.7.3](https://mariadb.com/kb/en/mariadb-1073-release-notes/) and [MariaDB 10.8.2](https://mariadb.com/kb/en/mariadb-1082-release-notes/) ([MDEV-27734](https://jira.mariadb.org/browse/MDEV-27734)) and the feature is deprecated and ignored from [MariaDB 10.9.0](https://mariadb.com/kb/en/mariadb-1090-release-notes/) ([MDEV-27735](https://jira.mariadb.org/browse/MDEV-27735)). Benchmarks attached to [MDEV-19514](https://jira.mariadb.org/browse/MDEV-19514) show that the change buffer sometimes reduces performance, and in the best case seem to bring a few per cent improvement to throughput. However, such improvement could come with a price: If the buffered changes are never merged ([MDEV-19514](https://jira.mariadb.org/browse/MDEV-19514), motivated by the reduction of random crashes and the removal of an innodb\_force\_recovery option that can inflict further corruption), then the InnoDB system tablespace can grow out of control ([MDEV-21952](https://jira.mariadb.org/browse/MDEV-21952)). INSERT, UPDATE and DELETE statements can be particularly heavy operations to perform, as all indexes need to be updated after each change. For this reason these changes are often buffered. Pages are modified in the [buffer pool](../innodb-buffer-pool/index), and not immediately on disk. When rows are deleted, a flag is set, thus rows are not immediately deleted on disk. Later the changes will be written to disk (''flushed'') by InnoDB background threads. Pages that have been modified in memory and not yet flushed are called dirty pages. The buffering of data changes is called Change Buffer. Before [MariaDB 5.5](../what-is-mariadb-55/index), only inserted rows could be buffered, so this buffer was called Insert Buffer. The old name still appears in several places, for example in the output of [SHOW ENGINE INNODB STATUS](../show-engine-innodb-status/index). The change buffer only contains changes to the indexes. Inserts to UNIQUE secondary indexes cannot be buffered unless unique\_checks=0 is used. Delete-mark and purge buffering of UNIQUE secondary indexes is allowed. The Change Buffer is an optimization because: * A page can be modified several times in memory and be flushed to disk only once. * Dirty pages are flushed together, so the number of IO operations is lower. If the server crashes, usually the Change Buffer is not empty. However, changes are not lost because they are written to the transaction logs, so they can be applied at server restart. The main server system variable here is [innodb\_change\_buffering](../innodb-system-variables/index#innodb_change_buffering), which determines which form of change buffering, if any, to use. The following settings are available: * inserts + Only buffer insert operations * deletes + Only buffer delete operations * changes + Buffer both insert and delete operations * purges + Buffer the actual physical deletes that occur in the background * all + Buffer inserts, deletes and purges. Default setting from [MariaDB 5.5](../what-is-mariadb-55/index) until [MariaDB 10.5.14](https://mariadb.com/kb/en/mariadb-10514-release-notes/), [MariaDB 10.6.6](https://mariadb.com/kb/en/mariadb-1066-release-notes/), [MariaDB 10.7.2](https://mariadb.com/kb/en/mariadb-1072-release-notes/) and [MariaDB 10.8.1](https://mariadb.com/kb/en/mariadb-1081-release-notes/). * none + Don't buffer any operations. Default from [MariaDB 10.5.15](https://mariadb.com/kb/en/mariadb-10515-release-notes/), [MariaDB 10.6.7](https://mariadb.com/kb/en/mariadb-1067-release-notes/), [MariaDB 10.7.3](https://mariadb.com/kb/en/mariadb-1073-release-notes/) and [MariaDB 10.8.2](https://mariadb.com/kb/en/mariadb-1082-release-notes/). Modifying the value of this variable only affects the buffering of new operations. The merging of already buffered changes is not affected. The [innodb\_change\_buffer\_max\_size](../innodb-system-variables/index#innodb_change_buffer_max_size) server system variable, determines the maximum size of the change buffer, expressed as a percentage of the buffer pool. See Also -------- * [InnoDB Buffer Pool](../innodb-buffer-pool/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Performance Schema table_io_waits_summary_by_index_usage Table Performance Schema table\_io\_waits\_summary\_by\_index\_usage Table ==================================================================== The `table_io_waits_summary_by_index_usage` table records table I/O waits by index. | Column | Description | | --- | --- | | `OBJECT_TYPE` | `TABLE` in the case of all indexes. | | `OBJECT_SCHEMA` | Schema name. | | `OBJECT_NAME` | Table name. | | `INDEX_NAME` | Index name, or `PRIMARY` for the primary index, `NULL` for no index (inserts are counted in this case). | | `COUNT_STAR` | Number of summarized events and the sum of the `x_READ` and `x_WRITE` columns. | | `SUM_TIMER_WAIT` | Total wait time of the summarized events that are timed. | | `MIN_TIMER_WAIT` | Minimum wait time of the summarized events that are timed. | | `AVG_TIMER_WAIT` | Average wait time of the summarized events that are timed. | | `MAX_TIMER_WAIT` | Maximum wait time of the summarized events that are timed. | | `COUNT_READ` | Number of all read operations, and the sum of the equivalent `x_FETCH` columns. | | `SUM_TIMER_READ` | Total wait time of all read operations that are timed. | | `MIN_TIMER_READ` | Minimum wait time of all read operations that are timed. | | `AVG_TIMER_READ` | Average wait time of all read operations that are timed. | | `MAX_TIMER_READ` | Maximum wait time of all read operations that are timed. | | `COUNT_WRITE` | Number of all write operations, and the sum of the equivalent `x_INSERT`, `x_UPDATE` and `x_DELETE` columns. | | `SUM_TIMER_WRITE` | Total wait time of all write operations that are timed. | | `MIN_TIMER_WRITE` | Minimum wait time of all write operations that are timed. | | `AVG_TIMER_WRITE` | Average wait time of all write operations that are timed. | | `MAX_TIMER_WRITE` | Maximum wait time of all write operations that are timed. | | `COUNT_FETCH` | Number of all fetch operations. | | `SUM_TIMER_FETCH` | Total wait time of all fetch operations that are timed. | | `MIN_TIMER_FETCH` | Minimum wait time of all fetch operations that are timed. | | `AVG_TIMER_FETCH` | Average wait time of all fetch operations that are timed. | | `MAX_TIMER_FETCH` | Maximum wait time of all fetch operations that are timed. | | `COUNT_INSERT` | Number of all insert operations. | | `SUM_TIMER_INSERT` | Total wait time of all insert operations that are timed. | | `MIN_TIMER_INSERT` | Minimum wait time of all insert operations that are timed. | | `AVG_TIMER_INSERT` | Average wait time of all insert operations that are timed. | | `MAX_TIMER_INSERT` | Maximum wait time of all insert operations that are timed. | | `COUNT_UPDATE` | Number of all update operations. | | `SUM_TIMER_UPDATE` | Total wait time of all update operations that are timed. | | `MIN_TIMER_UPDATE` | Minimum wait time of all update operations that are timed. | | `AVG_TIMER_UPDATE` | Average wait time of all update operations that are timed. | | `MAX_TIMER_UPDATE` | Maximum wait time of all update operations that are timed. | | `COUNT_DELETE` | Number of all delete operations. | | `SUM_TIMER_DELETE` | Total wait time of all delete operations that are timed. | | `MIN_TIMER_DELETE` | Minimum wait time of all delete operations that are timed. | | `AVG_TIMER_DELETE` | Average wait time of all delete operations that are timed. | | `MAX_TIMER_DELETE` | Maximum wait time of all delete operations that are timed. | You can [TRUNCATE](../truncate-table/index) the table, which will reset all counters to zero. The table is also truncated if the [table\_io\_waits\_summary\_by\_table](../performance-schema-table_io_waits_summary_by_table-table/index) table is truncated. If a table's index structure is changed, index statistics recorded in this table may also be reset. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb Installing MariaDB AX / MariaDB ColumnStore from the Package Repositories - 1.1.X Installing MariaDB AX / MariaDB ColumnStore from the Package Repositories - 1.1.X ================================================================================= Introduction ============ Installing MariaDB AX and MariaDB ColumnStore individual packages can be done from the yum, apt-get, and zypper Repositories based on the OS. MariaDB AX packages which consist of: * MariaDB ColumnStore Platform * MariaDB ColumnStore API (Bulk Write SDK) * MariaDB ColumnStore Data-Adapters * MariaDB ColumnStore Tools * MariaDB Maxscale * MariaDB Connectors + MariaDB Maxscale CDC Connector + MariaDB ODBC Connector + MariaDB Java-client Connector jar file You can install packages from the Repositories for Single-Server installs and for Multi-Server installs utilizing the Non-Distributed feature where the packages are installed on all the servers in the cluster before the configuration and setup is performed. NOTE: Document shows installing the latest GA version of each package by using 'latest' in the download paths. You can also install other version by entering the specific release ID, like 1.1.6-1. MariaDB AX Packages =================== This section shows how to setup and install all associated packages for MariaDB AX. Start by doing the MariaDB Connector Packages. Go to that section and install the connectors first. CentOS 6 -------- ### Adding the MariaDB AX YUM repository Add new file with repository information, /etc/yum.repos.d/mariadb-columnstore.repo ``` [mariadb-columnstore] name=MariaDB ColumnStore baseurl=https://downloads.mariadb.com/MariaDB/mariadb-columnstore/latest/yum/centos/6/x86_64/ gpgkey=https://downloads.mariadb.com/MariaDB/mariadb-columnstore/RPM-GPG-KEY-MariaDB-ColumnStore gpgcheck=1 ``` Add new file with repository information, /etc/yum.repos.d/mariadb-columnstore-tools.repo ``` [mariadb-columnstore-tools] name=MariaDB ColumnStore Tools baseurl=https://downloads.mariadb.com/MariaDB/mariadb-columnstore-tools/latest/yum/centos/6/x86_64/ gpgkey=https://downloads.mariadb.com/MariaDB/mariadb-columnstore/RPM-GPG-KEY-MariaDB-ColumnStore gpgcheck=1 ``` Add new file with repository information, /etc/yum.repos.d/mariadb-maxscale.repo ``` [mariadb-maxscale] name=MariaDB MaxScale baseurl=https://downloads.mariadb.com/MaxScale/latest/centos/6/x86_64 gpgkey=https://downloads.mariadb.com/MaxScale/MariaDB-MaxScale-GPG-KEY gpgcheck=1 ``` ### Installing MariaDB AX With the repo file in place you can now install MariaDB ColumnStore like so: ``` sudo yum --enablerepo=mariadb-columnstore clean metadata sudo yum groups mark remove "MariaDB ColumnStore" sudo yum groupinstall "MariaDB ColumnStore" sudo yum --enablerepo=mariadb-columnstore-tools clean metadata sudo yum install mariadb-columnstore-tools sudo yum --enablerepo=mariadb-maxscale clean metadata sudo yum install maxscale maxscale-cdc-connector ``` CentOS 7 -------- ### Adding the MariaDB AX YUM repository Add new file with repository information, /etc/yum.repos.d/mariadb-columnstore.repo ``` [mariadb-columnstore] name=MariaDB ColumnStore baseurl=https://downloads.mariadb.com/MariaDB/mariadb-columnstore/latest/yum/centos/7/x86_64/ gpgkey=https://downloads.mariadb.com/MariaDB/mariadb-columnstore/RPM-GPG-KEY-MariaDB-ColumnStore gpgcheck=1 ``` Add new file with repository information, /etc/yum.repos.d/mariadb-columnstore-api.repo ``` [mariadb-columnstore-api] name=MariaDB ColumnStore API baseurl=https://downloads.mariadb.com/MariaDB/mariadb-columnstore-api/latest/yum/centos/7/x86_64/ gpgkey=https://downloads.mariadb.com/MariaDB/mariadb-columnstore/RPM-GPG-KEY-MariaDB-ColumnStore gpgcheck=1 ``` ### Adding the MariaDB ColumnStore Tools YUM repository Add new file with repository information, /etc/yum.repos.d/mariadb-columnstore-tools.repo ``` [mariadb-columnstore-tools] name=MariaDB ColumnStore Tools baseurl=https://downloads.mariadb.com/MariaDB/mariadb-columnstore-tools/latest/yum/centos/7/x86_64/ gpgkey=https://downloads.mariadb.com/MariaDB/mariadb-columnstore/RPM-GPG-KEY-MariaDB-ColumnStore gpgcheck=1 ``` Add new file with repository information, /etc/yum.repos.d/mariadb-maxscale.repo ``` [mariadb-maxscale] name=MariaDB MaxScale baseurl=https://downloads.mariadb.com/MaxScale/latest/centos/7/x86_64 gpgkey=https://downloads.mariadb.com/MaxScale/MariaDB-MaxScale-GPG-KEY gpgcheck=1 ``` ### Adding the MariaDB ColumnStore Data Adapters YUM repository Add new file with repository information, /etc/yum.repos.d/mariadb-columnstore-data-adapters.repo ``` [mariadb-columnstore-data-adapters] name=MariaDB ColumnStore Data Adapters baseurl=https://downloads.mariadb.com/MariaDB/data-adapters/mariadb-streaming-data-adapters/latest/yum/centos/7/x86_64/ gpgkey=https://downloads.mariadb.com/MariaDB/mariadb-columnstore/RPM-GPG-KEY-MariaDB-ColumnStore gpgcheck=1 ``` ### Installing MariaDB AX With the repo file in place you can now install MariaDB ColumnStore like so: ``` sudo yum --enablerepo=mariadb-columnstore clean metadata sudo yum groups mark remove "MariaDB ColumnStore" sudo yum groupinstall "MariaDB ColumnStore" sudo yum --enablerepo=mariadb-columnstore-api clean metadata sudo yum install mariadb-columnstore-api sudo yum --enablerepo=mariadb-columnstore-tools clean metadata sudo yum install mariadb-columnstore-tools sudo yum --enablerepo=mariadb-maxscale clean metadata sudo yum install maxscale maxscale-cdc-connector sudo yum --enablerepo=mariadb-columnstore-data-adapters clean metadata sudo yum install mariadb-columnstore-maxscale-cdc-adapters sudo yum install mariadb-columnstore-kafka-adapters ``` SUSE 12 ------- ### Adding the MariaDB ColumnStore ZYPPER repository Add new file with repository information, /etc/zypp/repos.d/mariadb-columnstore.repo ``` [mariadb-columnstore] name=mariadb-columnstore enabled=1 autorefresh=0 baseurl=https://downloads.mariadb.com/MariaDB/mariadb-columnstore/latest/yum/sles/12/x86_64 type=rpm-md ``` Add new file with repository information, /etc/zypp/repos.d/mariadb-columnstore-tools.repo ``` [mariadb-columnstore-tools] name=mariadb-columnstore-tools enabled=1 autorefresh=0 baseurl=https://downloads.mariadb.com/MariaDB/mariadb-columnstore-tools/latest/yum/sles/12/x86_64 type=rpm-md ``` Add new file with repository information, /etc/zypp/repos.d/mariadb-maxscale.repo ``` [mariadb-maxscale] name=mariadb-maxscale enabled=1 autorefresh=0 baseurl=https://downloads.mariadb.com/MaxScale/latest/sles/12/x86_64 type=rpm-md ``` Download the MariaDB ColumnStore and MaxScale keys ``` rpm --import https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key rpm --import https://downloads.mariadb.com/MaxScale/MariaDB-MaxScale-GPG-KEY ``` ### Installing MariaDB ColumnStore With the repo file in place you can now install MariaDB ColumnStore like so: ``` sudo zypper refresh sudo zypper install mariadb-columnstore* sudo zypper install mariadb-columnstore-tools sudo zypper install maxscale maxscale-cdc-connector ``` Debian 8 -------- ### Adding the MariaDB ColumnStore APT-GET repository Install package: ``` sudo apt-get install apt-transport-https ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore.list ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore/latest/repo/debian8 jessie main ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-api.list ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore-api/latest/repo/debian8 jessie main ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-tools.list ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore-tools/latest/repo/debian8 jessie main ``` Add new file with repository information, /etc/apt/sources.list.d/mariadb-maxscale.list ``` deb https://downloads.mariadb.com/MaxScale/latest/debian jessie main ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-data-adapters.list ``` deb https://downloads.mariadb.com/MariaDB/data-adapters/mariadb-streaming-data-adapters/latest/repo/debian8 jessie main ``` Download the MariaDB ColumnStore key ``` wget -qO - https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` Download the MariaDB MaxScale key ``` apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 28C12247 ``` ### Installing MariaDB ColumnStore With the repo file in place you can now install MariaDB ColumnStore like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore* sudo apt-get install mariadb-columnstore-api sudo apt-get install mariadb-columnstore-tools sudo apt-get install maxscale maxscale-cdc-connector sudo apt-get install mariadb-columnstore-maxscale-cdc-adapters sudo apt-get install mariadb-columnstore-kafka-adapters ``` Debian 9 -------- ### Adding the MariaDB ColumnStore APT-GET repository Install package: ``` sudo apt-get install apt-transport-https ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore.list ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore/latest/repo/debian9 stretch main ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-api.list ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore-api/latest/repo/debian9 stretch main ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-tools.list ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore-tools/latest/repo/debian9 stretch main ``` Add new file with repository information, /etc/apt/sources.list.d/mariadb-maxscale.list ``` deb https://downloads.mariadb.com/MaxScale/latest/debian stretch main ``` ``` deb https://downloads.mariadb.com/MariaDB/data-adapters/mariadb-streaming-data-adapters/latest/repo/debian9 stretch main ``` Download the MariaDB ColumnStore key ``` wget -qO - https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` Download the MariaDB MaxScale key ``` apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 28C12247 ``` ### Installing MariaDB ColumnStore With the repo file in place you can now install MariaDB ColumnStore like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore* sudo apt-get install mariadb-columnstore-api sudo apt-get install mariadb-columnstore-tools sudo apt-get install maxscale maxscale-cdc-connector sudo apt-get install mariadb-columnstore-maxscale-cdc-adapters sudo apt-get install mariadb-columnstore-kafka-adapters ``` Ubuntu 16 --------- ### Adding the MariaDB ColumnStore APT-GET repository Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore.list ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore/latest/repo/ubuntu16 xenial main ``` ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore-api/latest/repo/ubuntu16 xenial main ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-tools.list ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore-tools/latest/repo/ubuntu16 xenial main ``` Add new file with repository information, /etc/apt/sources.list.d/mariadb-maxscale.list ``` deb https://downloads.mariadb.com/MaxScale/latest/ubuntu xenial main ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-data-adapters.list ``` deb https://downloads.mariadb.com/MariaDB/data-adapters/mariadb-streaming-data-adapters/latest/repo/ubuntu16 xenial main ``` Download the MariaDB ColumnStore key ``` wget -qO - https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` Download the MariaDB MaxScale key ``` apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 28C12247 ``` Ubuntu 18 --------- ### Adding the MariaDB ColumnStore APT-GET repository Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore.list ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore/latest/repo/ubuntu18 bionic main ``` ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore-api/latest/repo/ubuntu18 bionic main ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-tools.list ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore-tools/latest/repo/ubuntu18 bionic main ``` Add new file with repository information, /etc/apt/sources.list.d/mariadb-maxscale.list ``` deb https://downloads.mariadb.com/MaxScale/latest/ubuntu xenial main ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-data-adapters.list ``` deb https://downloads.mariadb.com/MariaDB/data-adapters/mariadb-streaming-data-adapters/latest/repo/ubuntu18 bionic main ``` Download the MariaDB ColumnStore key ``` wget -qO - https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` Download the MariaDB MaxScale key ``` apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 28C12247 ``` ### Installing MariaDB ColumnStore With the repo file in place you can now install MariaDB ColumnStore like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore* sudo apt-get install mariadb-columnstore-api sudo apt-get install mariadb-columnstore-tools sudo apt-get install maxscale maxscale-cdc-connector sudo apt-get install mariadb-columnstore-maxscale-cdc-adapters sudo apt-get install mariadb-columnstore-kafka-adapters ``` MariaDB ColumnStore Packages ============================ Before install, make sure you go through the preparation guide to complete the system setup before installs the packages [https://mariadb.com/kb/en/library/preparing-for-columnstore-installation-11x/](../library/preparing-for-columnstore-installation-11x/index) CentOS 6 -------- ### Adding the MariaDB ColumnStore YUM repository Add new file with repository information, /etc/yum.repos.d/mariadb-columnstore.repo ``` [mariadb-columnstore] name=MariaDB ColumnStore baseurl=https://downloads.mariadb.com/MariaDB/mariadb-columnstore/latest/yum/centos/6/x86_64/ gpgkey=https://downloads.mariadb.com/MariaDB/mariadb-columnstore/RPM-GPG-KEY-MariaDB-ColumnStore gpgcheck=1 ``` ### Installing MariaDB ColumnStore With the repo file in place you can now install MariaDB ColumnStore like so: ``` sudo yum --enablerepo=mariadb-columnstore clean metadata sudo yum groups mark remove "MariaDB ColumnStore" sudo yum groupinstall "MariaDB ColumnStore" ``` You can also install this way: ``` sudo yum --enablerepo=mariadb-columnstore clean metadata sudo yum install mariadb-columnstore* ``` CentOS 7 -------- ### Adding the MariaDB ColumnStore YUM repository Add new file with repository information, /etc/yum.repos.d/mariadb-columnstore.repo ``` [mariadb-columnstore] name=MariaDB ColumnStore baseurl=https://downloads.mariadb.com/MariaDB/mariadb-columnstore/latest/yum/centos/7/x86_64/ gpgkey=https://downloads.mariadb.com/MariaDB/mariadb-columnstore/RPM-GPG-KEY-MariaDB-ColumnStore gpgcheck=1 ``` ### Installing MariaDB ColumnStore With the repo file in place you can now install MariaDB ColumnStore like so: ``` sudo yum --enablerepo=mariadb-columnstore clean metadata sudo yum groups mark remove "MariaDB ColumnStore" sudo yum groupinstall "MariaDB ColumnStore" ``` You can also install this way: ``` sudo yum --enablerepo=mariadb-columnstore clean metadata sudo yum install mariadb-columnstore* ``` SUSE 12 ------- ### Adding the MariaDB ColumnStore ZYPPER repository Add new file with repository information, /etc/zypp/repos.d/mariadb-columnstore.repo ``` [mariadb-columnstore] name=mariadb-columnstore enabled=1 autorefresh=0 baseurl=https://downloads.mariadb.com/MariaDB/mariadb-columnstore/latest/yum/sles/12/x86_64 type=rpm-md ``` Download the MariaDB ColumnStore key ``` rpm --import https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key ``` ### Installing MariaDB ColumnStore With the repo file in place you can now install MariaDB ColumnStore like so: ``` sudo zypper refresh sudo zypper install mariadb-columnstore* ``` Debian 8 -------- ### Adding the MariaDB ColumnStore APT-GET repository Install package: ``` sudo apt-get install apt-transport-https ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore.list ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore/latest/repo/debian8 jessie main ``` Download the MariaDB ColumnStore key ``` wget -qO - https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` ### Installing MariaDB ColumnStore With the repo file in place you can now install MariaDB ColumnStore like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore* ``` Debian 9 -------- ### Adding the MariaDB ColumnStore APT-GET repository Install package: ``` sudo apt-get install apt-transport-https ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore.list ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore/latest/repo/debian9 stretch main ``` Download the MariaDB ColumnStore key ``` wget -qO - https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` ### Installing MariaDB ColumnStore With the repo file in place you can now install MariaDB ColumnStore like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore* ``` Ubuntu 16 --------- ### Adding the MariaDB ColumnStore APT-GET repository Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore.list ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore/latest/repo/ubuntu16 xenial main ``` Download the MariaDB ColumnStore key ``` wget -qO - https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` ### Installing MariaDB ColumnStore With the repo file in place you can now install MariaDB ColumnStore like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore* ``` Ubuntu 18 --------- ### Adding the MariaDB ColumnStore APT-GET repository Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore.list ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore/latest/repo/ubuntu18 bionic main ``` Download the MariaDB ColumnStore key ``` wget -qO - https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` ### Installing MariaDB ColumnStore With the repo file in place you can now install MariaDB ColumnStore like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore* ``` ### After installation After the installation completes, follow the configuration and startup steps in the Single-Node and Multi-Node Installation guides using the [Non-Distributed Install feature](../library/installing-and-configuring-a-multi-server-columnstore-system-11x/index#non-distributed-install). MariaDB ColumnStore API (Bulk Write SDK) Package ================================================ Additional information on the ColumnStore API (Bulk Write SDK): [https://mariadb.com/kb/en/library/columnstore-bulk-write-sdk/](../library/columnstore-bulk-write-sdk/index) CentOS 7 -------- ### Adding the MariaDB ColumnStore API YUM repository Add new file with repository information, /etc/yum.repos.d/mariadb-columnstore-api.repo ``` [mariadb-columnstore-api] name=MariaDB ColumnStore API baseurl=https://downloads.mariadb.com/MariaDB/mariadb-columnstore-api/latest/yum/centos/7/x86_64/ gpgkey=https://downloads.mariadb.com/MariaDB/mariadb-columnstore/RPM-GPG-KEY-MariaDB-ColumnStore gpgcheck=1 ``` ### Installing MariaDB ColumnStore API With the repo file in place you can now install MariaDB ColumnStore API like so: ``` sudo yum --enablerepo=mariadb-columnstore-api clean metadata sudo yum install mariadb-columnstore-api ``` Debian 8 -------- ### Adding the MariaDB ColumnStore API APT-GET repository Install package: ``` sudo apt-get install apt-transport-https ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-api.list ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore-api/latest/repo/debian8 jessie main ``` Download the MariaDB ColumnStore key ``` wget -qO - https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` ### Installing MariaDB ColumnStore API With the repo file in place you can now install MariaDB ColumnStore API like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-api ``` Debian 9 -------- ### Adding the MariaDB ColumnStore API APT-GET repository Install package: ``` sudo apt-get install apt-transport-https ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-api.list ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore-api/latest/repo/debian9 stretch main ``` Download the MariaDB ColumnStore key ``` wget -qO - https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` ### Installing MariaDB ColumnStore API With the repo file in place you can now install MariaDB ColumnStore API like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-api ``` Ubuntu 16 --------- ### Adding the MariaDB ColumnStore API APT-GET repository Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-api.list ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore-api/latest/repo/ubuntu16 xenial main ``` Download the MariaDB ColumnStore key ``` wget -qO - https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` Ubuntu 18 --------- ### Adding the MariaDB ColumnStore API APT-GET repository Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-api.list ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore-api/latest/repo/ubuntu18 bionic main ``` Download the MariaDB ColumnStore key ``` wget -qO - https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` ### Installing MariaDB ColumnStore API With the repo file in place you can now install MariaDB ColumnStore API like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-api ``` MariaDB ColumnStore Tools Package ================================= Additional information on the Backup and Restore Tool: [https://mariadb.com/kb/en/library/backup-and-restore-for-mariadb-columnstore-110-onwards/](../library/backup-and-restore-for-mariadb-columnstore-110-onwards/index) CentOS 6 -------- ### Adding the MariaDB ColumnStore Tools YUM repository Add new file with repository information, /etc/yum.repos.d/mariadb-columnstore-tools.repo ``` [mariadb-columnstore-tools] name=MariaDB ColumnStore Tools baseurl=https://downloads.mariadb.com/MariaDB/mariadb-columnstore-tools/latest/yum/centos/6/x86_64/ gpgkey=https://downloads.mariadb.com/MariaDB/mariadb-columnstore/RPM-GPG-KEY-MariaDB-ColumnStore gpgcheck=1 ``` ### Installing MariaDB ColumnStore Tools With the repo file in place you can now install MariaDB ColumnStore Tools like so: ``` sudo yum --enablerepo=mariadb-columnstore-tools clean metadata sudo yum install mariadb-columnstore-tools ``` CentOS 7 -------- ### Adding the MariaDB ColumnStore Tools YUM repository Add new file with repository information, /etc/yum.repos.d/mariadb-columnstore-tools.repo ``` [mariadb-columnstore-tools] name=MariaDB ColumnStore Tools baseurl=https://downloads.mariadb.com/MariaDB/mariadb-columnstore-tools/latest/yum/centos/7/x86_64/ gpgkey=https://downloads.mariadb.com/MariaDB/mariadb-columnstore/RPM-GPG-KEY-MariaDB-ColumnStore gpgcheck=1 ``` ### Installing MariaDB ColumnStore Tools With the repo file in place you can now install MariaDB ColumnStore Tools like so: ``` sudo yum --enablerepo=mariadb-columnstore-tools clean metadata sudo yum install mariadb-columnstore-tools ``` SUSE 12 ------- ### Adding the MariaDB ColumnStore Tools ZYPPER repository Add new file with repository information, /etc/zypp/repos.d/mariadb-columnstore-tools.repo ``` [mariadb-columnstore-tools] name=mariadb-columnstore-tools enabled=1 autorefresh=0 baseurl=https://downloads.mariadb.com/MariaDB/mariadb-columnstore-tools/latest/yum/sles/12/x86_64 type=rpm-md ``` Download the MariaDB ColumnStore key ``` rpm --import https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key ``` ### Installing MariaDB ColumnStore With the repo file in place you can now install MariaDB ColumnStore like so: ``` sudo zypper refresh sudo zypper install mariadb-columnstore-tools ``` Debian 8 -------- ### Adding the MariaDB ColumnStore Tools APT-GET repository Install package: ``` sudo apt-get install apt-transport-https ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-tools.list ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore-tools/latest/repo/debian8 jessie main ``` Download the MariaDB ColumnStore key ``` wget -qO - https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` ### Installing MariaDB ColumnStore Tools With the repo file in place you can now install MariaDB ColumnStore Tools like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-tools ``` Debian 9 -------- ### Adding the MariaDB ColumnStore Tools APT-GET repository Install package: ``` sudo apt-get install apt-transport-https ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-tools.list ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore-tools/latest/repo/debian9 stretch main ``` Download the MariaDB ColumnStore key ``` wget -qO - https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` ### Installing MariaDB ColumnStore Tools With the repo file in place you can now install MariaDB ColumnStore Tools like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-tools ``` Ubuntu 16 --------- ### Adding the MariaDB ColumnStore Tools APT-GET repository Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-tools.list ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore-tools/latest/repo/ubuntu16 xenial main ``` Download the MariaDB ColumnStore key ``` wget -qO - https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` Ubuntu 18 --------- ### Adding the MariaDB ColumnStore Tools APT-GET repository Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-tools.list ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore-tools/latest/repo/ubuntu18 bionic main ``` Download the MariaDB ColumnStore key ``` wget -qO - https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` ### Installing MariaDB ColumnStore Tools With the repo file in place you can now install MariaDB ColumnStore Tools like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-tools ``` MariaDB MaxScale Packages ========================= CentOS 6 -------- ### Adding the MariaDB MaxScale YUM repository Add new file with repository information, /etc/yum.repos.d/mariadb-maxscale.repo ``` [mariadb-maxscale] name=MariaDB MaxScale baseurl=https://downloads.mariadb.com/MaxScale/latest/centos/6/x86_64 gpgkey=https://downloads.mariadb.com/MaxScale/MariaDB-MaxScale-GPG-KEY gpgcheck=1 ``` ### Installing MariaDB MaxScale With the repo file in place you can now install MariaDB MaxScale like so: You can also install this way: ``` sudo yum --enablerepo=mariadb-maxscale clean metadata sudo yum install maxscale maxscale-cdc-connector ``` CentOS 7 -------- ### Adding the MariaDB MaxScale YUM repository Add new file with repository information, /etc/yum.repos.d/mariadb-maxscale.repo ``` [mariadb-maxscale] name=MariaDB MaxScale baseurl=https://downloads.mariadb.com/MaxScale/latest/centos/7/x86_64 gpgkey=https://downloads.mariadb.com/MaxScale/MariaDB-MaxScale-GPG-KEY gpgcheck=1 ``` ### Installing MariaDB MaxScale You can also install this way: ``` sudo yum --enablerepo=mariadb-maxscale clean metadata sudo yum install maxscale maxscale-cdc-connector ``` SUSE 12 ------- ### Adding the MariaDB MaxScale ZYPPER repository Add new file with repository information, /etc/zypp/repos.d/mariadb-maxscale.repo ``` [mariadb-maxscale] name=mariadb-maxscale enabled=1 autorefresh=0 baseurl=https://downloads.mariadb.com/MaxScale/latest/sles/12/x86_64 type=rpm-md ``` Download the MariaDB MaxScale key ``` rpm --import https://downloads.mariadb.com/MaxScale/MariaDB-MaxScale-GPG-KEY ``` ### Installing MariaDB MaxScale With the repo file in place you can now install MariaDB MaxScale like so: ``` sudo zypper refresh sudo zypper install maxscale maxscale-cdc-connector ``` Debian 8 -------- ### Adding the MariaDB MaxScale APT-GET repository Install package: ``` sudo apt-get install apt-transport-https ``` Add new file with repository information, /etc/apt/sources.list.d/mariadb-maxscale.list ``` deb https://downloads.mariadb.com/MaxScale/latest/debian jessie main ``` Download the MariaDB MaxScale key ``` apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 28C12247 ``` ### Installing MariaDB MaxScale Additional information on setting to Maxscale: [https://mariadb.com/kb/en/mariadb-enterprise/mariadb-maxscale-14/mariadb-maxscale-installation-guide/](../mariadb-enterprise/mariadb-maxscale-14/mariadb-maxscale-installation-guide/index) With the repo file in place you can now install MariaDB MaxScale like so: ``` sudo apt-get update sudo apt-get install maxscale maxscale-cdc-connector ``` Debian 9 -------- ### Adding the MariaDB MaxScale APT-GET repository Install package: ``` sudo apt-get install apt-transport-https ``` Add new file with repository information, /etc/apt/sources.list.d/mariadb-maxscale.list ``` deb https://downloads.mariadb.com/MaxScale/latest/debian stretch main ``` Download the MariaDB MaxScale key ``` apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 28C12247 ``` ### Installing MariaDB MaxScale With the repo file in place you can now install MariaDB MaxScale like so: ``` sudo apt-get update sudo apt-get install maxscale maxscale-cdc-connector ``` Ubuntu 16 --------- ### Adding the MariaDB MaxScale APT-GET repository Add new file with repository information, /etc/apt/sources.list.d/mariadb-maxscale.list ``` deb https://downloads.mariadb.com/MaxScale/latest/ubuntu xenial main ``` Download the MariaDB MaxScale key ``` apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 28C12247 ``` Ubuntu 18 --------- ### Adding the MariaDB MaxScale APT-GET repository Add new file with repository information, /etc/apt/sources.list.d/mariadb-maxscale.list ``` deb https://downloads.mariadb.com/MaxScale/latest/ubuntu bionic main ``` Download the MariaDB MaxScale key ``` apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 28C12247 ``` ### Installing MariaDB MaxScale With the repo file in place you can now install MariaDB MaxScale like so: ``` sudo apt-get update sudo apt-get install maxscale maxscale-cdc-connector ``` MariaDB Connector Packages ========================== ODBC Connector -------------- Additional Information on the ODBC connector: [https://mariadb.com/kb/en/library/mariadb-connector-odbc/](../library/mariadb-connector-odbc/index) How to Install the ODBC Connector: [https://mariadb.com/kb/en/library/about-mariadb-connector-odbc/](../library/about-mariadb-connector-odbc/index) Java Connector -------------- Additional information on the Java Connector: [https://mariadb.com/kb/en/library/mariadb-connector-j/](../library/mariadb-connector-j/index) How to Install the Java Connector: [https://mariadb.com/kb/en/library/getting-started-with-the-java-connector/](../library/getting-started-with-the-java-connector/index) MariaDB ColumnStore Data Adapters Packages ========================================== Additional information on the Data Adapters: [https://mariadb.com/kb/en/library/columnstore-streaming-data-adapters/](../library/columnstore-streaming-data-adapters/index) NOTE: MaxScale CDC Connector requires the MariaDB MaxScale package be installed first. The MariaDB ColumnStore Data Adapters Packages are: * Kafka Adapters * Maxscale CDC Adapters Kafka install package dependencies: * N/A Maxscale CDC install package dependencies:: * MaxScale CDC Connector * MariaDB ColumnStore API * MariaDB MaxScale CentOS 7 -------- ### Adding the MariaDB ColumnStore Data Adapters YUM repository Add new file with repository information, /etc/yum.repos.d/mariadb-columnstore-data-adapters.repo ``` [mariadb-columnstore-data-adapters] name=MariaDB ColumnStore Data Adapters baseurl=https://downloads.mariadb.com/MariaDB/data-adapters/mariadb-streaming-data-adapters/latest/yum/centos/7/x86_64/ gpgkey=https://downloads.mariadb.com/MariaDB/mariadb-columnstore/RPM-GPG-KEY-MariaDB-ColumnStore gpgcheck=1 ``` ### Installing MariaDB ColumnStore Data Adapters With the repo file in place you can now install MariaDB ColumnStore Maxscale CDC Data Adapters like so: ``` sudo yum --enablerepo=mariadb-columnstore-data-adapters clean metadata sudo yum install mariadb-columnstore-maxscale-cdc-adapters ``` With the repo file in place you can now install MariaDB ColumnStore Kafka Data Adapters like so: ``` sudo yum --enablerepo=mariadb-columnstore-data-adapters clean metadata sudo yum install mariadb-columnstore-kafka-adapters ``` Debian 8 -------- ### Adding the MariaDB ColumnStore Data Adapters APT-GET repository Install package: ``` sudo apt-get install apt-transport-https ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-data-adapters.list ``` deb https://downloads.mariadb.com/MariaDB/data-adapters/mariadb-streaming-data-adapters/latest/repo/debian8 jessie main ``` Download the MariaDB ColumnStore key ``` wget -qO - https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` ### Installing MariaDB ColumnStore Data Adapters With the repo file in place you can now install MariaDB ColumnStore Maxscale CDC Data Adapters like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-maxscale-cdc-adapters ``` With the repo file in place you can now install MariaDB ColumnStore Kafka Data Adapters like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-kafka-adapters ``` Debian 9 -------- ### Adding the MariaDB ColumnStore Data Adapters APT-GET repository Install package: ``` sudo apt-get install apt-transport-https ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-data-adapters.list ``` deb https://downloads.mariadb.com/MariaDB/data-adapters/mariadb-streaming-data-adapters/latest/repo/debian9 stretch main ``` Download the MariaDB ColumnStore key ``` wget -qO - https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` ### Installing MariaDB ColumnStore Data Adapters With the repo file in place you can now install MariaDB ColumnStores Maxscale CDC Data Adapters like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-maxscale-cdc-adapters ``` With the repo file in place you can now install MariaDB ColumnStores Kafka Data Adapters like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-kafka-adapters ``` Ubuntu 16 --------- ### Adding the MariaDB ColumnStore Data Adapters APT-GET repository Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-data-adapters.list ``` deb https://downloads.mariadb.com/MariaDB/data-adapters/mariadb-streaming-data-adapters/latest/repo/ubuntu16 xenial main ``` Download the MariaDB ColumnStore key ``` wget -qO - https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` Ubuntu 18 --------- ### Adding the MariaDB ColumnStore Data Adapters APT-GET repository Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-data-adapters.list ``` deb https://downloads.mariadb.com/MariaDB/data-adapters/mariadb-streaming-data-adapters/latest/repo/ubuntu18 bionic main ``` Download the MariaDB ColumnStore key ``` wget -qO - https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` ### Installing MariaDB ColumnStore Data Adapters With the repo file in place you can now install MariaDB ColumnStore Maxscale CDC Data Adapters like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-maxscale-cdc-adapters ``` With the repo file in place you can now install MariaDB ColumnStore Kafka Data Adapters like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-kafka-adapters ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb mysql.innodb_index_stats mysql.innodb\_index\_stats ========================== The `mysql.innodb_index_stats` table stores data related to particular [InnoDB Persistent Statistics](../innodb-persistent-statistics/index), and contains multiple rows for each index. This table, along with the related [mysql.innodb\_table\_stats](../mysqlinnodb_table_stats/index) table, can be manually updated in order to force or test differing query optimization plans. After updating, `FLUSH TABLE innodb_index_stats` is required to load the changes. `mysql.innodb_index_stats` is not replicated, although any [ANALYZE TABLE](../analyze-table/index) statements on the table will be by default.. It contains the following fields: | Field | Type | Null | Key | Default | Description | | --- | --- | --- | --- | --- | --- | | `database_name` | `varchar(64)` | NO | PRI | `NULL` | Database name. | | `table_name` | `varchar(64)` | NO | PRI | `NULL` | Table, partition or subpartition name. | | `index_name` | `varchar(64)` | NO | PRI | `NULL` | Index name. | | `last_update` | `timestamp` | NO | | `current_timestamp()` | Time that this row was last updated. | | `stat_name` | `varchar(64)` | NO | PRI | `NULL` | Statistic name. | | `stat_value` | `bigint(20) unsigned` | NO | | `NULL` | Estimated statistic value. | | `sample_size` | `bigint(20) unsigned` | YES | | `NULL` | Number of pages sampled for the estimated statistic value. | | `stat_description` | `varchar(1024)` | NO | | `NULL` | Statistic description. | Example ------- ``` SELECT * FROM mysql.innodb_index_stats\G *************************** 1. row *************************** database_name: mysql table_name: gtid_slave_pos index_name: PRIMARY last_update: 2017-08-19 20:38:34 stat_name: n_diff_pfx01 stat_value: 0 sample_size: 1 stat_description: domain_id *************************** 2. row *************************** database_name: mysql table_name: gtid_slave_pos index_name: PRIMARY last_update: 2017-08-19 20:38:34 stat_name: n_diff_pfx02 stat_value: 0 sample_size: 1 stat_description: domain_id,sub_id *************************** 3. row *************************** database_name: mysql table_name: gtid_slave_pos index_name: PRIMARY last_update: 2017-08-19 20:38:34 stat_name: n_leaf_pages stat_value: 1 sample_size: NULL stat_description: Number of leaf pages in the index *************************** 4. row *************************** database_name: mysql table_name: gtid_slave_pos index_name: PRIMARY last_update: 2017-08-19 20:38:34 stat_name: size stat_value: 1 sample_size: NULL stat_description: Number of pages in the index *************************** 5. row *************************** database_name: test table_name: ft index_name: FTS_DOC_ID_INDEX last_update: 2017-09-15 12:58:39 stat_name: n_diff_pfx01 stat_value: 0 sample_size: 1 stat_description: FTS_DOC_ID *************************** 6. row *************************** database_name: test table_name: ft index_name: FTS_DOC_ID_INDEX last_update: 2017-09-15 12:58:39 stat_name: n_leaf_pages stat_value: 1 sample_size: NULL stat_description: Number of leaf pages in the index ... ``` See Also -------- * [InnoDB Persistent Statistics](../innodb-persistent-statistics/index) * [mysql.innodb\_table\_stats](../mysqlinnodb_table_stats/index) * [ANALYZE TABLE](../analyze-table/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Function and Operator Reference Function and Operator Reference =============================== | Name | Description | | --- | --- | | [+](../addition-operator/index) | Addition operator | | [/](../division-operator/index) | Division operator | | [\*](../multiplication-operator/index) | Multiplication operator | | [%](../modulo-operator/index) | Modulo operator. Returns the remainder of N divided by M | | [-](../subtraction-operator-/index) | Subtraction operator | | [!=](../not-equal/index) | Not equals | | [<](../less-than/index) | Less than | | [<=](../less-than-or-equal/index) | Less than or equal | | [<=>](../null-safe-equal/index) | NULL-safe equal | | [=](../equal/index) | Equal | | [>](../greater-than/index) | Greater than | | [>=](../greater-than-or-equal/index) | Greater than or equal | | [&](../bitwise_and/index) | Bitwise AND | | [<<](../shift-left/index) | Shift left | | [>>](../shift-right/index) | Shift right | | [^](../bitwise-xor/index) | Bitwise XOR | | [!](../not/index) | Logical NOT | | [&&](../and/index) | Logical AND | | [XOR](../xor/index) | Logical XOR | | `||` | Logical OR | | `|` | [Bitwise OR](../bitwise-or/index) | | [:=](../assignment-operator/index) | Assignment operator | | [=](../assignment-operators-assignment-operator/index) | Assignment and comparison operator | | ~ | [Bitwise NOT](../bitwise-not/index) | | [ABS](../abs/index) | Returns an absolute value | | [ACOS](../acos/index) | Returns an arc cosine | | [ADD\_MONTHS](../add_months/index) | Add months to a date | | [ADDDATE](../adddate/index) | Add days or another interval to a date | | [ADDTIME](../addtime/index) | Adds a time to a time or datetime | | [AES\_DECRYPT](../aes_decrypt/index) | Decryption data encrypted with AES\_ENCRYPT | | [AES\_ENCRYPT](../aes_encrypt/index) | Encrypts a string with the AES algorithm | | [AREA](../area/index) | Synonym for ST\_AREA | | [AsBinary](../asbinary/index) | Synonym for ST\_AsBinary | | [ASCII](../ascii/index) | Numeric ASCII value of leftmost character | | [ASIN](../asin/index) | Returns the arc sine | | [AsText](../astext/index) | Synonym for ST\_AsText | | [AsWKB](../aswkb/index) | Synonym for ST\_AsBinary | | [AsWKT](../aswkt/index) | Synonym for ST\_AsText | | [ATAN](../atan/index) | Returns the arc tangent | | [ATAN2](../atan2/index) | Returns the arc tangent of two variables | | [AVG](../avg/index) | Returns the average value | | [BENCHMARK](../benchmark/index) | Executes an expression repeatedly | | [BETWEEN AND](../between-and/index) | True if expression between two values | | [BIN](../bin/index) | Returns binary value | | [BINARY OPERATOR](../binary-operator/index) | Casts to a binary string | | [BINLOG\_GTID\_POS](../binlog_gtid_pos/index) | Returns a string representation of the corresponding GTID position | | [BIT\_AND](../bit_and/index) | Bitwise AND | | [BIT\_COUNT](../bit_count/index) | Returns the number of set bits | | [BIT\_LENGTH](../bit_length/index) | Returns the length of a string in bits | | [BIT\_OR](../bit_or/index) | Bitwise OR | | [BIT\_XOR](../bit_xor/index) | Bitwise XOR | | [BOUNDARY](../boundary/index) | Synonym for ST\_BOUNDARY | | [BUFFER](../buffer/index) | Synonym for ST\_BUFFER | | [CASE](../case-operator/index) | Returns the result where value=compare\_value or for the first condition that is true | | [CAST](../cast/index) | Casts a value of one type to another type | | [CEIL](../ceil/index) | Synonym for CEILING() | | [CEILING](../ceiling/index) | Returns the smallest integer not less than X | | [CENTROID](../centroid/index) | Synonym for ST\_CENTROID | | [CHAR Function](../char-function/index) | Returns string based on the integer values for the individual characters | | [CHARACTER\_LENGTH](../character_length/index) | Synonym for CHAR\_LENGTH() | | [CHAR\_LENGTH](../char_length/index) | Length of the string in characters | | [CHARSET](../charset/index) | Returns the character set | | [CHR](../chr/index) | Returns a string consisting of the character given by the code values of the integer | | [COALESCE](../coalesce/index) | Returns the first non-NULL parameter | | [COERCIBILITY](../coercibility/index) | Returns the collation coercibility value | | [COLLATION](../collation/index) | Collation of the string argument | | [COLUMN\_ADD](../column_add/index) | Adds or updates dynamic columns | | [COLUMN\_CHECK](../column_check/index) | Checks if a dynamic column blob is valid | | [COLUMN\_CREATE](../column_create/index) | Returns a dynamic columns blob | | [COLUMN\_DELETE](../column_delete/index) | Deletes a dynamic column | | [COLUMN\_EXISTS](../column_exists/index) | Checks is a column exists | | [COLUMN\_GET](../column_get/index) | Gets a dynamic column value by name | | [COLUMN\_JSON](../column_json/index) | Returns a JSON representation of dynamic column blob data | | [COLUMN\_LIST](../column_list/index) | Returns comma-separated list | | [COMPRESS](../compress/index) | Returns a binary, compressed string | | [CONCAT](../concat/index) | Returns concatenated string | | [CONCAT\_WS](../concat_ws/index) | Concatenate with separator | | [CONNECTION\_ID](../connection_id/index) | Connection thread ID | | [CONTAINS](../contains/index) | Whether one geometry contains another | | [CONVERT](../convert/index) | Convert a value from one type to another type | | [CONV](../conv/index) | Converts numbers between different number bases | | [CONVERT\_TZ](../convert_tz/index) | Converts a datetime from on time zone to another | | [CONVEXHULL](../convexhull/index) | Synonym for ST\_CONVEXHULL | | [COS](../cos/index) | Returns the cosine | | [COT](../cot/index) | Returns the cotangent | | [COUNT](../count/index) | Returns count of non-null values | | [COUNT DISTINCT](../count-distinct/index) | Returns count of number of different non-NULL values | | [CRC32](../crc32/index) | Computes a cyclic redundancy check value | | [CROSSES](../crosses/index) | Whether two geometries spatially cross | | [CUME\_DIST](../cume_dist/index) | Window function that returns the cumulative distribution of a given row | | [CURDATE](../curdate/index) | Returns the current date | | [CURRENT\_DATE](../current_date/index) | Synonym for CURDATE() | | [CURRENT\_ROLE](../current_role/index) | Current role name | | [CURRENT\_TIME](../current_time/index) | Synonym for CURTIME() | | [CURRENT\_TIMESTAMP](../current_timestamp/index) | Synonym for NOW() | | [CURRENT\_USER](../current_user/index) | Username/host that authenicated the current client | | [CURTIME](../curtime/index) | Returns the current time | | [DATABASE](../database/index) | Current default database | | [DATE FUNCTION](../date-function/index) | Extracts the date portion of a datetime | | [DATEDIFF](../datediff/index) | Difference in days between two date/time values | | [DATE\_ADD](../date_add/index) | Date arithmetic - addition | | [DATE\_FORMAT](../date_format/index) | Formats the date value according to the format string | | [DATE\_SUB](../date_sub/index) | Date arithmetic - subtraction | | [DAY](../day/index) | Synonym for DAYOFMONTH() | | [DAYNAME](../dayname/index) | Return the name of the weekday | | [DAYOFMONTH](../dayofmonth/index) | Returns the day of the month | | [DAYOFWEEK](../dayofweek/index) | Returns the day of the week index | | [DAYOFYEAR](../dayofyear/index) | Returns the day of the year | | [DECODE](../decode/index) | Decrypts a string encoded with ENCODE() | | [DECODE\_HISTOGRAM](../decode_histogram/index) | Returns comma separated numerics corresponding to a probability distribution represented by a histogram | | [DEFAULT](../default/index) | Returns column default | | [DEGREES](../degrees/index) | Converts from radians to degrees | | [DENSE\_RANK](../dense_rank/index) | Rank of a given row with identical values receiving the same result, no skipping | | [DES\_DECRYPT](../des_decrypt/index) | Decrypts a string encrypted with DES\_ENCRYPT() | | [DES\_ENCRYPT](../des_encrypt/index) | Encrypts a string using the Triple-DES algorithm | | [DIMENSION](../dimension/index) | Synonym for ST\_DIMENSION | | [DISJOINT](../disjoint/index) | Whether the two elements do not intersect | | [DIV](../div/index) | Integer division | | [ELT](../elt/index) | Returns the N'th element from a set of strings | | [ENCODE](../encode/index) | Encrypts a string | | [ENCRYPT](../encrypt/index) | Encrypts a string with Unix crypt() | | [ENDPOINT](../endpoint/index) | Synonym for ST\_ENDPOINT | | [ENVELOPE](../envelope/index) | Synonym for ST\_ENVELOPE | | [EQUALS](../equals/index) | Indicates whether two geometries are spatially equal | | [EXP](../exp/index) | e raised to the power of the argument | | [EXPORT\_SET](../export_set/index) | Returns an on string for every bit set, an off string for every bit not set | | [ExteriorRing](../exteriorring/index) | Synonym for ST\_ExteriorRing | | [EXTRACT](../extract/index) | Extracts a portion of the date | | [EXTRACTVALUE](../extractvalue/index) | Returns the text of the first text node matched by the XPath expression | | [FIELD](../field/index) | Returns the index position of a string in a list | | [FIND\_IN\_SET](../find_in_set/index) | Returns the position of a string in a set of strings | | [FLOOR](../floor/index) | Largest integer value not greater than the argument | | [FORMAT](../format/index) | Formats a number | | [FOUND\_ROWS](../found_rows/index) | Number of (potentially) returned rows | | [FROM\_BASE64](../from_base64/index) | Given a base-64 encoded string, returns the decoded result as a binary string | | [FROM\_DAYS](../from_days/index) | Returns a date given a day | | [FROM\_UNIXTIME](../from_unixtime/index) | Returns a datetime from a Unix timestamp | | [GeomCollFromText](../geomcollfromtext/index) | Synonym for ST\_GeomCollFromText | | [GeomCollFromWKB](../geomcollfromwkb/index) | Synonym for ST\_GeomCollFromWKB | | [GeometryCollectionFromText](../geometrycollectionfromtext/index) | Synonym for ST\_GeomCollFromText | | [GeometryCollectionFromWKB](../geometrycollectionfromwkb/index) | Synonym for ST\_GeomCollFromWKB | | [GeometryFromText](../geometryfromtext/index) | Synonym for ST\_GeomFromText | | [GeometryFromWKB](../geometryfromwkb/index) | Synonym for ST\_GeomFromWKB | | [GeomFromText](../geomfromtext/index) | Synonym for ST\_GeomFromText | | [GeomFromWKB](../geomfromwkb/index) | Synonym for ST\_GeomFromWKB | | [GeometryN](../geometryn/index) | Synonym for ST\_GeometryN | | [GEOMETRYCOLLECTION](../geometrycollection/index) | Constructs a WKB GeometryCollection | | [GeometryType](../geometrytype/index) | Synonym for ST\_GeometryType | | [GET\_FORMAT](../get_format/index) | Returns a format string | | [GET\_LOCK](../get_lock/index) | Obtain LOCK | | [GLENGTH](../glength/index) | Length of a LineString value | | [GREATEST](../greatest/index) | Returns the largest argument | | [GROUP\_CONCAT](../group_concat/index) | Returns string with concatenated values from a group | | [HEX](../hex/index) | Returns hexadecimal value | | [HOUR](../hour/index) | Returns the hour | | [IF](../if-function/index) | If expr1 is TRUE, returns expr2; otherwise returns expr3 | | [IFNULL](../ifnull/index) | Check whether an expression is NULL | | [IN](../in/index) | True if expression equals any of the values in the list | | [INTERVAL](../interval/index) | Index of the argument that is less than the first argument | | [INET6\_ATON](../inet6_aton/index) | Given an IPv6 or IPv4 network address, returns a VARBINARY numeric value | | [INET6\_NTOA](../inet6_ntoa/index) | Given an IPv6 or IPv4 network address, returns the address as a nonbinary string | | [INET\_ATON](../inet_aton/index) | Returns numeric value of IPv4 address | | [INET\_NTOA](../inet_ntoa/index) | Returns dotted-quad representation of IPv4 address | | [INSERT Function](../insert-function/index) | Replaces a part of a string with another string | | [INSTR](../instr/index) | Returns the position of a string withing a string | | [InteriorRingN](../interiorringn/index) | Synonym for ST\_InteriorRingN | | [INTERSECTS](../intersects/index) | Indicates whether two geometries spatially intersect | | [IS](../is/index) | Tests whether a boolean is TRUE, FALSE, or UNKNOWN | | [IsClosed](../isclosed/index) | Synonym for ST\_IsClosed | | [IsEmpty](../isempty/index) | Synonym for ST\_IsEmpty | | [IS\_FREE\_LOCK](../is_free_lock/index) | Checks whether lock is free to use | | [IS\_IPV4](../is_ipv4/index) | Whether or not an expression is a valid IPv4 address | | [IS\_IPV4\_COMPAT](../is_ipv4_compat/index) | Whether or not an IPv6 address is IPv4-compatible | | [IS\_IPV4\_MAPPED](../is_ipv4_mapped/index) | Whether an IPv6 address is a valid IPv4-mapped address | | [IS\_IPV6](../is_ipv6/index) | Whether or not an expression is a valid IPv6 address | | [IS NOT](../is-not/index) | Tests whether a boolean value is not TRUE, FALSE, or UNKNOWN | | [IS NOT NULL](../is-not-null/index) | Tests whether a value is not NULL | | [IS NULL](../is-null/index) | Tests whether a value is NULL | | [ISNULL](../isnull/index) | Checks if an expression is NULL | | [IsRing](../isring/index) | Synonym for ST\_IsRing | | [IsSimple](../issimple/index) | Synonym for ST\_IsSimple | | [IS\_USED\_LOCK](../is_used_lock/index) | Check if lock is in use | | [JSON\_ARRAY](../json_array/index) | Returns a JSON array containing the listed values | | [JSON\_ARRAY\_APPEND](../json_array_append/index) | Appends values to the end of the given arrays within a JSON document | | [JSON\_ARRAY\_INSERT](../json_array_insert/index) | Inserts a value into a JSON document | | [JSON\_COMPACT](../json_compact/index) | Removes all unnecessary spaces so the json document is as short as possible | | [JSON\_CONTAINS](../json_contains/index) | Whether a value is found in a given JSON document or at a specified path within the document | | [JSON\_CONTAINS\_PATH](../json_contains_path/index) | Indicates whether the given JSON document contains data at the specified path or paths | | [JSON\_DEPTH](../json_depth/index) | Maximum depth of a JSON document | | [JSON\_DETAILED](../json_detailed/index) | Represents JSON in the most understandable way emphasizing nested structures | | [JSON\_EQUALS](../json_equals/index) | Check for equality between JSON objects. | | [JSON\_EXISTS](../json_exists/index) | Determines whether a specified JSON value exists in the given data | | [JSON\_EXTRACT](../json_extract/index) | Extracts data from a JSON document. | | [JSON\_INSERT](../json_insert/index) | Inserts data into a JSON document | | [JSON\_KEYS](../json_keys/index) | Returns keys from top-level value of a JSON object or top-level keys from the path | | [JSON\_LENGTH](../json_length/index) | Returns the length of a JSON document, or the length of a value within the document | | [JSON\_LOOSE](../json_loose/index) | Adds spaces to a JSON document to make it look more readable | | [JSON\_MERGE](../json_merge/index) | Merges the given JSON documents | | [JSON\_MERGE\_PATCH](../json_merge/index) | RFC 7396-compliant merge of the given JSON documents | | [JSON\_MERGE\_PRESERVE](../json_merge/index) | Synonym for [JSON\_MERGE\_PATCH](../json_merge/index). | | [JSON\_NORMALIZE](../json_normalize/index) | Recursively sorts keys and removes spaces, allowing comparison of json documents for equality | | [JSON\_OBJECT](../json_object/index) | Returns a JSON object containing the given key/value pairs | | [JSON\_OBJECTAGG](../json_objectagg/index) | Returns a JSON object containing key-value pairs | | [JSON\_OVERLAPS](../json_overlaps/index) | Compares two json documents for overlaps | | [JSON\_QUERY](../json_query/index) | Given a JSON document, returns an object or array specified by the path | | [JSON\_QUOTE](../json_quote/index) | Quotes a string as a JSON value | | [JSON\_REMOVE](../json_remove/index) | Removes data from a JSON document | | [JSON\_REPLACE](../json_replace/index) | Replaces existing values in a JSON document | | [JSON\_SEARCH](../json_search/index) | Returns the path to the given string within a JSON document | | [JSON\_SET](../json_set/index) | Updates or inserts data into a JSON document | | [JSON\_TABLE](../json_table/index) | Returns a representation of a JSON document as a relational table | | [JSON\_TYPE](../json_type/index) | Returns the type of a JSON value | | [JSON\_UNQUOTE](../json_unquote/index) | Unquotes a JSON value, returning a string | | [JSON\_VALID](../json_valid/index) | Whether a value is a valid JSON document or not | | [JSON\_VALUE](../json_value/index) | Given a JSON document, returns the specified scalar | | [LAST\_DAY](../last_day/index) | Returns the last day of the month | | [LAST\_INSERT\_ID](../last_insert_id/index) | Last inserted autoinc value | | [LAST\_VALUE](../last_value/index) | Returns the last value in a list | | [LASTVAL](../previous-value-for-sequence_name/index) | Get last value generated from a sequence | | [LCASE](../lcase/index) | Synonym for [LOWER() | | [LEAST](../least/index) | Returns the smallest argument | | [LEFT](../left/index) | Returns the leftmost characters from a string | | [LENGTH](../length/index) | Length of the string in bytes | | [LIKE](../like/index) | Whether expression matches a pattern | | [LineFromText](../linefromtext/index) | Synonym for ST\_LineFromText | | [LineFromWKB](../linefromwkb/index) | Synonym for ST\_LineFromWKB | | [LINESTRING](../linestring/index) | Constructs a WKB LineString value from a number of WKB Point arguments | | [LineStringFromText](../linestringfromtext/index) | Synonym for ST\_LineFromText | | [LineStringFromWKB](../linestringfromwkb/index) | Synonym for ST\_LineFromWKB | | [LN](../ln/index) | Returns natural logarithm | | [LOAD\_FILE](../load_file/index) | Returns file contents as a string | | [LOCALTIME](../localtime/index) | Synonym for NOW() | | [LOCALTIMESTAMP](../localtimestamp/index) | Synonym for NOW() | | [LOCATE](../locate/index) | Returns the position of a substring in a string | | [LOG](../log/index) | Returns the natural logarithm | | [LOG10](../log10/index) | Returns the base-10 logarithm | | [LOG2](../log2/index) | Returns the base-2 logarithm | | [LOWER](../lower/index) | Returns a string with all characters changed to lowercase | | [LPAD](../lpad/index) | Returns the string left-padded with another string to a given length | | [LTRIM](../ltrim/index) | Returns the string with leading space characters removed | | [MAKE\_SET](../make_set/index) | Make a set of strings that matches a bitmask | | [MAKEDATE](../makedate/index) | Returns a date given a year and day | | [MAKETIME](../maketime/index) | Returns a time | | [MASTER\_GTID\_WAIT](../master_gtid_wait/index) | Wait until slave reaches the GTID position | | [MASTER\_POS\_WAIT](../master_pos_wait/index) | Blocks until the slave has applied all specified updates | | [MATCH AGAINST](../match-against/index) | Perform a fulltext search on a fulltext index | | [MAX](../max/index) | Returns the maximum value | | [MBRContains](../mbrcontains/index) | Indicates one Minimum Bounding Rectangle contains another | | [MBRDisjoint](../mbrdisjoint/index) | Indicates whether the Minimum Bounding Rectangles of two geometries are disjoint | | [MBREqual](../mbrequal/index) | Whether the Minimum Bounding Rectangles of two geometries are the same. | | [MBRIntersects](../mbrintersects/index) | Indicates whether the Minimum Bounding Rectangles of the two geometries intersect | | [MBROverlaps](../mbroverlaps/index) | Whether the Minimum Bounding Rectangles of two geometries overlap. | | [MBRTouches](../mbrtouches/index) | Whether the Minimum Bounding Rectangles of two geometries touch. | | [MBRWithin](../mbrwithin/index) | Indicates whether one Minimum Bounding Rectangle is within another | | [MD5](../md5/index) | MD5 checksum | | [MEDIAN](../median/index) | Window function that returns the median value of a range of values | | [MICROSECOND](../microsecond/index) | Returns microseconds from a date or datetime | | [MID](../mid/index) | Synonym for SUBSTRING(str,pos,len) | | [MIN](../min/index) | Returns the minimum value | | [MINUTE](../minute/index) | Returns a minute from 0 to 59 | | [MLineFromText](../mlinefromtext/index) | Constructs MULTILINESTRING using its WKT representation and SRID | | [MLineFromWKB](../mlinefromwkb/index) | Constructs a MULTILINESTRING | | [MOD](../mod/index) | Modulo operation. Remainder of N divided by M | | [MONTH](../month/index) | Returns a month from 1 to 12 | | [MONTHNAME](../monthname/index) | Returns the full name of the month | | [MPointFromText](../mpointfromtext/index) | Constructs a MULTIPOINT value using its WKT and SRID | | [MPointFromWKB](../mpointfromwkb/index) | Constructs a MULTIPOINT value using its WKB representation and SRID | | [MPolyFromText](../mpolyfromtext/index) | Constructs a MULTIPOLYGON value | | [MPolyFromWKB](../mpolyfromwkb/index) | Constructs a MULTIPOLYGON value using its WKB representation and SRID | | [MultiLineStringFromText](../multilinestringfromtext/index) | Synonym for MLineFromText | | [MultiLineStringFromWKB](../multilinestringfromwkb/index) | A synonym for MLineFromWKB | | [MULTIPOINT](../multipoint/index) | Constructs a WKB MultiPoint value | | [MultiPointFromText](../multipointfromtext/index) | Synonym for MPointFromText | | [MultiPointFromWKB](../multipointfromwkb/index) | Synonym for MPointFromWKB | | [MULTIPOLYGON](../multipolygon/index) | Constructs a WKB MultiPolygon | | [MultiPolygonFromText](../multipolygonfromtext/index) | Synonym for MPolyFromText | | [MultiPolygonFromWKB](../multipolygonfromwkb/index) | Synonym for MPolyFromWKB | | [MULTILINESTRING](../multilinestring/index) | Constructs a MultiLineString value | | [NAME\_CONST](../name_const/index) | Returns the given value | | [NATURAL\_SORT\_KEY](../natural_sort_key/index) | Sorting that is more more similar to natural human sorting | | [NOT LIKE](../not-like/index) | Same as NOT(expr LIKE pat [ESCAPE 'escape\_char']) | | [NOT REGEXP](../not-regexp/index) | Same as NOT (expr REGEXP pat) | | [NULLIF](../nullif/index) | Returns NULL if expr1 = expr2 | | [NEXTVAL](../next-value-for-sequence_name/index) | Generate next value for sequence | | [NOT BETWEEN](../not-between/index) | Same as NOT (expr BETWEEN min AND max) | | [NOT IN](../not-in/index) | Same as NOT (expr IN (value,...)) | | [NOW](../now/index) | Returns the current date and time | | [NTILE](../ntile/index) | Returns an integer indicating which group a given row falls into | | [NumGeometries](../numgeometries/index) | Synonym for ST\_NumGeometries | | [NumInteriorRings](../numinteriorrings/index) | Synonym for NumInteriorRings | | [NumPoints](../numpoints/index) | Synonym for ST\_NumPoints | | [OCT](../oct/index) | Returns octal value | | [OCTET\_LENGTH](../octet_length/index) | Synonym for LENGTH() | | [OLD\_PASSWORD](../old_password/index) | Pre MySQL 4.1 password implementation | | [ORD](../ord/index) | Return ASCII or character code | | [OVERLAPS](../overlaps/index) | Indicates whether two elements spatially overlap | | [PASSWORD](../password/index) | Calculates a password string | | [PERCENT\_RANK](../percent_rank/index) | Window function that returns the relative percent rank of a given row | | [PERCENTILE\_CONT](../percentile_cont/index) | Returns a value which corresponds to the given fraction in the sort order. | | [PERCENTILE\_DISC](../percentile_disc/index) | Returns the first value in the set whose ordered position is the same or more than the specified fraction. | | [PERIOD\_ADD](../period_add/index) | Add months to a period | | [PERIOD\_DIFF](../period_diff/index) | Number of months between two periods | | [PI](../pi/index) | Returns the value of π (pi) | | [POINT](../point/index) | Constructs a WKB Point | | [PointFromText](../pointfromtext/index) | Synonym for ST\_PointFromText | | [PointFromWKB](../pointfromwkb/index) | Synonym for PointFromWKB | | [PointN](../pointn/index) | Synonym for PointN | | [PointOnSurface](../pointonsurface/index) | Synonym for ST\_PointOnSurface | | [POLYGON](../polygon/index) | Constructs a WKB Polygon value from a number of WKB LineString arguments | | [PolyFromText](../polyfromtext/index) | Synonym for ST\_PolyFromText | | [PolyFromWKB](../polyfromwkb/index) | Synonym for ST\_PolyFromWKB | | [PolygonFromText](../polygonfromtext/index) | Synonym for ST\_PolyFromText | | [PolygonFromWKB](../polygonfromwkb/index) | Synonym for ST\_PolyFromWKB | | [POSITION](../position/index) | Returns the position of a substring in a string | | [POW](../pow/index) | Returns X raised to the power of Y | | [POWER](../power/index) | Synonym for POW() | | [QUARTER](../quarter/index) | Returns year quarter from 1 to 4 | | [QUOTE](../quote/index) | Returns quoted, properly escaped string | | [RADIANS](../radians/index) | Converts from degrees to radians | | [RAND](../rand/index) | Random floating-point value | | [RANK](../rank/index) | Rank of a given row with identical values receiving the same result | | [REGEXP](../regexp/index) | Performs pattern matching | | [REGEXP\_INSTR](../regexp_instr/index) | Position of the first appearance of a regex | | [REGEXP\_REPLACE](../regexp_replace/index) | Replaces all occurrences of a pattern | | [REGEXP\_SUBSTR](../regexp_substr/index) | Returns the matching part of a string | | [RELEASE\_LOCK](../release_lock/index) | Releases lock obtained with GET\_LOCK() | | [REPEAT Function](../repeat-function/index) | Returns a string repeated a number of times | | [REPLACE Function](../replace-function/index) | Replace occurrences of a string | | [REVERSE](../reverse/index) | Reverses the order of a string | | [RIGHT](../right/index) | Returns the rightmost N characters from a string | | [RLIKE](../rlike/index) | Synonym for REGEXP() | | [RPAD](../rpad/index) | Returns the string right-padded with another string to a given length | | [ROUND](../round/index) | Rounds a number | | [ROW\_COUNT](../row_count/index) | Number of rows affected by previous statement | | [ROW\_NUMBER](../row_number/index) | Row number of a given row with identical values receiving a different result | | [RTRIM](../rtrim/index) | Returns the string with trailing space characters removed | | [SCHEMA](../schema/index) | Synonym for DATABASE() | | [SECOND](../second/index) | Returns the second of a time | | [SEC\_TO\_TIME](../sec_to_time/index) | Converts a second to a time | | [SETVAL](../setval/index) | Set the next value to be returned by a sequence | | [SESSION\_USER](../session_user/index) | Synonym for USER() | | [SHA](sha) | Synonym for SHA1() | | [SHA1](../sha1/index) | Calculates an SHA-1 checksum | | [SHA2](../sha2/index) | Calculates an SHA-2 checksum | | [SIGN](../sign/index) | Returns 1, 0 or -1 | | [SIN](../sin/index) | Returns the sine | | [SLEEP](../sleep/index) | Pauses for the given number of seconds | | [SOUNDEX](../soundex/index) | Returns a string based on how the string sounds | | [SOUNDS LIKE](../sounds-like/index) | SOUNDEX(expr1) = SOUNDEX(expr2) | | [SPACE](../space/index) | Returns a string of space characters | | [SPIDER\_BG\_DIRECT\_SQL](../spider_bg_direct_sql/index) | Background SQL execution | | [SPIDER\_COPY\_TABLES](../spider_copy_tables/index) | Copy table data | | [SPIDER\_DIRECT\_SQL](../spider_direct_sql/index) | Execute SQL on the remote server | | [SPIDER\_FLUSH\_TABLE\_MON\_CACHE](../spider_flush_table_mon_cache/index) | Refreshing Spider monitoring server information | | [SQRT](../sqrt/index) | Square root | | [SRID](../srid/index) | Synonym for ST\_SRID | | [ST\_AREA](../st_area/index) | Area of a Polygon | | [ST\_AsBinary](../st_asbinary/index) | Converts a value to its WKB representation | | [ST\_AsText](../st_astext/index) | Converts a value to its WKT-Definition | | [ST\_AsWKB](../st_aswkb/index) | Synonym for ST\_AsBinary | | [ST\_ASWKT](../st_aswkt/index) | Synonym for ST\_ASTEXT() | | [ST\_BOUNDARY](../st_boundary/index) | Returns a geometry that is the closure of a combinatorial boundary | | [ST\_BUFFER](../st_buffer/index) | A new geometry with a buffer added to the original geometry | | [ST\_CENTROID](../st_centroid/index) | The mathematical centroid (geometric center) for a MultiPolygon | | [ST\_CONTAINS](../st_contains/index) | Whether one geometry is contained by another | | [ST\_CONVEXHULL](../st_convexhull/index) | The minimum convex geometry enclosing all geometries within the set | | [ST\_CROSSES](../st_crosses/index) | Whether two geometries spatially cross | | [ST\_DIFFERENCE](../st_difference/index) | Point set difference | | [ST\_DIMENSION](../st_dimension/index) | Inherent dimension of a geometry value | | [ST\_DISJOINT](../st_disjoint/index) | Whether one geometry is spatially disjoint from another | | [ST\_DISTANCE](../st_distance/index) | The distance between two geometries | | [ST\_DISTANCE\_SPHERE](../st_distance_sphere/index) | The spherical distance between two geometries | | [ST\_ENDPOINT](../st_endpoint/index) | Returns the endpoint of a LineString | | [ST\_ENVELOPE](../st_envelope/index) | Returns the Minimum Bounding Rectangle for a geometry value | | [ST\_EQUALS](../st_equals/index) | Whether two geometries are spatoially equal | | [ST\_ExteriorRing](../st_exteriorring/index) | Returns the exterior ring of a Polygon as a LineString | | [ST\_GeomCollFromText](../st_geomcollfromtext/index) | Constructs a GEOMETRYCOLLECTION value | | [ST\_GeomCollFromWKB](../st_geomcollfromwkb/index) | Constructs a GEOMETRYCOLLECTION value from a WKB | | [ST\_GeometryCollectionFromText](../st_geometrycollectionfromtext/index) | Synonym for ST\_GeomCollFromText | | [ST\_GeometryCollectionFromWKB](../st_geometrycollectionfromwkb/index) | Synonym for ST\_GeomCollFromWKB | | [ST\_GeometryFromText](../st_geometryfromtext/index) | Synonym for ST\_GeomFromText | | [ST\_GeometryFromWKB](../st_geometryfromwkb/index) | Synonym for ST\_GeomFromWKB | | [ST\_GEOMETRYN](../st_geometryn/index) | Returns the N-th geometry in a GeometryCollection | | [ST\_GEOMETRYTYPE](../st_geometrytype/index) | Returns name of the geometry type of which a given geometry instance is a member | | [ST\_GeomFromText](../st_geomfromtext/index) | Constructs a geometry value using its WKT and SRID | | [ST\_GeomFromWKB](../st_geomfromwkb/index) | Constructs a geometry value using its WKB representation and SRID | | [ST\_InteriorRingN](../st_interiorringn/index) | Returns the N-th interior ring for a Polygon | | [ST\_INTERSECTION](../st_intersection/index) | The intersection, or shared portion, of two geometries | | [ST\_INTERSECTS](../st_intersects/index) | Whether two geometries spatially intersect | | [ST\_ISCLOSED](../st_isclosed/index) | Returns true if a given LINESTRING's start and end points are the same | | [ST\_ISEMPTY](../st_isempty/index) | Indicated validity of geometry value | | [ST\_IsRing](../st_isring/index) | Returns true if a given LINESTRING is both ST\_IsClosed and ST\_IsSimple | | [ST\_IsSimple](../st_issimple/index) | Returns true if the given Geometry has no anomalous geometric points | | [ST\_LENGTH](../st_length/index) | Length of a LineString value | | [ST\_LineFromText](../st_linefromtext/index) | Creates a linestring value | | [ST\_LineFromWKB](../st_linefromwkb/index) | Constructs a LINESTRING using its WKB and SRID | | [ST\_LineStringFromText](../st_linestringfromtext/index) | Synonym for ST\_LineFromText | | [ST\_LineStringFromWKB](../st_linestringfromwkb/index) | Synonym for ST\_LineFromWKB | | [ST\_NUMGEOMETRIES](../st_numgeometries/index) | Number of geometries in a GeometryCollection | | [ST\_NumInteriorRings](../st_numinteriorrings/index) | Number of interior rings in a Polygon | | [ST\_NUMPOINTS](../st_numpoints/index) | Returns the number of Point objects in a LineString | | [ST\_OVERLAPS](../st_overlaps/index) | Whether two geometries overlap | | [ST\_PointFromText](../st_pointfromtext/index) | Constructs a POINT value | | [ST\_PointFromWKB](../st_pointfromwkb/index) | Constructs POINT using its WKB and SRID | | [ST\_POINTN](../st_pointn/index) | Returns the N-th Point in the LineString | | [ST\_POINTONSURFACE](../st_pointonsurface/index) | Returns a POINT guaranteed to intersect a surface | | [ST\_PolyFromText](../st_polyfromtext/index) | Constructs a POLYGON value | | [ST\_PolyFromWKB](../st_polyfromwkb/index) | Constructs POLYGON value using its WKB representation and SRID | | [ST\_PolygonFromText](../st_polygonfromtext/index) | Synonym for ST\_PolyFromText | | [ST\_PolygonFromWKB](../st_polygonfromwkb/index) | Synonym for ST\_PolyFromWKB | | [ST\_RELATE](../st_relate/index) | Returns true if two geometries are related | | [ST\_SRID](../st_srid/index) | Returns a Spatial Reference System ID | | [ST\_STARTPOINT](../st_startpoint/index) | Returns the start point of a LineString | | [ST\_SYMDIFFERENCE](../st_symdifference/index) | Portions of two geometries that don't intersect | | [ST\_TOUCHES](../st_touches/index) | Whether one geometry g1 spatially touches another | | [ST\_UNION](../st_union/index) | Union of two geometries | | [ST\_WITHIN](../st_within/index) | Whether one geometry is within another | | [ST\_X](../st_x/index) | X-coordinate value for a point | | [ST\_Y](../st_y/index) | Y-coordinate for a point | | [STARTPOINT](../startpoint/index) | Synonym for ST\_StartPoint | | [STD](../std/index) | Population standard deviation | | [STDDEV](../stddev/index) | Population standard deviation | | [STDDEV\_POP](../stddev_pop/index) | Returns the population standard deviation | | [STDDEV\_SAMP](../stddev_samp/index) | Standard deviation | | [STR\_TO\_DATE](../str_to_date/index) | Converts a string to date | | [STRCMP](../strcmp/index) | Compares two strings in sort order | | [SUBDATE](../subdate/index) | Subtract a date unit or number of days | | [SUBSTR](../substr/index) | Returns a substring from string starting at a given position | | [SUBSTRING](../substring/index) | Returns a substring from string starting at a given position | | [SUBSTRING\_INDEX](../substring_index/index) | Returns the substring from string before count occurrences of a delimiter | | [SUBTIME](../subtime/index) | Subtracts a time from a date/time | | [SUM](../sum/index) | Sum total | | [SYS\_GUID](../sys_guid/index) | Generates a globally unique identifier | | [SYSDATE](../sysdate/index) | Returns the current date and time | | [SYSTEM\_USER](../system_user/index) | Synonym for USER() | | [TAN](../tan/index) | Returns the tangent | | [TIME function](../time-function/index) | Extracts the time | | [TIMEDIFF](../timediff/index) | Returns the difference between two date/times | | [TIMESTAMP FUNCTION](../timestamp-function/index) | Return the datetime, or add a time to a date/time | | [TIMESTAMPADD](../timestampadd/index) | Add interval to a date or datetime | | [TIMESTAMPDIFF](../timestampdiff/index) | Difference between two datetimes | | [TIME\_FORMAT](../time_format/index) | Formats the time value according to the format string | | [TIME\_TO\_SEC](../time_to_sec/index) | Returns the time argument, converted to seconds | | [TO\_BASE64](../to_base64/index) | Converts a string to its base-64 encoded form | | [TO\_CHAR](../to_char/index) | Converts a date/time type to a char | | [TO\_DAYS](../to_days/index) | Number of days since year 0 | | [TO\_SECONDS](../to_seconds/index) | Number of seconds since year 0 | | [TOUCHES](../touches/index) | Whether two geometries spatially touch | | [TRIM](../trim/index) | Returns a string with all given prefixes or suffixes removed | | [TRUNCATE](../truncate/index) | Truncates X to D decimal places | | [UCASE](../ucase/index) | Synonym for UPPER]]() | | [UNHEX](../unhex/index) | Interprets pairs of hex digits as a number and converts to the character represented by the number | | [UNCOMPRESS](../uncompress/index) | Uncompresses string compressed with COMPRESS() | | [UNCOMPRESSED\_LENGTH](../uncompressed_length/index) | Returns length of a string before being compressed with COMPRESS() | | [UNIX\_TIMESTAMP](../unix_timestamp/index) | Returns a Unix timestamp | | [UPDATEXML](../updatexml/index) | Replace XML | | [UPPER](../upper/index) | Changes string to uppercase | | [USER](../user/index) | Current user/host | | [UTC\_DATE](../utc_date/index) | Returns the current UTC date | | [UTC\_TIME](../utc_time/index) | Returns the current UTC time | | [UTC\_TIMESTAMP](../utc_timestamp/index) | Returns the current UTC date and time | | [UUID](../uuid/index) | Returns a Universal Unique Identifier | | [UUID\_SHORT](../uuid_short/index) | Return short universal identifier | | [VALUES or VALUE](../values-value/index) | Refer to columns in INSERT ... ON DUPLICATE KEY UPDATE | | [VAR\_POP](../var_pop/index) | Population standard variance | | [VAR\_SAMP](../var_samp/index) | Returns the sample variance | | [VARIANCE](../variance/index) | Population standard variance | | [VERSION](../version/index) | MariaDB server version | | [WEEK](../week/index) | Returns the week number | | [WEEKDAY](../weekday/index) | Returns the weekday index | | [WEEKOFYEAR](../weekofyear/index) | Returns the calendar week of the date as a number in the range from 1 to 53 | | [WEIGHT\_STRING](../weight_string/index) | Weight of the input string | | [WITHIN](../within/index) | Indicate whether a geographic element is spacially within another | | [WSREP\_LAST\_SEEN\_GTID](../wsrep_last_seen_gtid/index) | Returns the Global Transaction ID of the most recent write transaction observed by the client. | | [WSREP\_LAST\_WRITTEN\_GTID](../wsrep_last_written_gtid/index) | Returns the Global Transaction ID of the most recent write transaction performed by the client. | | [WSREP\_SYNC\_WAIT\_UPTO\_GTID](../wsrep_sync_wait_upto_gtid/index) | Blocks the client until the transaction specified by the given Global Transaction ID is applied and committed by the node | | [X](../x/index) | Synonym for ST\_X | | [Y](../y/index) | Synonym for ST\_Y | | [YEAR](../year/index) | Returns the year for the given date | | [YEARWEEK](../yearweek/index) | Returns year and week for a date | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb Identifier Names Identifier Names ================ Databases, tables, indexes, columns, aliases, views, stored routines, triggers, events, variables, partitions, tablespaces, savepoints, labels, users, roles, are collectively known as identifiers, and have certain rules for naming. Identifiers may be quoted using the backtick character - ```. Quoting is optional for identifiers that don't contain special characters, or for identifiers that are not [reserved words](../reserved-words/index). If the `ANSI_QUOTES` [SQL\_MODE](../sql-mode/index) flag is set, double quotes (`"`) can also be used to quote identifiers. If the `[MSSQL](../sql_modemssql/index)` flag is set, square brackets (`[` and `]`) can be used for quoting. Even when using reserved words as names, [fully qualified names](../identifier-qualifiers/index) do not need to be quoted. For example, `test.select` has only one possible meaning, so it is correctly parsed even without quotes. ### Unquoted The following characters are valid, and allow identifiers to be unquoted: * ASCII: [0-9,a-z,A-Z$\_] (numerals 0-9, basic Latin letters, both lowercase and uppercase, dollar sign, underscore) * Extended: U+0080 .. U+FFFF ### Quoted The following characters are valid, but identifiers using them must be quoted: * ASCII: U+0001 .. U+007F (full Unicode Basic Multilingual Plane (BMP) except for U+0000) * Extended: U+0080 .. U+FFFF * Identifier quotes can themselves be used as part of an identifier, as long as they are quoted. ### Further Rules There are a number of other rules for identifiers: * Identifiers are stored as Unicode (UTF-8) * Identifiers may or may not be case-sensitive. See [Indentifier Case-sensitivity](../identifier-case-sensitivity/index). * Database, table and column names can't end with space characters * Identifier names may begin with a numeral, but can't only contain numerals unless quoted. * An identifier starting with a numeral, followed by an 'e', may be parsed as a floating point number, and needs to be quoted. * Identifiers are not permitted to contain the ASCII NUL character (U+0000) and supplementary characters (U+10000 and higher). * Names such as 5e6, 9e are not prohibited, but it's strongly recommended not to use them, as they could lead to ambiguity in certain contexts, being treated as a number or expression. * User variables cannot be used as part of an identifier, or as an identifier in an SQL statement. ### Quote Character The regular quote character is the backtick character - ```, but if the `ANSI_QUOTES` [SQL\_MODE](../sql-mode/index) option is specified, a regular double quote - `"` may be used as well. The backtick character can be used as part of an identifier. In that case the identifier needs to be quoted. The quote character can be the backtick, but in that case, the backtick in the name must be escaped with another backtick. ### Maximum Length * Databases, tables, columns, indexes, constraints, stored routines, triggers, events, views, tablespaces, servers and log file groups have a maximum length of 64 characters. * Compound statement [labels](../labels/index) have a maximum length of 16 characters * Aliases have a maximum length of 256 characters, except for column aliases in [CREATE VIEW](../create-view/index) statements, which are checked against the maximum column length of 64 characters (not the maximum alias length of 256 characters). * Users have a maximum length of 80 characters. * [Roles](../roles/index) have a maximum length of 128 characters. * Multi-byte characters do not count extra towards towards the character limit. ### Multiple Identifiers MariaDB allows the column name to be used on its own if the reference will be unambiguous, or the table name to be used with the column name, or all three of the database, table and column names. A period is used to separate the identifiers, and the period can be surrounded by spaces. ### Examples Using the period to separate identifiers: ``` CREATE TABLE t1 (i int); INSERT INTO t1(i) VALUES (10); SELECT i FROM t1; +------+ | i | +------+ | 10 | +------+ SELECT t1.i FROM t1; +------+ | i | +------+ | 10 | +------+ SELECT test.t1.i FROM t1; +------+ | i | +------+ | 10 | +------+ ``` The period can be separated by spaces: ``` SELECT test . t1 . i FROM t1; +------+ | i | +------+ | 10 | +------+ ``` Resolving ambiguity: ``` CREATE TABLE t2 (i int); SELECT i FROM t1 LEFT JOIN t2 ON t1.i=t2.i; ERROR 1052 (23000): Column 'i' in field list is ambiguous SELECT t1.i FROM t1 LEFT JOIN t2 ON t1.i=t2.i; +------+ | i | +------+ | 10 | +------+ ``` Creating a table with characters that require quoting: ``` CREATE TABLE 123% (i int); ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near '123% (i int)' at line 1 CREATE TABLE `123%` (i int); Query OK, 0 rows affected (0.85 sec) CREATE TABLE `TABLE` (i int); Query OK, 0 rows affected (0.36 sec) ``` Using double quotes as a quoting character: ``` CREATE TABLE "SELECT" (i int); ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near '"SELECT" (i int)' at line 1 SET sql_mode='ANSI_QUOTES'; Query OK, 0 rows affected (0.03 sec) CREATE TABLE "SELECT" (i int); Query OK, 0 rows affected (0.46 sec) ``` Using an identifier quote as part of an identifier name: ``` SHOW VARIABLES LIKE 'sql_mode'; +---------------+-------------+ | Variable_name | Value | +---------------+-------------+ | sql_mode | ANSI_QUOTES | +---------------+-------------+ CREATE TABLE "fg`d" (i int); Query OK, 0 rows affected (0.34 sec) ``` Creating the table named `*` (Unicode number: U+002A) requires quoting. ``` CREATE TABLE `*` (a INT); ``` Floating point ambiguity: ``` CREATE TABLE 8984444cce5d (x INT); Query OK, 0 rows affected (0.38 sec) CREATE TABLE 8981e56cce5d (x INT); ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near '8981e56cce5d (x INT)' at line 1 CREATE TABLE `8981e56cce5d` (x INT); Query OK, 0 rows affected (0.39 sec) ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Database Design Phase 3: Implementation Database Design Phase 3: Implementation ======================================= This article follows on from [Database Design Phase 2: Logical and Physical Design](../database-design-phase-2-logical-and-physical-design/index). The implementation phase is where you install the DBMS on the required hardware, optimize the database to run best on that hardware and software platform, and create the database and load the data. The initial data could be either new data captured directly or existing data imported from a MariaDB database or another DBMS. You also establish database security in this phase and give the various users that you've identified access applicable to their requirements. Finally, you also initiate backup plans in this phase. The following are steps in the implementation phase: 1. Install the DBMS. 2. Tune the setup variables according to the hardware, software and usage conditions. 3. Create the database and tables. 4. Load the data. 5. Set up the users and security. 6. Implement the backup regime. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb PROCEDURE PROCEDURE ========= The `PROCEDURE` clause of [SELECT](../select/index) passes the whole result set to a Procedure which will process it. These Procedures are not [Stored Procedures](../stored-procedures/index), and can only be written in the C language, so it is necessary to recompile the server. Currently, the only available procedure is [ANALYSE](../procedure-analyse/index), which examines the resultset and suggests the optimal datatypes for each column. It is defined in the `sql/sql_analyse.cc` file, and can be used as an example to create more Procedures. This clause cannot be used in a [view](../views/index)'s definition. See Also -------- * [SELECT](../select/index) * [Stored Procedures](../stored-procedures/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb ALTER ALTER ====== This category is for documentation on the various ALTER statements. | Title | Description | | --- | --- | | [ALTER TABLE](../alter-table/index) | Modify a table's definition. | | [ALTER DATABASE](../alter-database/index) | Change the overall characteristics of a database. | | [ALTER EVENT](../alter-event/index) | Change an existing event. | | [ALTER FUNCTION](../alter-function/index) | Change the characteristics of a stored function. | | [ALTER LOGFILE GROUP](../alter-logfile-group/index) | Only useful with MySQL Cluster, and has no effect in MariaDB. | | [ALTER PROCEDURE](../alter-procedure/index) | Change stored procedure characteristics. | | [ALTER SEQUENCE](../alter-sequence/index) | Change options for a SEQUENCE. | | [ALTER SERVER](../alter-server/index) | Updates mysql.servers table. | | [ALTER TABLESPACE](../alter-tablespace/index) | ALTER TABLESPACE is not available in MariaDB. | | [ALTER USER](../alter-user/index) | Modify an existing MariaDB account. | | [ALTER VIEW](../alter-view/index) | Change a view definition. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Authentication Plugins Authentication Plugins ======================= When a user attempts to log in, the authentication plugin controls how MariaDB Server determines whether the connection is from a legitimate user. When creating or altering a user account with the [GRANT](../grant/index), [CREATE USER](../create-user/index) or [ALTER USER](../alter-user/index) statements, you can specify the authentication plugin you want the user account to use by providing the `IDENTIFIED VIA` clause. By default, when you create a user account without specifying an authentication plugin, MariaDB uses the [mysql\_native\_password](../authentication-plugin-mysql_native_password/index) plugin. **MariaDB starting with [10.4](../what-is-mariadb-104/index)**In [MariaDB 10.4](../what-is-mariadb-104/index) and later, there are some notable changes, such as: * You can specify multiple authentication plugins for each user account. * The `root@localhost` user created by [mysql\_install\_db](../mysql_install_db/index) is created with the ability to use two authentication plugins. First, it is configured to try to use the [unix\_socket](../authentication-plugin-unix-socket/index) authentication plugin. This allows the the `root@localhost` user to login without a password via the local Unix socket file defined by the [socket](../server-system-variables/index#socket) system variable, as long as the login is attempted from a process owned by the operating system `root` user account. Second, if authentication fails with the [unix\_socket](../authentication-plugin-unix-socket/index) authentication plugin, then it is configured to try to use the [mysql\_native\_password](../authentication-plugin-mysql_native_password/index) authentication plugin. However, an invalid password is initially set, so in order to authenticate this way, a password must be set with [SET PASSWORD](../set-password/index). | Title | Description | | --- | --- | | [Pluggable Authentication Overview](../pluggable-authentication-overview/index) | The authentication of users is delegated to plugins. | | [Authentication Plugin - mysql\_native\_password](../authentication-plugin-mysql_native_password/index) | Uses the password hashing algorithm introduced in MySQL 4.1. | | [Authentication Plugin - mysql\_old\_password](../authentication-plugin-mysql_old_password/index) | The mysql\_old\_password authentication plugin uses the pre-MySQL 4.1 password hashing algorithm. | | [Authentication Plugin - ed25519](../authentication-plugin-ed25519/index) | Uses the Elliptic Curve Digital Signature Algorithm to securely store users' passwords. | | [Authentication Plugin - GSSAPI](../authentication-plugin-gssapi/index) | The gssapi authentication plugin uses the GSSAPI interface to authenticate with Kerberos or NTLM. | | [Authentication with Pluggable Authentication Modules (PAM)](../authentication-with-pluggable-authentication-modules-pam/index) | Uses the Pluggable Authentication Module (PAM) framework to authenticate MariaDB users. | | [Authentication Plugin - Unix Socket](../authentication-plugin-unix-socket/index) | Uses the user name that owns the process connected to MariaDB's unix socket file. | | [Authentication Plugin - Named Pipe](../authentication-plugin-named-pipe/index) | Uses the user name that owns the process connected to MariaDB's named pipe on Windows. | | [Authentication Plugin - SHA-256](../authentication-plugin-sha-256/index) | MySQL supports the sha256\_password and caching\_sha2\_password authentication plugins. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb sysbench v0.5 - Single Five Minute Runs on work sysbench v0.5 - Single Five Minute Runs on work =============================================== MariDB/MySQL sysbench benchmark comparison in % Each test was run for 5 minutes. ``` Number of threads 1 4 8 16 32 64 128 sysbench test delete 121.52 144.77 117.70 115.15 100.48 75.39 66.56 insert 114.89 181.50 118.06 136.00 125.53 141.83 113.88 oltp_complex_ro 103.13 100.99 94.65 104.14 97.87 90.18 79.93 oltp_complex_rw 131.65 149.90 120.88 128.58 116.71 89.92 80.63 oltp_simple 102.32 102.57 97.33 96.34 93.99 78.81 59.71 select 102.12 102.05 96.64 97.28 93.55 81.53 59.83 update_index 114.08 103.98 115.59 124.90 123.51 104.38 99.11 update_non_index 134.04 147.94 150.91 150.04 152.12 108.34 89.24 insert/4 is a glitch (MariaDB q/s / MySQL q/s * 100) ``` Benchmark was run on work: Linux openSUSE 11.1 (x86\_64), daul socket quad-core Intel 3.0GHz. with 6MB L2 cache, 8 GB RAM, data\_dir on single disk. MariaDB and MySQL were compiled with ``` BUILD/compile-amd64-max ``` MariaDB revision was: ``` revno: 2821 committer: Sergei Golubchik <[email protected]> branch nick: maria-5.1 timestamp: Tue 2010-02-23 13:04:58 +0100 message: fix for a possible DoS in the my_net_skip_rest() ``` MySQL revision was: ``` revno: 2929 committer: Alexander Nozdrin <[email protected]> branch nick: mysql-trunk timestamp: Sat 2010-02-20 12:26:22 +0300 message: Fix default.conf. ``` sysbench was run with these parameters: ``` --oltp-table-size=2000000 \ --max-time=300 \ --max-requests=0 \ --mysql-table-engine=InnoDB \ --mysql-user=root \ --mysql-engine-trx=yes ``` and this variable part of parameters ``` --num-threads=$THREADS --test=${TEST_DIR}/${SYSBENCH_TEST} ``` Configuration used for MariaDB and MySQL: ``` --no-defaults \ --skip-grant-tables \ --language=./sql/share/english \ --datadir=$DATA_DIR \ --tmpdir=$TEMP_DIR \ --socket=$MY_SOCKET \ --table_open_cache=512 \ --thread_cache=512 \ --query_cache_size=0 \ --query_cache_type=0 \ --innodb_data_home_dir=$DATA_DIR \ --innodb_data_file_path=ibdata1:128M:autoextend \ --innodb_log_group_home_dir=$DATA_DIR \ --innodb_buffer_pool_size=1024M \ --innodb_additional_mem_pool_size=32M \ --innodb_log_file_size=256M \ --innodb_log_buffer_size=16M \ --innodb_flush_log_at_trx_commit=1 \ --innodb_lock_wait_timeout=50 \ --innodb_doublewrite=0 \ --innodb_flush_method=O_DIRECT \ --innodb_thread_concurrency=0 \ --innodb_max_dirty_pages_pct=80" ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb InnoDB Buffer Pool InnoDB Buffer Pool ================== The [InnoDB](../innodb/index) buffer pool is a key component for optimizing MariaDB. It stores data and indexes, and you usually want it as large as possible so as to keep as much of the data and indexes in memory, reducing disk IO, as main bottleneck. How the Buffer Pool Works ------------------------- The buffer pool attempts to keep frequently-used blocks in the buffer, and so essentially works as two sublists, a *new* sublist of recently-used information, and an *old* sublist of older information. By default, 37% of the list is reserved for the old list. When new information is accessed that doesn't appear in the list, it is placed at the top of the old list, the oldest item in the old list is removed, and everything else bumps back one position in the list. When information is accessed that appears in the *old* list, it is moved to the top the new list, and everything above moves back one position. innodb\_buffer\_pool\_size -------------------------- The most important [server system variable](../server-system-variables/index) is [innodb\_buffer\_pool\_size](../innodb-system-variables/index#innodb_buffer_pool_size). This size should contain most of the active data set of your server so that SQL request can work directly with information in the buffer pool cache. Starting at several gigabytes of memory is a good starting point if you have that RAM available. Once warmed up to its normal load there should be very few [innodb\_buffer\_pool\_reads](../innodb-status-variables/index#innodb_buffer_pool_reads) compared to [innodb\_buffer\_pool\_read\_requests](../innodb-status-variables/index#innodb_buffer_pool_read_requests). Look how these values change over a minute. If the change in [innodb\_buffer\_pool\_reads](../innodb-status-variables/index#innodb_buffer_pool_reads) is less than 1% of the change in [innodb\_buffer\_pool\_read\_requests](../innodb-status-variables/index#innodb_buffer_pool_read_requests) then you have a good amount of usage. If you are getting the status variable [innodb\_buffer\_pool\_wait\_free](../innodb-status-variables/index#innodb_buffer_wait_free) increasing then you don't have enough buffer pool (or your flushing isn't occurring frequently enough). Be aware that before [MariaDB 10.4.4](https://mariadb.com/kb/en/mariadb-1044-release-notes/) the total memory allocated is about 10% more than the specified size as extra space is also reserved for control structures and buffers. The larger the size, the longer it will take to initialize. On a modern 64-bit server with a 10GB memory pool, this can take five seconds or more. Increasing [innodb\_buffer\_pool\_chunk\_size](../innodb-system-variables/index#innodb_buffer_pool_chunk_size) by several factors will reduce this significantly. Make sure that the size is not too large, causing swapping. The benefit of a larger buffer pool size is more than undone if your operating system is regularly swapping. Since [MariaDB 10.2.2](https://mariadb.com/kb/en/mariadb-1022-release-notes/), the buffer pool can be set dynamically, and new variables are introduced that may affect the size and performance. See [Setting Innodb Buffer Pool Size Dynamically](../setting-innodb-buffer-pool-size-dynamically/index). innodb\_buffer\_pool\_instances ------------------------------- The functionality described below was disabled in [MariaDB 10.5](../what-is-mariadb-105/index), and removed in [MariaDB 10.6](../what-is-mariadb-106/index), as the original reasons for for splitting the buffer pool have mostly gone away. If innodb\_buffer\_pool\_size is set to more than 1GB, [innodb\_buffer\_pool\_instances](../innodb-system-variables/index#innodb_buffer_pool_instances) divides the InnoDB buffer pool into a specific number of instances. The default was 1 in [MariaDB 5.5](../what-is-mariadb-55/index), but for large systems with buffer pools of many gigabytes, many instances can help reduce contention concurrency. The default is 8 in [MariaDB 10.0](../what-is-mariadb-100/index), with the exception of 32-bit Windows, where it depends on the value of [innodb\_buffer\_pool\_size](../innodb-system-variables/index#innodb_buffer_pool_instances). Each instance manages its own data structures and takes an equal portion of the total buffer pool size, so for example if innodb\_buffer\_pool\_size is 4GB and innodb\_buffer\_pool\_instances is set to 4, each instance will be 1GB. Each instance should ideally be at least 1GB in size. innodb\_old\_blocks\_pct and innodb\_old\_blocks\_time ------------------------------------------------------ The default 37% reserved for the old list can be adjusted by changing the value of [innodb\_old\_blocks\_pct](../innodb-system-variables/index#innodb_old_blocks_pct). It can accept anything between between 5% and 95%. The [innodb\_old\_blocks\_time](../innodb-system-variables/index#innodb_old_blocks_time) variable specifies the delay before a block can be moved from the old to the new sublist. `0` means no delay, while the default has been set to `1000`. Before changing either of these values from their defaults, make sure you understand the impact and how your system currently uses the buffer. Their main reason for existence is to reduce the impact of full table scans, which are usually infrequent, but large, and previously could clear everything from the buffer. Setting a non-zero delay could help in situations where full table scans are performed in quick succession. Temporarily changing these values can also be useful to avoid the negative impact of a full table scan, as explained in [InnoDB logical backups](../backup-and-restore-overview/index#innodb-logical-backups). Dumping and Restoring the Buffer Pool ------------------------------------- When the server starts, the buffer pool is empty. As it starts to access data, the buffer pool will slowly be populated. As more data will be accessed, the most frequently accessed data will be put into the buffer pool, and old data may be evicted. This means that a certain period of time is necessary before the buffer pool is really useful. This period of time is called the warmup. Since [MariaDB 10.0](../what-is-mariadb-100/index), InnoDB can dump the buffer pool before the server shuts down, and restore it when it starts again. If this feature is used (default since [MariaDB 10.2](../what-is-mariadb-102/index)), no warmup is necessary. Use the [innodb\_buffer\_pool\_dump\_at\_shutdown](../innodb-system-variables/index#innodb_buffer_pool_dump_at_shutdown) and [innodb\_buffer\_pool\_load\_at\_startup](../innodb-system-variables/index#innodb_buffer_pool_load_at_startup) system variables to enable or disable the buffer pool dump at shutdown and the restore at startup respectively. It is also possible to dump the InnoDB buffer pool at any moment while the server is running, and it is possible to restore the last buffer pool dump at any moment. To do this, the special [innodb\_buffer\_pool\_dump\_now](../innodb-system-variables/index#innodb_buffer_pool_dump_now) and [innodb\_buffer\_pool\_load\_now](../innodb-system-variables/index#innodb_buffer_pool_load_now) system variables can be set to ON. When selected, their value is always OFF. A buffer pool restore, both at startup or at any other moment, can be aborted by setting [innodb\_buffer\_pool\_load\_abort](../innodb-system-variables/index#innodb_buffer_pool_load_abort) to ON. The file which contains the buffer pool dump is specified via the [innodb\_buffer\_pool\_filename](../innodb-system-variables/index#innodb_buffer_pool_filename) system variable. See Also -------- * [InnoDB Change Buffering](../innodb-change-buffering/index) * [Information Schema INNODB\_BUFFER\_POOL\_STATS Table](../information-schema-innodb_buffer_pool_stats-table/index) * [Setting Innodb Buffer Pool Size Dynamically](../setting-innodb-buffer-pool-size-dynamically/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb Upgrading from MySQL to MariaDB Upgrading from MySQL to MariaDB ================================ | Title | Description | | --- | --- | | [Upgrading from MySQL to MariaDB](../upgrading-from-mysql-to-mariadb/index) | Upgrading from MySQL to MariaDB. | | [Moving from MySQL to MariaDB in Debian 9](../moving-from-mysql-to-mariadb-in-debian-9/index) | MariaDB 10.1 is the default mysql server in Debian 9 "Stretch" | | [Screencast for Upgrading MySQL to MariaDB](../screencast-for-upgrading-mysql-to-mariadb/index) | Screencast for upgrading MySQL 5.1.55 to MariaDB | | [Upgrading from MySQL 5.7 to MariaDB 10.2](../upgrading-from-mysql-57-to-mariadb-102/index) | Following compatibility report was done on 10.2.4 and may get some fixing i... | | [Upgrading to MariaDB From MySQL 5.0 or Older](../upgrading-to-mariadb-from-mysql-50-or-older/index) | Upgrading to MariaDB from MySQL 5.0 (or older version) | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb CSV Overview CSV Overview ============ The CSV Storage Engine can read and append to files stored in CSV (comma-separated-values) format. However, since [MariaDB 10.0](../what-is-mariadb-100/index), a better storage engine is able to read and write such files: [CONNECT](../connect/index). The CSV storage engine and logging to tables -------------------------------------------- The CSV storage engine is the default storage engine when using [logging of SQL queries](../writing-logs-into-tables/index) to tables. ``` mysqld --log-output=table ``` CSV Storage Engine files ------------------------ When you create a table using the CSV storage engine, three files are created: * `<table_name>.frm` * `<table_name>.CSV` * `<table_name>.CSM` The `.frm` file is the table format file. The `.CSV` file is a plain text file. Data you enter into the table is stored as plain text in comma-separated-values format. The `.CSM` file stores metadata about the table such as the state and the number of rows in the table. Limitations ----------- * CSV tables do not support indexing. * CSV tables cannot be partitioned. * Columns in CSV tables must be declared as NOT NULL. * No [transactions](../transactions/index). * The original CSV-format does not enable IETF-compatible parsing of embedded quote and comma characters. From [MariaDB 10.1.8](https://mariadb.com/kb/en/mariadb-1018-release-notes/), it is possible to do so by setting the [IETF\_QUOTES](../create-table/index#ietf_quotes) option when creating a table. Examples -------- Forgetting to add NOT NULL: ``` CREATE TABLE csv_test (x INT, y DATE, z CHAR(10)) ENGINE=CSV; ERROR 1178 (42000): The storage engine for the table doesn't support nullable columns ``` Creating, inserting and selecting: ``` CREATE TABLE csv_test ( x INT NOT NULL, y DATE NOT NULL, z CHAR(10) NOT NULL ) ENGINE=CSV; ``` ``` INSERT INTO csv_test VALUES (1,CURDATE(),'one'), (2,CURDATE(),'two'), (3,CURDATE(),'three'); ``` ``` SELECT * FROM csv_test; +---+------------+-------+ | x | y | z | +---+------------+-------+ | 1 | 2011-11-16 | one | | 2 | 2011-11-16 | two | | 3 | 2011-11-16 | three | +---+------------+-------+ ``` Viewing in a text editor: ``` $ cat csv_test.CSV 1,"2011-11-16","one" 2,"2011-11-16","two" 3,"2011-11-16","three" ``` See Also -------- * [Checking and Repairing CSV Tables](../checking-and-repairing-csv-tables/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb perror perror ====== *perror* is a utility that displays descriptions for system or storage engine error codes. See [MariaDB Error Codes](../mariadb-error-codes/index) for a full list of MariaDB error codes, and [Operating System Error Codes](../operating-system-error-codes/index) for a list of Linux and Windows error codes. Usage ----- ``` perror [OPTIONS] [ERRORCODE [ERRORCODE...]] ``` If you need to describe a negative error code, use `--` before the first error code to end the options. Options ------- | Option | Description | | --- | --- | | `-?`, `--help` | Display help and exit. | | `-I`, `--info` | Synonym for `--help`. | | `-s`, `--silent` | Only print the error message. | | `-v`, `--verbose` | Print error code and message (default). (Defaults to on; use `--skip-verbose` to disable.) | | `-V`, `--version` | Displays version information and exits. | Examples -------- System error code: ``` shell> perror 96 OS error code 96: Protocol family not supported ``` MariaDB/MySQL [error code](../mariadb-error-codes/index): ``` shell> perror 1005 1006 MySQL error code 1005 (ER_CANT_CREATE_TABLE): Can't create table %`s.%`s (errno: %M) MySQL error code 1006 (ER_CANT_CREATE_DB): Can't create database '%-.192s' (errno: %M) ``` ``` shell> perror --silent 1979 You are not owner of query %lu ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Data Definition Data Definition ================ SQL Commands for defining data, such as ALTER, CREATE, DROP, RENAME etc. | Title | Description | | --- | --- | | [CREATE](../create/index) | Articles on the various CREATE statements. | | [ALTER](../alter/index) | The various ALTER statements in MariaDB. | | [DROP](../drop/index) | Articles on various DROP commands. | | [Atomic DDL](../atomic-ddl/index) | Making DDL Atomic/Crash-safe. | | [CONSTRAINT](../constraint/index) | Define a CHECK or FOREIGN KEY constraint. | | [MERGE](../merge/index) | Allows you to access a collection of identical MyISAM tables as one. | | [RENAME TABLE](../rename-table/index) | Change a table's name. | | [TRUNCATE TABLE](../truncate-table/index) | DROP and re-CREATE a table. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Information Schema THREAD_POOL_STATS Table Information Schema THREAD\_POOL\_STATS Table ============================================ **MariaDB starting with [10.5](../what-is-mariadb-105/index)**The [Information Schema](../information_schema/index) `THREAD_POOL_STATS` table was introduced in [MariaDB 10.5.0](https://mariadb.com/kb/en/mariadb-1050-release-notes/). The table provides performance counter information for the [thread pool](../thread-pool-in-mariadb/index), and contains the following columns: | Column | Description | | --- | --- | | `GROUP_ID` | | | `THREAD_CREATIONS` | | | `THREAD_CREATIONS_DUE_TO_STALL` | | | `WAKES` | | | `WAKES_DUE_TO_STALL` | | | `THROTTLES` | | | `STALLS` | | | `POLLS_BY_LISTENER` | | | `POLLS_BY_WORKER` | | | `DEQUEUES_BY_LISTENER` | | | `DEQUEUES_BY_WORKER` | | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Transactions Transactions ============= "An SQL-transaction (transaction) is a sequence of executions of SQL-statements that is atomic with respect to recovery. That is to say: either the execution result is completely successful, or it has no effect on any SQL-schemas or SQL-data." — The SQL Standard The [InnoDB](../xtradb-and-innodb/index) storage engine supports [ACID](../acid-concurrency-control-with-transactions/index)-compliant transactions. Transaction Articles -------------------- | Title | Description | | --- | --- | | [START TRANSACTION](../start-transaction/index) | Basic transaction control statements. | | [COMMIT](../commit/index) | Ends a transaction, making changes visible to subsequent transactions | | [ROLLBACK](../rollback/index) | Cancel current transaction and the changes to data | | [SET TRANSACTION](../set-transaction/index) | Sets the transaction isolation level. | | [LOCK TABLES](../lock-tables/index) | Explicitly lock tables. | | [SAVEPOINT](../savepoint/index) | SAVEPOINT for a ROLLBACK. | | [Metadata Locking](../metadata-locking/index) | A lock which protects each transaction from external DDL statements. | | [SQL statements That Cause an Implicit Commit](../sql-statements-that-cause-an-implicit-commit/index) | List of statements which implicitly commit the current transaction | | [Transaction Timeouts](../transaction-timeouts/index) | Timing out idle transactions | | [UNLOCK TABLES](../transactions-unlock-tables/index) | Explicitly releases any table locks held by the current session. | | [WAIT and NOWAIT](../wait-and-nowait/index) | Extended syntax so that it is possible to set lock wait timeout for certain statements. | | [XA Transactions](../xa-transactions/index) | Transactions designed to allow distributed transactions. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Aria Group Commit Aria Group Commit ================= Since [MariaDB 5.2](../what-is-mariadb-52/index), the [Aria storage engine](../aria/index) has included a feature to group commits to speed up concurrent threads doing many inserts into the same or different Aria tables. By default, group commit for Aria is turned off. It is controlled by the [aria\_group\_commit](../aria-server-system-variables/index#aria_group_commit) and [aria\_group\_commit\_interval](../aria-server-system-variables/index#aria_group_commit_interval) system variables. Information on setting server variables can be found on the [Server System Variables](../server-system-variables/index) page. Terminology ----------- * A `commit` is `flush of logs` followed by a sync. * `sent to disk` means written to disk but not sync()ed, * `flushed` mean sent to disk and synced(). * `LSN` means log serial number. It's refers to the position in the transaction log. Non Group commit logic (aria\_group\_commit="none") --------------------------------------------------- The thread which first started the `commit` is performing the actual flush of logs. Other threads set the new goal (LSN) of the next pass (if it is maximum) and wait for the pass end or just wait for the pass end. The effect of this is that a flush (write of logs + sync) will save all data for all threads/transactions that have been waiting since the last flush. If hard group commit is enabled (aria\_group\_commit="hard") ------------------------------------------------------------ ### If hard commit and aria\_group\_commit\_interval=0 The first thread sends all changed buffers to disk. This is repeated as long as there are new LSNs added. The process can not loop forever because we have a limited number of threads and they will wait for the data to be synced. Pseudo code: ``` do send changed buffers to disk while new_goal sync ``` ### If hard commit and aria\_group\_commit\_interval > 0 If less than rate microseconds has passed since the last sync, then after buffers have been sent to disk, wait until rate microseconds has passed since last sync, do sync and return. This ensures that if we call sync infrequently we don't do any waits. If soft group commit is enabled (aria\_group\_commit="soft") ------------------------------------------------------------ Note that soft group commit should only be used if you can afford to lose a few rows if your machine shuts down hard (as in the case of a power failure). Works like in `non group commit'` but the thread doesn't do any real sync(). If aria\_group\_commit\_interval is not zero, the sync() will be performed by a service thread with the given rate when needed (new LSN appears). If aria\_group\_commit\_interval is zero, there will be no sync() calls. Code ---- The code for this can be found in storage/maria/ma\_loghandler.c::translog\_flush() Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb ROW ROW === **MariaDB starting with [10.3.0](https://mariadb.com/kb/en/mariadb-1030-release-notes/)**The `ROW` data type was introduced in [MariaDB 10.3.0](https://mariadb.com/kb/en/mariadb-1030-release-notes/). Syntax ------ ``` ROW (<field name> <data type> [{, <field name> <data type>}... ]) ``` Description ----------- `ROW` is a data type for [stored procedure](../stored-procedures/index) variables. Features -------- ### ROW fields as normal variables `ROW` fields (members) act as normal variables, and are able to appear in all query parts where a stored procedure variable is allowed: * Assignment is using the `:=` operator and the [SET](../set/index) command: ``` a.x:= 10; a.x:= b.x; SET a.x= 10, a.y=20, a.z= b.z; ``` * Passing to functions and operators: ``` SELECT f1(rec.a), rec.a<10; ``` * Clauses (select list, WHERE, HAVING, LIMIT, etc...,): ``` SELECT var.a, t1.b FROM t1 WHERE t1.b=var.b LIMIT var.c; ``` * `INSERT` values: ``` INSERT INTO t1 VALUES (rec.a, rec.b, rec.c); ``` * `SELECT .. INTO` targets ``` SELECT a,b INTO rec.a, rec.b FROM t1 WHERE t1.id=10; ``` * Dynamic SQL out parameters ([EXECUTE](../execute-statement/index) and [EXECUTE IMMEDIATE](../execute-immediate/index)) ``` EXECUTE IMMEDIATE 'CALL proc_with_out_param(?)' USING rec.a; ``` ### ROW type variables as FETCH targets `ROW` type variables are allowed as [FETCH](../fetch/index) targets: ``` FETCH cur INTO rec; ``` where `cur` is a `CURSOR` and `rec` is a `ROW` type stored procedure variable. Note, currently an attempt to use `FETCH` for a `ROW` type variable returns this error: ``` ERROR 1328 (HY000): Incorrect number of FETCH variables ``` `FETCH` from a cursor `cur` into a `ROW` variable `rec` works as follows: * The number of fields in `cur` must match the number of fields in `rec`. Otherwise, an error is reported. * Assignment is done from left to right. The first cursor field is assigned to the first variable field, the second cursor field is assigned to the second variable field, etc. * Field names in `rec` are not important and can differ from field names in `cur`. See [FETCH Examples](#fetch-examples) (below) for examples of using this with `sql_mode=ORACLE` and `sql_mode=DEFAULT`. ### ROW type variables as `SELECT...INTO` targets `ROW` type variables are allowed as `SELECT..INTO` targets with some differences depending on which `sql_mode` is in use. * When using `sql_mode=ORACLE`, `table%ROWTYPE` and `cursor%ROWTYPE` variables can be used as `SELECT...INTO` targets. * Using multiple `ROW` variables in the `SELECT..INTO` list will report an error. * Using `ROW` variables with a different column count than in the `SELECT..INTO` list will report an error. See [SELECT...INTO Examples](#selectinto-examples) (below) for examples of using this with `sql_mode=ORACLE` and `sql_mode=DEFAULT`. Features not implemented ------------------------ The following features are planned, but not implemented yet: * Returning a ROW type expression from a stored function (see [MDEV-12252](https://jira.mariadb.org/browse/MDEV-12252)). This will need some grammar change to support field names after parentheses: ``` SELECT f1().x FROM DUAL; ``` * Returning a ROW type expression from a built-in hybrid type function, such as `CASE`, `IF`, etc. * ROW of ROWs Examples -------- ### Declaring a ROW in a stored procedure ``` DELIMITER $$ CREATE PROCEDURE p1() BEGIN DECLARE r ROW (c1 INT, c2 VARCHAR(10)); SET r.c1= 10; SET r.c2= 'test'; INSERT INTO t1 VALUES (r.c1, r.c2); END; $$ DELIMITER ; CALL p1(); ``` ### FETCH Examples A complete `FETCH` example for `sql_mode=ORACLE`: ``` DROP TABLE IF EXISTS t1; CREATE TABLE t1 (a INT, b VARCHAR(32)); INSERT INTO t1 VALUES (10,'b10'); INSERT INTO t1 VALUES (20,'b20'); INSERT INTO t1 VALUES (30,'b30'); SET sql_mode=oracle; DROP PROCEDURE IF EXISTS p1; DELIMITER $$ CREATE PROCEDURE p1 AS rec ROW(a INT, b VARCHAR(32)); CURSOR c IS SELECT a,b FROM t1; BEGIN OPEN c; LOOP FETCH c INTO rec; EXIT WHEN c%NOTFOUND; SELECT ('rec=(' || rec.a ||','|| rec.b||')'); END LOOP; CLOSE c; END; $$ DELIMITER ; CALL p1(); ``` A complete `FETCH` example for `sql_mode=DEFAULT`: ``` DROP TABLE IF EXISTS t1; CREATE TABLE t1 (a INT, b VARCHAR(32)); INSERT INTO t1 VALUES (10,'b10'); INSERT INTO t1 VALUES (20,'b20'); INSERT INTO t1 VALUES (30,'b30'); SET sql_mode=DEFAULT; DROP PROCEDURE IF EXISTS p1; DELIMITER $$ CREATE PROCEDURE p1() BEGIN DECLARE done INT DEFAULT FALSE; DECLARE rec ROW(a INT, b VARCHAR(32)); DECLARE c CURSOR FOR SELECT a,b FROM t1; DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE; OPEN c; read_loop: LOOP FETCH c INTO rec; IF done THEN LEAVE read_loop; END IF; SELECT CONCAT('rec=(',rec.a,',',rec.b,')'); END LOOP; CLOSE c; END; $$ DELIMITER ; CALL p1(); ``` ### SELECT...INTO Examples A `SELECT...INTO` example for `sql_mode=DEFAULT`: ``` SET sql_mode=DEFAULT; DROP TABLE IF EXISTS t1; DROP PROCEDURE IF EXISTS p1; CREATE TABLE t1 (a INT, b VARCHAR(32)); INSERT INTO t1 VALUES (10,'b10'); DELIMITER $$ CREATE PROCEDURE p1() BEGIN DECLARE rec1 ROW(a INT, b VARCHAR(32)); SELECT * FROM t1 INTO rec1; SELECT rec1.a, rec1.b; END; $$ DELIMITER ; CALL p1(); ``` The above example returns: ``` +--------+--------+ | rec1.a | rec1.b | +--------+--------+ | 10 | b10 | +--------+--------+ ``` A `SELECT...INTO` example for `sql_mode=ORACLE`: ``` SET sql_mode=ORACLE; DROP TABLE IF EXISTS t1; DROP PROCEDURE IF EXISTS p1; CREATE TABLE t1 (a INT, b VARCHAR(32)); INSERT INTO t1 VALUES (10,'b10'); DELIMITER $$ CREATE PROCEDURE p1 AS rec1 ROW(a INT, b VARCHAR(32)); BEGIN SELECT * FROM t1 INTO rec1; SELECT rec1.a, rec1.b; END; $$ DELIMITER ; CALL p1(); ``` The above example returns: ``` +--------+--------+ | rec1.a | rec1.b | +--------+--------+ | 10 | b10 | +--------+--------+ ``` An example for `sql_mode=ORACLE` using `table%ROWTYPE` variables as `SELECT..INTO` targets: ``` SET sql_mode=ORACLE; DROP TABLE IF EXISTS t1; DROP PROCEDURE IF EXISTS p1; CREATE TABLE t1 (a INT, b VARCHAR(32)); INSERT INTO t1 VALUES (10,'b10'); DELIMITER $$ CREATE PROCEDURE p1 AS rec1 t1%ROWTYPE; BEGIN SELECT * FROM t1 INTO rec1; SELECT rec1.a, rec1.b; END; $$ DELIMITER ; CALL p1(); ``` The above example returns: ``` +--------+--------+ | rec1.a | rec1.b | +--------+--------+ | 10 | b10 | +--------+--------+ ``` An example for `sql_mode=ORACLE` using `cursor%ROWTYPE` variables as `SELECT..INTO` targets: ``` SET sql_mode=ORACLE; DROP TABLE IF EXISTS t1; DROP PROCEDURE IF EXISTS p1; CREATE TABLE t1 (a INT, b VARCHAR(32)); INSERT INTO t1 VALUES (10,'b10'); DELIMITER $$ CREATE PROCEDURE p1 AS CURSOR cur1 IS SELECT * FROM t1; rec1 cur1%ROWTYPE; BEGIN SELECT * FROM t1 INTO rec1; SELECT rec1.a, rec1.b; END; $$ DELIMITER ; CALL p1(); ``` The above example returns: ``` +--------+--------+ | rec1.a | rec1.b | +--------+--------+ | 10 | b10 | +--------+--------+ ``` See Also -------- * [STORED PROCEDURES](../stored-procedures/index) * [DECLARE Variable](../declare-variable/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb SET Data Type SET Data Type ============= Syntax ------ ``` SET('value1','value2',...) [CHARACTER SET charset_name] [COLLATE collation_name] ``` Description ----------- A set. A string object that can have zero or more values, each of which must be chosen from the list of values 'value1', 'value2', ... A SET column can have a maximum of 64 members. SET values are represented internally as integers. SET values cannot contain commas. If a SET contains duplicate values, an error will be returned if [strict mode](../sql-mode/index#strict-mode) is enabled, or a warning if strict mode is not enabled. See Also -------- * [Character Sets and Collations](../character-sets-and-collations/index) * [Data Type Storage Requirements](../data-type-storage-requirements/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Password Validation Plugin API Password Validation Plugin API ============================== “Password validation” means ensuring that user passwords meet certain minimal security requirements. A dedicated plugin API allows the creation of password validation plugins that will check user passwords as they are set (in [SET PASSWORD](../set-password/index) and [GRANT](../grant/index) statements) and either allow or reject them. SQL-Level Extensions -------------------- MariaDB comes with three password validation plugins — the [simple\_password\_check](../simple_password_check/index) plugin, the [cracklib\_password\_check](../cracklib_password_check/index) plugin and the [password\_reuse\_check](../password-reuse-check-plugin/index) plugin. They are not enabled by default; use [INSTALL SONAME](../install-soname/index) (or [INSTALL PLUGIN](../install-plugin/index)) statement to install them. When at least one password plugin is loaded, all new passwords will be validated and password-changing statements will fail if the password will not pass validation checks. Several password validation plugin can be loaded at the same time — in this case a password must pass **all** validation checks by **all** plugins. ### Password-Changing Statements One can use various SQL statements to change a user password: #### With Plain Text Password ``` SET PASSWORD = PASSWORD('plain-text password'); SET PASSWORD FOR `user`@`host` = PASSWORD('plain-text password'); SET PASSWORD = OLD_PASSWORD('plain-text password'); SET PASSWORD FOR `user`@`host` = OLD_PASSWORD('plain-text password'); CREATE USER `user`@`host` IDENTIFIED BY 'plain-text password'; GRANT privileges TO `user`@`host` IDENTIFIED BY 'plain-text password'; ``` These statements are subject to password validation. If at least one password validation plugin is loaded, plain-text passwords specified in these statements will be validated. #### With Password Hash ``` SET PASSWORD = 'password hash'; SET PASSWORD FOR `user`@`host` = 'password hash'; CREATE USER `user`@`host` IDENTIFIED BY PASSWORD 'password hash'; CREATE USER `user`@`host` IDENTIFIED VIA mysql_native_password USING 'password hash'; CREATE USER `user`@`host` IDENTIFIED VIA mysql_old_password USING 'password hash'; GRANT privileges TO `user`@`host` IDENTIFIED BY PASSWORD 'password hash'; GRANT privileges TO `user`@`host` IDENTIFIED VIA mysql_native_password USING 'password hash'; GRANT privileges TO `user`@`host` IDENTIFIED VIA mysql_old_password USING 'password hash'; ``` These statements can not possibly use password validation — there is nothing to validate, the original plain-text password is not available. MariaDB introduces a **strict password validation** mode — controlled by a [strict\_password\_validation](../server-system-variables/index#strict_password_validation) global server variable. If the strict password validation is enabled and at least one password validation plugin is loaded then these “unvalidatable” passwords will be rejected. Otherwise they will be accepted. By default a strict password validation is enabled (but note that it has no effect if no password validation plugin is loaded). Examples -------- Failed password validation: ``` GRANT SELECT ON *.* to foobar IDENTIFIED BY 'raboof'; ERROR HY000: Your password does not satisfy the current policy requirements SHOW WARNINGS; +---------+------+----------------------------------------------------------------+ | Level | Code | Message | +---------+------+----------------------------------------------------------------+ | Warning | 1819 | cracklib: it is based on your username | | Error | 1819 | Your password does not satisfy the current policy requirements | +---------+------+----------------------------------------------------------------+ ``` Strict password validation: ``` GRANT SELECT ON *.* TO foo IDENTIFIED BY PASSWORD '2222222222222222'; ERROR HY000: The MariaDB server is running with the --strict-password-validation option so it cannot execute this statement ``` Plugin API ---------- Password validation plugin API is very simple. A plugin must implement only one method — `validate_password()`. This method takes two arguments — user name and the plain-text password. And it returns 0 when the password has passed the validation and 1 otherwise, See also `mysql/plugin_password_validation.h` and password validation plugins in `plugin/simple_password_check/` and `plugins/cracklib_password_check/`. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb GeomFromWKB GeomFromWKB =========== A synonym for [ST\_GeomFromWKB](../st_geomfromwkb/index). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Cassandra Storage Engine Use Example Cassandra Storage Engine Use Example ==================================== CassandraSE is no longer actively being developed and has been removed in [MariaDB 10.6](../what-is-mariadb-106/index). See [MDEV-23024](https://jira.mariadb.org/browse/MDEV-23024). This page is a short demo of what using [Cassandra Storage Engine](../cassandra-storage-engine/index) looks like. First, a keyspace and column family must be created in Cassandra: ``` cqlsh> CREATE KEYSPACE mariadbtest2 ... WITH strategy_class = 'org.apache.cassandra.locator.SimpleStrategy' ... AND strategy_options:replication_factor='1'; cqlsh> USE mariadbtest2; cqlsh:mariadbtest2> create columnfamily cf1 ( pk varchar primary key, data1 varchar, data2 bigint); cqlsh:mariadbtest2> select * from cf1; cqlsh:mariadbtest2> ``` Now, let's try to connect an SQL table to it: ``` MariaDB [test]> create table t1 ( -> rowkey varchar(36) primary key, -> data1 varchar(60), data2 varchar(60) -> ) engine=cassandra thrift_host='localhost' keyspace='mariadbtest2' column_family='cf1'; ERROR 1928 (HY000): Internal error: 'Failed to map column data2 to datatype org.apache.cassandra.db.marshal.LongType' ``` We've used a wrong datatype. Let's try again: ``` MariaDB [test]> create table t1 ( -> rowkey varchar(36) primary key, -> data1 varchar(60), data2 bigint -> ) engine=cassandra thrift_host='localhost' keyspace='mariadbtest2' column_family='cf1'; Query OK, 0 rows affected (0.04 sec) ``` Ok. Let's insert some data: ``` MariaDB [test]> insert into t1 values ('rowkey10', 'data1-value', 123456); Query OK, 1 row affected (0.01 sec) MariaDB [test]> insert into t1 values ('rowkey11', 'data1-value2', 34543); Query OK, 1 row affected (0.00 sec) MariaDB [test]> insert into t1 values ('rowkey12', 'data1-value3', 454); Query OK, 1 row affected (0.00 sec) ``` Let's select it back: ``` MariaDB [test]> select * from t1 where rowkey='rowkey11'; +----------+--------------+-------+ | rowkey | data1 | data2 | +----------+--------------+-------+ | rowkey11 | data1-value2 | 34543 | +----------+--------------+-------+ 1 row in set (0.00 sec) ``` Now, let's check if it can be seen in Cassandra: ``` cqlsh:mariadbtest2> select * from cf1; pk | data1 | data2 ----------+--------------+-------- rowkey12 | data1-value3 | 454 rowkey10 | data1-value | 123456 rowkey11 | data1-value2 | 34543 ``` Or, in cassandra-cli: ``` [default@mariadbtest2] list cf1; Using default limit of 100 Using default column limit of 100 ------------------- RowKey: rowkey12 => (column=data1, value=data1-value3, timestamp=1345452471835) => (column=data2, value=454, timestamp=1345452471835) ------------------- RowKey: rowkey10 => (column=data1, value=data1-value, timestamp=1345452467728) => (column=data2, value=123456, timestamp=1345452467728) ------------------- RowKey: rowkey11 => (column=data1, value=data1-value2, timestamp=1345452471831) => (column=data2, value=34543, timestamp=1345452471831) 3 Rows Returned. Elapsed time: 5 msec(s). ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb DROP PACKAGE DROP PACKAGE ============ **MariaDB starting with [10.3.5](https://mariadb.com/kb/en/mariadb-1035-release-notes/)**Oracle-style packages were introduced in [MariaDB 10.3.5](https://mariadb.com/kb/en/mariadb-1035-release-notes/). Syntax ------ ``` DROP PACKAGE [IF EXISTS] [ db_name . ] package_name ``` Description ----------- The `DROP PACKAGE` statement can be used when [Oracle SQL\_MODE](../sql_modeoracle-from-mariadb-103/index) is set. The `DROP PACKAGE` statement drops a stored package entirely: * Drops the package specification (earlier created using the [CREATE PACKAGE](../create-package/index) statement). * Drops the package implementation, if the implementation was already created using the [CREATE PACKAGE BODY](../create-package-body/index) statement. See Also -------- * [SHOW CREATE PACKAGE](../show-create-package/index) * [CREATE PACKAGE](../create-package/index) * [CREATE PACKAGE BODY](../create-package-body/index) * [DROP PACKAGE BODY](../drop-package-body/index) * [Oracle SQL\_MODE](../sql_modeoracle-from-mariadb-103/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Performance Schema events_transactions_summary_by_host_by_event_name Table Performance Schema events\_transactions\_summary\_by\_host\_by\_event\_name Table ================================================================================= **MariaDB starting with [10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/)**The events\_transactions\_summary\_by\_host\_by\_event\_name table was introduced in [MariaDB 10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/). The `events_transactions_summary_by_host_by_event_name` table contains information on transaction events aggregated by host and event name. The table contains the following columns: | Column | Type | Description | | --- | --- | --- | | HOST | char(60) | Host for which summary is generated. | | EVENT\_NAME | varchar(128) | Event name for which summary is generated. | | COUNT\_STAR | bigint(20) unsigned | The number of summarized events. This value includes all events, whether timed or nontimed. | | SUM\_TIMER\_WAIT | bigint(20) unsigned | The total wait time of the summarized timed events. This value is calculated only for timed events because nontimed events have a wait time of NULL. The same is true for the other xxx\_TIMER\_WAIT values. | | MIN\_TIMER\_WAIT | bigint(20) unsigned | The minimum wait time of the summarized timed events. | | AVG\_TIMER\_WAIT | bigint(20) unsigned | The average wait time of the summarized timed events. | | MAX\_TIMER\_WAIT | bigint(20) unsigned | The maximum wait time of the summarized timed events. | | COUNT\_READ\_WRITE | bigint(20) unsigned | The total number of only READ/WRITE transaction events. | | SUM\_TIMER\_READ\_WRITE | bigint(20) unsigned | The total wait time of only READ/WRITE transaction events. | | MIN\_TIMER\_READ\_WRITE | bigint(20) unsigned | The minimum wait time of only READ/WRITE transaction events. | | AVG\_TIMER\_READ\_WRITE | bigint(20) unsigned | The average wait time of only READ/WRITE transaction events. | | MAX\_TIMER\_READ\_WRITE | bigint(20) unsigned | The maximum wait time of only READ/WRITE transaction events. | | COUNT\_READ\_ONLY | bigint(20) unsigned | The total number of only READ ONLY transaction events. | | SUM\_TIMER\_READ\_ONLY | bigint(20) unsigned | The total wait time of only READ ONLY transaction events. | | MIN\_TIMER\_READ\_ONLY | bigint(20) unsigned | The minimum wait time of only READ ONLY transaction events. | | AVG\_TIMER\_READ\_ONLY | bigint(20) unsigned | The average wait time of only READ ONLY transaction events. | | MAX\_TIMER\_READ\_ONLY | bigint(20) unsigned | The maximum wait time of only READ ONLY transaction events. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Sys Schema Sys Schema =========== **MariaDB starting with [10.6.0](https://mariadb.com/kb/en/mariadb-1060-release-notes/)**The sys\_schema is a collection of views, functions and procedures to help administrators get insight into database usage. This article is currently incomplete. | Title | Description | | --- | --- | | [Sys Schema sys\_config Table](../sys-schema-sys_config-table/index) | Configuration options for the Sys Schema. | | [Sys Schema Stored Functions](../sys-schema-stored-functions/index) | Stored functions available in the Sys Schema. | | [Sys Schema Stored Procedures](../sys-schema-stored-procedures/index) | Stored procedures available in the Sys Schema. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb IP Range Table Performance IP Range Table Performance ========================== The situation ------------- Your data includes a large set of non-overlapping 'ranges'. These could be IP addresses, datetimes (show times for a single station), zipcodes, etc. You have pairs of start and end values; one 'item' belongs to each such 'range'. So, instinctively, you create a table with start and end of the range, plus info about the item. Your queries involve a WHERE clause that compares for being between the start and end values. The problem ----------- Once you get a large set of items, performance degrades. You play with the indexes, but find nothing that works well. The indexes fail to lead to optimal functioning because the database does not understand that the ranges are non-overlapping. The solution ------------ I will present a solution that enforces the fact that items cannot have overlapping ranges. The solution builds a table to take advantage of that, then uses Stored Routines to get around the clumsiness imposed by it. Performance ----------- The instinctive solution often leads to scanning half the table to do just about anything, such as finding the item containing an 'address'. In complexity terms, this is Order(N). The solution here can usually get the desired information by fetching a single row, or a small number of rows. It is Order(1). In a large table, "counting the disk hits" is the important part of performance. Since InnoDB is used, and the PRIMARY KEY (clustered) is used, most operations hit only 1 block. Finding the 'block' where a given IP address lives: * For start of block: One single-row fetch using the PRIMARY KEY * For end of block: Ditto. The record containing this will be 'adjacent' to the other record. For allocating or freeing a block: * 2-7 SQL statements, hitting the clustered PRIMARY KEY for the rows containing and immediately adjacent to the block. * One SQL statement is a DELETE; if hits as many rows as are needed for the block. * The other statements hit one row each. Design decisions ---------------- This is crucial to the design and its performance: * Having just one address in the row. These were alternative designs; they seemed to be no better, and possibly worse: * That one address could have been the 'end' address. * The routine parameters for a 'block' could have be start of this block and start of next block. * The IPv4 parameters could have been dotted quads; I chose to keep the reference implemetation simpler instead. * The IPv6 parameters are 32-digit hex because it was the simpler that BINARY(16) or IPv5 for a reference implementation. The interesting work is in the Ips, not the second table, so I focus on it. The inconvenience of JOINing to the second table is small compared to the performance gains. Details ------- Two, not one, tables will be used. The first table (`Ips` in the reference implementations) is carefully designed to be optimal for all the basic operations needed. The second table contains other infomation about the 'owner' of each 'item'. In the reference implementations `owner` is an id used to JOIN the two tables. This discussion centers around `Ips` and how to efficiently map IP(s) to/from owner(s). The second table has "PRIMARY KEY(owner)". In addition to the two-table schema, there are a set of Stored Routines to encapsulate the necessary code. One row of Ips represents one 'item' by specifying the starting IP address and the 'owner'. The next row gives the starting IP address of the next "address block", thereby indirectly providing the ending address for the current block. This lack of explicitly stating the "end address" leads to some clumsiness. The stored routines hide it from the user. A special owner (indicated by '0') is reserved for "free" or "not-owned" blocks. Hence, sparse allocation of address blocks is no problem. Also, the 'free' owner is handled no differently than real owners, so there are no extra Stored Routines for such. Links below give "reference" implementations for IPv4 and IPv6. You will need to make changes for non-IP situations, and may need to make changes even for IP situations. These are the main stored routines provided: * IpIncr, IpDecr -- for adding/subtracting 1 * IpStore -- for allocating/freeing a range * IpOwner, IpRangeOwners, IpFindRanges, Owner2IpStarts, Owner2IpRanges -- for lookups * IpNext, IpEnd -- IP of start of next block, or end of current block None of the provided routines JOIN to the other table; you may wish to develop custom queries based on the given reference Stored Procedures. The Ips table's size is proportional to the number of blocks. A million 'owned' blocks may be 20-50MB. This varies due to * number of 'free' gaps (between zero and the number of owned blocks) * datatypes used for `ip` and `owner` * [InnoDB](../innodb/index) overhead Even 100M blocks is quite manageable in today's hardware. Once things are cached, most operations would take only a few milliseconds. A trillion blocks would work, but most operations would hit the disk a few times -- only a few times. Reference implementation of IPv4 -------------------------------- This specific to IPv4 (32 bit, a la '196.168.1.255'). It can handle anywhere from 'nothing assigned' (1 row) to 'everything assigned' (4B rows) 'equally' well. That is, to ask the question "who owns '11.22.33.44'" is equally efficient regardless of how many blocks of IP addresses exist in the table. (OK, caching, disk hits, etc may make a slight difference.) The one function that can vary is the one that reassigns a range to a new owner. Its speed is a function of how many existing ranges need to be consumed, since those rows will be DELETEd. (It helps that they are, by schema design, 'clustered'.) Notes on the [Reference implementation for IPv4](http://mysql.rjweb.org/doc.php/ipv4.sql): * Externally, the user may use the dotted quad notation (11.22.33.44), but needs to convert to INT UNSIGNED for calling the Stored Procs. * The user is responsible for converting to/from the calling datatype (INT UNSIGNED) when accessing the stored routine; suggest [INET\_ATON](../inet_aton/index)/[INET\_NTOA](../inet_ntoa/index). * The internal datatype for addresses is the same as the calling datatype (INT UNSIGNED). * Adding and subtracting 1 (simple arithmetic). * The datatype of an 'owner' (MEDIUMINT UNSIGNED: 0..16M) -- adjust if needed. * The address "Off the end" (255.255.255.255+1 - represented as NULL). * The table is initialized to one row: (ip=0, owner=0), meaning "all addresses are free See the comments in the code for more details. (The reference implementation does not handle CDRs. Such should be easy to add on, by first turning it into an IP range.) Reference implementation of IPv6 -------------------------------- The code for handling IP address is more complex, but the overall structure is the same as for IPv4. Launch into it only if you need IPv6. Notes on the [reference implementation for IPv6](http://mysql.rjweb.org/doc.php/ipv6.sql): * Externally, IPv6 has a complex string, VARCHAR(39) CHARACTER SET ASCII. The Stored Procedure IpStr2Hex() is provided. * The user is responsible for converting to/from the calling datatype (BINARY(16)) when accessing the stored routine; suggest [INET6\_ATON](../inet6_aton/index)/[INET6\_NTOA](../inet6_ntoa/index). * The internal datatype for addresses is the same as the calling datatype (BINARY(16)). * Communication with the Stored routines is via 32-char hex strings. * Inside the Procedures, and in the Ips table, an address is stored as BINARY(16) for efficiency. HEX() and UNHEX() are used at the boundaries. * Adding/subtracting 1 is rather complex (see the code). * The datatype of an 'owner' (MEDIUMINT UNSIGNED: 0..16M); 'free' is represented by 0. You may need a bigger datatype. * The address "Off the end" (ffff.ffff.ffff.ffff.ffff.ffff.ffff.ffff+1 is represented by NULL). * The table is initialized to one row: (UNHEX('00000000000000000000000000000000'), 0), meaning "all addresses are free. * You may need to decide on a canonical representation of IPv4 in IPv6. See the comments in the code for more details. The INET6\* functions were first available in MySQL 5.6.3 and [MariaDB 10.0.3](https://mariadb.com/kb/en/mariadb-1003-release-notes/) Adapting to a different non-IP 'address range' data * The external datatype for an 'address' should be whatever is convenient for the application. * The datatype for the 'address' in the table must be ordered, and should be as compact as possible. * You must write the Stored functions (IpIncr, IpDecr) for incrementing/decrementing an 'address'. * An 'owner' is an id of your choosing, but smaller is better. * A special value (such as 0 or '') must be provided for 'free'. * The table must be initialized to one row: (SmallestAddress, Free) "Owner" needs a special value to represent "not owned". The reference implementations use "=" and "!=" to compare two 'owners'. Numeric values and strings work nicely with those operators; NULL does not. Hence, please do not use NULL for "not owned". Since the datatypes are pervasive in the stored routines, adapting a reference implementation to a different concept of 'address' would require multiple minor changes. The code enforces that consecutive blocks never have the same 'owner', so the table is of 'minimal' size. Your application can assume that such is always the case. Postlog ------- Original writing -- Oct, 2012; Notes on INET6 functions -- May, 2015. See also -------- * [Related blog](http://jorgenloland.blogspot.co.uk/2011/09/tips-and-tricks-killer-response-time.html) * [Another approach](http://dba.stackexchange.com/questions/83458/mysql-select-with-between-optimization/83471#83471) * [Free IP tables](https://lite.ip2location.com/) Rick James graciously allowed us to use this article in the Knowledge Base. [Rick James' site](http://mysql.rjweb.org/) has other useful tips, how-tos, optimizations, and debugging tips. Original source: <http://mysql.rjweb.org/doc.php/ipranges> Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb MultiLineStringFromText MultiLineStringFromText ======================= A synonym for [MLineFromText](../mlinefromtext/index). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Disabling InnoDB Encryption Disabling InnoDB Encryption =========================== The process involved in safely disabling encryption for your InnoDB tables is a little more complicated than that of [enabling encryption](../enabling-innodb-encryption/index). Turning off the relevant system variables doesn't decrypt the tables. If you turn it off and remove the encryption key management plugin, it'll render the encrypted data inaccessible. In order to safely disable encryption, you first need to decrypt the tablespaces and the Redo Log, then turn off the system variables. The specifics of this process depends on whether you are using automatic or manual encryption of the InnoDB tablespaces. ### Disabling Encryption for Automatically Encrypted Tablespaces When an InnoDB tablespace has the [ENCRYPTED](../create-table/index#encrypted) table option set to `DEFAULT` and the [innodb\_encrypt\_tables](../innodb-system-variables/index#innodb_encrypt_tables) system variable is set to `ON` or `FORCE`, the tablespace's encryption is automatically managed by the background encryption threads. When you want to disable encryption for these tablespaces, you must ensure that the background encryption threads decrypt the tablespaces before removing the encryption keys. Otherwise, the tablespace remains encrypted and becomes inaccessible once you've removed the keys. To safely decrypt the tablespaces, first, set the [innodb\_encrypt\_tables](../innodb-system-variables/index#innodb_encrypt_tables) system variable to `OFF`: ``` SET GLOBAL innodb_encrypt_tables = OFF; ``` Next, set the [innodb\_encryption\_threads](../innodb-system-variables/index#innodb_encryption_threads) system variable to a non-zero value: ``` SET GLOBAL innodb_encryption_threads = 4; ``` Then, set the [innodb\_encryption\_rotate\_key\_age](../innodb-system-variables/index#innodb_encryption_rotate_key_age) system variable to `1`: ``` SET GLOBAL innodb_encryption_rotate_key_age = 1; ``` Once set, any InnoDB tablespaces that have the [ENCRYPTED](../create-table/index#encrypted) table option set to `DEFAULT` will be [decrypted](../innodb-background-encryption-threads/index#background-operations) in the background by the InnoDB [background encryption threads](../innodb-background-encryption-threads/index#background-encryption-threads). #### Decryption Status You can [check the status](../innodb-background-encryption-threads/index#checking-the-status-of-background-operations) of the decryption process using the [INNODB\_TABLESPACES\_ENCRYPTION](../information-schema-innodb_tablespaces_encryption-table/index) table in the [information\_schema](../information-schema/index) database. ``` SELECT COUNT(*) AS "Number of Encrypted Tablespaces" FROM information_schema.INNODB_TABLESPACES_ENCRYPTION WHERE ENCRYPTION_SCHEME != 0 OR ROTATING_OR_FLUSHING != 0; ``` This query shows the number of InnoDB tablespaces that currently using background encryption threads. Once the count reaches 0, then all of your InnoDB tablespaces are unencrypted. Be sure to also remove encryption on the [Redo Log](#disabling-encryption-for-the-redo-log) and the [Aria](../aria-encryption/index) storage engine before removing the encryption key management settings from your configuration file. ### Disabling Encryption for Manually Encrypted Tablespaces In the case of manually encrypted InnoDB tablespaces, (that is, those where the [ENCRYPTED](../create-table/index#encrypted) table option is set to `YES`), you must issue an [ALTER TABLE](../alter-table/index) statement to decrypt each tablespace before removing the encryption keys. Otherwise, the tablespace remains encrypted and becomes inaccessible without the keys. First, query the Information Schema [TABLES](../information-schema-tables-table/index) table to find the encrypted tables. This can be done with a `WHERE` clause filtering the `CREATE_OPTIONS` column. ``` SELECT TABLE_SCHEMA AS "Database", TABLE_NAME AS "Table" FROM information_schema.TABLES WHERE ENGINE='InnoDB' AND CREATE_OPTIONS LIKE '%`ENCRYPTED`=YES%'; ``` For each table in the result-set, issue an [ALTER TABLE](../alter-table/index) statement, setting the [ENCRYPTED](../create-table/index#encrypted) table option to `NO`. ``` SELECT NAME, ENCRYPTION_SCHEME, CURRENT_KEY_ID FROM information_schema.INNODB_TABLESPACES_ENCRYPTION WHERE NAME='db1/tab1'; +----------+-------------------+----------------+ | NAME | ENCRYPTION_SCHEME | CURRENT_KEY_ID | +----------+-------------------+----------------+ | db1/tab1 | 1 | 100 | +----------+-------------------+----------------+ ALTER TABLE tab1 ENCRYPTED=NO; SELECT NAME, ENCRYPTION_SCHEME, CURRENT_KEY_ID FROM information_schema.INNODB_TABLESPACES_ENCRYPTION WHERE NAME='db1/tab1'; +----------+-------------------+----------------+ | NAME | ENCRYPTION_SCHEME | CURRENT_KEY_ID | +----------+-------------------+----------------+ | db1/tab1 | 0 | 100 | +----------+-------------------+----------------+ ``` Once you have removed encryption from all the tables, your InnoDB deployment is unencrypted. Be sure to also remove encryption from the [Redo Log](#disabling-encryption-for-the-redo-log) as well as [Aria](../aria-encryption/index) and any other storage engines that support encryption before removing the encryption key management settings from your configuration file. InnoDB does not permit manual encryption changes to tables in the [system](../innodb-system-tablespaces/index) tablespace using [ALTER TABLE](../alter-table/index). Encryption of the [system](../innodb-system-tablespaces/index) tablespace can only be configured by setting the value of the [innodb\_encrypt\_tables](../innodb-system-variables/index#innodb_encrypt_tables) system variable. This means that when you want to encrypt or decrypt the [system](../innodb-system-tablespaces/index) tablespace, you must also set a non-zero value for the [innodb\_encryption\_threads](../innodb-system-variables/index#innodb_encryption_threads) system variable, and you must also set the [innodb\_system\_rotate\_key\_age](../innodb-system-variables/index#innodb_encryption_rotate_key_age) system variable to `1` to ensure that the system tablespace is properly encrypted or decrypted by the background threads. See [MDEV-14398](https://jira.mariadb.org/browse/MDEV-14398) for more information. ### Disabling Encryption for Temporary Tablespaces The [innodb\_encrypt\_temporary\_tables](../innodb-system-variables/index#innodb_encrypt_temporary_tables) system variable controls the configuration of encryption for the [temporary tablespace](../innodb-temporary-tablespaces/index). To disable it, remove the system variable from your server's [option file](../configuring-mariadb-with-option-files/index), and then restart the server. ### Disabling Encryption for the Redo Log InnoDB uses the [Redo Log](../innodb-redo-log/index) in crash recovery. By default, these events are written to file in an unencrypted state. In removing data-at-rest encryption for InnoDB, be sure to also disable encryption for the Redo Log before removing encryption key settings. Otherwise the Redo Log can become inaccessible without the encryption keys. First, check the value of the [innodb\_fast\_shutdown](../innodb-system-variables/index#innodb_fast_shutdown) system variable with the [SHOW VARIABLES](../show-variables/index) statement. For example: ``` SHOW VARIABLES LIKE 'innodb_fast_shutdown'; +----------------------+-------+ | Variable_name | Value | +----------------------+-------+ | innodb_fast_shutdown | 2 | +----------------------+-------+ ``` When the value is set to `2`, InnoDB performs an unclean shutdown, so it will need the [Redo Log](../innodb-redo-log/index) at the next server startup. Ensure that the variable is set to `0`, `1`, or `3`. For performance reasons, `1` is usually the best option. It can be changed dynamically with [SET GLOBAL](../set/index#global-session). For example: ``` SET GLOBAL innodb_fast_shutdown = 1; ``` Then, set the [innodb\_encrypt\_log](../innodb-system-variables/index#innodb_encrypt_log) system variable to `OFF` in a server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index). Once this is done, [restart](../starting-and-stopping-mariadb-starting-and-stopping-mariadb/index) the MariaDB Server. When the Server comes back online, it begins writing unencrypted data to the Redo Log. ### See Also * [Enabling InnoDB encryption](../enabling-innodb-encryption/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb MyRocks and Group Commit with Binary log MyRocks and Group Commit with Binary log ======================================== MyRocks supports group commit with the [binary log](../binary-log/index) ([MDEV-11934](https://jira.mariadb.org/browse/MDEV-11934)). Counter Values to Watch ----------------------- (The following is only necessary if you are studying MyRocks internals) MariaDB's group commit counters are: [Binlog\_commits](../replication-and-binary-log-status-variables/index#binlog_commits) - how many transactions were written to the binary log [Binlog\_group\_commits](../replication-and-binary-log-status-variables/index#binlog_group_commits) - how many group commits happened. (e.g. if each group had two transactions, this will be twice as small as [Binlog\_commits](../replication-and-binary-log-status-variables/index#binlog_commits)) On the RocksDB side, there is one relevant counter: [Rocksdb\_wal\_synced](../myrocks-status-variables/index#rocksdb_wal_synced) - How many times RocksDB's WAL file was synced. (TODO: this is after group commit happened, right?) On the Value of rocksdb\_wal\_group\_syncs ------------------------------------------ FB/MySQL-5.6 has a [rocksdb\_wal\_group\_syncs](../myrocks-status-variables/index#rocksdb_wal_group_syncs) counter (The counter is provided by MyRocks, it is not a view of a RocksDB counter). It is increased in rocksdb\_flush\_wal() when doing the rdb->FlushWAL() call. rocksdb\_flush\_wal() is called by MySQL's Group Commit when it wants to make the effect of several rocksdb\_prepare() calls persistent. So, the value of [rocksdb\_wal\_group\_syncs](../myrocks-status-variables/index#rocksdb_wal_group_syncs) in FB/MySQL-5.6 is similar to [Binlog\_group\_commits](../replication-and-binary-log-status-variables/index#binlog_group_commits) in MariaDB. MariaDB doesn't have that call, each rocksdb\_prepare() call takes care of being persistent on its own. Because of that, [rocksdb\_wal\_group\_syncs](../myrocks-status-variables/index#rocksdb_wal_group_syncs) is zero for MariaDB. (Currently, it is only incremented when the binlog is rotated). Examples -------- So for a workload with concurrency=50, n\_queries=10K, one gets * Binlog\_commits=10K * Binlog\_group\_commits=794 * Rocksdb\_wal\_synced=8362 This is on a RAM disk For a workload with concurrency=50, n\_queries=10K, rotating laptop hdd, one gets * Binlog\_commits= 10K * Binlog\_group\_commits=1403 * Rocksdb\_wal\_synced=400 The test took 38 seconds, Number of syncs was 1400+400=1800, which gives 45 syncs/sec which looks normal for this slow rotating desktop hdd. Note that the WAL was synced fewer times than there were binlog commit groups (?) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb PERCENTILE_DISC PERCENTILE\_DISC ================ **MariaDB starting with [10.3.3](https://mariadb.com/kb/en/mariadb-1033-release-notes/)**The PERCENTILE\_DISC() [window function](../window-functions/index) was first introduced with in [MariaDB 10.3.3](https://mariadb.com/kb/en/mariadb-1033-release-notes/). Syntax ------ Description ----------- `PERCENTILE_DISC()` (standing for discrete percentile) is a [window function](../window-functions/index) which returns the first value in the set whose ordered position is the same or more than the specified fraction. Essentially, the following process is followed to find the value to return: * Get the number of rows in the partition. * Walk through the partition, in order, until finding the the first row with [CUME\_DIST()](../cume_dist/index) >= function\_argument. Examples -------- ``` CREATE TABLE book_rating (name CHAR(30), star_rating TINYINT); INSERT INTO book_rating VALUES ('Lord of the Ladybirds', 5); INSERT INTO book_rating VALUES ('Lord of the Ladybirds', 3); INSERT INTO book_rating VALUES ('Lady of the Flies', 1); INSERT INTO book_rating VALUES ('Lady of the Flies', 2); INSERT INTO book_rating VALUES ('Lady of the Flies', 5); SELECT name, PERCENTILE_DISC(0.5) WITHIN GROUP (ORDER BY star_rating) OVER (PARTITION BY name) AS pc FROM book_rating; +-----------------------+------+ | name | pc | +-----------------------+------+ | Lord of the Ladybirds | 3 | | Lord of the Ladybirds | 3 | | Lady of the Flies | 2 | | Lady of the Flies | 2 | | Lady of the Flies | 2 | +-----------------------+------+ 5 rows in set (0.000 sec) SELECT name, PERCENTILE_DISC(0) WITHIN GROUP (ORDER BY star_rating) OVER (PARTITION BY name) AS pc FROM book_rating; +-----------------------+------+ | name | pc | +-----------------------+------+ | Lord of the Ladybirds | 3 | | Lord of the Ladybirds | 3 | | Lady of the Flies | 1 | | Lady of the Flies | 1 | | Lady of the Flies | 1 | +-----------------------+------+ 5 rows in set (0.000 sec) SELECT name, PERCENTILE_DISC(1) WITHIN GROUP (ORDER BY star_rating) OVER (PARTITION BY name) AS pc FROM book_rating; +-----------------------+------+ | name | pc | +-----------------------+------+ | Lord of the Ladybirds | 5 | | Lord of the Ladybirds | 5 | | Lady of the Flies | 5 | | Lady of the Flies | 5 | | Lady of the Flies | 5 | +-----------------------+------+ 5 rows in set (0.000 sec) SELECT name, PERCENTILE_DISC(0.6) WITHIN GROUP (ORDER BY star_rating) OVER (PARTITION BY name) AS pc FROM book_rating; +-----------------------+------+ | name | pc | +-----------------------+------+ | Lord of the Ladybirds | 5 | | Lord of the Ladybirds | 5 | | Lady of the Flies | 2 | | Lady of the Flies | 2 | | Lady of the Flies | 2 | +-----------------------+------ ``` See Also -------- * [CUME\_DIST()](../cume_dist/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb System and Status Variables Added By Major Release System and Status Variables Added By Major Release =================================================== No new variables added in 10.7 and 10.8. | Title | Description | | --- | --- | | [System Variables Added in MariaDB 10.9](../system-variables-added-in-mariadb-109/index) | List of system variables that were added in the MariaDB 10.9 series. | | [System Variables Added in MariaDB 10.6](../system-variables-added-in-mariadb-106/index) | List of system variables that were added in the MariaDB 10.6 series. | | [Status Variables Added in MariaDB 10.6](../status-variables-added-in-mariadb-106/index) | List of status variables that were added in the MariaDB 10.6 series. | | [System Variables Added in MariaDB 10.5](../system-variables-added-in-mariadb-105/index) | List of system variables that were added in the MariaDB 10.5 series. | | [Status Variables Added in MariaDB 10.5](../status-variables-added-in-mariadb-105/index) | List of status variables that were added in the MariaDB 10.5 series. | | [System Variables Added in MariaDB 10.4](../system-variables-added-in-mariadb-104/index) | List of system variables that were added in the MariaDB 10.4 series. | | [Status Variables Added in MariaDB 10.4](../status-variables-added-in-mariadb-104/index) | List of status variables that were added in the MariaDB 10.4 series. | | [System Variables Added in MariaDB 10.3](../system-variables-added-in-mariadb-103/index) | List of system variables that were added in the MariaDB 10.3 series. | | [Status Variables Added in MariaDB 10.3](../status-variables-added-in-mariadb-103/index) | List of status variables that were added in the MariaDB 10.3 series. | | [System Variables Added in MariaDB 10.2](../system-variables-added-in-mariadb-102/index) | List of system variables that were added in the MariaDB 10.2 series. | | [Status Variables Added in MariaDB 10.2](../status-variables-added-in-mariadb-102/index) | List of status variables that were added in the MariaDB 10.2 series. | | [System Variables Added in MariaDB 10.1](../system-variables-added-in-mariadb-101/index) | List of system variables that were added in the MariaDB 10.1 series. | | [Status Variables Added in MariaDB 10.1](../status-variables-added-in-mariadb-101/index) | List of status variables that were added in the MariaDB 10.1 series. | | [System Variables Added in MariaDB 10.0](../system-variables-added-in-mariadb-100/index) | List of system variables that were added in the MariaDB 10.0 series. | | [Status Variables Added in MariaDB 10.0](../status-variables-added-in-mariadb-100/index) | List of status variables that were added in the MariaDB 10.0 series | | [System Variables Added in MariaDB 5.5](../system-variables-added-in-mariadb-55/index) | List of system variables that were added in the MariaDB 5.5 series | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Writing Logs Into Tables Writing Logs Into Tables ======================== By default, all logs are disabled or written into files. The [general query log](../general-query-log/index) and the [slow query log](../slow-query-log/index) can also be written to special tables in the `mysql` database. During the startup, entries will always be written into files. Note that [EXPLAIN output](../explain-in-the-slow-query-log/index) will only be recorded if the slow query log is written to a file and not to a table. To write logs into tables, the [log\_output](../server-system-variables/index#log_output) server system variable is used. Allowed values are `FILE`, `TABLE` and `NONE`. It is possible to specify multiple values, separated with commas, to write the logs into both tables and files. `NONE` disables logging and has precedence over the other values. So, to write logs into tables, one of the following settings can be used: ``` SET GLOBAL log_output = 'TABLE'; SET GLOBAL log_output = 'FILE,TABLE'; ``` The general log will be written into the [general\_log](../mysqlgeneral_log-table/index) table, and the slow query log will be written into the [slow\_log](../mysqlslow_log-table/index) table. Only a limited set of operations are supported for those special tables. For example, direct DML statements (like `INSERT`) on those tables will fail with an error similar to the following: ``` ERROR 1556 (HY000): You can't use locks with log tables. ``` To flush data to the tables, use [FLUSH TABLES](../flush/index) instead of [FLUSH LOGS](../flush/index). To empty the contents of the log tables, [TRUNCATE TABLE](../truncate-table/index) can be used. The log tables use the [CSV](../csv/index) storage engine by default. This allows an external program to read the files if needed: normal CSV files are stored in the `mysql` subdirectory, in the data dir. However that engine is slow because it does not support indexes, so you can convert the tables to [MyISAM](../myisam/index) (but not other storage engines). To do so, first temporarily disable logging: ``` SET GLOBAL general_log = 'OFF'; ALTER TABLE mysql.general_log ENGINE = MyISAM; ALTER TABLE mysql.slow_log ENGINE = MyISAM; SET GLOBAL general_log = @old_log_state; ``` [CHECK TABLE](../sql-commands-check-table/index) and [CHECKSUM TABLE](../checksum-table/index) are supported. [CREATE TABLE](../create-table/index) is supported. [ALTER TABLE](../alter-table/index), [RENAME TABLE](../rename-table/index) and [DROP TABLE](../drop-table/index) are supported when logging is disabled, but log tables cannot be partitioned. The contents of the log tables is not logged in the [binary log](../binary-log/index) thus cannot be replicated. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb MariaDB for DirectAdmin Using RPMs MariaDB for DirectAdmin Using RPMs ================================== If you are using DirectAdmin and you encounter any issues with [Installing MariaDB with YUM](../installing-mariadb-with-yum/index), then the directions below may help. The process is very straightforward. **Note:** Installing with YUM is preferable to installing the MariaDB RPM packages manually, so only do this if you are having issues such as: ``` Starting httpd: httpd: Syntax error on line 18 of /etc/httpd/conf/httpd.conf: Syntax error on line 1 of /etc/httpd/conf/extra/httpd-phpmodules.conf: Cannot load /usr/lib/apache/libphp5.so into server: libmysqlclient.so.18: cannot open shared object file: No such file or directory ``` Or: ``` Starting httpd: httpd: Syntax error on line 18 of /etc/httpd/conf/httpd.conf: Syntax error on line 1 of /etc/httpd/conf/extra/httpd-phpmodules.conf: Cannot load /usr/lib/apache/libphp5.so into server: /usr/lib/apache/libphp5.so: undefined symbol: client_errors ``` RPM Installation ---------------- To install the RPMs, there is a quick and easy guide to [Installing MariaDB with the RPM Tool](../installing-mariadb-with-the-rpm-tool/index). Follow the instructions there. Necessary Edits --------------- We do not want DirectAdmin's custombuild to remove/overwrite our MariaDB installation whenever an update is performed. To rectify this, disable automatic MySQL installation. Edit `/usr/local/directadmin/custombuild/options.conf` Change: ``` mysql_inst=yes ``` To: ``` mysql_inst=no ``` **Note:** When MariaDB is installed manually (i.e. not using YUM), updates are not automatic. You will need to update the RPMs yourself. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Other Plugins Other Plugins ============== | Title | Description | | --- | --- | | [Compression Plugins](../compression-plugins/index) | Five MariaDB compression libraries are available as plugins. | | [Disks Plugin](../disks-plugin/index) | Shows metadata about disks on the system. | | [Feedback Plugin](../feedback-plugin/index) | Collect and send user statistics. | | [Locales Plugin](../locales-plugin/index) | List compiled-in locales. | | [METADATA\_LOCK\_INFO Plugin](../metadata-lock-info-plugin/index) | Active metadata locks. | | [MYSQL\_JSON](../mysql_json/index) | Converting MySQL's JSON data type to MariaDB's format. | | [Query Cache Information Plugin](../query-cache-information-plugin/index) | Examines the contents of the query cache. | | [Query Response Time Plugin](../query-response-time-plugin/index) | Records statistics on the time to execute queries on MariaDB Server. | | [SQL Error Log Plugin](../sql-error-log-plugin/index) | Records SQL-level errors to a log file. | | [User Statistics](../user-statistics/index) | User Statistics. | | [User Variables Plugin](../user-variables-plugin/index) | User Variables plugin. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb MLineFromText MLineFromText ============= Syntax ------ ``` MLineFromText(wkt[,srid]) MultiLineStringFromText(wkt[,srid]) ``` Description ----------- Constructs a [MULTILINESTRING](../multilinestring/index) value using its [WKT](../wkt-definition/index) representation and [SRID](../srid/index). `MLineFromText()` and `MultiLineStringFromText()` are synonyms. Examples -------- ``` CREATE TABLE gis_multi_line (g MULTILINESTRING); SHOW FIELDS FROM gis_multi_line; INSERT INTO gis_multi_line VALUES (MultiLineStringFromText('MULTILINESTRING((10 48,10 21,10 0),(16 0,16 23,16 48))')), (MLineFromText('MULTILINESTRING((10 48,10 21,10 0))')), (MLineFromWKB(AsWKB(MultiLineString( LineString(Point(1, 2), Point(3, 5)), LineString(Point(2, 5), Point(5, 8), Point(21, 7)))))); ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb MONTHNAME MONTHNAME ========= Syntax ------ ``` MONTHNAME(date) ``` Description ----------- Returns the full name of the month for date. The language used for the name is controlled by the value of the [lc\_time\_names](../server-system-variables/index#lc_time_names) system variable. See [server locale](../server-locale/index) for more on the supported locales. Examples -------- ``` SELECT MONTHNAME('2019-02-03'); +-------------------------+ | MONTHNAME('2019-02-03') | +-------------------------+ | February | +-------------------------+ ``` Changing the locale: ``` SET lc_time_names = 'fr_CA'; SELECT MONTHNAME('2019-05-21'); +-------------------------+ | MONTHNAME('2019-05-21') | +-------------------------+ | mai | +-------------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Binary Log Binary Log =========== The binary log contains a record of all changes to the databases, both data and structure. It consists of a set of binary log files and an index. It is necessary for [replication](../replication/index), and can also be used to restore data after a backup. | Title | Description | | --- | --- | | [Overview of the Binary Log](../overview-of-the-binary-log/index) | The binary log contains a record of all changes to the databases | | [Activating the Binary Log](../activating-the-binary-log/index) | Activating the Binary Log. | | [Using and Maintaining the Binary Log](../using-and-maintaining-the-binary-log/index) | Using and maintaining the binary log. | | [Binary Log Formats](../binary-log-formats/index) | The three binary logging formats. | | [Binary Logging of Stored Routines](../binary-logging-of-stored-routines/index) | Stored routines require extra consideration when binary logging. | | [SHOW BINARY LOGS](../show-binary-logs/index) | SHOW BINARY LOGS lists all binary logs on the server. | | [PURGE BINARY LOGS](../purge-binary-logs/index) | PURGE BINARY LOGS removes all binary logs from the server, prior to the provided date or log file. | | [SHOW BINLOG EVENTS](../show-binlog-events/index) | Show events in the binary log. | | [SHOW MASTER STATUS](../show-binlog-status/index) | Status information about the binary log. | | [Binlog Event Checksums](../binlog-event-checksums/index) | Including a checksum in binlog events. | | [Binlog Event Checksum Interoperability](../binlog-event-checksum-interoperability/index) | Replicating between servers with differing binlog checksum availability | | [Group Commit for the Binary Log](../group-commit-for-the-binary-log/index) | Optimization when the server is run with innodb\_flush\_logs\_at\_trx\_commit or sync\_binlog. | | [mysqlbinlog](../mysqlbinlog/index) | mysqlbinlog utility for processing binary log files. | | [Transaction Coordinator Log](../transaction-coordinator-log/index) | The transaction coordinator log (tc\_log) is used to coordinate transactions... | | [Compressing Events to Reduce Size of the Binary Log](../compressing-events-to-reduce-size-of-the-binary-log/index) | Binlog events can be compressed to save space on disk and in network transfers | | [Encrypting Binary Logs](../encrypting-binary-logs/index) | Data-at-rest encryption for binary logs and relay logs. | | [Flashback](../flashback/index) | Rollback instances/databases/tables to an old snapshot. | | [Relay Log](../relay-log/index) | Event log created by the replica from the primary binary log. | | [Replication and Binary Log System Variables](../replication-and-binary-log-system-variables/index) | Replication and binary log system variables. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb LOAD DATA FROM MASTER (removed) LOAD DATA FROM MASTER (removed) =============================== Syntax ------ ``` LOAD DATA FROM MASTER ``` Description ----------- This feature has been removed from recent versions of MariaDB. Since the current implementation of `LOAD DATA FROM MASTER` and `[LOAD TABLE FROM MASTER](../load-table-from-master/index)` is very limited, these statements are deprecated in versions 4.1 of MySQL and above. We will introduce a more advanced technique (called "online backup") in a future version. That technique will have the additional advantage of working with more storage engines. For MySQL 5.1 and earlier, the recommended alternative solution to using `LOAD DATA FROM MASTER` or `LOAD TABLE FROM MASTER` is using [mysqldump](../mysqldump/index) or [mysqlhotcopy](../mysqlhotcopy/index). The latter requires Perl and two Perl modules (DBI and DBD:mysql) and works for [MyISAM](../myisam/index) and [ARCHIVE](../archive/index) tables only. With mysqldump, you can create SQL dumps on the master and pipe (or copy) these to a mysql client on the slave. This has the advantage of working for all storage engines, but can be quite slow, since it works using `SELECT`. This statement takes a snapshot of the master and copies it to the slave. It updates the values of `MASTER_LOG_FILE` and `MASTER_LOG_POS` so that the slave starts replicating from the correct position. Any table and database exclusion rules specified with the `--replicate-*-do-*` and `--replicate-*-ignore-*` options are honored. `--replicate-rewrite-db` is not taken into account because a user could use this option to set up a non-unique mapping such as `--replicate-rewrite-db="db1->db3"` and `--replicate-rewrite-db="db2->db3"`, which would confuse the slave when loading tables from the master. Use of this statement is subject to the following conditions: * It works only for MyISAM tables. Attempting to load a non-MyISAM table results in the following error: `ERROR 1189 (08S01): Net error reading from master` * It acquires a global read lock on the master while taking the snapshot, which prevents updates on the master during the load operation. If you are loading large tables, you might have to increase the values of `net_read_timeout` and `net_write_timeout` on both the master and slave servers. See [Server System Variables](../server-system-variables/index). Note that `LOAD DATA FROM MASTER` does not copy any tables from the mysql database. This makes it easy to have different users and privileges on the master and the slave. To use `LOAD DATA FROM MASTER`, the replication account that is used to connect to the master must have the `RELOAD` and `[SUPER](../grant/index#global-privileges)` privileges on the master and the `SELECT` privilege for all master tables you want to load. All master tables for which the user does not have the `SELECT` privilege are ignored by `LOAD DATA FROM MASTER`. This is because the master hides them from the user: `LOAD DATA FROM MASTER` calls `SHOW DATABASES` to know the master databases to load, but `[SHOW DATABASES](../show-databases/index)` returns only databases for which the user has some privilege. On the slave side, the user that issues `LOAD DATA FROM MASTER` must have privileges for dropping and creating the databases and tables that are copied. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb More Advanced Joins More Advanced Joins =================== This article is a follow up to the [Introduction to JOINs](../introduction-to-joins/index) page. If you're just getting started with JOINs, go through that page first and then come back here. The Employee Database --------------------- Let us begin by using an example employee database of a fairly small family business, which does not anticipate expanding in the future. First, we create the table that will hold all of the employees and their contact information: ``` CREATE TABLE `Employees` ( `ID` TINYINT(3) UNSIGNED NOT NULL AUTO_INCREMENT, `First_Name` VARCHAR(25) NOT NULL, `Last_Name` VARCHAR(25) NOT NULL, `Position` VARCHAR(25) NOT NULL, `Home_Address` VARCHAR(50) NOT NULL, `Home_Phone` VARCHAR(12) NOT NULL, PRIMARY KEY (`ID`) ) ENGINE=MyISAM; ``` Next, we add a few employees to the table: ``` INSERT INTO `Employees` (`First_Name`, `Last_Name`, `Position`, `Home_Address`, `Home_Phone`) VALUES ('Mustapha', 'Mond', 'Chief Executive Officer', '692 Promiscuous Plaza', '326-555-3492'), ('Henry', 'Foster', 'Store Manager', '314 Savage Circle', '326-555-3847'), ('Bernard', 'Marx', 'Cashier', '1240 Ambient Avenue', '326-555-8456'), ('Lenina', 'Crowne', 'Cashier', '281 Bumblepuppy Boulevard', '328-555-2349'), ('Fanny', 'Crowne', 'Restocker', '1023 Bokanovsky Lane', '326-555-6329'), ('Helmholtz', 'Watson', 'Janitor', '944 Soma Court', '329-555-2478'); ``` Now, we create a second table, containing the hours which each employee clocked in and out during the week: ``` CREATE TABLE `Hours` ( `ID` TINYINT(3) UNSIGNED NOT NULL, `Clock_In` DATETIME NOT NULL, `Clock_Out` DATETIME NOT NULL ) ENGINE=MyISAM; ``` Finally, although it is a lot of information, we add a full week of hours for each of the employees into the second table that we created: ``` INSERT INTO `Hours` VALUES ('1', '2005-08-08 07:00:42', '2005-08-08 17:01:36'), ('1', '2005-08-09 07:01:34', '2005-08-09 17:10:11'), ('1', '2005-08-10 06:59:56', '2005-08-10 17:09:29'), ('1', '2005-08-11 07:00:17', '2005-08-11 17:00:47'), ('1', '2005-08-12 07:02:29', '2005-08-12 16:59:12'), ('2', '2005-08-08 07:00:25', '2005-08-08 17:03:13'), ('2', '2005-08-09 07:00:57', '2005-08-09 17:05:09'), ('2', '2005-08-10 06:58:43', '2005-08-10 16:58:24'), ('2', '2005-08-11 07:01:58', '2005-08-11 17:00:45'), ('2', '2005-08-12 07:02:12', '2005-08-12 16:58:57'), ('3', '2005-08-08 07:00:12', '2005-08-08 17:01:32'), ('3', '2005-08-09 07:01:10', '2005-08-09 17:00:26'), ('3', '2005-08-10 06:59:53', '2005-08-10 17:02:53'), ('3', '2005-08-11 07:01:15', '2005-08-11 17:04:23'), ('3', '2005-08-12 07:00:51', '2005-08-12 16:57:52'), ('4', '2005-08-08 06:54:37', '2005-08-08 17:01:23'), ('4', '2005-08-09 06:58:23', '2005-08-09 17:00:54'), ('4', '2005-08-10 06:59:14', '2005-08-10 17:00:12'), ('4', '2005-08-11 07:00:49', '2005-08-11 17:00:34'), ('4', '2005-08-12 07:01:09', '2005-08-12 16:58:29'), ('5', '2005-08-08 07:00:04', '2005-08-08 17:01:43'), ('5', '2005-08-09 07:02:12', '2005-08-09 17:02:13'), ('5', '2005-08-10 06:59:39', '2005-08-10 17:03:37'), ('5', '2005-08-11 07:01:26', '2005-08-11 17:00:03'), ('5', '2005-08-12 07:02:15', '2005-08-12 16:59:02'), ('6', '2005-08-08 07:00:12', '2005-08-08 17:01:02'), ('6', '2005-08-09 07:03:44', '2005-08-09 17:00:00'), ('6', '2005-08-10 06:54:19', '2005-08-10 17:03:31'), ('6', '2005-08-11 07:00:05', '2005-08-11 17:02:57'), ('6', '2005-08-12 07:02:07', '2005-08-12 16:58:23'); ``` Working with the Employee Database ---------------------------------- Now that we have a cleanly structured database to work with, let us begin this tutorial by stepping up one notch from the last tutorial and filtering our information a little. ### Filtering by Name Earlier in the week, an anonymous employee reported that Helmholtz came into work almost four minutes late; to verify this, we will begin our investigation by filtering out employees whose first names are "Helmholtz": ``` SELECT `Employees`.`First_Name`, `Employees`.`Last_Name`, `Hours`.`Clock_In`, `Hours`.`Clock_Out` FROM `Employees` INNER JOIN `Hours` ON `Employees`.`ID` = `Hours`.`ID` WHERE `Employees`.`First_Name` = 'Helmholtz'; ``` The result: ``` +------------+-----------+---------------------+---------------------+ | First_Name | Last_Name | Clock_In | Clock_Out | +------------+-----------+---------------------+---------------------+ | Helmholtz | Watson | 2005-08-08 07:00:12 | 2005-08-08 17:01:02 | | Helmholtz | Watson | 2005-08-09 07:03:44 | 2005-08-09 17:00:00 | | Helmholtz | Watson | 2005-08-10 06:54:19 | 2005-08-10 17:03:31 | | Helmholtz | Watson | 2005-08-11 07:00:05 | 2005-08-11 17:02:57 | | Helmholtz | Watson | 2005-08-12 07:02:07 | 2005-08-12 16:58:23 | +------------+-----------+---------------------+---------------------+ 5 rows in set (0.00 sec) ``` This is obviously more information than we care to trudge through, considering we only care about when he arrived past 7:00:59 on any given day within this week; thus, we need to add a couple more conditions to our WHERE clause. ### Filtering by Name, Date and Time In the following example, we will filter out all of the times which Helmholtz clocked in that were before 7:01:00 and during the work week that lasted from the 8th to the 12th of August: ``` SELECT `Employees`.`First_Name`, `Employees`.`Last_Name`, `Hours`.`Clock_In`, `Hours`.`Clock_Out` FROM `Employees` INNER JOIN `Hours` ON `Employees`.`ID` = `Hours`.`ID` WHERE `Employees`.`First_Name` = 'Helmholtz' AND DATE_FORMAT(`Hours`.`Clock_In`, '%Y-%m-%d') >= '2005-08-08' AND DATE_FORMAT(`Hours`.`Clock_In`, '%Y-%m-%d') <= '2005-08-12' AND DATE_FORMAT(`Hours`.`Clock_In`, '%H:%i:%S') > '07:00:59'; ``` The result: ``` +------------+-----------+---------------------+---------------------+ | First_Name | Last_Name | Clock_In | Clock_Out | +------------+-----------+---------------------+---------------------+ | Helmholtz | Watson | 2005-08-09 07:03:44 | 2005-08-09 17:00:00 | | Helmholtz | Watson | 2005-08-12 07:02:07 | 2005-08-12 16:58:23 | +------------+-----------+---------------------+---------------------+ 2 rows in set (0.00 sec) ``` We have now, by merely adding a few more conditions, eliminated all of the irrelevant information; Helmholtz was late to work on the 9th and the 12th of August. ### Displaying Total Work Hours per Day Suppose you would like to—based on the information stored in both of our tables in the employee database—develop a quick list of the total hours each employee has worked for each day recorded; a simple way to estimate the time each employee worked per day is exemplified below: ``` SELECT `Employees`.`ID`, `Employees`.`First_Name`, `Employees`.`Last_Name`, `Hours`.`Clock_In`, `Hours`.`Clock_Out`, DATE_FORMAT(`Hours`.`Clock_Out`, '%T')-DATE_FORMAT(`Hours`.`Clock_In`, '%T') AS 'Total_Hours' FROM `Employees` INNER JOIN `Hours` ON `Employees`.`ID` = `Hours`.`ID`; ``` The result (limited by 10): ``` +----+------------+-----------+---------------------+---------------------+-------------+ | ID | First_Name | Last_Name | Clock_In | Clock_Out | Total_Hours | +----+------------+-----------+---------------------+---------------------+-------------+ | 1 | Mustapha | Mond | 2005-08-08 07:00:42 | 2005-08-08 17:01:36 | 10 | | 1 | Mustapha | Mond | 2005-08-09 07:01:34 | 2005-08-09 17:10:11 | 10 | | 1 | Mustapha | Mond | 2005-08-10 06:59:56 | 2005-08-10 17:09:29 | 11 | | 1 | Mustapha | Mond | 2005-08-11 07:00:17 | 2005-08-11 17:00:47 | 10 | | 1 | Mustapha | Mond | 2005-08-12 07:02:29 | 2005-08-12 16:59:12 | 9 | | 2 | Henry | Foster | 2005-08-08 07:00:25 | 2005-08-08 17:03:13 | 10 | | 2 | Henry | Foster | 2005-08-09 07:00:57 | 2005-08-09 17:05:09 | 10 | | 2 | Henry | Foster | 2005-08-10 06:58:43 | 2005-08-10 16:58:24 | 10 | | 2 | Henry | Foster | 2005-08-11 07:01:58 | 2005-08-11 17:00:45 | 10 | | 2 | Henry | Foster | 2005-08-12 07:02:12 | 2005-08-12 16:58:57 | 9 | +----+------------+-----------+---------------------+---------------------+-------------+ 10 rows in set (0.00 sec) ``` See Also -------- * [Introduction to JOINs](../introduction-to-joins/index) *The first version of this article was copied, with permission, from <http://hashmysql.org/wiki/More_Advanced_Joins> on 2012-10-05.* Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb DATE_SUB DATE\_SUB ========= Syntax ------ ``` DATE_SUB(date,INTERVAL expr unit) ``` Description ----------- Performs date arithmetic. The *date* argument specifies the starting date or datetime value. *expr* is an expression specifying the interval value to be added or subtracted from the starting date. *expr* is a string; it may start with a "`-`" for negative intervals. *unit* is a keyword indicating the units in which the expression should be interpreted. See [Date and Time Units](../date-and-time-units/index) for a complete list of permitted units. See also `[DATE\_ADD()](../date_add/index)`. Examples -------- ``` SELECT DATE_SUB('1998-01-02', INTERVAL 31 DAY); +-----------------------------------------+ | DATE_SUB('1998-01-02', INTERVAL 31 DAY) | +-----------------------------------------+ | 1997-12-02 | +-----------------------------------------+ ``` ``` SELECT DATE_SUB('2005-01-01 00:00:00', INTERVAL '1 1:1:1' DAY_SECOND); +----------------------------------------------------------------+ | DATE_SUB('2005-01-01 00:00:00', INTERVAL '1 1:1:1' DAY_SECOND) | +----------------------------------------------------------------+ | 2004-12-30 22:58:59 | +----------------------------------------------------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb DAYNAME DAYNAME ======= Syntax ------ ``` DAYNAME(date) ``` Description ----------- Returns the name of the weekday for date. The language used for the name is controlled by the value of the [lc\_time\_names](../server-system-variables/index#lc_time_names) system variable. See [server locale](../server-locale/index) for more on the supported locales. Examples -------- ``` SELECT DAYNAME('2007-02-03'); +-----------------------+ | DAYNAME('2007-02-03') | +-----------------------+ | Saturday | +-----------------------+ ``` ``` CREATE TABLE t1 (d DATETIME); INSERT INTO t1 VALUES ("2007-01-30 21:31:07"), ("1983-10-15 06:42:51"), ("2011-04-21 12:34:56"), ("2011-10-30 06:31:41"), ("2011-01-30 14:03:25"), ("2004-10-07 11:19:34"); ``` ``` SELECT d, DAYNAME(d) FROM t1; +---------------------+------------+ | d | DAYNAME(d) | +---------------------+------------+ | 2007-01-30 21:31:07 | Tuesday | | 1983-10-15 06:42:51 | Saturday | | 2011-04-21 12:34:56 | Thursday | | 2011-10-30 06:31:41 | Sunday | | 2011-01-30 14:03:25 | Sunday | | 2004-10-07 11:19:34 | Thursday | +---------------------+------------+ ``` Changing the locale: ``` SET lc_time_names = 'fr_CA'; SELECT DAYNAME('2013-04-01'); +-----------------------+ | DAYNAME('2013-04-01') | +-----------------------+ | lundi | +-----------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Mroonga System Variables Mroonga System Variables ======================== This page documents system variables related to the [Mroonga storage engine](../mroonga/index). See [Server System Variables](../server-system-variables/index) for a complete list of system variables and instructions on setting them. See also the [Full list of MariaDB options, system and status variables](../full-list-of-mariadb-options-system-and-status-variables/index). #### `mroonga_action_on_fulltext_query_error` * **Description:** Action to take when encountering a Mroonga fulltext error. + `ERROR`: Report an error without logging. + `ERROR_AND_LOG`: Report an error with logging (the default) + `IGNORE`: No logging or reporting - the error is ignored. + `IGNORE_AND_LOG`: Log the error without reporting it. * **Commandline:** `--mroonga-action-on-fulltext-query-error=value` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `enum` * **Default Value:** `ERROR_AND_LOG` --- #### `mroonga_boolean_mode_syntax_flags` * **Description:** Flags to customize syntax in BOOLEAN MODE searches. Available flags: + `DEFAULT`: (=SYNTAX\_QUERY,ALLOW\_LEADING\_NOT) + `ALLOW_COLUMN`: Allows `COLUMN:...` syntax in query syntax, an incompatible change to the regular BOOLEAN MODE syntax. Permits multiple indexes in one `MATCH () AGAINST ()`. Can be used in other operations besides full-text search, such as equal, and prefix search. See [Groonga query syntax](http://groonga.org/docs/reference/grn_expr/query_syntax.html) for more details. + `ALLOW_LEADING_NOT` Permits using the `NOT_INCLUDED_KEYWORD` syntax in the query syntax. + `ALLOW_UPDATE`: Permits updating values with the `COLUMN:=NEW_VALUE` syntax in the query syntax. + `SYNTAX_QUERY`: Mroonga will use Groonga's query syntax, compatible with MariaDB's BOOLEAN MODE syntax. Unless `SYNTAX_SCRIPT` is specified, this mode is always in use. + `SYNTAX_SCRIPT`: Mroonga will use Groonga's script syntax, a JavaScript-like syntax. If both `SYNTAX_QUERY` and `SYNTAX_SCRIPT` are specified, `SYNTAX_SCRIPT` will take precedence.. * **Commandline:** `--mroonga-boolean-mode-syntax-flags=value` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `enum` * **Default Value:** `DEFAULT` --- #### `mroonga_database_path_prefix` * **Description:** The database path prefix. * **Commandline:** `--mroonga-database-path-prefix=value` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `string` * **Default Value:** (Empty) --- #### `mroonga_default_parser` * **Description:** The fulltext default parser, for example `TokenBigramSplitSymbolAlphaDigit` or `TokenBigram` (the default). See the list of options at [Mroonga Overview:Parser](../mroonga-overview/index#parser). Deprecated since Mroonga 5.04, use [mroonga\_default\_tokenizer](#mroonga_default_tokenizer) instead. * **Commandline:** `--mroonga-default-parser=value` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `string` * **Default Value:** `TokenBigram` * **Deprecated:** [MariaDB 10.1.6](https://mariadb.com/kb/en/mariadb-1016-release-notes/), Mroonga 5.0.4 --- #### `mroonga_default_tokenizer` * **Description:** The fulltext default parser, for example `TokenBigramSplitSymbolAlphaDigit` or `TokenBigram` (the default). See the list of options at [Mroonga Overview:Parser](../mroonga-overview/index#parser). * **Commandline:** `--mroonga-default-tokenizer=value` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `string` * **Default Value:** `TokenBigram` * **Introduced:** [MariaDB 10.1.6](https://mariadb.com/kb/en/mariadb-1016-release-notes/), Mroonga 5.0.4 --- #### `mroonga_default_wrapper_engine` * **Description:** The default engine for wrapper mode. * **Commandline:** `--mroonga-default-wrapper-engine=value` * **Scope:** Global * **Dynamic:** No * **Data Type:** `string` * **Default Value:** (Empty) --- #### `mroonga_dry_write` * **Description:** If set to `on`, (`off` is default), data is not actually written to the Groonga database. Only really useful to change for benchmarking. * **Commandline:** `--mroonga-dry-write[={0|1}]` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `off` --- #### `mroonga_enable_operations_recording` * **Description:** Whether recording operations for recovery to the Groonga database is enabled (default) or not. Requires reopening the database with [FLUSH TABLES](../flush/index) after changing the variable. * **Commandline:** `--mroonga-enable-operations-recording={0|1}` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `ON` * **Introduced:** [MariaDB 10.2.11](https://mariadb.com/kb/en/mariadb-10211-release-notes/), [MariaDB 10.1.29](https://mariadb.com/kb/en/mariadb-10129-release-notes/) --- #### `mroonga_enable_optimization` * **Description:** If set to `on` (the default), optimization is enabled. Only really useful to change for benchmarking. * **Commandline:** `--mroonga-enable-optimization={0|1}` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `on` --- #### `mroonga_libgroonga_embedded` * **Description:** Whether libgroonga is embedded or not. * **Commandline:** None * **Scope:** Global * **Dynamic:** No * **Data Type:** `boolean` * **Default Value:** `ON` * **Introduced:** [MariaDB 10.1.6](https://mariadb.com/kb/en/mariadb-1016-release-notes/) --- #### `mroonga_libgroonga_support_lz4` * **Description:** Whether libgroonga supports lz4 or not. * **Commandline:** None * **Scope:** Global * **Dynamic:** No * **Data Type:** `boolean` * **Default Value:** `OFF` --- #### `mroonga_libgroonga_support_zlib` * **Description:** Whether libgroonga supports zlib or not. * **Commandline:** None * **Scope:** Global * **Dynamic:** No * **Data Type:** `boolean` * **Default Value:** `ON` --- #### `mroonga_libgroonga_support_zstd` * **Description:** Whether libgroonga supports Zstandard or not. * **Commandline:** None * **Scope:** Global * **Dynamic:** No * **Data Type:** `boolean` * **Default Value:** `OFF` * **Introduced:** [MariaDB 10.2.11](https://mariadb.com/kb/en/mariadb-10211-release-notes/), [MariaDB 10.1.29](https://mariadb.com/kb/en/mariadb-10129-release-notes/) --- #### `mroonga_libgroonga_version` * **Description:** Groonga library version. * **Commandline:** None * **Scope:** Global * **Dynamic:** No * **Data Type:** `string` --- #### `mroonga_lock_timeout` * **Description:** Lock timeout used in Groonga. * **Commandline:** `<<code>>`--mroonga-lock-timeout=#</code>> * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `900000` * **Range:** `-1` to `2147483647` --- #### `mroonga_log_file` * **Description:** Name and path of the Mroonga log file. * **Commandline:** `--mroonga-log-file=value` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `string` * **Default Value:** `groonga.log` --- #### `mroonga_log_level` * **Description:** Mroonga log file output level, which determines what is logged. Valid levels include: + `NONE` No output. + `EMERG`: Only emergency error messages, such as database corruption. + `ALERT`: Alert messages, such as internal errors. + `CRIT` : Critical error messages, such as deadlocks. + `ERROR` : Errors, such as API errors. + `WARNING`: Warnings, such as invalid arguments. + `NOTICE`: Notices, such as a change in configuration or a status change. + `INFO`: Information messages, such as file system operations. + `DEBUG`: Debug messages, suggested for developers or testers. + `DUMP`: Dump messages. * **Commandline:** `--mroonga-log-level=value` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `enum` * **Default Value:** `NOTICE` --- #### `mroonga_match_escalation_threshold` * **Description:** The threshold to determine whether the match method is escalated. `-1` means never escalate. * **Commandline:** `--mroonga-match-escalation-threshold=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `0` * **Range:** `-1` to `9223372036854775807` --- #### `mroonga_max_n_records_for_estimate` * **Description:** The max number of records to estimate the number of matched records * **Commandline:** `--mroonga-max-n-records-for-estimate=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `1000` * **Range:** `-1` to `2147483647` --- #### `mroonga_query_log_file` * **Description:** Query log file for Mroonga. * **Commandline:** `--mroonga-query-log-file=filename` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `string` * **Default Value:** (Empty string) * **Introduced:** [MariaDB 10.2.11](https://mariadb.com/kb/en/mariadb-10211-release-notes/) --- #### `mroonga_vector_column_delimiter` * **Description:** Delimiter to use when outputting a vector column. The default is a white space. * **Commandline:** `--mroonga-vector-column-delimiter=value` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `string` * **Default Value:** (white space) --- #### `mroonga_version` * **Description:** Mroonga version * **Commandline:** None * **Scope:** Global * **Dynamic:** No * **Data Type:** `string` --- Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Installing MariaDB ColumnStore from the Development Buildbot Package Repositories Installing MariaDB ColumnStore from the Development Buildbot Package Repositories ================================================================================= NOTE: Document for internal use only Introduction ============ Installing Latest MariaDB ColumnStore developer built packages can be done from the yum, apt-get, and zypper Repositories based on the OS. These are the latest builds from the develop-1.1 branch for the 1.1.x build. MariaDB ColumnStore packages which consist of: * MariaDB ColumnStore Platform * MariaDB ColumnStore API (Bulk Write SDK) * MariaDB ColumnStore Data-Adapters * MariaDB ColumnStore Tools You can install MariaDB ColumnStore Packages from the Repositories for Single-Server installs and for Multi-Server installs utilizing the Non-Distributed feature where the packages are installed on all the servers in the cluster before the configuration and setup is performed. MariaDB ColumnStore Packages ============================ Before install, make sure you go through the preparation guide to complete the system setup before installs the packages [https://mariadb.com/kb/en/library/preparing-for-columnstore-installation-11x/](../library/preparing-for-columnstore-installation-11x/index) CentOS 6 -------- ### Using wget to retrieve packages ``` wget http://18.232.251.159/repos/latest/mariadb-columnstore/centos/x86_64/6/mariadb-columnstore-1.1.4-1-centos6.x86_64.bin.tar.gz wget http://18.232.251.159/repos/latest/mariadb-columnstore/centos/x86_64/6/mariadb-columnstore-1.1.4-1-centos6.x86_64.rpm.tar.gz ``` ### Adding the MariaDB ColumnStore YUM repository Add new file with repository information, /etc/yum.repos.d/mariadb-columnstore.repo ``` [mariadb-columnstore] name=MariaDB ColumnStore baseurl=http://18.232.251.159/repos/latest/mariadb-columnstore/yum/centos/6/x86_64/ gpgkey=http://18.232.251.159/repos/RPM-GPG-KEY-MariaDB-ColumnStore gpgcheck=1 ``` ### Installing MariaDB ColumnStore With the repo file in place you can now install MariaDB ColumnStore like so: ``` sudo yum --enablerepo=mariadb-columnstore clean metadata sudo yum groups mark remove "MariaDB ColumnStore" sudo yum groupinstall "MariaDB ColumnStore" ``` You can also install this way: ``` sudo yum --enablerepo=mariadb-columnstore clean metadata sudo yum install mariadb-columnstore* ``` Install binary package: ``` wget http://18.232.251.159/repos/latest/mariadb-columnstore/centos/x86_64/6/mariadb-columnstore-1.1.4-1-centos6.x86_64.bin.tar.gz ``` CentOS 7 -------- ### Using wget to retrieve packages ``` wget http://18.232.251.159/repos/latest/mariadb-columnstore/centos/x86_64/7/mariadb-columnstore-1.1.4-1-centos7.x86_64.bin.tar.gz wget http://18.232.251.159/repos/latest/mariadb-columnstore/centos/x86_64/7/mariadb-columnstore-1.1.4-1-centos7.x86_64.rpm.tar.gz ``` ### Adding the MariaDB ColumnStore YUM repository Add new file with repository information, /etc/yum.repos.d/mariadb-columnstore.repo ``` [mariadb-columnstore] name=MariaDB ColumnStore baseurl=http://18.232.251.159/repos/latest/mariadb-columnstore/yum/centos/7/x86_64/ gpgkey=http://18.232.251.159/repos/RPM-GPG-KEY-MariaDB-ColumnStore gpgcheck=1 ``` ### Installing MariaDB ColumnStore With the repo file in place you can now install MariaDB ColumnStore like so: ``` sudo yum --enablerepo=mariadb-columnstore clean metadata sudo yum groups mark remove "MariaDB ColumnStore" sudo yum groupinstall "MariaDB ColumnStore" ``` You can also install this way: ``` sudo yum --enablerepo=mariadb-columnstore clean metadata sudo yum install mariadb-columnstore* ``` Install binary package: ``` wget http://18.232.251.159/repos/latest/mariadb-columnstore/centos/x86_64/7/mariadb-columnstore-1.1.4-1-centos7.x86_64.bin.tar.gz ``` SUSE 12 ------- ### Using wget to retrieve packages ``` wget http://18.232.251.159/repos/latest/mariadb-columnstore/suse/x86_64/12//mariadb-columnstore-1.1.4-1-sles12.x86_64.bin.tar.gz wget http://18.232.251.159/repos/latest/mariadb-columnstore/suse/x86_64/12//mariadb-columnstore-1.1.4-1-sles12.x86_64.rpm.tar.gz ``` ### Adding the MariaDB ColumnStore ZYPPER repository Add new file with repository information, /etc/zypp/repos.d/mariadb-columnstore.repo ``` [mariadb-columnstore] name=mariadb-columnstore enabled=1 autorefresh=0 baseurl=http://18.232.251.159/repos/latest/mariadb-columnstore/yum/sles/12/x86_64 type=rpm-md ``` Download the MariaDB ColumnStore key ``` rpm --import http://18.232.251.159/repos/RPM-GPG-KEY-MariaDB-ColumnStore ``` ### Installing MariaDB ColumnStore With the repo file in place you can now install MariaDB ColumnStore like so: ``` sudo zypper refresh sudo zypper install mariadb-columnstore* ``` Install binary package: ``` wget http://18.232.251.159/repos/latest/mariadb-columnstore/suse/x86_64/12/mariadb-columnstore-1.1.4-1-sles12.x86_64.bin.tar.gz ``` Debian 8 -------- ### Using wget to retrieve packages ``` wget http://18.232.251.159/repos/latest/mariadb-columnstore/debian/dists/jessie/main/binary_amd64/mariadb-columnstore-1.1.4-1-jessie.amd64.bin.tar.gz wget http://18.232.251.159/repos/latest/mariadb-columnstore/debian/dists/jessie/main/binary_amd64/mariadb-columnstore-1.1.4-1-jessie.amd64.deb.tar.gz ``` ### Adding the MariaDB ColumnStore APT-GET repository Install package: ``` sudo apt-get install apt-transport-https ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore.list ``` deb http://18.232.251.159/repos/latest/mariadb-columnstore/repo/debian8 jessie main ``` Download the MariaDB ColumnStore key ``` wget -qO - http://18.232.251.159/repos/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` ### Installing MariaDB ColumnStore With the repo file in place you can now install MariaDB ColumnStore like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore* ``` Install binary package: ``` wget http://18.232.251.159/repos/latest/mariadb-columnstore/debian/dists/jessie/main/binary_adm64/mariadb-columnstore-1.1.4-1-jessie.amd64.bin.tar.gz ``` Debian 9 -------- ### Using wget to retrieve packages ``` wget http://18.232.251.159/repos/latest/mariadb-columnstore/debian/dists/stretch/main/binary_amd64/mariadb-columnstore-1.1.4-1-stretch.amd64.bin.tar.gz wget http://18.232.251.159/repos/latest/mariadb-columnstore/debian/dists/stretch/main/binary_amd64/mariadb-columnstore-1.1.4-1-stretch.amd64.deb.tar.gz ``` ### Adding the MariaDB ColumnStore APT-GET repository Install package: ``` sudo apt-get install apt-transport-https ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore.list ``` deb http://18.232.251.159/repos/latest/mariadb-columnstore/repo/debian9 stretch main ``` Download the MariaDB ColumnStore key ``` wget -qO - http://18.232.251.159/repos/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` ### Installing MariaDB ColumnStore With the repo file in place you can now install MariaDB ColumnStore like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore* ``` Install binary package: ``` wget http://18.232.251.159/repos/latest/mariadb-columnstore/debian/dists/stretch/main/binary_adm64/mariadb-columnstore-1.1.4-1-stretch.amd64.bin.tar.gz ``` Ubuntu 16 --------- ### Using wget to retrieve packages ``` wget http://18.232.251.159/repos/latest/mariadb-columnstore/ubuntu/dists/xenial/main/binary_amd64/mariadb-columnstore-1.1.4-1-xenial.amd64.bin.tar.gz wget http://18.232.251.159/repos/latest/mariadb-columnstore/ubuntu/dists/xenial/main/binary_amd64/mariadb-columnstore-1.1.4-1-xenial.amd64.deb.tar.gz ``` ### Adding the MariaDB ColumnStore APT-GET repository Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore.list ``` deb http://18.232.251.159/repos/latest/mariadb-columnstore/repo/ubuntu16 xenial main ``` Download the MariaDB ColumnStore key ``` wget -qO - http://18.232.251.159/repos/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` ### Installing MariaDB ColumnStore With the repo file in place you can now install MariaDB ColumnStore like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore* ``` After installation ------------------ After the installation completes, follow the configuration and startup steps in the Single-Node and Multi-Node Installation guides using the [Non-Distributed Install feature](../library/installing-and-configuring-a-multi-server-columnstore-system-11x/index#non-distributed-install). MariaDB ColumnStore API (Bulk Write SDK) Package ================================================ Additional information on the ColumnStore API (Bulk Write SDK): [https://mariadb.com/kb/en/library/columnstore-bulk-write-sdk/](../library/columnstore-bulk-write-sdk/index) CentOS 7 -------- ### Using wget to retrieve packages ``` wget http://18.232.251.159/repos/latest/mariadb-columnstore-api/yum/centos/7/x86_64/mariadb-columnstore-api-1.1.4-1-x86_64-centos7.rpm ``` ### Adding the MariaDB ColumnStore API YUM repository Add new file with repository information, /etc/yum.repos.d/mariadb-columnstore-api.repo ``` [mariadb-columnstore-api] name=MariaDB ColumnStore API baseurl=http://18.232.251.159/repos/latest/mariadb-columnstore-api/yum/centos/7/x86_64/ gpgkey=http://18.232.251.159/repos/RPM-GPG-KEY-MariaDB-ColumnStore gpgcheck=1 ``` ### Installing MariaDB ColumnStore API With the repo file in place you can now install MariaDB ColumnStore API like so: ``` sudo yum --enablerepo=mariadb-columnstore-api clean metadata sudo yum install mariadb-columnstore-api ``` Debian 8 -------- ### Using wget to retrieve packages ``` wget http://18.232.251.159/repos/latest/mariadb-columnstore-api/repo/debian8/pool/main/m/mariadb-columnstore-api/mariadb-columnstore-api_1.1.4_amd64.deb ``` ### Adding the MariaDB ColumnStore API APT-GET repository Install package: ``` sudo apt-get install apt-transport-https ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-api.list ``` deb http://18.232.251.159/repos/latest/mariadb-columnstore-api/repo/debian8 jessie main ``` <</code>> Download the MariaDB ColumnStore key ``` wget -qO - http://18.232.251.159/repos/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` ### Installing MariaDB ColumnStore API With the repo file in place you can now install MariaDB ColumnStore API like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-api ``` Debian 9 -------- ### Using wget to retrieve packages ``` wget http://18.232.251.159/repos/latest/mariadb-columnstore-api/repo/debian9/pool/main/m/mariadb-columnstore-api/mariadb-columnstore-api_1.1.4_amd64.deb ``` ### Adding the MariaDB ColumnStore API APT-GET repository Install package: ``` sudo apt-get install apt-transport-https ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-api.list ``` deb http://18.232.251.159/repos/latest/mariadb-columnstore-api/repo/debian9 stretch main ``` Download the MariaDB ColumnStore key ``` wget -qO - http://18.232.251.159/repos/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` ### Installing MariaDB ColumnStore API With the repo file in place you can now install MariaDB ColumnStore API like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-api ``` Ubuntu 16 --------- ### Using wget to retrieve packages ``` wget http://18.232.251.159/repos/latest/mariadb-columnstore-api/repo/ubuntu16/pool/main/m/mariadb-columnstore-api/mariadb-columnstore-api_1.1.4_amd64.deb ``` ### Adding the MariaDB ColumnStore API APT-GET repository Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-api.list ``` deb http://18.232.251.159/repos/latest/mariadb-columnstore-api/repo/ubuntu16 xenial main ``` Download the MariaDB ColumnStore key ``` wget -qO - http://18.232.251.159/repos/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` ### Installing MariaDB ColumnStore API With the repo file in place you can now install MariaDB ColumnStore API like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-api ``` MariaDB ColumnStore Tools Package ================================= Additional information on the Backup and Restore Tool: [https://mariadb.com/kb/en/library/backup-and-restore-for-mariadb-columnstore-110-onwards/](../library/backup-and-restore-for-mariadb-columnstore-110-onwards/index) CentOS 6 -------- ### Adding the MariaDB ColumnStore Tools YUM repository Add new file with repository information, /etc/yum.repos.d/mariadb-columnstore-tools.repo ``` [mariadb-columnstore-tools] name=MariaDB ColumnStore Tools baseurl=http://18.232.251.159/repos/latest/mariadb-columnstore-tools/yum/centos/6/x86_64/ gpgkey=http://18.232.251.159/repos/RPM-GPG-KEY-MariaDB-ColumnStore gpgcheck=1 ``` ### Installing MariaDB ColumnStore Tools With the repo file in place you can now install MariaDB ColumnStore Tools like so: ``` sudo yum --enablerepo=mariadb-columnstore-tools clean metadata sudo yum install mariadb-columnstore-tools ``` CentOS 7 -------- ### Adding the MariaDB ColumnStore Tools YUM repository Add new file with repository information, /etc/yum.repos.d/mariadb-columnstore-tools.repo ``` [mariadb-columnstore-tools] name=MariaDB ColumnStore Tools baseurl=http://18.232.251.159/repos/latest/mariadb-columnstore-tools/yum/centos/7/x86_64/ gpgkey=http://18.232.251.159/repos/RPM-GPG-KEY-MariaDB-ColumnStore gpgcheck=1 ``` ### Installing MariaDB ColumnStore Tools With the repo file in place you can now install MariaDB ColumnStore Tools like so: ``` sudo yum --enablerepo=mariadb-columnstore-tools clean metadata sudo yum install mariadb-columnstore-tools ``` SUSE 12 ------- ### Adding the MariaDB ColumnStore Tools ZYPPER repository Add new file with repository information, /etc/zypp/repos.d/mariadb-columnstore-tools.repo ``` [mariadb-columnstore-tools] name=mariadb-columnstore-tools enabled=1 autorefresh=0 baseurl=http://18.232.251.159/repos/latest/mariadb-columnstore-tools/yum/sles/12/x86_64 type=rpm-md ``` Download the MariaDB ColumnStore key ``` rpm --import http://18.232.251.159/repos/RPM-GPG-KEY-MariaDB-ColumnStore ``` ### Installing MariaDB ColumnStore With the repo file in place you can now install MariaDB ColumnStore like so: ``` sudo zypper refresh sudo zypper install mariadb-columnstore-tools ``` Debian 8 -------- ### Adding the MariaDB ColumnStore Tools APT-GET repository Install package: ``` sudo apt-get install apt-transport-https ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-tools.list ``` deb http://18.232.251.159/repos/latest/mariadb-columnstore-tools/repo/debian8 jessie main ``` <</code>> Download the MariaDB ColumnStore key ``` wget -qO - http://18.232.251.159/repos/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` ### Installing MariaDB ColumnStore Tools With the repo file in place you can now install MariaDB ColumnStore Tools like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-tools ``` Debian 9 -------- ### Adding the MariaDB ColumnStore Tools APT-GET repository Install package: ``` sudo apt-get install apt-transport-https ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-tools.list ``` deb http://18.232.251.159/repos/latest/mariadb-columnstore-tools/repo/debian9 stretch main ``` Download the MariaDB ColumnStore key ``` wget -qO - http://18.232.251.159/repos/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` ### Installing MariaDB ColumnStore Tools With the repo file in place you can now install MariaDB ColumnStore Tools like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-tools ``` Ubuntu 16 --------- ### Adding the MariaDB ColumnStore Tools APT-GET repository Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-tools.list ``` deb http://18.232.251.159/repos/latest/mariadb-columnstore-tools/repo/ubuntu16 xenial main ``` Download the MariaDB ColumnStore key ``` wget -qO - http://18.232.251.159/repos/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` ### Installing MariaDB ColumnStore Tools With the repo file in place you can now install MariaDB ColumnStore Tools like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-tools ``` MariaDB ColumnStore Data Adapters Packages ========================================== Additional information on the Data Adapters: [https://mariadb.com/kb/en/library/columnstore-streaming-data-adapters/](../library/columnstore-streaming-data-adapters/index) NOTE: MaxScale CDC Connector requires the MariaDB MaxScale package be installed first. The MariaDB ColumnStore Data Adapters Packages are: * Kafka Adapters * Maxscale CDC Adapters Kafka install package dependencies: * N/A Maxscale CDC install package dependencies:: * MaxScale CDC Connector * MariaDB ColumnStore API * MariaDB MaxScale CentOS 7 -------- ### Using wget to retrieve packages ``` wget http://18.232.251.159/repos/latest/mariadb-columnstore-data-adapters/yum/centos/7/x86_64/mariadb-columnstore-kafka-adapters-1.1.4-1-x86_64-centos7.rpm wget http://18.232.251.159/repos/latest/mariadb-columnstore-data-adapters/yum/centos/7/x86_64/mariadb-columnstore-maxscale-cdc-adapters-1.1.4-1-x86_64-centos7.rpm ``` ### Adding the MariaDB ColumnStore Data Adapters YUM repository Add new file with repository information, /etc/yum.repos.d/mariadb-columnstore-data-adapters.repo ``` [mariadb-columnstore-data-adapters] name=MariaDB ColumnStore Data Adapters baseurl=http://18.232.251.159/repos/latest/mariadb-columnstore-data-adapters/yum/centos/7/x86_64/ gpgkey=http://18.232.251.159/repos/RPM-GPG-KEY-MariaDB-ColumnStore gpgcheck=1 ``` ### Installing MariaDB ColumnStore Data Adapters With the repo file in place you can now install MariaDB ColumnStore Maxscale CDC Data Adapters like so: ``` sudo yum --enablerepo=mariadb-columnstore-data-adapters clean metadata sudo yum install mariadb-columnstore-maxscale-cdc-adapters ``` With the repo file in place you can now install MariaDB ColumnStore Kafka Data Adapters like so: ``` sudo yum --enablerepo=mariadb-columnstore-data-adapters clean metadata sudo yum install mariadb-columnstore-kafka-adapters ``` Debian 8 -------- ### Adding the MariaDB ColumnStore Data Adapters APT-GET repository ### Using wget to retrieve packages ``` wget http://18.232.251.159/repos/latest/mariadb-columnstore-data-adapters/repo/debian8/pool/main/m/mariadb-columnstore-kafka-adapters/mariadb-columnstore-kafka-adapters_1.1.4_amd64.deb wget http://18.232.251.159/repos/latest/mariadb-columnstore-data-adapters/repo/debian8/pool/main/m/mariadb-columnstore-maxscale-cdc-adapters/mariadb-columnstore-maxscale-cdc-adapters_1.1.4_amd64.deb ``` Install package: ``` sudo apt-get install apt-transport-https ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-data-adapters.list ``` deb http://18.232.251.159/repos/latest/mariadb-columnstore-data-adapters/repo/debian8 jessie main ``` <</code>> Download the MariaDB ColumnStore key ``` wget -qO - http://18.232.251.159/repos/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` ### Installing MariaDB ColumnStore Data Adapters With the repo file in place you can now install MariaDB ColumnStore Maxscale CDC Data Adapters like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-maxscale-cdc-adapters ``` With the repo file in place you can now install MariaDB ColumnStore Kafka Data Adapters like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-kafka-adapters ``` Debian 9 -------- ### Adding the MariaDB ColumnStore Data Adapters APT-GET repository ``` wget http://18.232.251.159/repos/latest/mariadb-columnstore-data-adapters/repo/debian9/pool/main/m/mariadb-columnstore-kafka-adapters/mariadb-columnstore-kafka-adapters_1.1.4_amd64.deb wget http://18.232.251.159/repos/latest/mariadb-columnstore-data-adapters/repo/debian9/pool/main/m/mariadb-columnstore-maxscale-cdc-adapters/mariadb-columnstore-maxscale-cdc-adapters_1.1.4_amd64.deb ``` Install package: ``` sudo apt-get install apt-transport-https ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-data-adapters.list ``` deb http://18.232.251.159/repos/latest/mariadb-columnstore-data-adapters/repo/debian9 stretch main ``` Download the MariaDB ColumnStore key ``` wget -qO - http://18.232.251.159/repos/latest/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` ### Installing MariaDB ColumnStore Data Adapters With the repo file in place you can now install MariaDB ColumnStores Maxscale CDC Data Adapters like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-maxscale-cdc-adapters ``` With the repo file in place you can now install MariaDB ColumnStores Kafka Data Adapters like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-kafka-adapters ``` Ubuntu 16 --------- ``` wget http://18.232.251.159/repos/latest/mariadb-columnstore-data-adapters/repo/ubuntu16/pool/main/m/mariadb-columnstore-kafka-adapters/mariadb-columnstore-kafka-adapters_1.1.4_amd64.deb wget http://18.232.251.159/repos/latest/mariadb-columnstore-data-adapters/repo/ubuntu16/pool/main/m/mariadb-columnstore-maxscale-cdc-adapters/mariadb-columnstore-maxscale-cdc-adapters_1.1.4_amd64.deb ``` ### Adding the MariaDB ColumnStore Data Adapters APT-GET repository Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-data-adapters.list ``` deb http://18.232.251.159/repos/latest/mariadb-columnstore-data-adapters/repo/ubuntu16 xenial main ``` Download the MariaDB ColumnStore key ``` wget -qO - http://18.232.251.159/repos/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` ### Installing MariaDB ColumnStore Data Adapters With the repo file in place you can now install MariaDB ColumnStore Maxscale CDC Data Adapters like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-maxscale-cdc-adapters ``` With the repo file in place you can now install MariaDB ColumnStore Kafka Data Adapters like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-kafka-adapters ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb Joins & Subqueries Joins & Subqueries =================== Documentation on the JOIN, UNION, EXCEPT and INTERSECT clauses, and on subqueries. | Title | Description | | --- | --- | | [Joins](../joins/index) | Querying from multiple tables. | | [Subqueries](../subqueries/index) | Queries within queries. | | [UNION](../union/index) | Combine the results from multiple SELECT statements into a single result set. | | [EXCEPT](../except/index) | Subtraction of two result sets. | | [INTERSECT](../intersect/index) | Records that are present in both result sets will be included in the result of the operation. | | [Precedence Control in Table Operations](../precedence-control-in-table-operations/index) | Controlling order of execution in SELECT, UNION, EXCEPT, and INTERSECT. | | [MINUS](../minus/index) | Synonym for EXCEPT. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb ColumnStore Database User Management ColumnStore Database User Management ==================================== Basic user management ===================== MariaDB ColumnStore allows permissions to be set for user accounts. The syntax of these grants follows the standard MariaDB syntax (see [GRANT](../grant/index)). For the root user, ColumnStore comes with full privileges. In order to set/restrict user accounts, privileges must be given/restricted. ColumnStore uses a dedicated schema called *infinidb\_vtable* for creation of all temporary tables used for ColumnStore query processing. The root user account has been given permission to this account by default, but full permission MUST be given for all user accounts to this schema: ``` GRANT CREATE TEMPORARY TABLES ON infinidb_vtable.* TO user_account; ``` where user\_account = user login, server and password characteristics Further permissions/restrictions can now be placed on any existing objects (tables, functions, procedures, views) for any access/limitations wanting to be placed on users: Example to give a user that has a password full access to all tables for a database (after the above grant has been given): ``` USE mysql; GRANT ALL ON my_schema.* TO ‘someuser’@’somehost’ IDENTIFIED BY ‘somepassword’; FLUSH PRIVILEGES; ``` Example to give a user that has a password read-only access to only 1 table (after the above grant has been given): ``` USE mysql; GRANT SELECT ON my_schema.table1 TO ‘someuser’@’somehost’ IDENTIFIED BY ‘somepassword’; FLUSH PRIVILEGES; ``` PAM Unix authentication ======================= Starting with ColumnStore 1.0.8, ColumnStore includes the necessary authentication plugin for PAM support. For general details see [pam-authentication-plugin](../pam-authentication-plugin/index) but here we will outline the steps necessary to configure this for os authentication specific to a ColumnStore installation. First ensure that the mysql user has read access to the /etc/shadow file, in this example a group is used to facilitate this: ``` $ sudo groupadd shadow $ sudo usermod -a -G shadow mysql $ sudo chown root:shadow /etc/shadow $ sudo chmod g+r /etc/shadow ``` Create a pam.d entry to configure unix password authentication: ``` $ vi /etc/pam.d/mysql auth required pam_unix.so account required pam_unix.so ``` Load the auth\_pam.so plugin and create a user: ``` $ mcsmysql > INSTALL SONAME 'auth_pam'; > GRANT SELECT ON test.* TO david IDENTIFIED VIA pam; > GRANT CREATE TEMPORARY TABLE ON infinidb_vtable.* TO david; ``` Restart ColumnStore so that the mariadb server process picks up the auth plugin and group changes: ``` $ sudo su - $ mcsadmin restartSystem ``` Now attempt to login to verify correct setup, entering the unix password for the account david when prompted: ``` $ mcsmysql -u david -p ``` If this still fails, try restartSystem once more and try logging in again as this seems to resolve the issue. PAM LDAP authentication ======================= Follow the instructions above for Pam UNIX authentication with the exception of the pam.d mysql file: ``` $ vi /etc/pam.d/mysql auth required pam_ldap.so account required pam_ldap.so ``` PAM LDAP group authentication ============================= The PAM plugin can also be utilized for LDAP group authentication. A good reference written by a MariaDB support engineer on setting up OpenLDAP can be found [here](http://www.geoffmontee.com/configuring-ldap-authentication-and-group-mapping-with-mariadb/). Some additional notes that may be of help: * if you get an error with the directory manager script, there are a couple of lines that may be wrapped if you cut and paste. Each line in the script must start with a command then a colon then a space. * 'authconfig --disableldapauth --disableldap --enableshadow --updateall' can be run to remove the ldap auth should you want to do this or if you made a mistake in the configuration values that you want to correct by re-running the command. This example assumes you have followed the initial instructions in that article and setup an LDAP user 'geoff' in group 'mysql-admins' in domain ' dc=support,dc=mariadb'. The following instructions are adapted to reflect ColumnStore and should replace the latter MariaDB setup of the blog. The PAM user mapping library must be built and installed locally: ``` wget https://raw.githubusercontent.com/MariaDB/server/10.1/plugin/auth_pam/mapper/pam_user_map.c gcc pam_user_map.c -shared -lpam -fPIC -o pam_user_map.so sudo install --mode=0755 pam_user_map.so /lib64/security/ ``` Ensure that the 'mysql' user has read access to the /etc/shadow file, in this example a group is used to facilitate this: ``` $ sudo groupadd shadow $ sudo usermod -a -G shadow mysql $ sudo chown root:shadow /etc/shadow $ sudo chmod g+r /etc/shadow ``` Create a pam.d entry to configure ldap password authentication: ``` $ sudo vi /etc/pam.d/mysql #%PAM-1.0 auth sufficient pam_ldap.so use_first_pass auth sufficient pam_unix.so nullok try_first_pass auth required pam_user_map.so account [default=bad success=ok user_unknown=ignore] pam_ldap.so account required pam_unix.so broken_shadow ``` Next the user mapping must be configured, this will map members of the ldap group 'mysql-admins' to the local 'dba' account (the @ character indicates that mysql-admins is a group): ``` $ sudo vi /etc/security/user_map.conf @mysql-admins: dba ``` As an alternative, specific accounts can be referenced as follows. ``` $ sudo vi /etc/security/user_map.conf geoff: dba ``` Due to the way that PAM works, a local 'dba' account must exist: ``` sudo useradd dba ``` Next, the pam plugin and mariadb accounts can be configured: ``` $ mcsmysql -- Install the plugin INSTALL SONAME 'auth_pam'; -- remove standard anonymous users if existing DELETE FROM mysql.user WHERE User=''; FLUSH PRIVILEGES; -- Create the "dba" user CREATE USER 'dba'@'localhost' IDENTIFIED BY 'strongpassword'; GRANT ALL PRIVILEGES ON *.* TO 'dba'@'localhost'; -- Create an anonymous catch-all user that will use the PAM plugin and the mysql PAM policy CREATE USER ''@'localhost' IDENTIFIED VIA pam USING 'mysql'; -- Allow the anonymous user to proxy as the dba user GRANT PROXY ON 'dba'@'localhost' TO ''@'localhost'; -- columnstore temp table permission grant GRANT CREATE TEMPORARY TABLE ON infinidb_vtable.* TO ''@'localhost' IDENTIFIED VIA pam; ``` Now restart columnstore since the user group permissions of mysql have changed and need to be picked up by the mysqld process: ``` mcsadmin restartSystem ``` Test that an ldap account can now authenticate: ``` $ mcsmysql -u geoff -h localhost [mariadb] Password: Welcome to the MariaDB monitor. Commands end with ; or \g. Your MariaDB connection id is 10 Server version: 10.1.23-MariaDB Columnstore 1.0.x-1 Copyright (c) 2000, 2017, Oracle, MariaDB Corporation Ab and others. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. MariaDB [(none)]> SELECT USER(), CURRENT_USER(); +-----------------+----------------+ | USER() | CURRENT_USER() | +-----------------+----------------+ | geoff@localhost | dba@localhost | +-----------------+----------------+ 1 row in set (0.00 sec) MariaDB [(none)]> select c1 from test.test_cs; +------+ | c1 | +------+ | 1 | +------+ 1 row in set (0.03 sec) ``` The first query shows that the authenticated user is 'geoff@localhost' while current user is 'dba@localhost'. This shows that the session authenticated as geoff and proxied to dba correctly. The second query just tests that a columnstore table can be queried correctly and should be updated for your local schema as appropriate. User Resource Allocation ======================== MariaDB ColumnStore supports the ability to give priority to resources allocated (CPU) based on a user. Users are allocated at least the % of CPU that they are assigned to by priority setting. Effectively a particular user or a set of users can be guaranteed a set amount of resources. E.g: * User 1 gets a minimum of 40% CPU Resources * User 2 gets a minimum of 30% CPU Resources * If any user logs in for a query while User 1 and User 2 are running queries, these new users (i.e., User 3,4 and 5) get only the remaining 30% of the CPU Resources." User Priority Management ------------------------ Three stored procedures were created in the *infinidb\_querystats* schema for the user to set, remove and view user priorities. The priority table associates a user with a priority level. A user that does not have an entry is given the low priority level by default. ``` CalSetUserPriority (host varchar, user varchar, priority varchar) ``` * Assigns a priority level to user@host. * Priority is case insensitive 'high', 'medium' or 'low'. * Host and user will be validated to exist in MariaDB ``` CalRemoveUserPriority(host varchar, user varchar) ``` * Removes the user entry, effectively restoring the default of 'low'. * User existence will not be validated. ``` CalShowProcessList() ``` * Prints a combination of mariadb 'show processlist' and user priority The MariaDB user needs to be granted the execute privileges for these procedures and the select privileges for the tables in the *infinidb\_querystats* schema. Or, chances are, the following should just work for a super user: ``` GRANT ALL ON infinidb_querystats.* TO 'user'@'host'; // user will now have the privilege to use the priority procedures and view query stats. ``` ### Enabling User Priority To enable this feature, the <UserPriority><Enabled> element in the MariaDB ColumnStore configuration file should be set to Y (default is N). ``` <UserPriority> <Enabled>Y</Enabled> </UserPriority> ``` Cross Engine Support must also be enabled. See the ”Cross-Engine Table Access” section in this guide. User Priority Processing ------------------------ The PrimProc process has one job queue for each priority level and thread assigned to each queue. The number of threads assigned to each queue is configurable using the following elements in the configuration file: ``` <PrimitiveServer><HighPriorityPercentage> <PrimitiveServer><MediumPriorityPercentage> <PrimitiveServer><LowPriorityPercentage> ``` The defaults are 60, 30, and 10 respectively. Each queue is given at least 1 thread so there is neither 'idle' priority configuration possible nor starvation. The number of threads started is normalized such that 100% = 2 \* (the number of cores on the machine). The user can overbook or underbook their CPUs however they want. This is an example of how threads are assigned on an 8-core system using the defaults. * 10% of 16 = 1.6, rounds down to 1 thread for the low priority queue. * 30% of 16 = 4.8, rounds down to 4 threads for the medium priority queue. * The high priority queue gets the remaining 11 threads. Each thread is given a preferred queue to get work from. If a thread's preferred queue is empty, it will choose jobs from the high, then medium, then low priority queues. If there are only low priority jobs running, on an 8-core system all 16 threads will process jobs from the low priority queue. If a medium priority query starts, using the defaults, the 15 threads assigned to the high and medium queues will process the medium queue, leaving the 1 assigned to the low queue to process the low priority jobs. Then, if a high priority query starts, the 11 threads assigned to the high priority queue will begin processing the high priority jobs, the 4 assigned to the medium queue will process those jobs, and the 1 assigned to the low queue will process those jobs. Given this algorithm, the configuration parameters could be thought of as minimum levels for each priority. Note that this implementation only affects the processing done by PrimProc. Depending on the work distribution of a given query, a user may or may not observe overall performance proportional to their priority level. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb DROP DROP ===== Articles on various DROP commands. | Title | Description | | --- | --- | | [DROP DATABASE](../drop-database/index) | Drop all tables and delete database. | | [DROP EVENT](../drop-event/index) | Removes an existing event. | | [DROP FUNCTION](../drop-function/index) | Drop a stored function. | | [DROP FUNCTION UDF](../drop-function-udf/index) | Drop a user-defined function. | | [DROP INDEX](../drop-index/index) | Drops an index from a table. | | [DROP LOGFILE GROUP](../drop-logfile-group/index) | The DROP LOGFILE GROUP statement is not supported by MariaDB. It was origin... | | [DROP PACKAGE](../drop-package/index) | Drops a stored package entirely. | | [DROP PACKAGE BODY](../drop-package-body/index) | Drops a package body (i.e the implementation) previously created using the CREATE PACKAGE BODY. | | [DROP PROCEDURE](../drop-procedure/index) | Drop stored procedure. | | [DROP ROLE](../drop-role/index) | Drop a role. | | [DROP SEQUENCE](../drop-sequence/index) | Deleting a SEQUENCE. | | [DROP SERVER](../drop-server/index) | Dropping a server definition. | | [DROP TABLE](../drop-table/index) | Removes definition and data from one or more tables. | | [DROP TABLESPACE](../drop-tablespace/index) | DROP TABLESPACE is not available in MariaDB. | | [DROP TRIGGER](../drop-trigger/index) | Drops a trigger. | | [DROP USER](../drop-user/index) | Remove one or more MariaDB accounts. | | [DROP VIEW](../drop-view/index) | Removes one or more views. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb SET GLOBAL SQL_SLAVE_SKIP_COUNTER SET GLOBAL SQL\_SLAVE\_SKIP\_COUNTER ==================================== Syntax ------ ``` SET GLOBAL sql_slave_skip_counter = N ``` Description ----------- This statement skips the next `*N*` events from the primary. This is useful for recovering from [replication](../replication/index) stops caused by a statement. If multi-source replication is used, this statement applies to the default connection. It could be necessary to change the value of the [default\_master\_connection](../replication-and-binary-log-server-system-variables/index#default_master_connection) system variable. Note that, if the event is a [transaction](../transactions/index), the whole transaction will be skipped. With non-transactional engines, an event is always a single statement. This statement is valid only when the replica threads are not running. Otherwise, it produces an error. The statement does not automatically restart the replica threads. Example ------- ``` SHOW SLAVE STATUS \G ... SET GLOBAL sql_slave_skip_counter = 1; START SLAVE; ``` Multi-source replication: ``` SET @@default_master_connection = 'master_01'; SET GLOBAL SQL_SLAVE_SKIP_COUNTER = 1; START SLAVE; ``` Multiple Replication Domains ---------------------------- `sql_slave_skip_counter` can't be used to skip transactions on a replica if [GTID replication](../gtid/index) is in use and if [gtid\_slave\_pos](../gtid/index#gtid_slave_pos) contains multiple [gtid\_domain\_id](../gtid/index#gtid_domain_id) values. In that case, you'll get an error like the following: ``` ERROR 1966 (HY000): When using parallel replication and GTID with multiple replication domains, @@sql_slave_skip_counter can not be used. Instead, setting @@gtid_slave_pos explicitly can be used to skip to after a given GTID position. ``` In order to skip transactions in cases like this, you will have to manually change [gtid\_slave\_pos](../gtid/index#gtid_slave_pos). See Also -------- * [Selectively Skipping Replication of Binlog Events](../selectively-skipping-replication-of-binlog-events/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb SHOW INDEX_STATISTICS SHOW INDEX\_STATISTICS ====================== Syntax ------ ``` SHOW INDEX_STATISTICS ``` Description ----------- The `SHOW INDEX_STATISTICS` statement was introduced in [MariaDB 5.2](../what-is-mariadb-52/index) as part of the [User Statistics](../user-statistics/index) feature. It was removed as a separate statement in [MariaDB 10.1.1](https://mariadb.com/kb/en/mariadb-1011-release-notes/), but effectively replaced by the generic [SHOW information\_schema\_table](../information-schema-plugins-show-and-flush-statements/index) statement. The [information\_schmea.INDEX\_STATISTICS](../information-schema-index_statistics-table/index) table shows statistics on index usage and makes it possible to do such things as locating unused indexes and generating the commands to remove them. The [userstat](../server-system-variables/index#userstat) system variable must be set to 1 to activate this feature. See the [User Statistics](../user-statistics/index) and [information\_schema.INDEX\_STATISTICS](../information-schema-index_statistics-table/index) table for more information. Example ------- ``` SHOW INDEX_STATISTICS; +--------------+-------------------+------------+-----------+ | Table_schema | Table_name | Index_name | Rows_read | +--------------+-------------------+------------+-----------+ | test | employees_example | PRIMARY | 1 | +--------------+-------------------+------------+-----------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb ST_PolygonFromWKB ST\_PolygonFromWKB ================== A synonym for [ST\_PolyFromWKB](../st_polyfromwkb/index). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Installing MariaDB with zypper Installing MariaDB with zypper ============================== On SLES, OpenSUSE, and other similar Linux distributions, it is highly recommended to install the relevant [RPM packages](../rpm/index) from MariaDB's repository using `[zypper](https://en.wikipedia.org/wiki/ZYpp)`. This page walks you through the simple installation steps using `zypper`. Adding the MariaDB ZYpp repository ---------------------------------- We currently have ZYpp repositories for the following Linux distributions: * SUSE Linux Enterprise Server (SLES) 12 * SUSE Linux Enterprise Server (SLES) 15 * OpenSUSE 15 * OpenSUSE 42 ### Using the MariaDB Package Repository Setup Script If you want to install MariaDB with `zypper`, then you can configure `zypper` to install from MariaDB Corporation's MariaDB Package Repository by using the [MariaDB Package Repository setup script](../mariadb-package-repository-setup-and-usage/index). MariaDB Corporation provides a MariaDB Package Repository for several Linux distributions that use `zypper` to manage packages. This repository contains software packages related to MariaDB Server, including the server itself, [clients and utilities](../clients-utilities/index), [client libraries](../client-libraries/index), [plugins](../plugins/index), and [Mariabackup](../mariabackup/index). The MariaDB Package Repository setup script automatically configures your system to install packages from the MariaDB Package Repository. To use the script, execute the following command: ``` curl -sS https://downloads.mariadb.com/MariaDB/mariadb_repo_setup | sudo bash ``` Note that this script also configures a repository for [MariaDB MaxScale](../maxscale/index) and a repository for MariaDB Tools, which currently only contains [Percona XtraBackup](../percona-xtrabackup/index) and its dependencies. See [MariaDB Package Repository Setup and Usage](../mariadb-package-repository-setup-and-usage/index) for more information. ### Using the MariaDB Repository Configuration Tool If you want to install MariaDB with `zypper`, then you can configure `zypper` to install from MariaDB Foundation's MariaDB Repository by using the [MariaDB Repository Configuration Tool](https://downloads.mariadb.org/mariadb/repositories/). The MariaDB Foundation provides a MariaDB repository for several Linux distributions that use `zypper` to manage packages. This repository contains software packages related to MariaDB Server, including the server itself, [clients and utilities](../clients-utilities/index), [client libraries](../client-libraries/index), [plugins](../plugins/index), and [Mariabackup](../mariabackup/index). The MariaDB Repository Configuration Tool can easily generate the appropriate commands to add the repository for your distribution. For example, if you wanted to use the repository to install [MariaDB 10.3](../what-is-mariadb-103/index) on SLES 15, then you could use the following commands to add the MariaDB `zypper` repository: ``` sudo zypper addrepo --gpgcheck --refresh https://yum.mariadb.org/10.3/sles/15/x86_64 mariadb sudo zypper --gpg-auto-import-keys refresh ``` ### Pinning the MariaDB Repository to a Specific Minor Release If you wish to pin the `zypper` repository to a specific minor release, or if you would like to downgrade to a specific minor release, then you can create a `zypper` repository with the URL hard-coded to that specific minor release. The MariaDB Foundation archives repositories of old minor releases at the following URL: * <http://archive.mariadb.org/> So if you can't find the repository of a specific minor release at `yum.mariadb.org`, then it would be a good idea to check the archive. For example, if you wanted to pin your repository to [MariaDB 10.3.14](https://mariadb.com/kb/en/mariadb-10314-release-notes/) on SLES 15, then you could use the following commands to add the MariaDB `zypper` repository: ``` sudo zypper removerepo mariadb sudo zypper addrepo --gpgcheck --refresh https://yum.mariadb.org/10.3.14/sles/15/x86_64 mariadb ``` Updating the MariaDB ZYpp repository to a New Major Release ----------------------------------------------------------- MariaDB's `zypper` repository can be updated to a new major release. How this is done depends on how you originally configured the repository. ### Updating the Major Release with the MariaDB Package Repository Setup Script If you configured `zypper` to install from MariaDB Corporation's MariaDB Package Repository by using the [MariaDB Package Repository setup script](../mariadb-package-repository-setup-and-usage/index), then you can update the major release that the repository uses by running the script again. ### Updating the Major Release with the MariaDB Repository Configuration Tool If you configured `zypper` to install from MariaDB Foundation's MariaDB Repository by using the [MariaDB Repository Configuration Tool](https://downloads.mariadb.org/mariadb/repositories/), then you can update the major release that the repository uses by removing the repository for the old version and adding the repository for the new version. First, you can remove the repository for the old version by executing the following command: ``` sudo zypper removerepo mariadb ``` After that, you can add the repository for the new version. For example, if you wanted to use the repository to install [MariaDB 10.3](../what-is-mariadb-103/index) on SLES 15, then you could use the following commands to add the MariaDB `zypper` repository: ``` sudo zypper addrepo --gpgcheck --refresh https://yum.mariadb.org/10.3/sles/15/x86_64 mariadb sudo zypper --gpg-auto-import-keys refresh ``` After that, the repository should refer to [MariaDB 10.3](../what-is-mariadb-103/index). Importing the MariaDB GPG Public Key ------------------------------------ Before MariaDB can be installed, you also have to import the GPG public key that is used to verify the digital signatures of the packages in our repositories. This allows the the `zypper` and `rpm` utilities to verify the integrity of the packages that they install. The id of our GPG public key is `0xcbcb082a1bb943db`. The short form of the id is `0x1BB943DB`. The full key fingerprint is: ``` 1993 69E5 404B D5FC 7D2F E43B CBCB 082A 1BB9 43DB ``` The `[rpm](https://linux.die.net/man/8/rpm)` utility can be used to import this key. For example: ``` sudo rpm --import https://yum.mariadb.org/RPM-GPG-KEY-MariaDB ``` Once the GPG public key is imported, you are ready to install packages from the repository. Installing MariaDB Packages with ZYpp ------------------------------------- After the `zypper` repository is configured, you can install MariaDB by executing the `[zypper](https://en.opensuse.org/SDB:Zypper_manual_(plain))` command. The specific command that you would use would depend on which specific packages that you want to install. ### Installing the Most Common Packages with ZYpp **MariaDB starting with [10.4](../what-is-mariadb-104/index)**In [MariaDB 10.4](../what-is-mariadb-104/index) and later, to Install the most common packages, execute the following command: ``` sudo zypper install MariaDB-server galera-4 MariaDB-client MariaDB-shared MariaDB-backup MariaDB-common ``` **MariaDB until [10.3](../what-is-mariadb-103/index)**In [MariaDB 10.3](../what-is-mariadb-103/index) and before, to Install the most common packages, execute the following command: ``` sudo zypper install MariaDB-server galera MariaDB-client MariaDB-shared MariaDB-backup MariaDB-common ``` ### Installing MariaDB Server with ZYpp To Install MariaDB Server, execute the following command: ``` sudo zypper install MariaDB-server ``` ### Installing MariaDB Galera Cluster with ZYpp The process to install MariaDB Galera Cluster with the MariaDB `zypper` repository is practically the same as installing standard MariaDB Server. In [MariaDB 10.1](../what-is-mariadb-101/index) and later, Galera Cluster support has been included in the standard MariaDB Server packages, so you will need to install the `MariaDB-server` package, as you normally would. In [MariaDB 10.4](../what-is-mariadb-104/index) and later, you also need to install the `galera-4` package to obtain the [Galera](../galera/index) 4 wsrep provider library. In [MariaDB 10.3](../what-is-mariadb-103/index) and before, you also need to install the `galera` package to obtain the [Galera](../galera/index) 3 wsrep provider library. **MariaDB starting with [10.4](../what-is-mariadb-104/index)**In [MariaDB 10.4](../what-is-mariadb-104/index) and later, to install MariaDB Galera Cluster, you could execute the following command: ``` sudo zypper install MariaDB-server MariaDB-client galera-4 ``` **MariaDB until [10.3](../what-is-mariadb-103/index)**In [MariaDB 10.3](../what-is-mariadb-103/index) and before, to install MariaDB Galera Cluster, you could execute the following command: ``` sudo zypper install MariaDB-server MariaDB-client galera ``` If you haven't yet imported the MariaDB GPG public key, then `zypper` will prompt you to import it after it downloads the packages, but before it prompts you to install them. See [MariaDB Galera Cluster](../galera/index) for more information on MariaDB Galera Cluster. ### Installing MariaDB Clients and Client Libraries with ZYpp In [MariaDB 10.2](../what-is-mariadb-102/index) and later, [MariaDB Connector/C](../about-mariadb-connector-c/index) has been included as the client library. However, the package name for the client library has not been changed. To Install the clients and client libraries, execute the following command: ``` sudo zypper install MariaDB-client MariaDB-shared ``` ### Installing Mariabackup with ZYpp To install [Mariabackup](../mariabackup/index), execute the following command: ``` sudo zypper install MariaDB-backup ``` ### Installing Plugins with ZYpp Some [plugins](../plugins/index) may also need to be installed. For example, to install the `[cracklib\_password\_check](../cracklib-password-check-plugin/index)` password validation plugin, execute the following command: ``` sudo zypper install MariaDB-cracklib-password-check ``` ### Installing Debug Info Packages with ZYpp **MariaDB starting with [5.5.64](https://mariadb.com/kb/en/mariadb-5564-release-notes/)**The MariaDB `zypper` repository first added `[debuginfo](https://en.opensuse.org/openSUSE:Packaging_guidelines#Debuginfo)` packages in [MariaDB 5.5.64](https://mariadb.com/kb/en/mariadb-5564-release-notes/), [MariaDB 10.1.39](https://mariadb.com/kb/en/mariadb-10139-release-notes/), [MariaDB 10.2.23](https://mariadb.com/kb/en/mariadb-10223-release-notes/), [MariaDB 10.3.14](https://mariadb.com/kb/en/mariadb-10314-release-notes/), and [MariaDB 10.4.4](https://mariadb.com/kb/en/mariadb-1044-release-notes/). The MariaDB `zypper` repository also contains `[debuginfo](https://en.opensuse.org/openSUSE:Packaging_guidelines#Debuginfo)` packages. These package may be needed when [debugging a problem](../how-to-produce-a-full-stack-trace-for-mysqld/index). #### Installing Debug Info for the Most Common Packages with ZYpp To install [debuginfo](https://en.opensuse.org/openSUSE:Packaging_guidelines#Debuginfo) for the most common packages, execute the following command: ``` sudo zypper install MariaDB-server-debuginfo MariaDB-client-debuginfo MariaDB-shared-debuginfo MariaDB-backup-debuginfo MariaDB-common-debuginfo ``` #### Installing Debug Info for MariaDB Server with ZYpp To install `[debuginfo](https://en.opensuse.org/openSUSE:Packaging_guidelines#Debuginfo)` for MariaDB Server, execute the following command: ``` sudo zypper install MariaDB-server-debuginfo ``` #### Installing Debug Info for MariaDB Clients and Client Libraries with ZYpp In [MariaDB 10.2](../what-is-mariadb-102/index) and later, [MariaDB Connector/C](../about-mariadb-connector-c/index) has been included as the client library. However, the package name for the client library has not been changed. To install `[debuginfo](https://en.opensuse.org/openSUSE:Packaging_guidelines#Debuginfo)` for the clients and client libraries, execute the following command: ``` sudo zypper install MariaDB-client-debuginfo MariaDB-shared-debuginfo ``` #### Installing Debug Info for Mariabackup with ZYpp To install `[debuginfo](https://en.opensuse.org/openSUSE:Packaging_guidelines#Debuginfo)` for [Mariabackup](../mariabackup/index), execute the following command: ``` sudo zypper install MariaDB-backup-debuginfo ``` #### Installing Debug Info for Plugins with ZYpp For some [plugins](../plugins/index), `[debuginfo](https://en.opensuse.org/openSUSE:Packaging_guidelines#Debuginfo)` may also need to be installed. For example, to install `[debuginfo](https://en.opensuse.org/openSUSE:Packaging_guidelines#Debuginfo)` for the `[cracklib\_password\_check](../cracklib-password-check-plugin/index)` password validation plugin, execute the following command: ``` sudo zypper install MariaDB-cracklib-password-check-debuginfo ``` ### Installing Older Versions from the Repository The MariaDB `zypper` repository contains the last few versions of MariaDB. To show what versions are available, use the following command: ``` zypper search --details MariaDB-server ``` In the output you will see the available versions. To install an older version of a package instead of the latest version we just need to specify the package name, a dash, and then the version number. And we only need to specify enough of the version number for it to be unique from the other available versions. However, when installing an older version of a package, if `zypper` has to install dependencies, then it will automatically choose to install the latest versions of those packages. To ensure that all MariaDB packages are on the same version in this scenario, it is necessary to specify them all. The packages that the MariaDB-server package depend on are: MariaDB-client, MariaDB-shared, and MariaDB-common. Therefore, to install [MariaDB 10.3.14](https://mariadb.com/kb/en/mariadb-10314-release-notes/) from this `zypper` repository, we would do the following: ``` sudo zypper install MariaDB-server-10.3.14 MariaDB-client-10.3.14 MariaDB-shared-10.3.14 MariaDB-backup-10.3.14 MariaDB-common-10.3.14 ``` The rest of the install and setup process is as normal. After Installation ------------------ After the installation is complete, you can [start MariaDB](../starting-and-stopping-mariadb-starting-and-stopping-mariadb/index). If you are using [MariaDB Galera Cluster](../galera/index), then keep in mind that the first node will have to be [bootstrapped](../getting-started-with-mariadb-galera-cluster/index#bootstrapping-a-new-cluster). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb Data-at-Rest Encryption Overview Data-at-Rest Encryption Overview ================================ Overview -------- Having tables encrypted makes it almost impossible for someone to access or steal a hard disk and get access to the original data. MariaDB got Data-at-Rest Encryption with [MariaDB 10.1](../what-is-mariadb-101/index). This functionality is also known as "Transparent Data Encryption (TDE)". This assumes that encryption keys are stored on another system. Using encryption has an overhead of roughly *3-5%*. Which Storage Engines Does MariaDB Encryption Support? ------------------------------------------------------ MariaDB encryption is fully supported for the [InnoDB](../innodb/index) storage engines. Encryption is also supported for the Aria storage engine, but only for tables created with `ROW_FORMAT=PAGE` (the default), and for the binary log (replication log). MariaDB allows the user to configure flexibly what to encrypt. In or InnoDB, one can choose to encrypt: * everything — all tablespaces (with all tables) * individual tables * everything, excluding individual tables Additionally, one can choose to encrypt InnoDB log files (recommended). Limitations ----------- These limitations exist in the data-at-rest encryption implementation: * Only **data** and only **at rest** is encrypted. Metadata (for example `.frm` files) and data sent to the client are not encrypted (but see [Secure Connections](../secure-connections/index)). * Only the MariaDB server knows how to decrypt the data, in particular + [mysqlbinlog](../mysqlbinlog/index) can read encrypted binary logs only when --read-from-remote-server is used ([MDEV-8813](https://jira.mariadb.org/browse/MDEV-8813)). + [Percona XtraBackup](../percona-xtrabackup/index) cannot back up instances that use encrypted InnoDB. However, MariaDB's fork, [MariaDB Backup](../mariadb-backup/index), can back up encrypted instances. * The disk-based [Galera gcache](https://galeracluster.com/library/documentation/state-transfer.html#write-set-cache-gcache) is not encrypted in the community version of MariaDB Server ([MDEV-9639](https://jira.mariadb.org/browse/MDEV-9639)). However, this file is encrypted in [MariaDB Enterprise Server 10.4](https://mariadb.com/docs/features/mariadb-enterprise-server/). * The [Audit plugin](../mariadb-audit-plugin/index) cannot create encrypted output. Send it to syslog and configure the protection there instead. * File-based [general query log](../general-query-log/index) and [slow query log](../slow-query-log/index) cannot be encrypted ([MDEV-9639](https://jira.mariadb.org/browse/MDEV-9639)). * The Aria log is not encrypted ([MDEV-8587](https://jira.mariadb.org/browse/MDEV-8587)). This affects only non-temporary Aria tables though. * The MariaDB [error log](../error-log/index) is not encrypted. The error log can contain query text and data in some cases, including crashes, assertion failures, and cases where InnoDB write monitor output to the log to aid in debugging. It can be sent to syslog too, if needed. Encryption Key Management ------------------------- MariaDB's data-at-rest encryption requires the use of a [key management and encryption plugin](../encryption-key-management/index). These plugins are responsible both for the management of encryption keys and for the actual encryption and decryption of data. MariaDB supports the use of [multiple encryption keys](../encryption-key-management/index#using-multiple-encryption-keys). Each encryption key uses a 32-bit integer as a key identifier. If the specific plugin supports [key rotation](../encryption-key-management/index#rotating-keys), then encryption keys can also be rotated, which creates a new version of the encryption key. How MariaDB manages encryption keys depends on which encryption key management solution you choose. Currently, MariaDB has three options: * [File Key Management Plugin](../file-key-management-encryption-plugin/index) * [AWS Key Management Plugin](../aws-key-management-encryption-plugin/index) * [Eperi Key Management Plugin](../eperi-key-management-encryption-plugin/index) Once you have an key management and encryption plugin set up and configured for your server, you can begin using encryption options to better secure your data. Encrypting Data --------------- Encryption occurs whenever MariaDB writes pages to disk. Encrypting table data requires that you install a [key management and encryption plugin](../encryption-key-management/index), such as the [File Key Management](../file-key-management-encryption-plugin/index) plugin. Once you have a plugin set up and configured, you can enable encryption for your InnoDB and Aria tables. ### Encrypting Table Data MariaDB supports data-at-rest encryption for InnoDB and Aria storage engines. Additionally, it supports encrypting the [InnoDB redo log](../xtradbinnodb-redo-log/index) and internal on-disk temporary tables that use the Aria storage engine.. * [Encrypting Data for InnoDB](../encrypting-data-for-innodb-xtradb/index) * [Encrypting Data for Aria](../encrypting-data-for-aria/index) ### Encrypting Temporary Files MariaDB also creates temporary files on disk. For example, a binary log cache will be written to a temporary file if the binary log cache exceeds `[binlog\_cache\_size](../replication-and-binary-log-system-variables/index#binlog_cache_size)` or `[binlog\_stmt\_cache\_size](../replication-and-binary-log-system-variables/index#binlog_stmt_cache_size)`, and temporary files are also often used for filesorts during query execution. Since [MariaDB 10.1.5](https://mariadb.com/kb/en/mariadb-1015-release-notes/), these temporary files can also be encrypted if [encrypt\_tmp\_files=ON](../server-system-variables/index#encrypt_tmp_files) is set. Since [MariaDB 10.1.27](https://mariadb.com/kb/en/mariadb-10127-release-notes/), [MariaDB 10.2.9](https://mariadb.com/kb/en/mariadb-1029-release-notes/) and [MariaDB 10.3.2](https://mariadb.com/kb/en/mariadb-1032-release-notes/), temporary files created internally by InnoDB, such as those used for merge sorts and row logs can also be encrypted if [innodb\_encrypt\_log=ON](../xtradbinnodb-server-system-variables/index#innodb_encrypt_log) is set. These files are encrypted regardless of whether the tables involved are encrypted or not, and regardless of whether [encrypt\_tmp\_files](../server-system-variables/index#encrypt_tmp_files) is set or not. ### Encrypting Binary Logs MariaDB can also encrypt [binary logs](../binary-log/index) (including [relay logs](../relay-log/index)). * [Encrypting Binary Logs](../encrypting-binary-logs/index) Encryption and Page Compression ------------------------------- Data-at-rest encryption and [InnoDB page compression](../compression/index) can be used together. When they are used together, data is first compressed, and then it is encrypted. In this case you save space and still have your data protected. Thanks ------ * Tablespace encryption was donated to the MariaDB project by Google. * Per-table encryption and key identifier support was donated to the MariaDB project by [eperi](http://eperi.de/en). We are grateful to these companies for their support of MariaDB! See Also -------- * [Encryption functions](../encryption-functions/index) * [DES\_DECRYPT()](../des_decrypt/index) * [DES\_ENCRYPT()](../des_encrypt/index) * A [blog post about table encryption](https://mariadb.com/blog/table-and-tablespace-encryption-mariadb-101/) with benchmark results Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb ocelotgui ocelotgui ========= The Ocelot GUI (ocelotgui), a database client, allows users to connect to a MySQL or MariaDB DBMS server, enter SQL statements, and receive results. Some of its features are: syntax highlighting, user-settable colors and fonts for each part of the screen, result-set displays with multi-line rows and resizable columns, and a debugger. Visit [ocelot.ca](http://ocelot.ca/) for more information and to download. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb CREATE TABLESPACE CREATE TABLESPACE ================= The `CREATE TABLESPACE` statement is not supported by MariaDB. It was originally inherited from MySQL NDB Cluster. In MySQL 5.7 and later, the statement is also supported for InnoDB. However, MariaDB has chosen not to include that specific feature. See [MDEV-19294](https://jira.mariadb.org/browse/MDEV-19294) for more information. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Server Locale Server Locale ============= The [lc\_time\_names](../server-system-variables/index#lc_time_names) server system variable sets the language used by the date and time functions [DAYNAME()](../dayname/index), [MONTHNAME()](../monthname/index) and [DATE\_FORMAT()](../date_format/index). The list of the locales supported by the current MariaDB installation can be obtained via the [LOCALES](../locales-plugin/index) plugin. MariaDB supports the following locale values: | Locale | Language | Country | | --- | --- | --- | | ar\_AE | Arabic | United Arab Emirates | | ar\_BH | Arabic | Bahrain | | ar\_DZ | Arabic | Algeria | | ar\_EG | Arabic | Egypt | | ar\_IN | Arabic | India | | ar\_IQ | Arabic | Iraq | | ar\_JO | Arabic | Jordan | | ar\_KW | Arabic | Kuwait | | ar\_LB | Arabic | Lebanon | | ar\_LY | Arabic | Libya | | ar\_MA | Arabic | Morocco | | ar\_OM | Arabic | Oman | | ar\_QA | Arabic | Qatar | | ar\_SA | Arabic | Saudi Arabia | | ar\_SD | Arabic | Sudan | | ar\_SY | Arabic | Syria | | ar\_TN | Arabic | Tunisia | | ar\_YE | Arabic | Yemen | | be\_BY | Belarusian | Belarus | | bg\_BG | Bulgarian | Bulgaria | | ca\_ES | Catalan | Spain | | cs\_CZ | Czech | Czech Republic | | da\_DK | Danish | Denmark | | de\_AT | German | Austria | | de\_BE | German | Belgium | | de\_CH | German | Switzerland | | de\_DE | German | Germany | | de\_LU | German | Luxembourg | | en\_AU | English | Australia | | en\_CA | English | Canada | | en\_GB | English | United Kingdom | | en\_IN | English | India | | en\_NZ | English | New Zealand | | en\_PH | English | Philippines | | en\_US | English | United States | | en\_ZA | English | South Africa | | en\_ZW | English | Zimbabwe | | es\_AR | Spanish | Argentina | | es\_BO | Spanish | Bolivia | | es\_CL | Spanish | Chile | | es\_CO | Spanish | Columbia | | es\_CR | Spanish | Costa Rica | | es\_DO | Spanish | Dominican Republic | | es\_EC | Spanish | Ecuador | | es\_ES | Spanish | Spain | | es\_GT | Spanish | Guatemala | | es\_HN | Spanish | Honduras | | es\_MX | Spanish | Mexico | | es\_NI | Spanish | Nicaragua | | es\_PA | Spanish | Panama | | es\_PE | Spanish | Peru | | es\_PR | Spanish | Puerto Rico | | es\_PY | Spanish | Paraguay | | es\_SV | Spanish | El Salvador | | es\_US | Spanish | United States | | es\_UY | Spanish | Uruguay | | es\_VE | Spanish | Venezuela | | et\_EE | Estonian | Estonia | | eu\_ES | Basque | Basque | | fi\_FI | Finnish | Finland | | fo\_FO | Faroese | Faroe Islands | | fr\_BE | French | Belgium | | fr\_CA | French | Canada | | fr\_CH | French | Switzerland | | fr\_FR | French | France | | fr\_LU | French | Luxembourg | | gl\_ES | Galician | Spain | | gu\_IN | Gujarati | India | | he\_IL | Hebrew | Israel | | hi\_IN | Hindi | India | | hr\_HR | Croatian | Croatia | | hu\_HU | Hungarian | Hungary | | id\_ID | Indonesian | Indonesia | | is\_IS | Icelandic | Iceland | | it\_CH | Italian | Switzerland | | it\_IT | Italian | Italy | | ja\_JP | Japanese | Japan | | ko\_KR | Korean | Republic of Korea | | lt\_LT | Lithuanian | Lithuania | | lv\_LV | Latvian | Latvia | | mk\_MK | Macedonian | FYROM | | mn\_MN | Mongolia | Mongolian | | ms\_MY | Malay | Malaysia | | nb\_NO | Norwegian(Bokmål) | Norway | | nl\_BE | Dutch | Belgium | | nl\_NL | Dutch | The Netherlands | | no\_NO | Norwegian | Norway | | pl\_PL | Polish | Poland | | pt\_BR | Portugese | Brazil | | pt\_PT | Portugese | Portugal | | rm\_CH | Romansh | Switzerland | | ro\_RO | Romanian | Romania | | ru\_RU | Russian | Russia | | ru\_UA | Russian | Ukraine | | sk\_SK | Slovak | Slovakia | | sl\_SI | Slovenian | Slovenia | | sq\_AL | Albanian | Albania | | sr\_YU | Serbian | Yugoslavia | | sv\_FI | Swedish | Finland | | sv\_SE | Swedish | Sweden | | ta\_IN | Tamil | India | | te\_IN | Telugu | India | | th\_TH | Thai | Thailand | | tr\_TR | Turkish | Turkey | | uk\_UA | Ukrainian | Ukraine | | ur\_PK | Urdu | Pakistan | | vi\_VN | Vietnamese | Viet Nam | | zh\_CN | Chinese | China | | zh\_HK | Chinese | Hong Kong | | zh\_TW | Chinese | Taiwan Province of China | Examples -------- Setting the [lc\_time\_names](../server-system-variables/index#lc_time_names) and [lc\_messages](../server-system-variables/index#lc_messages) variables to localize the units of date and time, and the server error messages. ``` SELECT DAYNAME('2013-04-01'), MONTHNAME('2013-04-01'); +-----------------------+-------------------------+ | DAYNAME('2013-04-01') | MONTHNAME('2013-04-01') | +-----------------------+-------------------------+ | Monday | April | +-----------------------+-------------------------+ SET lc_time_names = 'fr_CA'; SELECT DAYNAME('2013-04-01'), MONTHNAME('2013-04-01'); +-----------------------+-------------------------+ | DAYNAME('2013-04-01') | MONTHNAME('2013-04-01') | +-----------------------+-------------------------+ | lundi | avril | +-----------------------+-------------------------+ SELECT blah; ERROR 1054 (42S22): Unknown column 'blah' in 'field' list' SET lc_messages = 'nl_NL'; SELECT blah; ERROR 1054 (42S22): Onbekende kolom 'blah' in field list ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb ANALYZE Statement ANALYZE Statement ================= Description ----------- The `ANALYZE statement` is similar to the `EXPLAIN statement`. `ANALYZE statement` will invoke the optimizer, execute the statement, and then produce `EXPLAIN` output instead of the result set. The `EXPLAIN` output will be annotated with statistics from statement execution. This lets one check how close the optimizer's estimates about the query plan are to the reality. `ANALYZE` produces an overview, while the [ANALYZE FORMAT=JSON](../analyze-formatjson/index) command provides a more detailed view of the query plan and the query execution. The syntax is ``` ANALYZE explainable_statement; ``` where the statement is any statement for which one can run [EXPLAIN](../explain/index). Command Output -------------- Consider an example: ``` ANALYZE SELECT * FROM tbl1 WHERE key1 BETWEEN 10 AND 200 AND col1 LIKE 'foo%'\G ``` ``` *************************** 1. row *************************** id: 1 select_type: SIMPLE table: tbl1 type: range possible_keys: key1 key: key1 key_len: 5 ref: NULL rows: 181 r_rows: 181 filtered: 100.00 r_filtered: 10.50 Extra: Using index condition; Using where ``` Compared to `EXPLAIN`, `ANALYZE` produces two extra columns: * **`r_rows`** is an observation-based counterpart of the **rows** column. It shows how many rows were actually read from the table. * **`r_filtered`** is an observation-based counterpart of the **filtered** column. It shows which fraction of rows was left after applying the WHERE condition. Interpreting the Output ----------------------- ### Joins Let's consider a more complicated example. ``` ANALYZE SELECT * FROM orders, customer WHERE customer.c_custkey=orders.o_custkey AND customer.c_acctbal < 0 AND orders.o_totalprice > 200*1000 ``` ``` +----+-------------+----------+------+---------------+-------------+---------+--------------------+--------+--------+----------+------------+-------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | r_rows | filtered | r_filtered | Extra | +----+-------------+----------+------+---------------+-------------+---------+--------------------+--------+--------+----------+------------+-------------+ | 1 | SIMPLE | customer | ALL | PRIMARY,... | NULL | NULL | NULL | 149095 | 150000 | 18.08 | 9.13 | Using where | | 1 | SIMPLE | orders | ref | i_o_custkey | i_o_custkey | 5 | customer.c_custkey | 7 | 10 | 100.00 | 30.03 | Using where | +----+-------------+----------+------+---------------+-------------+---------+--------------------+--------+--------+----------+------------+-------------+ ``` Here, one can see that * For table customer, **customer.rows=149095, customer.r\_rows=150000**. The estimate for number of rows we will read was fairly precise * **customer.filtered=18.08, customer.r\_filtered=9.13**. The optimizer somewhat overestimated the number of records that will match selectivity of condition attached to `customer` table (in general, when you have a full scan and r\_filtered is less than 15%, it's time to consider adding an appropriate index). * For table orders, **orders.rows=7, orders.r\_rows=10**. This means that on average, there are 7 orders for a given c\_custkey, but in our case there were 10, which is close to the expectation (when this number is consistently far from the expectation, it may be time to run ANALYZE TABLE, or even edit the table statistics manually to get better query plans). * **orders.filtered=100, orders.r\_filtered=30.03**. The optimizer didn't have any way to estimate which fraction of records will be left after it checks the condition that is attached to table orders (it's orders.o\_totalprice > 200\*1000). So, it used 100%. In reality, it is 30%. 30% is typically not selective enough to warrant adding new indexes. For joins with many tables, it might be worth to collect and use [column statistics](../engine-independent-table-statistics/index) for columns in question, this may help the optimizer to pick a better query plan. ### Meaning of NULL in r\_rows and r\_filtered Let's modify the previous example slightly ``` ANALYZE SELECT * FROM orders, customer WHERE customer.c_custkey=orders.o_custkey AND customer.c_acctbal < -0 AND customer.c_comment LIKE '%foo%' AND orders.o_totalprice > 200*1000; ``` ``` +----+-------------+----------+------+---------------+-------------+---------+--------------------+--------+--------+----------+------------+-------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | r_rows | filtered | r_filtered | Extra | +----+-------------+----------+------+---------------+-------------+---------+--------------------+--------+--------+----------+------------+-------------+ | 1 | SIMPLE | customer | ALL | PRIMARY,... | NULL | NULL | NULL | 149095 | 150000 | 18.08 | 0.00 | Using where | | 1 | SIMPLE | orders | ref | i_o_custkey | i_o_custkey | 5 | customer.c_custkey | 7 | NULL | 100.00 | NULL | Using where | +----+-------------+----------+------+---------------+-------------+---------+--------------------+--------+--------+----------+------------+-------------+ ``` Here, one can see that **orders.r\_rows=NULL** and **orders.r\_filtered=NULL**. This means that table orders was not scanned even once. Indeed, we can also see customer.r\_filtered=0.00. This shows that a part of WHERE attached to table `customer` was never satisfied (or, satisfied in less than 0.01% of cases). ANALYZE FORMAT=JSON ------------------- [ANALYZE FORMAT=JSON](../analyze-formatjson/index) produces JSON output. It produces much more information than tabular `ANALYZE`. Notes ----- * `ANALYZE UPDATE` or `ANALYZE DELETE` will actually make updates/deletes (`ANALYZE SELECT` will perform the select operation and then discard the resultset). * PostgreSQL has a similar command, `EXPLAIN ANALYZE`. * The [EXPLAIN in the slow query log](../explain-in-the-slow-query-log/index) feature allows MariaDB to have `ANALYZE` output of slow queries printed into the [slow query log](../slow-query-log/index) (see [MDEV-6388](https://jira.mariadb.org/browse/MDEV-6388)). See Also -------- * [ANALYZE FORMAT=JSON](../analyze-formatjson/index) * [ANALYZE TABLE](../analyze-table/index) * JIRA task for ANALYZE statement, [MDEV-406](https://jira.mariadb.org/browse/MDEV-406) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb DROP SERVER DROP SERVER =========== Syntax ------ ``` DROP SERVER [ IF EXISTS ] server_name ``` Description ----------- Drops the server definition for the server named *server\_name*. The corresponding row within the [mysql.servers table](../mysqlservers-table/index) will be deleted. This statement requires the [SUPER](../grant/index#super) privilege or, from [MariaDB 10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/), the [FEDERATED ADMIN](../grant/index#federated-admin) privilege. Dropping a server for a table does not affect any [FederatedX](../federatedx/index), [FEDERATED](../federated-storage-engine/index), [Connect](../connect/index) or [Spider](../spider/index) tables that used this connection information when they were created. DROP SERVER is not written to the [binary log](../binary-log/index), irrespective of the [binary log format](../binary-log-formats/index) being used. From [MariaDB 10.1.13](https://mariadb.com/kb/en/mariadb-10113-release-notes/), [Galera](../galera/index) replicates the [CREATE SERVER](../create-server/index), [ALTER SERVER](../alter-server/index) and DROP SERVER statements. #### IF EXISTS If the IF EXISTS clause is used, MariaDB will not return an error if the server does not exist. Unlike all other statements, DROP SERVER IF EXISTS does not issue a note if the server does not exist. See [MDEV-9400](https://jira.mariadb.org/browse/MDEV-9400). Examples -------- ``` DROP SERVER s; ``` IF EXISTS: ``` DROP SERVER s; ERROR 1477 (HY000): The foreign server name you are trying to reference does not exist. Data source error: s DROP SERVER IF EXISTS s; Query OK, 0 rows affected (0.00 sec) ``` See Also -------- * [CREATE SERVER](../create-server/index) * [ALTER SERVER](../alter-server/index) * [Spider Storage Engine](../spider/index) * [FederatedX Storage Engine](../federatedx/index) * [Connect Storage Engine](../connect/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb dbForge Data Generator dbForge Data Generator ====================== [**dbForge Data Generator for MariaDB and MySQL**](https://www.devart.com/dbforge/mysql/data-generator/) is a powerful solution that helps create massive volumes of meaningful and realistic data. This tool performs various predefined data generators with customizable options. Data Generator Key Features: ---------------------------- ### 1. Extensive support for all column data types Enjoy the advantage of various data types support ### 2. Multiple generators with unique test data Enjoy multiple customization options with individual generators for every data type supported ### 3. MariaDB data generation and data integrity support Generate consistent random data through multiple tables Disable triggers and constraints to avoid interference with database logic ### 4. MariaDB data distribution modes Fine-tune the way you want your data to be generated ### 5. Multiple ways to generate data in MySQL Generate a data population script, execute it against a MariaDB database, save or edit it later ### 6. Basic generators Populate tables with a great variety of values types, like JSON, Python, XML, etc. ![basic-generators-1](https://mariadb.com/kb/en/dbforge-data-generator/+image/basic-generators-1 "basic-generators-1") ### 7. Meaningful test data generators Select any of 200+ real-world generators and populate tables with realistic data related to various spheres ![meaningful-generators-1](https://mariadb.com/kb/en/dbforge-data-generator/+image/meaningful-generators-1 "meaningful-generators-1") ### 8. User-defined generators Create, save and use your own data generators tailored for your needs ### 9. Real-time data generation preview Enjoy real-time visualization of the alterations you make Visually assess the data to be generated ### 10. Command-line interface Schedule your routine data generation tasks Create a command-line execution file for running database documentation tasks ### 11. Broad compatibility options MariaDB server versions 5.5-10.6 Various cloud services: Amazon RDS, Amazon Aurora, Google Cloud, Oracle MySQL Cloud, Alibaba Cloud Security connections: Secure Socket Layer (SSL), Secure Shell (SSH), HTTP Tunneling, PAM Percona Download a free 30-day trial of dbForge Data Generator [here](https://www.devart.com/dbforge/mysql/data-generator/download.html). [Documentation](https://docs.devart.com/data-generator-for-mysql/) | Version | Introduced | | --- | --- | | dbForge Data Generator 2.4 | Connectivity support for [MariaDB 10.5](../what-is-mariadb-105/index) is added | | dbForge Data Generator 2.2 | Support for [MariaDB 10.4](../what-is-mariadb-104/index) | | dbForge Data Generator 2.1 | Support for [MariaDB 10.3](../what-is-mariadb-103/index) | | dbForge Data Generator 2.0 | Support for [MariaDB 10.2](../what-is-mariadb-102/index), Support for [MariaDB 10.1](../what-is-mariadb-101/index) | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Adding DataFlex 3.1c .dat Files As An External Table Type With CONNECT Adding DataFlex 3.1c .dat Files As An External Table Type With CONNECT ====================================================================== I'm using MariaDB's CONNECT engine to access / utilize a set of Visual FoxPro / dBase files as part of supporting an extremely old piece of software for a client. It's works SO well, and I'm extremely happy with it. In fact, my client is so happy with my support that he recommended me to a friend of his. His friend's ridiculously old piece of software uses DataFlex 3.1c files as it's tables. They're simply stored as a bunch of .dat files in a folder. I've found enough documentation to pretty much nail down the file format. The CONNECT engine recognizes them just fine as DOS or BIN types files. The one and only problem is that MariaDB expects the first record to begin at the beginning of the file, but the .dat files contain a header portion that describes the table itself. I can read that and calculate the correct CREATE TABLE statement just fine, but I can't seem to find a way to compensate for the header being where MariaDB expects records to be. How can I tell MariaDB where the first record actually begins? I've actually written a functional parser for the .dat files in Python based of of the notes here [here](https://hwiegman.home.xs4all.nl/fileformats/dat/DATAFLEX.txt) and [here](https://code.activestate.com/lists/perl-dbi-dev/1529/). I also used [this](https://github.com/tforsberg/DataFlexToSQLite) GitHub project as a guide / template (being as I didn't want to convert the DataFlex files, just read and write to them in place). I was advised by @montywi on the Freenode IRC channel that this was the best place for my question. I will happily supply reference .dat files and support their inclusion in CONNECT however I can. I'm just at a total loss for how to proceed. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb dbForge Studio for MySQL/MariaDB dbForge Studio for MySQL/MariaDB ================================ **dbForge Studio for MySQL** is an advanced and powerful GUI toolset designed specifically for specialists who deal with databases on MySQL and MariaDB. The purpose is to equip you with all tools needed to set up and perform the database-related routines on MariaDB. It saves time and costs, allowing you to work much more productively overall. As a [MariaDB IDE](https://www.devart.com/dbforge/mysql/studio/mariadb-gui-client.html), this Studio offers the superior functionality to resolve all work tasks on this RDBMS. *Database Development* The available functionality lets you produce high-quality code much faster. In particular, the advanced automated code completion feature helps you speed up the code writing. The syntax validator detects errors immediately. The code formatter with customized templates lets you set and follow the code standards across your projects. Code refactoring supports intelligent renaming operations for better readability. *Database Management* When you have the job to compare and synchronize MariaDB databases, the Studio will do these jobs. It covers both the data and schema comparison and generates the syncing scripts to deploy changes on MariaDB (also on MySQL and Percona). You can automate all these routines. Other helpful options allow you to profile queries as well as optimize them and detect any issues in them to fix. Also, you can generate reasonable test data in any volume, create detailed database documentation, design in-depth reports, etc. *Database Administration* With the tools available in this IDE, you get all the functionality necessary to create, configure, and manage users and their rights. Other features cover the tasks of backing up and restoring, data importing and exporting, and copying and migrating databases in several ways. You can maintain tables, generate database scripts, manage server variables and sessions, etc. The Express edition with basic features is offered *free of charge*. Also, a free trial with full functionality of the Studio is available *for 30 days*. * [**Learn more about dbForge Studio here**](https://www.devart.com/dbforge/mysql/studio/mariadb-gui-client.html). * [**Download a 30-day free trial here**](https://www.devart.com/dbforge/mysql/studio/download.html). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Locales Plugin Locales Plugin ============== The `LOCALES` plugin creates the [LOCALES](../information-schema-locales-table/index) table in the [INFORMATION\_SCHEMA](../information-schema/index) database. The plugin also adds the [SHOW LOCALES](../show-locales/index) statement.The table and statement can be queried to see all [locales](../server-locale/index) that are compiled into the server. Installing the Plugin --------------------- Although the plugin's shared library is distributed with MariaDB by default, the plugin is not actually installed by MariaDB by default. There are two methods that can be used to install the plugin with MariaDB. The first method can be used to install the plugin without restarting the server. You can install the plugin dynamically by executing [INSTALL SONAME](../install-soname/index) or [INSTALL PLUGIN](../install-plugin/index). For example: ``` INSTALL SONAME 'locales'; ``` The second method can be used to tell the server to load the plugin when it starts up. The plugin can be installed this way by providing the [--plugin-load](../mysqld-options/index#-plugin-load) or the [--plugin-load-add](../mysqld-options/index#-plugin-load-add) options. This can be specified as a command-line argument to [mysqld](../mysqld-options/index) or it can be specified in a relevant server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index). For example: ``` [mariadb] ... plugin_load_add = locales ``` Uninstalling the Plugin ----------------------- You can uninstall the plugin dynamically by executing [UNINSTALL SONAME](../uninstall-soname/index) or [UNINSTALL PLUGIN](../uninstall-plugin/index). For example: ``` UNINSTALL SONAME 'locales'; ``` If you installed the plugin by providing the [--plugin-load](../mysqld-options/index#-plugin-load) or the [--plugin-load-add](../mysqld-options/index#-plugin-load-add) options in a relevant server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index), then those options should be removed to prevent the plugin from being loaded the next time the server is restarted. Example ------- ``` SELECT * FROM INFORMATION_SCHEMA.LOCALES; +-----+-------+-------------------------------------+-----------------------+---------------------+---------------+--------------+------------------------+ | ID | NAME | DESCRIPTION | MAX_MONTH_NAME_LENGTH | MAX_DAY_NAME_LENGTH | DECIMAL_POINT | THOUSAND_SEP | ERROR_MESSAGE_LANGUAGE | +-----+-------+-------------------------------------+-----------------------+---------------------+---------------+--------------+------------------------+ | 0 | en_US | English - United States | 9 | 9 | . | , | english | | 1 | en_GB | English - United Kingdom | 9 | 9 | . | , | english | | 2 | ja_JP | Japanese - Japan | 3 | 3 | . | , | japanese | | 3 | sv_SE | Swedish - Sweden | 9 | 7 | , | | swedish | | 4 | de_DE | German - Germany | 9 | 10 | , | . | german | | 5 | fr_FR | French - France | 9 | 8 | , | | french | | 6 | ar_AE | Arabic - United Arab Emirates | 6 | 8 | . | , | english | | 7 | ar_BH | Arabic - Bahrain | 6 | 8 | . | , | english | | 8 | ar_JO | Arabic - Jordan | 12 | 8 | . | , | english | ... | 106 | no_NO | Norwegian - Norway | 9 | 7 | , | . | norwegian | | 107 | sv_FI | Swedish - Finland | 9 | 7 | , | | swedish | | 108 | zh_HK | Chinese - Hong Kong SAR | 3 | 3 | . | , | english | | 109 | el_GR | Greek - Greece | 11 | 9 | , | . | greek | | 110 | rm_CH | Romansh - Switzerland | 9 | 9 | , | . | english | +-----+-------+-------------------------------------+-----------------------+---------------------+---------------+--------------+------------------------+ ``` Versions -------- | Version | Status | Introduced | | --- | --- | --- | | 1.0 | Stable | [MariaDB 10.1.13](https://mariadb.com/kb/en/mariadb-10113-release-notes/) | | 1.0 | Gamma | [MariaDB 10.0.10](https://mariadb.com/kb/en/mariadb-10010-release-notes/) | | 1.0 | Alpha | [MariaDB 10.0.4](https://mariadb.com/kb/en/mariadb-1004-release-notes/) | Options ------- ### `locales` * **Description:** Controls how the server should treat the plugin when the server starts up. + Valid values are: - `OFF` - Disables the plugin without removing it from the [mysql.plugins](../mysqlplugin-table/index) table. - `ON` - Enables the plugin. If the plugin cannot be initialized, then the server will still continue starting up, but the plugin will be disabled. - `FORCE` - Enables the plugin. If the plugin cannot be initialized, then the server will fail to start with an error. - `FORCE_PLUS_PERMANENT` - Enables the plugin. If the plugin cannot be initialized, then the server will fail to start with an error. In addition, the plugin cannot be uninstalled with [UNINSTALL SONAME](../uninstall-soname/index) or [UNINSTALL PLUGIN](../uninstall-plugin/index) while the server is running. + See [Plugin Overview: Configuring Plugin Activation at Server Startup](../plugin-overview/index#configuring-plugin-activation-at-server-startup) for more information. * **Commandline:** `--locales=value` * **Data Type:** `enumerated` * **Default Value:** `ON` * **Valid Values:** `OFF`, `ON`, `FORCE`, `FORCE_PLUS_PERMANENT` --- Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb CONNECT - Security CONNECT - Security ================== The use of the CONNECT engine requires the `[FILE](../grant/index#global-privileges)` privilege for ["outward"](../inward-and-outward-tables/index#outward-tables) tables. This should not be an important restriction. The use of CONNECT "outward" tables on a remote server seems of limited interest without knowing the files existing on it and must be protected anyway. On the other hand, using it on the local client machine is not an issue because it is always possible to create locally a user with the `FILE` privilege. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb General Development Information General Development Information ================================ | Title | Description | | --- | --- | | [MariaDB Releases](../mariadb-releases/index) | List of releases of MariaDB software and what they contain. | | [Plans](../development-plans/index) | MariaDB Development Plans | | [MariaDB Users & Developers](../resources/index) | Connect and interact with other MariaDB users and developers. | | [Contributing to the MariaDB Project](../contributing-to-the-mariadb-project/index) | How to contribute to the MariaDB project: code, documentation, feedback, etc. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Running MariaDB ColumnStore Docker containers on Linux, Windows and MacOS Running MariaDB ColumnStore Docker containers on Linux, Windows and MacOS ========================================================================= Introduction ============ Docker allows for a simple and lightweight setup of a MariaDB ColumnStore single server instance for evaluation purposes. The configuration is designed for simplified developer / evaluation setup rather than production use. It allows to evaluate ColumnStore on a Windows or MacOS system, setting up a Linux system in a container. The Docker image uses a base OS of CentOS and currently require separate download of the CentOS RPM install bundle. Windows Linux Subsystem ======================= If you have Windows 10 Creators update installed, then you can install the Ubuntu installation into the Bash console. Please follow the Ubuntu instructions in getting started. If you have recently upgraded and had Bash installed previously, ensure you uninstall and reinstall Bash first to have a clean Ubuntu installation. Note that ColumnStore will be terminated should you terminate the Bash console. Docker ====== [Docker](../docker-and-mariadb/index) manages lightweight containers that allows for creation of lightweight and reproducible containers with a dedicated function. On Windows and MacOS systems, Docker transparently runs on a Linux virtual machine. Since MariaDB ColumnStore relies on a Syslog daemon, the container must start both ColumnStore and rsyslogd and the runit utility is used to achieve this. A single node docker image can be found at [MariaDB on docker hub](https://hub.docker.com/r/mariadb/columnstore/). ``` docker run -d --name mcs mariadb/columnstore docker exec -it mcs bash ``` A ColumnStore cluster can be brought up using a compose file provided in the ColumnStore github repository: ``` git clone https://github.com/mariadb-corporation/mariadb-columnstore-docker.git cd mariadb-columnstore-docker/columnstore docker-compose up -d ``` For more information about how to manage Docker containers, see [Installing and Using MariaDB via Docker](../installing-and-using-mariadb-via-docker/index). To test an application that uses ColumnStore, it is desirable to setup several containers that will communicate with each other. To do this, we can use Docker Compose. See [Setting Up a LAMP Stack with Docker Compose](../setting-up-a-lamp-stack-with-docker-compose/index) for more information. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb STARTPOINT STARTPOINT ========== A synonym for [ST\_STARTPOINT](../st_startpoint/index). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Building MariaDB on FreeBSD Building MariaDB on FreeBSD =========================== It is relatively straightforward to build MariaDB from source on FreeBSD. When working with an individual host, you can use Ports to compile particular or multiple versions of MariaDB. When working with multiple hosts, you can use Poudriere to build MariaDB once, then serve it as a package to multiple FreeBSD hosts. Using Ports ----------- The FreeBSD Ports Collection provides a series of Makefiles that you can use to retrieve source code, configure builds, install dependencies and compile software. This allows you to use more advanced releases than what is normally available through the package managers as well as enable any additional features that interest you. In the event that you have not used Ports before on your system, you need to first fetch and extract the Ports tree. This downloads the Ports tree from FreeBSD and extracts it onto your system, placing the various Makefiles, patches and so on in the `/usr/ports/` directory. ``` # portsnap fetch extract ``` In the event that you have used Ports before on this system, run Portsnap again to download and install any updates to the Ports tree. ``` # portsnap fetch update ``` This ensures that you are using the most up to date release of the Ports tree that is available on your system. ### Building MariaDB from Ports Once Portsnap has installed or updated your Ports tree, you can change into the relevant directory and install MariaDB. Ports for MariaDB are located in the `/usr/ports/databases/` directory. ``` $ ls /usr/ports/databases | grep mariadb mariadb-connector-c mariadb-connector-odbc mariadb100-client mariadb100-server mariadb101-client mariadb101-server mariadb102-client mariadb102-server mariadb103-client mariadb103-server mariadb55-client mariadb55-server ``` Note that FreeBSD treats the Server and Client as separate packages. The Client is a dependency of the Server, so you only need to build the Server to get both. It also provides a number of different versions. You can search the available ports from [Fresh Ports](http://www.freshports.org/databases). Decide what version of MariaDB you want to install, the change into the relevant directory. Once in the directory, run Make to build MariaDB. ``` # cd /usr/ports/databases/mariadb103-server # make ``` In addition to downloading and building MariaDB, Ports also downloads and build any libraries on which MariaDB depends. Each port it builds will take you to a GUI window where you can select various build options. In the case of MariaDB, this includes various storage engines and specific features you need in your build. Once you finish building the ports, install MariaDB on your system and clean the directory to free up disk space. ``` # make install clean ``` This installs FreeBSD on your server. You can now enable, configure and start the service as you normally would after installing MariaDB from a package. Using Poudriere --------------- Poudriere is a utility for building FreeBSD packages. It allows you to build MariaDB from a FreeBSD Jail, then serve it as a binary package to other FreeBSD hosts. You may find this is particularly useful when building to deploy multiple MariaDB servers on FreeBSD, such as with Galera Cluster or similar deployments. ### Building MariaDB Once you've configured your host to use Jails and Poudriere, initialize a jail to use in building packages and a jail for managing ports. ``` # poudriere jail -c -j package-builder -v 11.2-RELEASE # poudriere ports -c -p local-ports ``` This creates two jails, `package-builder` and `local-ports`, which you can then use to build MariaDB. Create a text file to define the packages you want to build. Poudriere will build these packages as well as their dependencies. MariaDB is located at `databases/mariadb103-server`. Adjust the path to match the version you want to install. ``` $ vi maraidb-package-builder.txt databases/mariadb103-server ``` Use the `options` command to initialize the build options for the packages you want Poudriere to compile. ``` # poudriere options -j package-builder -p local-ports -z mariadb-builder -f mariadb-package-builder.txt ``` Lastly, use the `bulk` command to compile the packages. ``` # poudriere bulk -j package-builder -p local-ports -z mariadb-builder -f mariadb-package-builder.txt ``` ### Using Poudriere Repositories In order to use Poudriere, you need to set up and configure a web server, such as Nginx or Apache to serve the directory that Poudriere built. For instance, in the case of the above example, you would map to the `package-builder` jail: `/usr/local/poudriere/data/packages/package-builder/`. You may find it useful to map this directory to a sub-domain, for instance `https*pkg.example.com*` or something similar. Lastly, you need to configure the FreeBSD hosts to use the Poudriere repository you just created. On each host, disable the FreeBSD official repositories and enable your Poudriere repository as an alternative. ``` # vi /usr/local/etc/pkg/repos/FreeBSD.conf FreeBSD: { enabled: no } ``` Then add the URL for your Poudriere repository to configuration file: ``` # vi /usr/local/etc/pkg/repos/mariadb.conf custom: { url: "https://pkg.example.com", enabled: yes } ``` You can then install MariaDB from Poudriere using the package manager. ``` # pkg install mariadb103-server ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb NOT IN NOT IN ====== Syntax ------ ``` expr NOT IN (value,...) ``` Description ----------- This is the same as NOT (expr [IN](../in/index) (value,...)). Examples -------- ``` SELECT 2 NOT IN (0,3,5,7); +--------------------+ | 2 NOT IN (0,3,5,7) | +--------------------+ | 1 | +--------------------+ ``` ``` SELECT 'wefwf' NOT IN ('wee','wefwf','weg'); +--------------------------------------+ | 'wefwf' NOT IN ('wee','wefwf','weg') | +--------------------------------------+ | 0 | +--------------------------------------+ ``` ``` SELECT 1 NOT IN ('1', '2', '3'); +--------------------------+ | 1 NOT IN ('1', '2', '3') | +--------------------------+ | 0 | +--------------------------+ ``` NULL: ``` SELECT NULL NOT IN (1, 2, 3); +-----------------------+ | NULL NOT IN (1, 2, 3) | +-----------------------+ | NULL | +-----------------------+ SELECT 1 NOT IN (1, 2, NULL); +-----------------------+ | 1 NOT IN (1, 2, NULL) | +-----------------------+ | 0 | +-----------------------+ SELECT 5 NOT IN (1, 2, NULL); +-----------------------+ | 5 NOT IN (1, 2, NULL) | +-----------------------+ | NULL | +-----------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Changing Times in MariaDB Changing Times in MariaDB ========================= The article entitled, [Doing Time with MariaDB](../doing-time-with-mariadb/index) dealt with time and date columns in MariaDB and how to selectively retrieve and format time and date elements. This article will go a little further by exploring special functions that are available in MariaDB to modify time and date. ##### The Nature of Time For most of us, there is a morning and an afternoon in each day. Days are measured in either two twelve-hour blocks or one twenty-four-hour block. There are twelve months in a year, with each month consisting of thirty or thirty-one days. The only exception is the month of February which contains twenty-eight days usually, but once every four years it contains twenty-nine. While this all may be rather natural, putting it into a computer program can make it seem very unnatural and frustrating. For the scenario in this article we have a MariaDB database in which customers enter work requests through the web. When they enter a trouble ticket, a record is entered into a MariaDB table called, tickets. This record contains several fields, one of which is the date that the ticket was entered called ticket\_date. Another contains the time the ticket was entered. It's called simply, entered. Yet another column is called promised; it's the time that the customer was promised that their problem would be resolved. Both the entered and the promised columns are time data type columns. The value of entered is determined from the current time of the server. The value of promised is determined by adding a number of hours to the value of entered, depending on the urgency of the ticket set by the customer. For instance, tickets marked "ASAP" are to be completed within two hours according to our company's policy. This all works nicely in testing, but occasionally customers create tickets at odd times and on odd days. ##### Around the Clock Setting aside the potential problems for a moment, let's look at a simple example of how we might add tickets. Suppose we wanted to write a CGI script (in Perl or PHP) that will allow users to create tickets on-line any time. We might use the following SQL statement in our script: ``` INSERT INTO tickets (client_id, urgency, trouble, ticket_date, entered, promised) VALUES('$client_id', '$urgency', '$trouble', CURDATE(), CURTIME(), SEC_TO_TIME(TIME_TO_SEC(CURTIME()) + 7200)); ``` If you're unfamiliar with [INSERT](../insert/index) statements and the use of script variables (e.g., $client\_id), you may want to go back and read an earlier article ([MariaDB Basics](../mariadb-basics/index)) in this series which explains both. For the purposes of this article, however, let's focus on the minor formula in the SQL statement above for calculating the promised time, the last line. The [TIME\_TO\_SEC( )](../time_to_sec/index) function converts a time to seconds so that a calculation may be performed. In this case, the current time is converted to seconds. The formula above then adds 7200 seconds (which is two hours) to that. In order to insert the seconds sum into a time column (i.e., promised), it needs to be converted to a time format. Hence, the calculation is wrapped up in the [SEC\_TO\_TIME( )](../sec_to_time/index) function. As nice as the SQL statement above is, a problem arises when a customer runs it at 11:00 p.m (or 23:00 in MariaDB time) and the promised time is to be two hours later. The SQL statement above will calculate a promised time of 25:00. What time is that in human or computer terms? As humans, we know that it's meant to be 1:00 a.m., but MariaDB will need this clarified. One solution would be to place the time formula above inside of an IF clause in MariaDB. To do this, the last line of the SQL statement would be replaced with these lines: ``` ... IF((TIME_TO_SEC(CURTIME()) + 7200) < 86400, SEC_TO_TIME(TIME_TO_SEC(CURTIME()) + 7200), SEC_TO_TIME((TIME_TO_SEC(CURTIME()) + 7200) - 86400))); ``` The first element in the IF clause is the test. The second piece is the value used if the test passes. The third is the value if the test fails. So, if the total seconds is less than 86,400 (i.e., the number of seconds in one day), then the total seconds of the current time, converted to the time format is to be used. Otherwise, the total seconds of the current time minus 86,400 seconds, converted to the time format is to be used. Incidentally, there's an extra closing parenthesis at the end of this SQL statement excerpt because there was an opening one as part of the `VALUES` clause that's not shown here. Although the statement above works, it's a bit excessive and can be accomplished a little more succinctly if one reconsiders the purpose of the IF clause. What we're trying to determine in the IF clause is the number of seconds into the day in which the work was promised to be done, meaning the excess amount of time of the day (i.e., one hour). For such a calculation, the modulo division operator (i.e., the `%`) can be used. The modulo division operator will give the remainder of a division. For instance, the result of `SELECT 14 % 5;` is `4`. That is to say, 5 goes into 14 two complete times with 4 left over. As another example, the result of `SELECT 3 % 5;` is 3; that is to say, 5 goes into 3 zero times with 3 left over. Using this arithmetic operator in the time formula above, we can eliminate the IF clause and use the following to accomplish our task: ``` ... SEC_TO_TIME((TIME_TO_SEC(CURTIME()) + 7200) % 86400)); ``` If the current time is 23:00, then the time in seconds will be 82,800. The formula above will add 7200 to 82,800 to make 90,000 seconds. The modulo division operator will divide 86,400 into 90,000 one time, giving a remainder of 3600 seconds. The SEC\_TO\_TIME function will then convert 3600 seconds to one hour or 1:00 a.m. ##### Today or Tomorrow? There is a problem with the results from the formula at the end of the previous section. If the customer is promised 1:00 a.m., is that time today or tomorrow? Again, as humans we know that since the promised time must be after the entered time, it must be 1:00 a.m. on the following day. Since computers don't make these assumptions, though, we'll have to make some adjustments to the tickets table and the SQL statement. To be able to record the date and time in each column, we'll first change the column types of entered and promised from time to datetime. We'll do the following SQL statements to migrate the data and to clean up the table: ``` ALTER TABLE tickets, CHANGE COLUMN entered entered_old TIME, CHANGE COLUMN promised promised_old TIME, ADD COLUMN entered DATETIME, ADD COLUMN promised DATETIME; UPDATE tickets SET entered = CONCAT(ticket_date, ' ', entered_old), promised = CONCAT(ticket_date, ' ', promised_old); ALTER TABLE tickets, DROP COLUMN entered_old, DROP COLUMN promised_old, DROP COLUMN ticket_date; ``` The first SQL statement above alters the table to change the names of the time columns temporarily and to add the new columns with datetime types. If we were instead just to change the existing time columns to datetime types without this two step process, the data would be clobbered and reset to all zeros. The next SQL statement copies the values of the ticket\_date column and pastes it together with the value of one of the old time columns to come up with the new date and time value for the entered and promised dates and times. The flaw in this statement, of course, is that it doesn't deal with the problems with some promised times that the previous layout caused. In fact, it reinforces it by giving a 1:00 a.m. promised time the date of the entered time. This will either have to be fixed manually if it's important to the developer, or with a script that will compare the two time columns. Either way, it's a little out of the scope of this article, so we'll move on. The last SQL statement above deletes the old time columns and the old date column now that the data has been migrated. By the way, it's a good practice to backup the data before altering a table. Also, you probably would run a [SELECT](../select/index) statement before the last SQL statement above to check the migrated data before dropping the old columns. Having changed the column types, we can now use the function [DATE\_ADD( )](../date_add/index), which can deal with times that exceed twenty-four hours so that the problem with times straddling the midnight hour won't reoccur. Therefore, our on-going SQL statement becomes this: ``` INSERT INTO tickets (client_id, urgency, trouble, entered, promised) VALUES('$client_id', '$urgency', '$trouble', NOW(), DATE_ADD(NOW(), INTERVAL 2 HOUR)); ``` First notice that the field ticket\_date was eliminated and [CURTIME()](../curtime/index) was replaced with [NOW( )](../now/index), which provides the date and time in one. In the last line we see [DATE\_ADD( )](../date_add/index): an interval of two hours is added to the date and time now (or rather when the record is created). If the time rolls into the next day, then the date is advanced by one and the correct hour is set accordingly. The [DATE\_ADD( )](../date_add/index) function will also allow for the addition of minutes. The directive `HOUR` would be replaced with `MINUTE`. To add both hours and minutes (e.g., two hours and thirty minutes), the last line of the SQL statement above could read like this: ``` ... DATE_ADD(NOW(), INTERVAL '2:30' HOUR_MINUTE)); ``` If the time in which the statement is run is 11:00 p.m., the result would be 1:30 a.m. on the next day. ##### Around the Calendar The dilemma that can occur with calculations involving hours that wrap around the clock, can similarly occur with calculations involving days that roll into a new month. This problem was fairly easy to resolve with an arithmetic operator when dealing with a constant like the number of seconds in a day. However, a formula to deal with the various number of days in each month would be very lengthy. For instance, if we were simply to add five days to the date February 27, we would get February 32. Imagine trying to create an SQL statement to figure out whether that's supposed to be March 1, 2, 3, or 4--depending on whether the previous month is a regular month with 30 or 31 days, or the one irregular month with 28 or 29 days, depending on the year. Fortunately (as you probably have already guessed), [DATE\_ADD( )](../date_add/index) will solve the month dilemma, as well. If instead of promising that tickets will be resolved within a couple hours of the time they are entered, we promise resolution within five days, the SQL statement would look like this: ``` INSERT INTO tickets (client_id, urgency, trouble, entered, promised) VALUES('$client_id', '$urgency', '$trouble', NOW(), DATE_ADD(NOW(), INTERVAL 5 DAY)); ``` If this statement is run on February 27, then the value of promised would be March 3 or 4, depending on whether it is a leap year. Which one will be determined by the [DATE\_ADD( )](../date_add/index) function, requiring no fancy formula. Just as hours and minutes can be mixed with [DATE\_ADD( )](../date_add/index), days and hours can be mixed, as well. To make the value of promised two days and six hours from now, the last line of the SQL statement above would read like this: ``` ... DATE_ADD(NOW(), INTERVAL '2 6' DAY_HOUR)); ``` The function [DATE\_ADD( )](../date_add/index) will also allow the addition of months and of years. For instance, to increase the date by one year and two months, the SQL statement would be adjusted to look like this: ``` ... DATE_ADD(NOW(), INTERVAL '1 2' YEAR_MONTH)); ``` This increases the year by one and the month by two. These intervals have no effect on time or day values, though. So, if the value of [NOW( )](../now/index) is `2017-09-15 23:00`, then the value of promised would become 2018-11-15 23:00, regardless of whether next year is a leap year and regardless of the number of days in each intervening month. ##### Stepping Back It stands to reason that if one wants to add days to the current date, then one will want to subtract days in an equally agreeable manner. For subtracting days we can still use the DATE\_ADD function. Just put a negative sign in front of the interval value like this: ``` ... DATE_ADD(NOW(), INTERVAL -5 DAY)); ``` This will give a value five days before the current date. An alternative would be to use the [DATE\_SUB( )](../date_sub/index) function which subtracts from the date given. The above amendment (subtracting five days from the current date) could be entered like so: ``` ... DATE_SUB(NOW(), INTERVAL 5 DAY)); ``` Notice that the 5 is not preceded by a negative sign. If it were, it would have the effect of adding five days. ##### Conclusion This article along with the previous one on time and date in MariaDB in no way exhaust the topic. There are many more functions and tricks to manipulating temporal values in MariaDB, not to mention what can be done with the extension of a script using a programming language like PHP. Plus, new functions are occasionally being added to MariaDB. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb ^ ^ = Syntax ------ ``` ^ ``` Description ----------- Bitwise XOR. Converts the values to binary and compares bits. If one (and only one) of the corresponding bits is 1 is the resulting bit also 1. Examples -------- ``` SELECT 1 ^ 1; +-------+ | 1 ^ 1 | +-------+ | 0 | +-------+ SELECT 1 ^ 0; +-------+ | 1 ^ 0 | +-------+ | 1 | +-------+ SELECT 11 ^ 3; +--------+ | 11 ^ 3 | +--------+ | 8 | +--------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb mariadb-find-rows mariadb-find-rows ================= **MariaDB starting with [10.4.6](https://mariadb.com/kb/en/mariadb-1046-release-notes/)**From [MariaDB 10.4.6](https://mariadb.com/kb/en/mariadb-1046-release-notes/), `mariadb-find-rows` is a symlink to `mysql_find_rows`, the tool for reading files containing SQL statements and extracting statements that match a given regular expression or that contain [USE db\_name](../use/index) or [SET](../set/index) statements. **MariaDB starting with [10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/)**From [MariaDB 10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/), `mariadb-find-rows` is the name of the tool, with `mysql_find_rows` a symlink . See [mysql\_find\_rows](../mysql_find_rows/index) for details. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb RQG Extensions for MariaDB RQG Extensions for MariaDB ========================== All recent reasonably stable changes can be found in [our Github repository](https://github.com/MariaDB/randgen). The link points to the master branch; there are other branches created for more specific cases. While all described changes were made in order to test MariaDB code, many of them are applicable to other MySQL flavors as well. Galera Mode ----------- A set of changes to support running RQG tests with multi-master Galera replication, implemented to test [MariaDB Galera cluster](../galera/index). The top-level script `runall-new.pl` got a new option --galera, which takes a string value. The string can be a combination of 'm' or 's', where each symbol represents a Galera node. 'm' stands for 'master', and 's' stands for 'slave'. The new module `GaleraMySQLd.pm` implements cluster initialization and startup. It is only interested in the number of nodes. Internals are adapted to the multi-master or mixed mode: * instead of executing data generation on each started server, it is only executed on the first 'master'; * test flow is executed on each 'master' (but not on 'slaves'); * no result comparison is performed after each query, the flow runs independently, but at the end, if no other errors were encountered, `runall-new.pl` performs dump comparison in the usual manner. Also, a sample grammar and data template are provided in `conf/galera`, they are slightly modified versions of conf/engines/engine\_stress.yy and engine\_stress.zz, adapted for Galera taking into account its limitations (e.g. no `LOCK`). *Note: `GaleraMySQLd.pm` has defaults for everything mandatory but `wsrep_provider`. If you run the test with more than 1 node, you need to provide the value on the command line in the usual manner (`--mysqld=--wsrep-provider=...`), otherwise the test fail with the corresponding error message.* So, if you provide ``` --galera=mms --mysqld=--wsrep-provider=<path to Galera library> ``` 3 nodes will be started, and Galera replication will be set up between them; the data will be generated on the first node; the test flow will be executed on the first and second nodes; at the end of the test, data dump from each node will be taken and compared; node vardirs will be placed under `<vardir>/node0`, `<vardir>/node1`, `<vardir>/node2`. CheckFieldValue Validator ------------------------- A grammar can set requirements on results of a query through a specifically formatted comment. If the validator finds a comment which matches the template, it performs the requested check. The validation is defined in the comment itself: it says which field in which row in the result set should be checked, and provides the condition (currently simple numeric comparisons: `=`, `<`, `>`, `<=`, `>=`). It allows to do simple verification without implementing a special validator. Example: A query in the grammar file ``` SELECT COUNT(*), MAX(`pk`) FROM _table /* Validate 2 > 10 for row all*/; ``` The comment means "Check that the value in field 2 is greater than 10 for all rows" (for this query "all rows" is overkill, it could just as well be "row 1"). Assuming that there is a table with not more than 10 rows, the validator will produce the error: ``` ERROR: For query 'SELECT COUNT(*), MAX(`pk`) FROM `BB` /* Validate 2 > 10 for row 1*/' on row 1 result 10 does not meet the condition > 10 Full row: [1] : 1; [2] : 10; ``` The exit code for this failure is `STATUS_REQUIREMENT_UNMET`. *Usage example: investigation of the sporadic failure [MDEV-4578](https://jira.mariadb.org/browse/MDEV-4578)* MariadbGtidCrashSafety Reporter ------------------------------- The reporter was created to test slave crash-safety with [MariaDB implementation of GTID](../global-transaction-id/index). It is similar to [SlaveCrashRecovery reporter](#slavecrashrecovery-reporter), but is adjusted to check GTID-specific aspects: * it restarts the slave with --skip-slave-start, and executes ``` CHANGE MASTER .. MASTER_USE_GTID=current_pos; STOP SLAVE; ``` So, regardless how the replication was set up initially, after the first crash/restart it will start using GTID for sure; * while the slave is running, and also before a crash and after restart the reporter checks `gtid*` variables and the contents of the system table `mysql.gtid_slave_pos` and verifies basic consistency of the data, e.g. watches that GTID seq\_no constantly grows. SlaveCrashRecovery Reporter --------------------------- The reporter can be used to test crash-safety of replication. It is a periodic reporter, every 30 seconds it kills the slave server using `SIGKILL`, and immediately restarts it on the old data directory, with the same parameters as before. On server restart, the reporter checks that the server and the replication started all right. The reporter itself does not check consistency of the data, but it can be used together with `ReplicationConsistency` reporter. It is supposed to be used with `runall-new.pl`, so that the server is started without MTR involvement. *Usage example: testing of [GTID in MariaDB 10.0](../global-transaction-id/index)* BinlogConsistency Reporter -------------------------- The reporter checks that the contents of the binary log correctly reflects the contents of the server. After the main test flow is finished, the reporter creates a data dump of the server, stores its binary logs, shuts down the server, starts a new one with the same parameters, but on a clean data directory, replays the binary logs into it, creates a dump of the new server, and compares two dumps. It is to be used with `runall-new.pl`. *Usage example: testing of binlog changes in [MariaDB 10.0](../what-is-mariadb-100/index) (e.g. [MDEV-181](https://jira.mariadb.org/browse/MDEV-181), [MDEV-232](https://jira.mariadb.org/browse/MDEV-232))* CrashRecovery Reporter ---------------------- The idea is very much the same as in the old Recovery reporter: crash the server at the end of the test, restart it and make sure it started all right, and the data is not corrupted. The main difference is that the old reporter restarts the server in a hardcoded pre-defined manner, which limits its use. Instead, CrashRecovery reporter starts the server with the same set of options as the initial one, which imitates a more realistic scenario, and also allows to use it on non-default InnoDB configurations. It is to be used with `runall-new.pl` LimitRowsExamined Transformer ----------------------------- The transformer was developed for testing new [LIMIT ROWS EXAMINED](../limit-rows-examined/index) functionality added in [MariaDB 5.5](../what-is-mariadb-55/index). It can be used in the usual way, by providing its name in the `--transformers` list. The transformer checks whether the original query already contains a `ROWS EXAMINED` clause. If it does not, it adds the clause either after the `LIMIT` clause, or at the end of the query. In any case (even if `ROWS EXAMINED` was already there), the transformer returns the following sequence of statements: * `FLUSH STATUS` * <the query with `ROWS EXAMINED`> * <a query which sums up status variables related to examined rows> The result of the main query is checked to be a subset of the original query's result set. The sum of status variables is checked to be not greater than the limit provided in the `ROWS EXAMINED` clause, plus a margin. The margin is configured in the transformer. If the result of the transformed query appears not to be a subset of the original result set, `STATUS_LENGTH_MISMATCH` is returned. If the sum of status variables is greater than the maximum allowed value, `STATUS_REQUIREMENT_UNMET` is returned. Note: Status values `STATUS_REQUIREMENT_UNMET` and `STATUS_REQUIREMENT_UNMET_SELECT` were added to `Constants.pm`. ShowExplain Validator --------------------- The validator was developed for testing the new functionality [SHOW EXPLAIN](../show-explain/index) introduced in [MariaDB 10.0](../what-is-mariadb-100/index). The validator checks that the output of `SHOW EXPLAIN` correlates with the output of traditional `EXPLAIN` executed for the same query. It also tries to filter out known expected mismatches between the produced plans. Comparison of VIEW Algorithms ----------------------------- RQG already provided `--views[=<view type>]` option, which means that in addition to the normal data generation, views of the requested types will be added and used in the test flow. However, you could only create views of the same type on servers that you were comparing. Now there are `--views1` and `--views2` options, which work the same way as `--basedir1`/`--basedir2`, `--mysqld1`/`--mysqld2`, etc. The backward compatibility is preserved, so you can still use `--views` which will be applied to both servers unless there is `--views1` or `--views2` to override it. The change was made in `gentest.pl` and both `runall.pl` and `runall-new.pl`. *Usage example: testing of MERGE view extension in [MariaDB 10.0](../what-is-mariadb-100/index) ([MDEV-3862](https://jira.mariadb.org/browse/MDEV-3862))* Multiple Redefining Grammars ---------------------------- RQG allows to provide `--redefine=<grammar file>` option to override or add rules to the main grammar. Sometimes you have a redefining grammar for a feature, and another redefining grammar for an engine, and yet another redefining grammar for a specific version, and combining them makes the number of grammars to grow uncontrollably. The simple change has been made to allow providing several redefining grammars at once, e.g.: ``` runall.pl ... --redefine=memory_engine_redefine.yy --redefine=binlog_format_stmt_redefine.yy --redefine=legacy_version_redefine.yy ``` *Warning: It is better not to allow them to override each other, since the result can be unexpected (that is, they should define different sets of rules)* The change was made in `gentest.pl` and both `runall.pl` and `runall-new.pl`. New Grammar Keywords \_basetable and \_view ------------------------------------------- The RQG keyword \_table means any table or view from the test dataset. Often it's good enough, but sometimes it badly increases the number of erroneous statements. Now tables and views can be differentiated in a grammar depending on what the goal is: \_table can still be used for both tables and views, while \_basetable will only pick tables, and \_view will only pick views. Example: If you create the following rule in your grammar ``` alter: ALTER TABLE _table ENGINE=MyISAM; ``` and you are running the test with views, you will be getting lots of `ER_WRONG_OBJECT` errors ("is not BASE TABLE"). It is hardly the goal, so you can improve the grammar by changing it to ``` alter: ALTER TABLE _basetable ENGINE=MyISAM; ``` This way the rule will only pick "real" tables. Of course, if you still want to pick views sometimes, as a sanity check that there is no crash or anything, you can make the rule a bit more complicated, but much better tuned than it was, e.g. ``` alter: ALTER TABLE alter_object ENGINE=MyISAM; alter_object: _basetable | _basetable | _basetable | _basetable | _basetable | _view ; ``` See Also -------- * [RQG Documentation](http://github.com/RQG/RQG-Documentation/wiki/Category:RandomQueryGenerator) * [RQG Performance Comparisons](../rqg-performance-comparisons/index) * [Optimizer Quality](../optimizer-quality/index) * [QA Tools](../qa-tools/index) * [Worklog Quality Checklist Template](../worklog-quality-checklist-template/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb User Account Management User Account Management ======================== Administering user accounts in MariaDB | Title | Description | | --- | --- | | [Account Management SQL Commands](../account-management-sql-commands/index) | CREATE/DROP USER, GRANT, REVOKE, SET PASSWORD etc. | | [Data-in-Transit Encryption](../data-in-transit-encryption/index) | Data can be encrypted in transit using the Transport Layer Security (TLS) protocol. | | [Roles](../roles/index) | Roles bundle privileges together to ease account management. | | [Account Locking](../account-locking/index) | Account locking permits privileged administrators to lock/unlock user accounts. | | [Authentication from MariaDB 10.4](../authentication-from-mariadb-104/index) | Authentication changes in MariaDB 10.4. | | [User Password Expiry](../user-password-expiry/index) | Password expiry permits administrators to expire user passwords. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb VAR_SAMP VAR\_SAMP ========= Syntax ------ ``` VAR_SAMP(expr) ``` Description ----------- Returns the sample variance of *`expr`*. That is, the denominator is the number of rows minus one. It is an [aggregate function](../aggregate-functions/index), and so can be used with the [GROUP BY](../group-by/index) clause. From [MariaDB 10.2.2](https://mariadb.com/kb/en/mariadb-1022-release-notes/), VAR\_SAMP() can be used as a [window function](../window-functions/index). VAR\_SAMP() returns `NULL` if there were no matching rows. Examples -------- As an [aggregate function](../aggregate-functions/index): ``` CREATE OR REPLACE TABLE stats (category VARCHAR(2), x INT); INSERT INTO stats VALUES ('a',1),('a',2),('a',3), ('b',11),('b',12),('b',20),('b',30),('b',60); SELECT category, STDDEV_POP(x), STDDEV_SAMP(x), VAR_POP(x) FROM stats GROUP BY category; +----------+---------------+----------------+------------+ | category | STDDEV_POP(x) | STDDEV_SAMP(x) | VAR_POP(x) | +----------+---------------+----------------+------------+ | a | 0.8165 | 1.0000 | 0.6667 | | b | 18.0400 | 20.1693 | 325.4400 | +----------+---------------+----------------+------------+ ``` As a [window function](../window-functions/index): ``` CREATE OR REPLACE TABLE student_test (name CHAR(10), test CHAR(10), score TINYINT); INSERT INTO student_test VALUES ('Chun', 'SQL', 75), ('Chun', 'Tuning', 73), ('Esben', 'SQL', 43), ('Esben', 'Tuning', 31), ('Kaolin', 'SQL', 56), ('Kaolin', 'Tuning', 88), ('Tatiana', 'SQL', 87); SELECT name, test, score, VAR_SAMP(score) OVER (PARTITION BY test) AS variance_results FROM student_test; +---------+--------+-------+------------------+ | name | test | score | variance_results | +---------+--------+-------+------------------+ | Chun | SQL | 75 | 382.9167 | | Chun | Tuning | 73 | 873.0000 | | Esben | SQL | 43 | 382.9167 | | Esben | Tuning | 31 | 873.0000 | | Kaolin | SQL | 56 | 382.9167 | | Kaolin | Tuning | 88 | 873.0000 | | Tatiana | SQL | 87 | 382.9167 | +---------+--------+-------+------------------+ ``` See Also -------- * [VAR\_POP](../var_pop/index) (variance) * [STDDEV\_POP](../stddev_pop/index) (population standard deviation) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb OCTET_LENGTH OCTET\_LENGTH ============= Syntax ------ ``` OCTET_LENGTH(str) ``` Description ----------- `OCTET_LENGTH()` returns the length of the given string, in octets (bytes). This is a synonym for [LENGTHB()](../lengthb/index), and, when [Oracle mode from MariaDB 10.3](../sql_modeoracle/index#functions) is not set, a synonym for [LENGTH()](../length/index). A multi-byte character counts as multiple bytes. This means that for a string containing five two-byte characters, `OCTET_LENGTH()` returns 10, whereas [CHAR\_LENGTH()](../char_length/index) returns 5. If `str` is not a string value, it is converted into a string. If `str` is `NULL`, the function returns `NULL`. Examples -------- When [Oracle mode](../sql_modeoracle/index) from [MariaDB 10.3](../what-is-mariadb-103/index) is not set: ``` SELECT CHAR_LENGTH('π'), LENGTH('π'), LENGTHB('π'), OCTET_LENGTH('π'); +-------------------+--------------+---------------+--------------------+ | CHAR_LENGTH('π') | LENGTH('π') | LENGTHB('π') | OCTET_LENGTH('π') | +-------------------+--------------+---------------+--------------------+ | 1 | 2 | 2 | 2 | +-------------------+--------------+---------------+--------------------+ ``` In [Oracle mode from MariaDB 10.3](../sql_modeoracle/index#functions): ``` SELECT CHAR_LENGTH('π'), LENGTH('π'), LENGTHB('π'), OCTET_LENGTH('π'); +-------------------+--------------+---------------+--------------------+ | CHAR_LENGTH('π') | LENGTH('π') | LENGTHB('π') | OCTET_LENGTH('π') | +-------------------+--------------+---------------+--------------------+ | 1 | 1 | 2 | 2 | +-------------------+--------------+---------------+--------------------+ ``` See Also -------- * [CHAR\_LENGTH()](../char_length/index) * [LENGTH()](../length/index) * [LENGTHB()](../lengthb/index) * [Oracle mode from MariaDB 10.3](../sql_modeoracle-from-mariadb-103/index#simple-syntax-compatibility) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Stuff in MySQL 5.6 Stuff in MySQL 5.6 ================== This is SergeyP's list of patches in MySQL 5.6 that he has found interesting. It is not a full list of interesting features or anything like that [WL#6071](http://askmonty.org/worklog/?tid=6071): Inline tmp tables into the nested loops algorithm. (Evgen, 2012-05-31) [WL#4443](http://askmonty.org/worklog/?tid=4443) - Prune partition locks (public WL) (April 2012) [WL#4897](http://askmonty.org/worklog/?tid=4897): Add EXPLAIN INSERT/UPDATE/DELETE (2011) * EXPLAIN EXTENDED UPDATE doesn't print warnings... [WL#5906](http://askmonty.org/worklog/?tid=5906) read before write removal (RBWR) (2012-04) * used by NDB only. (Bug#37153 NDB Cluster reports affected rows incorrectly, etc) * but the SQL layer still does reads before doing writes. This code is not suitable for update-without-reads. * The main idea is that we do [deleted|updated]= table->file->end\_read\_removal(); at the end. This only counts #of affected rows. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb LENGTHB LENGTHB ======= **MariaDB starting with [10.3.1](https://mariadb.com/kb/en/mariadb-1031-release-notes/)**Introduced in [MariaDB 10.3.1](https://mariadb.com/kb/en/mariadb-1031-release-notes/) as part of the [Oracle compatibility enhancements](../sql_modeoracle/index). Syntax ------ ``` LENGTHB(str) ``` Description ----------- `LENGTHB()` returns the length of the given string, in bytes. When [Oracle mode](../sql_modeoracle/index) is not set, this is a synonym for [LENGTH](../length/index). A multi-byte character counts as multiple bytes. This means that for a string containing five two-byte characters, `LENGTHB()` returns 10, whereas [CHAR\_LENGTH()](../char_length/index) returns 5. If `str` is not a string value, it is converted into a string. If `str` is `NULL`, the function returns `NULL`. Examples -------- When [Oracle mode](../sql_modeoracle/index) from [MariaDB 10.3](../what-is-mariadb-103/index) is not set: ``` SELECT CHAR_LENGTH('π'), LENGTH('π'), LENGTHB('π'), OCTET_LENGTH('π'); +-------------------+--------------+---------------+--------------------+ | CHAR_LENGTH('π') | LENGTH('π') | LENGTHB('π') | OCTET_LENGTH('π') | +-------------------+--------------+---------------+--------------------+ | 1 | 2 | 2 | 2 | +-------------------+--------------+---------------+--------------------+ ``` In [Oracle mode from MariaDB 10.3](../sql_modeoracle/index#functions): ``` SELECT CHAR_LENGTH('π'), LENGTH('π'), LENGTHB('π'), OCTET_LENGTH('π'); +-------------------+--------------+---------------+--------------------+ | CHAR_LENGTH('π') | LENGTH('π') | LENGTHB('π') | OCTET_LENGTH('π') | +-------------------+--------------+---------------+--------------------+ | 1 | 1 | 2 | 2 | +-------------------+--------------+---------------+--------------------+ ``` See Also -------- * [CHAR\_LENGTH()](../char_length/index) * [LENGTH()](../length/index) * [OCTET\_LENGTH()](../octet_length/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb JIRA - Project Planning and Tracking JIRA - Project Planning and Tracking ==================================== JIRA is the tool that is used for [bug reporting](../mariadb-community-bug-reporting/index), project planning and tracking in MariaDB development. It replaced the previous tool called [WorkLog](../worklog/index). JIRA is also where you can find the [MariaDB roadmap](https://jira.mariadb.org). The MariaDB JIRA is located at <https://jira.mariadb.org> Everyone is welcome to sign up for a free account and submit issues, post new tasks or ideas, or to comment on existing issues. The sign up can be found next to the log in boxes on the front page or directly through [this link](https://jira.mariadb.org/secure/Signup!default.jspa). After filling out the sign up form you can log in. ### Links to JIRA Tasks You can easily create links to JIRA tasks in the Knowledge Base using their "mdev" number. For example, the text '`mdev-191`', when entered into the Knowledge Base becomes: [MDEV-191](https://jira.mariadb.org/browse/MDEV-191). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb SELECT INTO OUTFILE SELECT INTO OUTFILE =================== Syntax ------ ``` SELECT ... INTO OUTFILE 'file_name' [CHARACTER SET charset_name] [export_options] export_options: [{FIELDS | COLUMNS} [TERMINATED BY 'string'] [[OPTIONALLY] ENCLOSED BY 'char'] [ESCAPED BY 'char'] ] [LINES [STARTING BY 'string'] [TERMINATED BY 'string'] ] ``` Description ----------- `SELECT INTO OUTFILE` writes the resulting rows to a file, and allows the use of column and row terminators to specify a particular output format. The default is to terminate fields with tabs (`\t`) and lines with newlines (`\n`). The file must not exist. It cannot be overwritten. A user needs the [FILE](../grant/index#global-privileges) privilege to run this statement. Also, MariaDB needs permission to write files in the specified location. If the [secure\_file\_priv](../server-system-variables/index#secure_file_priv) system variable is set to a non-empty directory name, the file can only be written to that directory. The `[LOAD DATA INFILE](../load-data-infile/index)` statement complements `SELECT INTO OUTFILE`. ### Character-sets The `CHARACTER SET` clause specifies the [character set](../data-types-character-sets-and-collations/index) in which the results are to be written. Without the clause, no conversion takes place (the binary character set). In this case, if there are multiple character sets, the output will contain these too, and may not easily be able to be reloaded. In cases where you have two servers using different character-sets, using `SELECT INTO OUTFILE` to transfer data from one to the other can have unexpected results. To ensure that MariaDB correctly interprets the escape sequences, use the `CHARACTER SET` clause on both the `SELECT INTO OUTFILE` statement and the subsequent `[LOAD DATA INFILE](../load-data-infile/index)` statement. Example ------- The following example produces a file in the CSV format: ``` SELECT customer_id, firstname, surname INTO OUTFILE '/exportdata/customers.txt' FIELDS TERMINATED BY ',' OPTIONALLY ENCLOSED BY '"' LINES TERMINATED BY '\n' FROM customers; ``` See Also -------- * [SELECT](../select/index) * [LOAD\_DATA()](../load_file/index) function * [LOAD DATA INFILE](../load-data-infile/index) * [SELECT INTO Variable](../select-into-variable/index) * [SELECT INTO DUMPFILE](../select-into-dumpfile/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb CALL CALL ==== Syntax ------ ``` CALL sp_name([parameter[,...]]) CALL sp_name[()] ``` Description ----------- The `CALL` statement invokes a [stored procedure](../stored-procedures/index) that was defined previously with [CREATE PROCEDURE](../create-procedure/index). Stored procedure names can be specified as `database_name.procedure_name`. Procedure names and database names can be quoted with backticks (). This is necessary if they are reserved words, or contain special characters. See [identifier qualifiers](../identifier-qualifiers/index) for details. `CALL p()` and `CALL p` are equivalent. If parentheses are used, any number of spaces, tab characters and newline characters are allowed between the procedure's name and the open parenthesis. `CALL` can pass back values to its caller using parameters that are declared as `OUT` or `INOUT` parameters. If no value is assigned to an `OUT` parameter, `NULL` is assigned (and its former value is lost). To pass such values from another stored program you can use [user-defined variables](../user-defined-variables/index), [local variables](../declare-variable/index) or routine's parameters; in other contexts, you can only use user-defined variables. `CALL` can also be executed as a prepared statement. Placeholders can be used for `IN` parameters in all versions of MariaDB; for `OUT` and `INOUT` parameters, placeholders can be used since [MariaDB 5.5](../what-is-mariadb-55/index). When the procedure returns, a client program can also obtain the number of rows affected for the final statement executed within the routine: At the SQL level, call the `[ROW\_COUNT()](../row_count/index)` function; from the C API, call the `mysql_affected_rows()` function. If the `CLIENT_MULTI_RESULTS` API flag is set, `CALL` can return any number of resultsets and the called stored procedure can execute prepared statements. If it is not set, at most one resultset can be returned and prepared statements cannot be used within procedures. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Buildbot Setup for Virtual Machines - Ubuntu 9.04 i386 Buildbot Setup for Virtual Machines - Ubuntu 9.04 i386 ====================================================== This vm is used to build source tarball and for Ubuntu 9.04 32-bit .deb. First create and install image: ``` qemu-img create -f qcow2 vm-jaunty-i386-base.qcow2 8G kvm -m 2047 -hda vm-jaunty-i386-base.qcow2 -cdrom ubuntu-9.04-server-i386.iso -redir tcp:2222::22 -boot d -cpu qemu32,-nx # Install ``` Create a vm, based on the first one, which is configured for serial port. ``` qemu-img create -b vm-jaunty-i386-base.qcow2 -f qcow2 vm-jaunty-i386-serial.qcow2 kvm -m 2047 -hda vm-jaunty-i386-base.qcow2 -redir tcp:2222::22 -boot c -cpu qemu32,-nx ``` To configure kernel and grub for serial console, add the following to /boot/grub/menu.lst: ``` serial --unit=0 --speed=115200 --word=8 --parity=no --stop=1 terminal --timeout=3 serial console ``` also add in menu.lst to kernel line (after removing `quiet splash'): ``` console=tty0 console=ttyS0,115200n8 ``` Create /etc/event.d/ttyS0: ``` # ttyS0 - getty # # This service maintains a getty on ttyS0 from the point the system is # started until it is shut down again. start on stopped rc2 start on stopped rc3 start on stopped rc4 start on stopped rc5 stop on runlevel 0 stop on runlevel 1 stop on runlevel 6 respawn exec /sbin/getty 115200 ttyS0 ``` Add an account: ``` sudo adduser --disabled-password buildbot ``` Copy public ssh key into /.ssh/authorized\_keys Enable passwordless sudo: ``` sudo adduser buildbot sudo # uncomment `%sudo ALL=NOPASSWD: ALL' line in `visudo`, and move to end. ``` Create a new vm for building source tarballs: ``` qemu-img create -b vm-jaunty-i386-serial.qcow2 -f qcow2 vm-jaunty-i386-deb-tarbake.qcow2 ``` Install compilers: ``` sudo apt-get build-dep mysql-5.1-server sudo apt-get install devscripts hardening-wrapper bzr ``` Copy in an existing bzr shared repository to buildbot/.bzr (or run bzr init-repo and bzr branch --no-tree lp:maria). Create a new vm for building .debs: ``` qemu-img create -b vm-jaunty-i386-serial.qcow2 -f qcow2 vm-jaunty-i386-deb-build.qcow2 ``` Install compilers: ``` sudo apt-get build-dep mysql-5.1-server sudo apt-get install devscripts hardening-wrapper ``` Create a new VM for testing .deb installs: ``` qemu-img create -b vm-jaunty-i386-serial.qcow2 -f qcow2 vm-jaunty-i386-deb-install.qcow2 ``` Install tools and local apt repository. ``` sudo apt-get install debconf-utils cat >>/etc/apt/sources.list <<END deb file:///home/buildbot/buildbot/debs binary/ deb-src file:///home/buildbot/buildbot/debs source/ END ``` Setup default package config for debconf to enable unattended install. Copy in my.seed (see above) to vm. ``` sudo debconf-set-selections /tmp/my.seed ``` Create a new VM for testing upgrades: ``` qemu-img create -b vm-jaunty-i386-deb-install.qcow2 -f qcow2 vm-jaunty-i386-deb-upgrade.qcow2 ``` Prepare initial MySQL install with some test data. ``` sudo apt-get install mysql-server-5.1 mysql -uroot -prootpass -e "create database mytest; use mytest; create table t(a int primary key); insert into t values (1); select * from t" ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb DENSE_RANK DENSE\_RANK =========== **MariaDB starting with [10.2](../what-is-mariadb-102/index)**The DENSE\_RANK() function was first introduced with [window functions](../window-functions/index) in [MariaDB 10.2.0](https://mariadb.com/kb/en/mariadb-1020-release-notes/). Syntax ------ ``` DENSE_RANK() OVER ( [ PARTITION BY partition_expression ] [ ORDER BY order_list ] ) ``` Description ----------- DENSE\_RANK() is a [window function](../window-functions/index) that displays the number of a given row, starting at one and following the [ORDER BY](../order-by/index) sequence of the window function, with identical values receiving the same result. Unlike the [RANK()](../rank/index) function, there are no skipped values if the preceding results are identical. It is also similar to the [ROW\_NUMBER()](../row_number/index) function except that in that function, identical values will receive a different row number for each result. Examples -------- The distinction between DENSE\_RANK(), [RANK()](../rank/index) and [ROW\_NUMBER()](../row_number/index): ``` CREATE TABLE student(course VARCHAR(10), mark int, name varchar(10)); INSERT INTO student VALUES ('Maths', 60, 'Thulile'), ('Maths', 60, 'Pritha'), ('Maths', 70, 'Voitto'), ('Maths', 55, 'Chun'), ('Biology', 60, 'Bilal'), ('Biology', 70, 'Roger'); SELECT RANK() OVER (PARTITION BY course ORDER BY mark DESC) AS rank, DENSE_RANK() OVER (PARTITION BY course ORDER BY mark DESC) AS dense_rank, ROW_NUMBER() OVER (PARTITION BY course ORDER BY mark DESC) AS row_num, course, mark, name FROM student ORDER BY course, mark DESC; +------+------------+---------+---------+------+---------+ | rank | dense_rank | row_num | course | mark | name | +------+------------+---------+---------+------+---------+ | 1 | 1 | 1 | Biology | 70 | Roger | | 2 | 2 | 2 | Biology | 60 | Bilal | | 1 | 1 | 1 | Maths | 70 | Voitto | | 2 | 2 | 2 | Maths | 60 | Thulile | | 2 | 2 | 3 | Maths | 60 | Pritha | | 4 | 3 | 4 | Maths | 55 | Chun | +------+------------+---------+---------+------+---------+ ``` See Also -------- * [RANK()](../rank/index) * [ROW\_NUMBER()](../row_number/index) * [ORDER BY](../order-by/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb ColumnStore Operating Mode ColumnStore Operating Mode ========================== ColumnStore has the ability to support full MariaDB query syntax through an operating mode. This operating mode may be set as a default for the instance or set at the session level. To set the operating mode at the session level, the following command is used. Once the session has ended, any subsequent session will return to the default for the instance. ``` set infinidb_vtable_mode = n ``` where n is: * 0) a generic, highly compatible row-by-row processing mode. Some WHERE clause components can be processed by ColumnStore, but joins are processed entirely by mysqld using a nested-loop join mechanism. * 1) (the default) query syntax is evaluated by ColumnStore for compatibility with distributed execution and incompatible queries are rejected. Queries executed in this mode take advantage of distributed execution and typically result in higher performance. * 2) auto-switch mode: ColumnStore will attempt to process the query internally, if it cannot, it will automatically switch the query to run in row-by-row mode. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb && && == Syntax ------ ``` AND, && ``` Description ----------- Logical AND. Evaluates to 1 if all operands are non-zero and not NULL, to 0 if one or more operands are 0, otherwise NULL is returned. For this operator, [short-circuit evaluation](../operator-precedence/index#short-circuit-evaluation) can be used. Examples -------- ``` SELECT 1 && 1; +--------+ | 1 && 1 | +--------+ | 1 | +--------+ SELECT 1 && 0; +--------+ | 1 && 0 | +--------+ | 0 | +--------+ SELECT 1 && NULL; +-----------+ | 1 && NULL | +-----------+ | NULL | +-----------+ SELECT 0 && NULL; +-----------+ | 0 && NULL | +-----------+ | 0 | +-----------+ SELECT NULL && 0; +-----------+ | NULL && 0 | +-----------+ | 0 | +-----------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb LEAD LEAD ==== **MariaDB starting with [10.2.2](https://mariadb.com/kb/en/mariadb-1022-release-notes/)**The LEAD() function was first introduced with other [window functions](../window-functions/index) in [MariaDB 10.2](../what-is-mariadb-102/index). Syntax ------ ``` LEAD (expr[, offset]) OVER ( [ PARTITION BY partition_expression ] [ ORDER BY order_list ] ) ``` Description ----------- The *LEAD* function accesses data from a following row in the same result set without the need for a self-join. The specific row is determined by the *offset* (default *1*), which specifies the number of rows ahead the current row to use. An offset of *0* is the current row. Example ------- ``` CREATE TABLE t1 (pk int primary key, a int, b int, c char(10), d decimal(10, 3), e real); INSERT INTO t1 VALUES ( 1, 0, 1, 'one', 0.1, 0.001), ( 2, 0, 2, 'two', 0.2, 0.002), ( 3, 0, 3, 'three', 0.3, 0.003), ( 4, 1, 2, 'three', 0.4, 0.004), ( 5, 1, 1, 'two', 0.5, 0.005), ( 6, 1, 1, 'one', 0.6, 0.006), ( 7, 2, NULL, 'n_one', 0.5, 0.007), ( 8, 2, 1, 'n_two', NULL, 0.008), ( 9, 2, 2, NULL, 0.7, 0.009), (10, 2, 0, 'n_four', 0.8, 0.010), (11, 2, 10, NULL, 0.9, NULL); SELECT pk, LEAD(pk) OVER (ORDER BY pk) AS l, LEAD(pk,1) OVER (ORDER BY pk) AS l1, LEAD(pk,2) OVER (ORDER BY pk) AS l2, LEAD(pk,0) OVER (ORDER BY pk) AS l0, LEAD(pk,-1) OVER (ORDER BY pk) AS lm1, LEAD(pk,-2) OVER (ORDER BY pk) AS lm2 FROM t1; +----+------+------+------+------+------+------+ | pk | l | l1 | l2 | l0 | lm1 | lm2 | +----+------+------+------+------+------+------+ | 1 | 2 | 2 | 3 | 1 | NULL | NULL | | 2 | 3 | 3 | 4 | 2 | 1 | NULL | | 3 | 4 | 4 | 5 | 3 | 2 | 1 | | 4 | 5 | 5 | 6 | 4 | 3 | 2 | | 5 | 6 | 6 | 7 | 5 | 4 | 3 | | 6 | 7 | 7 | 8 | 6 | 5 | 4 | | 7 | 8 | 8 | 9 | 7 | 6 | 5 | | 8 | 9 | 9 | 10 | 8 | 7 | 6 | | 9 | 10 | 10 | 11 | 9 | 8 | 7 | | 10 | 11 | 11 | NULL | 10 | 9 | 8 | | 11 | NULL | NULL | NULL | 11 | 10 | 9 | +----+------+------+------+------+------+------+ ``` See Also -------- * [LAG](../lag/index) - Window function to access a previous row Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb GET_LOCK GET\_LOCK ========= Syntax ------ ``` GET_LOCK(str,timeout) ``` Description ----------- Tries to obtain a lock with a name given by the string `str`, using a timeout of `timeout` seconds. Returns `1` if the lock was obtained successfully, `0` if the attempt timed out (for example, because another client has previously locked the name), or `NULL` if an error occurred (such as running out of memory or the thread was killed with [mysqladmin](../mysqladmin/index) kill). A lock is released with [RELEASE\_LOCK()](../release_lock/index), when the connection terminates (either normally or abnormally). A connection can hold multiple locks at the same time, so a lock that is no longer needed needs to be explicitly released. The [IS\_FREE\_LOCK](../is_free_lock/index) function returns whether a specified lock a free or not, and the [IS\_USED\_LOCK](../is_used_lock/index) whether the function is in use or not. Locks obtained with `GET_LOCK()` do not interact with transactions. That is, committing a transaction does not release any such locks obtained during the transaction. It is also possible to recursively set the same lock. If a lock with the same name is set `n` times, it needs to be released `n` times as well. `str` is case insensitive for `GET_LOCK()` and related functions. If `str` is an empty string or `NULL`, `GET_LOCK()` returns `NULL` and does nothing. From [MariaDB 10.2.2](https://mariadb.com/kb/en/mariadb-1022-release-notes/), `timeout` supports microseconds. Before then, it was rounded to the closest integer. If the [metadata\_lock\_info](../metadata-lock-info/index) plugin is installed, locks acquired with this function are visible in the [Information Schema](../information_schema/index) [METADATA\_LOCK\_INFO](../information-schema-metadata_lock_info-table/index) table. This function can be used to implement application locks or to simulate record locks. Names are locked on a server-wide basis. If a name has been locked by one client, `GET_LOCK()` blocks any request by another client for a lock with the same name. This allows clients that agree on a given lock name to use the name to perform cooperative advisory locking. But be aware that it also allows a client that is not among the set of cooperating clients to lock a name, either inadvertently or deliberately, and thus prevent any of the cooperating clients from locking that name. One way to reduce the likelihood of this is to use lock names that are database-specific or application-specific. For example, use lock names of the form `db_name.str` or `app_name.str`. Statements using the `GET_LOCK` function are [not safe for statement-based replication](../unsafe-statements-for-statement-based-replication/index). The patch to permit multiple locks was [contributed by Konstantin "Kostja" Osipov](http://kostja-osipov.livejournal.com/46410.html) ([MDEV-3917](https://jira.mariadb.org/browse/MDEV-3917)). Examples -------- ``` SELECT GET_LOCK('lock1',10); +----------------------+ | GET_LOCK('lock1',10) | +----------------------+ | 1 | +----------------------+ SELECT IS_FREE_LOCK('lock1'), IS_USED_LOCK('lock1'); +-----------------------+-----------------------+ | IS_FREE_LOCK('lock1') | IS_USED_LOCK('lock1') | +-----------------------+-----------------------+ | 0 | 46 | +-----------------------+-----------------------+ SELECT IS_FREE_LOCK('lock2'), IS_USED_LOCK('lock2'); +-----------------------+-----------------------+ | IS_FREE_LOCK('lock2') | IS_USED_LOCK('lock2') | +-----------------------+-----------------------+ | 1 | NULL | +-----------------------+-----------------------+ ``` Multiple locks can be held: ``` SELECT GET_LOCK('lock2',10); +----------------------+ | GET_LOCK('lock2',10) | +----------------------+ | 1 | +----------------------+ SELECT IS_FREE_LOCK('lock1'), IS_FREE_LOCK('lock2'); +-----------------------+-----------------------+ | IS_FREE_LOCK('lock1') | IS_FREE_LOCK('lock2') | +-----------------------+-----------------------+ | 0 | 0 | +-----------------------+-----------------------+ SELECT RELEASE_LOCK('lock1'), RELEASE_LOCK('lock2'); +-----------------------+-----------------------+ | RELEASE_LOCK('lock1') | RELEASE_LOCK('lock2') | +-----------------------+-----------------------+ | 1 | 1 | +-----------------------+-----------------------+ ``` It is possible to hold the same lock recursively. This example is viewed using the [metadata\_lock\_info](../metadata-lock-info/index) plugin: ``` SELECT GET_LOCK('lock3',10); +----------------------+ | GET_LOCK('lock3',10) | +----------------------+ | 1 | +----------------------+ SELECT GET_LOCK('lock3',10); +----------------------+ | GET_LOCK('lock3',10) | +----------------------+ | 1 | +----------------------+ SELECT * FROM INFORMATION_SCHEMA.METADATA_LOCK_INFO; +-----------+---------------------+---------------+-----------+--------------+------------+ | THREAD_ID | LOCK_MODE | LOCK_DURATION | LOCK_TYPE | TABLE_SCHEMA | TABLE_NAME | +-----------+---------------------+---------------+-----------+--------------+------------+ | 46 | MDL_SHARED_NO_WRITE | NULL | User lock | lock3 | | +-----------+---------------------+---------------+-----------+--------------+------------+ SELECT RELEASE_LOCK('lock3'); +-----------------------+ | RELEASE_LOCK('lock3') | +-----------------------+ | 1 | +-----------------------+ SELECT * FROM INFORMATION_SCHEMA.METADATA_LOCK_INFO; +-----------+---------------------+---------------+-----------+--------------+------------+ | THREAD_ID | LOCK_MODE | LOCK_DURATION | LOCK_TYPE | TABLE_SCHEMA | TABLE_NAME | +-----------+---------------------+---------------+-----------+--------------+------------+ | 46 | MDL_SHARED_NO_WRITE | NULL | User lock | lock3 | | +-----------+---------------------+---------------+-----------+--------------+------------+ SELECT RELEASE_LOCK('lock3'); +-----------------------+ | RELEASE_LOCK('lock3') | +-----------------------+ | 1 | +-----------------------+ SELECT * FROM INFORMATION_SCHEMA.METADATA_LOCK_INFO; Empty set (0.000 sec) ``` Timeout example: Connection 1: ``` SELECT GET_LOCK('lock4',10); +----------------------+ | GET_LOCK('lock4',10) | +----------------------+ | 1 | +----------------------+ ``` Connection 2: ``` SELECT GET_LOCK('lock4',10); ``` After 10 seconds... ``` +----------------------+ | GET_LOCK('lock4',10) | +----------------------+ | 0 | +----------------------+ ``` Deadlocks are automatically detected and resolved. Connection 1: ``` SELECT GET_LOCK('lock5',10); +----------------------+ | GET_LOCK('lock5',10) | +----------------------+ | 1 | +----------------------+ ``` Connection 2: ``` SELECT GET_LOCK('lock6',10); +----------------------+ | GET_LOCK('lock6',10) | +----------------------+ | 1 | +----------------------+ ``` Connection 1: ``` SELECT GET_LOCK('lock6',10); +----------------------+ | GET_LOCK('lock6',10) | +----------------------+ | 0 | +----------------------+ ``` Connection 2: ``` SELECT GET_LOCK('lock5',10); ERROR 1213 (40001): Deadlock found when trying to get lock; try restarting transaction ``` See Also -------- * [RELEASE\_LOCK](../release_lock/index) * [IS\_FREE\_LOCK](../is_free_lock/index) * [IS\_USED\_LOCK](../is_used_lock/index) * [RELEASE\_ALL\_LOCKS](../release_all_locks/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb Information Schema PARTITIONS Table Information Schema PARTITIONS Table =================================== The [Information Schema](../information_schema/index) `PARTITIONS` contains information about table partitions, with each record corresponding to a single partition or subpartition of a partitioned table. Each non-partitioned table also has a record in the `PARTITIONS` table, but most of the values are `NULL`. It contains the following columns: | Column | Description | | --- | --- | | `TABLE_CATALOG` | Always `def`. | | `TABLE_SCHEMA` | Database name. | | `TABLE_NAME` | Table name containing the partition. | | `PARTITION_NAME` | Partition name. | | `SUBPARTITION_NAME` | Subpartition name, or `NULL` if not a subpartition. | | `PARTITION_ORDINAL_POSITION` | Order of the partition starting from 1. | | `SUBPARTITION_ORDINAL_POSITION` | Order of the subpartition starting from 1. | | `PARTITION_METHOD` | The partitioning type; one of `RANGE`, `LIST`, `HASH`, `LINEAR HASH`, `KEY` or `LINEAR KEY`. | | `SUBPARTITION_METHOD` | Subpartition type; one of `HASH`, `LINEAR HASH`, `KEY` or `LINEAR KEY`, or `NULL` if not a subpartition. | | `PARTITION_EXPRESSION` | Expression used to create the partition by the `[CREATE TABLE](../create-table/index)` or `[ALTER TABLE](../alter-table/index)` statement. | | `SUBPARTITION_EXPRESSION` | Expression used to create the subpartition by the `[CREATE TABLE](../create-table/index)` or `[ALTER TABLE](../alter-table/index)` statement, or `NULL` if not a subpartition. | | `PARTITION_DESCRIPTION` | For a `RANGE` partition, contains either `MAXINTEGER` or an integer, as set in the `VALUES LESS THAN` clause. For a `LIST` partition, contains a comma-separated list of integers, as set in the `VALUES IN`. `NULL` if another type of partition. | | `TABLE_ROWS` | Number of rows in the table (may be an estimate for some storage engines). | | `AVG_ROW_LENGTH` | Average row length, that is `DATA_LENGTH` divided by `TABLE_ROWS` | | `DATA_LENGTH` | Total number of bytes stored in all rows of the partition. | | `MAX_DATA_LENGTH` | Maximum bytes that could be stored in the partition. | | `INDEX_LENGTH` | Size in bytes of the partition index file. | | `DATA_FREE` | Unused bytes allocated to the partition. | | `CREATE_TIME` | Time the partition was created | | `UPDATE_TIME` | Time the partition was last modified. | | `CHECK_TIME` | Time the partition was last checked, or `NULL` for storage engines that don't record this information. | | `CHECKSUM` | Checksum value, or `NULL` if none. | | `PARTITION_COMMENT` | Partition comment, truncated to 80 characters, or an empty string if no comment. | | `NODEGROUP` | Node group, only used for MySQL Cluster, defaults to `0`. | | `TABLESPACE_NAME` | Always `default`. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Compiling MariaDB with TCMalloc Compiling MariaDB with TCMalloc =============================== [TCMalloc](http://goog-perftools.sourceforge.net/doc/tcmalloc.html) is a malloc replacement library optimized for multi-threaded usage. It also features a built-in heap debugger and profiler. To build [MariaDB 5.5](../what-is-mariadb-55/index) with `TCMalloc`, you need to use the following command ``` cmake -DCMAKE_EXE_LINKER_FLAGS='-ltcmalloc' -DWITH_SAFEMALLOC=OFF ``` Many other malloc replacement libraries (as well as heap debuggers and profilers) can be used with MariaDB in a similar fashion. You can also start a standard MariaDB server with `TCmalloc` with: ``` /usr/sbin/mysqld_safe --malloc-lib=tcmalloc ``` ### See Also * [Debugging a running server on Linux](../debugging-a-running-server-on-linux/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Installing MariaDB Alongside MySQL Installing MariaDB Alongside MySQL ================================== MariaDB was designed as a drop-in replacement of MySQL, with more features, new storage engines, fewer bugs, and better performance, but you can also install it alongside MySQL. (This can be useful, for example, if you want to migrate databases/applications one by one.) Here are the steps to install MariaDB near an existing MySQL installation. * Download the compiled binary tar.gz that contains the latest version ([mariadb-5.5.24-linux-x86\_64.tar.gz](http://downloads.mariadb.org/mariadb/5.5.24/#bits=64&file_type=tar_gz) - as of writing this article) and extract the files in a directory of your choice. I will assume for this article that the directory was **/opt**. ``` [root@mariadb-near-mysql ~]# cat /etc/issue CentOS release 6.2 (Final) [root@mariadb-near-mysql ~]# rpm -qa mysql* mysql-5.1.61-1.el6_2.1.x86_64 mysql-libs-5.1.61-1.el6_2.1.x86_64 mysql-server-5.1.61-1.el6_2.1.x86_64 [root@mariadb-near-mysql ~]# ps axf | grep mysqld 2072 pts/0 S+ 0:00 \_ grep mysqld 1867 ? S 0:01 /bin/sh /usr/bin/mysqld_safe --datadir=/var/lib/mysql --socket=/var/lib/mysql/mysql.sock ... 1974 ? Sl 0:06 \_ /usr/libexec/mysqld --basedir=/usr --datadir=/var/lib/mysql --user=mysql ... ``` * Create data directory and symlinks as below: ``` [root@mariadb-near-mysql opt]# mkdir mariadb-data [root@mariadb-near-mysql opt]# ln -s mariadb-5.5.24-linux-x86_64 mariadb [root@mariadb-near-mysql opt]# ls -al total 20 drwxr-xr-x. 5 root root 4096 2012-06-06 07:27 . dr-xr-xr-x. 23 root root 4096 2012-06-06 06:38 .. lrwxrwxrwx. 1 root root 27 2012-06-06 07:27 mariadb -> mariadb-5.5.24-linux-x86_64 drwxr-xr-x. 13 root root 4096 2012-06-06 07:07 mariadb-5.5.24-linux-x86_64 drwxr-xr-x. 2 root root 4096 2012-06-06 07:26 mariadb-data ``` * Create group **mariadb** and user **mariadb** and set correct ownerships: ``` [root@mariadb-near-mysql opt]# groupadd --system mariadb [root@mariadb-near-mysql opt]# useradd -c "MariaDB Server" -d /opt/mariadb -g mariadb --system mariadb [root@mariadb-near-mysql opt]# chown -R mariadb:mariadb mariadb-5.5.24-linux-x86_64/ [root@mariadb-near-mysql opt]# chown -R mariadb:mariadb mariadb-data/ ``` * Create a new **my.cnf** in **/opt/mariadb** from support files: ``` [root@mariadb-near-mysql opt]# cp mariadb/support-files/my-medium.cnf mariadb-data/my.cnf [root@mariadb-near-mysql opt]# chown mariadb:mariadb mariadb-data/my.cnf ``` * Edit the file **/opt/mariadb-data/my.cnf** and add custom paths, socket, port, user and the most important of all: data directory and base directory. Finally the file should have at least the following: ``` [client] port = 3307 socket = /opt/mariadb-data/mariadb.sock [mysqld] datadir = /opt/mariadb-data basedir = /opt/mariadb port = 3307 socket = /opt/mariadb-data/mariadb.sock user = mariadb ``` * Copy the init.d script from support files in the right location: ``` [root@mariadb-near-mysql opt]# cp mariadb/support-files/mysql.server /etc/init.d/mariadb [root@mariadb-near-mysql opt]# chmod +x /etc/init.d/mariadb ``` * Edit **/etc/init.d/mariadb** replacing **mysql** with **mariadb** as below: ``` - # Provides: mysql + # Provides: mariadb - basedir= + basedir=/opt/mariadb - datadir= + datadir=/opt/mariadb-data - lock_file_path="$lockdir/mysql" + lock_file_path="$lockdir/mariadb" ``` The trickiest part will be the last changes to this file. You need to tell mariadb to use only one cnf file. In the **start** section after **$bindir/mysqld\_safe** add **--defaults-file=/opt/mariadb-data/my.cnf**. Finally the lines should look like: ``` # Give extra arguments to mysqld with the my.cnf file. This script # may be overwritten at next upgrade. $bindir/mysqld_safe --defaults-file=/opt/mariadb-data/my.cnf --datadir="$datadir" --pid-file="$mysqld_pid_file_path" $other_args >/dev/null 2>&1 & ``` The same change needs to be made to the mysqladmin command below in the wait\_for\_ready() function so that the mariadb start command can properly listen for the server start. In the **wait\_for\_ready()** function, after **$bindir/mysqladmin** add **--defaults-file=/opt/mariadb-data/my.cnf**. The lines should look like: ``` wait_for_ready () { [...] if $bindir/mysqladmin --defaults-file=/opt/mariadb-data/my.cnf ping >/dev/null 2>&1; then ``` * Run **mysql\_install\_db** by explicitly giving it the my.cnf file as argument: ``` [root@mariadb-near-mysql opt]# cd mariadb [root@mariadb-near-mysql mariadb]# scripts/mysql_install_db --defaults-file=/opt/mariadb-data/my.cnf ``` * Now you can start MariaDB by ``` [root@mariadb-near-mysql opt]# /etc/init.d/mariadb start Starting MySQL... [ OK ] ``` * Make MariaDB start at system start: ``` [root@mariadb-near-mysql opt]# cd /etc/init.d [root@mariadb-near-mysql init.d]# chkconfig --add mariadb [root@mariadb-near-mysql init.d]# chkconfig --levels 3 mariadb on ``` * Finally test that you have both instances running: ``` [root@mariadb-near-mysql ~]# mysql -e "SELECT VERSION();" +-----------+ | VERSION() | +-----------+ | 5.1.61 | +-----------+ [root@mariadb-near-mysql ~]# mysql -e "SELECT VERSION();" --socket=/opt/mariadb-data/mariadb.sock +----------------+ | VERSION() | +----------------+ | 5.5.24-MariaDB | +----------------+ ``` What about MariaDB Upgrades ? ----------------------------- By having the **mariadb.socket**, **my.cnf** file and **databases** in **/opt/mariadb-data** if you want to upgrade the MariaDB version you will will only need to: * extract the new version from the archive in **/opt** near the current version * stop MariaDB * change the symlink **mariadb** to point to the new directory * start MariaDB * run upgrade script... but remember you will need to provide the socket option **--socket=/opt/mariadb-data/mariadb.sock** Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Creating a Custom Docker Image Creating a Custom Docker Image ============================== OCI containers, frequently called Docker containers, are created from OCI images. An image contains software that can be launched, including the underlying system. A container is an instance of that software. When we want to automate MariaDB, creating an image with MariaDB and the desired configuration, we may want to create an image by ourselves, which fulfils our needs. Images Architecture ------------------- One "source code" of an image is a Dockerfile. A Dockerfile is written in Docker specific language, and can be compiled into an image by the `docker` binary, using the `docker build` command. It can also be compiled by `[buildah](https://buildah.io/)` using `buildah bud`. Most images are based on another image. The base image is specified at the beginning of the Dockerfile, with the `FROM` directive. If the base image is not present in the local system, it is downloaded from the repository specified, or if not specified, from the default repository of the build program. This is often Docker Hub. For example, we can build a `mariadb-rocksdb:10.5` image starting from the `debian:13` image. In this way, we'll have all the software included in a standard Debian image, and we'll add MariaDB and its configuration upon that image. All the following Dockerfile directives are compiled into a new Docker image, identified by an SHA256 string. Each of these images is based on the image compiled from the previous directive. A physical compiled image can serve as a base for any number of images. This mechanism saves a lot of disk space, download time and build time. The following diagram shows the relationship between Dockerfiles, images and containers: Dockerfile Syntax ----------------- Here's a simple Dockerfile example: ``` FROM ubuntu:20.04 RUN apt-get update RUN apt-get install -y mariadb-server EXPOSE 3306 LABEL version="1.0" LABEL description="MariaDB Server" HEALTHCHECK --start-period=5m \ CMD mariadb -e 'SELECT @@datadir;' || exit 1 CMD ["mysqld"] ``` This example is not very good for practical purposes, but it shows what a Dockerfile looks like. First, we declare that the base image to use is `ubuntu:20.04`. Then we run some commands to install MariaDB from the Ubuntu default repositories and stop the MariaDB service. We define some metadata about the image with `LABEL`. Any label is valid. We declare that the port 3306 (MariaDB default port) should be exposed. However, this has no effect if the port is not exposed at container creation. We also define a healthcheck. This is a command that is run to check if the container is healthy. If the return code is 0 the healthcheck succeeds, if it's 1 it fails. In the MariaDB specific case, we want to check that it's running and able to answer a simple query. This is better than just checking that MariaDB process is running, because MariaDB could be running but unable to respond, for example because [max\_connections](../server-system-variables/index#max_connections) was reached or data si corrupted. We read a system variable, because we should not assume that any user-created table exists. We also specify `--start-period` to allow some time for MariaDB to start, keeping in mind that restarting it may take some time if some data is corrupted. Note that there can be only one healthcheck: if the command is specified multiple times, only the last occurrence will take effect. Finally, we start the container command: [mysqld](../mysqld-options/index). This command is run when a container based on this image starts. When the process stops or crashes, the container will immediately stop. Note that, in a container, we normally run mysqld directly, rather than running [mysqld\_safe](../mysqld_safe/index) or running MariaDB as a service. Containers restart can be handled by the container service. See [automatic restart](../installing-and-using-mariadb-via-docker/index#automatic-restart). See the documentation links below to learn the syntax allowed in a Dockerfile. ### Using Variables It is possible to use variables in a Dockerfile. This allows us, for example, to install different packages, install different versions of a package, or configure software differently depending on how variables are set, without modifying the Dockerfile itself. To use a variable, we can do something like this: ``` FROM ubuntu:20.04 ARG MARIADB_CONFIG_FILE ... RUN mysqld --defaults-file=$MARIADB_CONFIG_FILE ``` Here `ARG` is used after the `FROM` directive, thus the variable cannot be used in `FROM`. It is also possible to declare a variable before `FROM`, so we can use a variable to select the base image to use or its tag, but in this case the variable cannot be used after the `FROM` directive. Here is an example: ``` ARG UBUNTU_VERSION FROM ubuntu:$UBUNTU_VERSION # But this will cause a build error: RUN echo 'Ubuntu version: $UBUNTU_VERSION' > /var/build_log ``` We'll have to assign variables a value when we build the Dockerfile, in this way: ``` docker build --build-arg UBUNTU_VERSION=20.04 . ``` Note that Dockerfile variables are just placeholders for values. Dockerfiles do not support assignment, conditionals or loops. Versioning and Deploying Images ------------------------------- Dockerfiles are normally versioned, as well as the files that are copied to the images. Once an image is built, it can be pushed to a containter registry. Whenever an image is needed on a host to start containers from it, it is pulled from the registry. ### Container registries A default container registry for OCI images is Docker Hub. It contains images created by both the Docker Library team and the community. Any individual or organization can open an account and push images to Docker Hub. Most Docker images are open source: the Dockerfiles and the needed files to build the images are usually on GitHub. It is also possible to setup a self-hosted registry. Images can be pushed to that registry and pulled from it, instead of using Docker Hub. If the registry is not publicly accessible, it can be used to store images used by the organization without making them publicly available. But a self-hosted registry can also be useful for open source images: if an image is available on Docker Hub and also on a self-hosted registry, in case Docker Hub is down or not reachable, it will still be possible to pull images. ### Choosing Image Names and Tags The names of images developed by the community follow this schema: ``` repository/maintainer/technology ``` It doesn't matter if the maintainer is an individual or an organization. For images available on Docker Hub, the maintainer is the name of a Docker Hub account. Official images maintained by the Docker Library maintainers don't contain the name of the maintainer. For example, the official MariaDB image is called `mariadb` which is an alias for `docker.io/library/mariadb`. All images have a tag, which identifies the version or the variant of an image. For example, all MariaDB versions available on Docker are used as image tags. [MariaDB 10.5](../what-is-mariadb-105/index) is called `mariadb:10.5`. By conversion, tags form a hierarchy. So for example, there is a `10.1.1` tag whose meaning will not change over time. `10.5` will always identify the latest version in the 10.5 branch. For some time it was `10.5.1`, then it became `10.5.2`, and so on. When we pull an image without specifying a tag (ie, `docker pull mariadb`), we are implicitly requiring the image with the `latest` tag. This is even more mutable: at different periods of time, it pointed to the latest `10.0` version, to the latest `10.1` version, and so on. In production, it is always better to know for sure which version we are installing. Therefore it is better to specify a tag whose meaning won't change over time, like `10.5.1`. ### Pushing and Pulling Images To pull an image from Docker Hub or a self-hosted registry, we use the `docker pull` command. For example: ``` docker pull mariadb:10.5 ``` This command downloads the specified image if it is not already present in the system, or if the local version is not up to date. After modifying a Dockerfile, we can build an image in this way: ``` docker build . ``` This step can be automated by services like Docker Hub and GitHub. Check those service's documentation to find out how this feature works. Once an image is created, it can be pushed to a registry. We can do it in this way: ``` docker push <image_name>:<tag> ``` ### Docker Content Trust Docker has a feature called Docker Content Trust (DCT). It is a system used to digitally sign images, based on PEM keys. For environments where security is a major concern, it is important to sign images before pushing them. This can be done with both Docker Hub and self-hosted registries. Good Practices and Caveats -------------------------- As mentioned, a Dockerfile is built by creating a new image for each directive that follows `FROM`. This leads to some considerations. * Sometimes it can be a good idea to run several shell commands in a single `RUN` directive to avoid creating images that are not useful. * Modifying a directive means that all subsequent directives also need to be rebuilt. When possible, directives that are expected to change often should follow directives that will change seldom. * Directives like `LABEL` or `EXPOSE` should be placed close to the end of Dockerfiles. In this way they will be rebuilt often, but this operation is cheap. On the other side, changing a label should not trigger a long rebuild process. * Variables should be used to avoid Dockerfiles proliferation. But if a variable is used, changing its value should be tested. So, be sure not to use variables without a good reason. * Writing logic into a Dockerfile is impossible or very hard. Call shell scripts instead, and write your logic into them. For example, in a shell script it is easy to perform a certain operation only if a variable is set to a certain value. * If you need MariaDB containers with different configurations or different sets of plugins, use the method explained above. Do not create several Dockerfiles, with different tags, for each desired configuration or plugin set. This may lead to undesired code duplication and increased maintenance costs. References ---------- More details can be found in the Docker documentation: * [Dockerfile reference](https://docs.docker.com/engine/reference/builder/). * [docker build](https://docs.docker.com/engine/reference/commandline/build/). * [Repositories](https://docs.docker.com/docker-hub/repos/). * [Deploy a registry server](https://docs.docker.com/registry/deploying/). * [Content trust in Docker](https://docs.docker.com/engine/security/trust/). See also: * [Privacy-Enhanced Mail](https://en.wikipedia.org/wiki/Privacy-Enhanced_Mail) on Wikipedia. --- Content initially contributed by [Vettabase Ltd](https://vettabase.com/). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb Running Multiple MariaDB Server Processes Running Multiple MariaDB Server Processes ========================================= It is possible to run multiple MariaDB Server processes on the same server, but there are certain things that need to be kept in mind. This page will go over some of those things. Configuring Multiple MariaDB Server Processes --------------------------------------------- If multiple MariaDB Server process are running on the same server, then at minimum, you will need to ensure that the different instances do not use the same `[datadir](../server-system-variables/index#datadir)`, `[port](../server-system-variables/index#port)`, and `[socket](../server-system-variables/index#socket)`. The following example shows these options set in an [option file](../configuring-mariadb-with-option-files/index): ``` [client] # TCP port to use to connect to mysqld server port=3306 # Socket to use to connect to mysqld server socket=/tmp/mysql.sock [mariadb] # TCP port to make available for clients port=3306 # Socket to make available for clients socket=/tmp/mysql.sock # Where MariaDB should store all its data datadir=/usr/local/mysql/data ``` The above values are the defaults. If you would like to run multiple MariaDB Server instances on the same server, then you will need to set unique values for each instance. There may be additional options that also need to be changed for each instance. Take a look at the full list of options for `[mysqld](../mysqld-options/index)`. To see the current values set for an instance, see [Checking Program Options](../configuring-mariadb-with-option-files/index#checking-program-options) for how to do so. To list the default values, check the end of: ``` mysqld --help --verbose ``` Starting Multiple MariaDB Server Processes ------------------------------------------ There are several different methods to start or stop the MariaDB Server process. There are two primary categories that most of these methods fall into: starting the process with the help of a service manager, and starting the process manually. See [Starting and Stopping MariaDB](../starting-and-stopping-mariadb-starting-and-stopping-mariadb/index) for more information. ### Service Managers [sysVinit](../sysvinit/index) and [systemd](../systemd/index) are the most common Linux service managers. [launchd](../launchd/index) is used in MacOS X. [Upstart](https://en.wikipedia.org/wiki/Upstart_(software)) is a less common service manager. #### Systemd RHEL/CentOS 7 and above, Debian 8 Jessie and above, and Ubuntu 15.04 and above use [systemd](../systemd/index) by default. For information on how to start and stop multiple MariaDB Server processes on the same server with this service manager, see [systemd: Interacting with Multiple MariaDB Server Processes](../systemd/index#interacting-with-multiple-mariadb-server-processes). ### Starting the Server Process Manually #### mysqld `[mysqld](../mysqld-options/index)` is the actual MariaDB Server binary. It can be started manually on its own. If you want to force each instance to read only a single [option file](../configuring-mariadb-with-option-files/index), then you can use the `[--defaults-file](../mysqld-options/index#-defaults-file)` option: ``` mysqld --defaults-file=/etc/my_instance1.cnf ``` #### mysqld\_safe `[mysqld\_safe](../mysqld_safe/index)` is a wrapper that can be used to start the `[mysqld](../mysqld-options/index)` server process. The script has some built-in safeguards, such as automatically restarting the server process if it dies. See [mysqld\_safe](../mysqld_safe/index) for more information. If you want to force each instance to read only a single [option file](../configuring-mariadb-with-option-files/index), then you can use the `[--defaults-file](../mysqld-options/index#-defaults-file)` option: ``` mysqld_safe --defaults-file=/etc/my_instance1.cnf ``` #### mysqld\_multi `[mysqld\_multi](../mysqld_multi/index)` is a wrapper that can be used to start the `[mysqld](../mysqld-options/index)` server process if you plan to run multiple server processes on the same host. See [mysqld\_multi](../mysqld_multi/index) for more information. Other Options ------------- In some cases, there may be easier ways to run multiple MariaDB Server instances on the same server, such as: * Using [dbdeployer](../dbdeployer/index). * Starting multiple [Docker](../installing-and-using-mariadb-via-docker/index) containers. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Using MariaDB Server Using MariaDB Server ===================== Documentation on using MariaDB Server. | Title | Description | | --- | --- | | [SQL Statements & Structure](../sql-statements-structure/index) | SQL statements, structure, and rules. | | [Built-in Functions](../built-in-functions/index) | Functions and procedures in MariaDB. | | [Clients & Utilities](../clients-utilities/index) | Client and utility programs for MariaDB. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb mysql.time_zone_name Table mysql.time\_zone\_name Table ============================ The `mysql.time_zone_name` table is one of the mysql system tables that can contain [time zone](../time-zones/index) information. It is usually preferable for the system to handle the time zone, in which case the table will be empty (the default), but you can populate the mysql time zone tables using the [mysql\_tzinfo\_to\_sql](../mysql_tzinfo_to_sql/index) utility. See [Time Zones](../time-zones/index) for details. **MariaDB starting with [10.4](../what-is-mariadb-104/index)**In [MariaDB 10.4](../what-is-mariadb-104/index) and later, this table uses the [Aria](../aria/index) storage engine. **MariaDB until [10.3](../what-is-mariadb-103/index)**In [MariaDB 10.3](../what-is-mariadb-103/index) and before, this table uses the [MyISAM](../myisam-storage-engine/index) storage engine. The `mysql.time_zone_name` table contains the following fields: | Field | Type | Null | Key | Default | Description | | --- | --- | --- | --- | --- | --- | | `Name` | `char(64)` | NO | PRI | `NULL` | Name of the time zone. | | `Time_zone_id` | `int(10) unsigned` | NO | PRI | `NULL` | ID field, auto\_increments. | Example ------- ``` SELECT * FROM mysql.time_zone_name; +--------------------+--------------+ | Name | Time_zone_id | +--------------------+--------------+ | Africa/Abidjan | 1 | | Africa/Accra | 2 | | Africa/Addis_Ababa | 3 | | Africa/Algiers | 4 | | Africa/Asmara | 5 | | Africa/Asmera | 6 | | Africa/Bamako | 7 | | Africa/Bangui | 8 | | Africa/Banjul | 9 | | Africa/Bissau | 10 | ... +--------------------+--------------+ ``` See Also -------- * [mysql.time\_zone table](../mysqltime_zone-table/index) * [mysql.time\_zone\_leap\_second table](../mysqltime_zone_leap_second-table/index) * [mysql.time\_zone\_transition table](../mysqltime_zone_transition-table/index) * [mysql.time\_zone\_transition\_type table](../mysqltime_zone_transition_type-table/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb DBT-3 Dataset DBT-3 Dataset ============= This page describes our setup for DBT-3 tests. A very cogent resource on the [DBT3 Benchmark](../dbt3-automation-scripts/index) is also available. See also [dbt-3-queries](../dbt-3-queries/index) Get and compile DBT3 -------------------- * Get [DBT3](http://osdldbt.sourceforge.net/) * Make sure that you have pg\_ctl and createdb of PostgreSQL installed. On Ubuntu look for postgresql and postgresql-client and make sure that pg\_ctl is in your PATH, for instance: ``` PATH=/usr/lib/postgresql/8.4/bin:$PATH ``` * Compile DBT3 ``` gunzip -c dbt3-1.9.tar.gz | tar xvf - cd dbt3-1.9 ./configure make cd src/dbgen make ``` * Generate data: ``` ./dbgen -s30 ``` DDL --- Substitute `${ENGINE}` with the storage engine you want to use: ``` CREATE TABLE supplier ( s_suppkey INTEGER PRIMARY KEY, s_name CHAR(25), s_address VARCHAR(40), s_nationkey INTEGER, s_phone CHAR(15), s_acctbal REAL, s_comment VARCHAR(101)) Engine ${ENGINE}; CREATE TABLE part ( p_partkey INTEGER PRIMARY KEY, p_name VARCHAR(55), p_mfgr CHAR(25), p_brand CHAR(10), p_type VARCHAR(25), p_size INTEGER, p_container CHAR(10), p_retailprice REAL, p_comment VARCHAR(23)) Engine ${ENGINE}; CREATE TABLE partsupp ( ps_partkey INTEGER, ps_suppkey INTEGER, ps_availqty INTEGER, ps_supplycost REAL, ps_comment VARCHAR(199), PRIMARY KEY (ps_partkey, ps_suppkey)) Engine ${ENGINE}; CREATE TABLE customer ( c_custkey INTEGER primary key, c_name VARCHAR(25), c_address VARCHAR(40), c_nationkey INTEGER, c_phone CHAR(15), c_acctbal REAL, c_mktsegment CHAR(10), c_comment VARCHAR(117)) Engine ${ENGINE}; CREATE TABLE orders ( o_orderkey INTEGER primary key, o_custkey INTEGER, o_orderstatus CHAR(1), o_totalprice REAL, o_orderDATE DATE, o_orderpriority CHAR(15), o_clerk CHAR(15), o_shippriority INTEGER, o_comment VARCHAR(79)) Engine ${ENGINE}; CREATE TABLE lineitem ( l_orderkey INTEGER, l_partkey INTEGER, l_suppkey INTEGER, l_linenumber INTEGER, l_quantity REAL, l_extendedprice REAL, l_discount REAL, l_tax REAL, l_returnflag CHAR(1), l_linestatus CHAR(1), l_shipDATE DATE, l_commitDATE DATE, l_receiptDATE DATE, l_shipinstruct CHAR(25), l_shipmode CHAR(10), l_comment VARCHAR(44), PRIMARY KEY (l_orderkey, l_linenumber)) Engine ${ENGINE}; CREATE TABLE nation ( n_nationkey INTEGER primary key, n_name CHAR(25), n_regionkey INTEGER, n_comment VARCHAR(152)) Engine ${ENGINE}; CREATE TABLE region ( r_regionkey INTEGER primary key, r_name CHAR(25), r_comment VARCHAR(152)) Engine ${ENGINE}; CREATE TABLE time_statistics ( task_name VARCHAR(40), s_time TIMESTAMP, e_time TIMESTAMP, int_time INTEGER) Engine ${ENGINE}; ``` Load data --------- Substitute `${DATA\_DIR}` with the path to your generated data. ``` LOAD DATA LOCAL INFILE '${DATA_DIR}/supplier.tbl' into table supplier fields terminated by '|'; LOAD DATA LOCAL INFILE '${DATA_DIR}/part.tbl' into table part fields terminated by '|'; LOAD DATA LOCAL INFILE '${DATA_DIR}/partsupp.tbl' into table partsupp fields terminated by '|'; LOAD DATA LOCAL INFILE '${DATA_DIR}/customer.tbl' into table customer fields terminated by '|'; LOAD DATA LOCAL INFILE '${DATA_DIR}/orders.tbl' into table orders fields terminated by '|'; LOAD DATA LOCAL INFILE '${DATA_DIR}/lineitem.tbl' into table lineitem fields terminated by '|'; LOAD DATA LOCAL INFILE '${DATA_DIR}/nation.tbl' into table nation fields terminated by '|'; LOAD DATA LOCAL INFILE '${DATA_DIR}/region.tbl' into table region fields terminated by '|'; ``` Indexes we need --------------- ``` ALTER TABLE lineitem ADD INDEX i_l_shipdate(l_shipdate), ADD INDEX i_l_suppkey_partkey (l_partkey, l_suppkey), ADD INDEX i_l_partkey (l_partkey), ADD INDEX i_l_suppkey (l_suppkey), ADD INDEX i_l_receiptdate (l_receiptdate), ADD INDEX i_l_orderkey (l_orderkey), ADD INDEX i_l_orderkey_quantity (l_orderkey, l_quantity), ADD INDEX i_l_commitdate (l_commitdate); CREATE INDEX i_c_nationkey ON customer (c_nationkey); ALTER TABLE orders ADD INDEX i_o_orderdate (o_orderdate), ADD INDEX i_o_custkey (o_custkey); CREATE INDEX i_s_nationkey ON supplier (s_nationkey); ALTER TABLE partsupp ADD INDEX i_ps_partkey (ps_partkey), ADD INDEX i_ps_suppkey (ps_suppkey); CREATE INDEX i_n_regionkey ON nation (n_regionkey); ``` Analyze tables -------------- ``` ANALYZE TABLE supplier; ANALYZE TABLE part; ANALYZE TABLE partsupp; ANALYZE TABLE customer; ANALYZE TABLE orders; ANALYZE TABLE lineitem; ANALYZE TABLE nation; ANALYZE TABLE region; ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb User Password Expiry User Password Expiry ==================== **MariaDB starting with [10.4.3](https://mariadb.com/kb/en/mariadb-1043-release-notes/)**User password expiry was introduced in [MariaDB 10.4.3](https://mariadb.com/kb/en/mariadb-1043-release-notes/). Password expiry permits administrators to expire user passwords, either manually or automatically. System Variables ---------------- There are two system variables which affect password expiry: [default\_password\_lifetime](../server-system-variables/index#default_password_lifetime), which determines the amount of time between requiring the user to change their password. `0`, the default, means automatic password expiry is not active. The second variable, [disconnect\_on\_expired\_password](../server-system-variables/index#disconnect_on_expired_password) determines whether a client is permitted to connect if their password has expired, or whether they are permitted to connect in sandbox mode, able to perform a limited subset of queries related to resetting the password, in particular [SET PASSWORD](../set-password/index) and [SET](../set/index). Setting a Password Expiry Limit for a User ------------------------------------------ Besides automatic password expiry, as determined by [default\_password\_lifetime](../server-system-variables/index#default_password_lifetime), password expiry times can be set on an individual user basis, overriding the global using the [CREATE USER](../create-user/index) or [ALTER USER](../alter-user/index) statements, for example: ``` CREATE USER 'monty'@'localhost' PASSWORD EXPIRE INTERVAL 120 DAY; ``` ``` ALTER USER 'monty'@'localhost' PASSWORD EXPIRE INTERVAL 120 DAY; ``` Limits can be disabled by use of the `NEVER` keyword, for example: ``` CREATE USER 'monty'@'localhost' PASSWORD EXPIRE NEVER; ``` ``` ALTER USER 'monty'@'localhost' PASSWORD EXPIRE NEVER; ``` A manually set limit can be restored the system default by use of `DEFAULT`, for example: ``` CREATE USER 'monty'@'localhost' PASSWORD EXPIRE DEFAULT; ``` ``` ALTER USER 'monty'@'localhost' PASSWORD EXPIRE DEFAULT; ``` SHOW CREATE USER ---------------- The [SHOW CREATE USER](../show-create-user/index) statement will display information about the password expiry status of the user. Unlike MySQL, it will not display if the user is unlocked, or if the password expiry is set to default. ``` CREATE USER 'monty'@'localhost' PASSWORD EXPIRE INTERVAL 120 DAY; CREATE USER 'konstantin'@'localhost' PASSWORD EXPIRE NEVER; CREATE USER 'amse'@'localhost' PASSWORD EXPIRE DEFAULT; SHOW CREATE USER 'monty'@'localhost'; +------------------------------------------------------------------+ | CREATE USER for monty@localhost | +------------------------------------------------------------------+ | CREATE USER 'monty'@'localhost' PASSWORD EXPIRE INTERVAL 120 DAY | +------------------------------------------------------------------+ SHOW CREATE USER 'konstantin'@'localhost'; +------------------------------------------------------------+ | CREATE USER for konstantin@localhost | +------------------------------------------------------------+ | CREATE USER 'konstantin'@'localhost' PASSWORD EXPIRE NEVER | +------------------------------------------------------------+ SHOW CREATE USER 'amse'@'localhost'; +--------------------------------+ | CREATE USER for amse@localhost | +--------------------------------+ | CREATE USER 'amse'@'localhost' | +--------------------------------+ ``` Checking When Passwords Expire ------------------------------ The following query can be used to check when the current passwords expire for all users: ``` WITH password_expiration_info AS ( SELECT User, Host, IF( IFNULL(JSON_EXTRACT(Priv, '$.password_lifetime'), -1) = -1, @@global.default_password_lifetime, JSON_EXTRACT(Priv, '$.password_lifetime') ) AS password_lifetime, JSON_EXTRACT(Priv, '$.password_last_changed') AS password_last_changed FROM mysql.global_priv ) SELECT pei.User, pei.Host, pei.password_lifetime, FROM_UNIXTIME(pei.password_last_changed) AS password_last_changed_datetime, FROM_UNIXTIME( pei.password_last_changed + (pei.password_lifetime * 60 * 60 * 24) ) AS password_expiration_datetime FROM password_expiration_info pei WHERE pei.password_lifetime != 0 AND pei.password_last_changed IS NOT NULL UNION SELECT pei.User, pei.Host, pei.password_lifetime, FROM_UNIXTIME(pei.password_last_changed) AS password_last_changed_datetime, 0 AS password_expiration_datetime FROM password_expiration_info pei WHERE pei.password_lifetime = 0 OR pei.password_last_changed IS NULL; ``` --connect-expired-password Client Option ---------------------------------------- The [mysql client](../mysql-command-line-client/index) `--connect-expired-password` option notifies the server that the client is prepared to handle expired password sandbox mode (even if the `--batch` option was specified). See Also -------- * [Account Locking and Password Expiry](https://www.youtube.com/watch?v=AWM_fWZ3XIw) video tutorial Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Slave Connection Thread States Slave Connection Thread States ============================== This article documents thread states that are related to connection threads that occur on a [replication](../replication/index) slave. These correspond to the `STATE` values listed by the [SHOW PROCESSLIST](../show-processlist/index) statement or in the [Information Schema PROCESSLIST Table](../information-schema-processlist-table/index) as well as the `PROCESSLIST_STATE` value listed in the [Performance Schema threads Table](../performance-schema-threads-table/index). | Value | Description | | --- | --- | | Changing master | Processing a [CHANGE MASTER TO](../change-master-to/index) statement. | | Killing slave | Processing a [STOP SLAVE](../stop-slave/index) statement. | | Opening master dump table | A table has been created from a master dump and is now being opened. | | Reading master dump table data | After the table created by a master dump (the `Opening master dump table` state) the table is now being read. | | Rebuilding the index on master dump table | After the table created by a master dump has been opened and read (the `Reading master dump table data` state), the index is built. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb INSERT - Default & Duplicate Values INSERT - Default & Duplicate Values =================================== Default Values -------------- If the `[SQL\_MODE](../sql-mode/index)` contains `STRICT_TRANS_TABLES` and you are [inserting](../insert/index) into a transactional table (like InnoDB), or if the SQL\_MODE contains `STRICT_ALL_TABLES`, all `NOT NULL` columns which do not have a `DEFAULT` value (and are not [AUTO\_INCREMENT](../auto_increment/index)) must be explicitly referenced in `INSERT` statements. If not, an error like this is produced: ``` ERROR 1364 (HY000): Field 'col' doesn't have a default value ``` In all other cases, if a `NOT NULL` column without a `DEFAULT` value is not referenced, an empty value will be inserted (for example, 0 for `INTEGER` columns and '' for `CHAR` columns). See [NULL Values in MariaDB:Inserting](../null-values-in-mariadb/index#inserting) for examples. If a `NOT NULL` column having a `DEFAULT` value is not referenced, `NULL` will be inserted. If a `NULL` column having a `DEFAULT` value is not referenced, its default value will be inserted. It is also possible to explicitly assign the default value using the `DEFAULT` keyword or the `[DEFAULT()](../default/index)` function. If the `DEFAULT` keyword is used but the column does not have a `DEFAULT` value, an error like this is produced: ``` ERROR 1364 (HY000): Field 'col' doesn't have a default value ``` Duplicate Values ---------------- By default, if you try to insert a duplicate row and there is a `UNIQUE` index, `INSERT` stops and an error like this is produced: ``` ERROR 1062 (23000): Duplicate entry 'dup_value' for key 'col' ``` To handle duplicates you can use the [IGNORE](../ignore/index) clause, [INSERT ON DUPLICATE KEY UPDATE](../insert-on-duplicate-key-update/index) or the [REPLACE](../replace/index) statement. Note that the IGNORE and DELAYED options are ignored when you use [ON DUPLICATE KEY UPDATE](../insert-on-duplicate-key-update/index). See Also -------- * [INSERT](../insert/index) * [INSERT DELAYED](../insert-delayed/index) * [INSERT SELECT](../insert-select/index) * [HIGH\_PRIORITY and LOW\_PRIORITY](../high_priority-and-low_priority/index) * [Concurrent Inserts](../concurrent-inserts/index) * [INSERT IGNORE](../insert-ignore/index) * [INSERT ON DUPLICATE KEY UPDATE](../insert-on-duplicate-key-update/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb Performance Schema rwlock_instances Table Performance Schema rwlock\_instances Table ========================================== The `rwlock_instances` table lists all read write lock (rwlock) instances that the Performance Schema sees while the server is executing. A read write is a mechanism for ensuring threads can either share access to common resources, or have exclusive access. The [performance\_schema\_max\_rwlock\_instances](../performance-schema-system-variables/index#performance_schema_max_rwlock_instances) system variable specifies the maximum number of instrumented rwlock objects. The `rwlock_instances` table contains the following columns: | Column | Description | | --- | --- | | `NAME` | Instrument name associated with the read write lock | | `OBJECT_INSTANCE_BEGIN` | Address in memory of the instrumented lock | | `WRITE_LOCKED_BY_THREAD_ID` | `THREAD_ID` of the locking thread if locked in write (exclusive) mode, otherwise `NULL`. | | `READ_LOCKED_BY_COUNT` | Count of current read locks held | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb SHOW CREATE DATABASE SHOW CREATE DATABASE ==================== Syntax ------ ``` SHOW CREATE {DATABASE | SCHEMA} db_name ``` Description ----------- Shows the [CREATE DATABASE](../create-database/index) statement that creates the given database. `SHOW CREATE SCHEMA` is a synonym for `SHOW CREATE DATABASE`. `SHOW CREATE DATABASE` quotes database names according to the value of the [sql\_quote\_show\_create](../server-system-variables/index#sql_quote_show_create) server system variable. Examples -------- ``` SHOW CREATE DATABASE test; +----------+-----------------------------------------------------------------+ | Database | Create Database | +----------+-----------------------------------------------------------------+ | test | CREATE DATABASE `test` /*!40100 DEFAULT CHARACTER SET latin1 */ | +----------+-----------------------------------------------------------------+ SHOW CREATE SCHEMA test; +----------+-----------------------------------------------------------------+ | Database | Create Database | +----------+-----------------------------------------------------------------+ | test | CREATE DATABASE `test` /*!40100 DEFAULT CHARACTER SET latin1 */ | +----------+-----------------------------------------------------------------+ ``` With `[sql\_quote\_show\_create](../server-system-variables/index#sql_quote_show_create)` off: ``` SHOW CREATE DATABASE test; +----------+---------------------------------------------------------------+ | Database | Create Database | +----------+---------------------------------------------------------------+ | test | CREATE DATABASE test /*!40100 DEFAULT CHARACTER SET latin1 */ | +----------+---------------------------------------------------------------+ ``` With a comment, from [MariaDB 10.5](../what-is-mariadb-105/index): ``` SHOW CREATE DATABASE p; +----------+--------------------------------------------------------------------------------------+ | Database | Create Database | +----------+--------------------------------------------------------------------------------------+ | p | CREATE DATABASE `p` /*!40100 DEFAULT CHARACTER SET latin1 */ COMMENT 'presentations' | +----------+--------------------------------------------------------------------------------------+ ``` See Also -------- * [CREATE DATABASE](../create-database/index) * [ALTER DATABASE](../alter-database/index) * [Character Sets and Collations](../character-sets-and-collations/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb DbVisualizer DbVisualizer ============ [DbVisualizer](https://dbvis.com/) is a cross-platform database tool for developers, DBAs, analysts and SQL programmers. Both Free and paid Pro version available. Supported databases: MySQL, MariaDB, PostgreSQL, Netezza, Db2, SQLite, Oracle, Amazon Redshift, Vertica, Snowflake and [more](https://www.dbvis.com/features/database-drivers/). For almost two decades DbVisualizer has been carefully developed by a small and dedicated team. Development decisions are based on user feedback. Example of features: * Simple navigation of database objects and their properties * Visual rendering of primary/foreign keys * Table data editing in spreadsheet with Export and import database schema * Flexible user interface in light and dark themes * Query optimization with an explain plan feature * Visual query builder using drag and drop * Flexible SQL scripts execution with parameter support * SQL formatting and Command-line interface for headless execution * [All features](https://www.dbvis.com/features/) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Data Warehousing Summary Tables Data Warehousing Summary Tables =============================== Preface ------- This document discusses the creation and maintenance of "Summary Tables". It is a companion to the document on [Data Warehousing Techniques](../data-warehousing-techniques/index). The basic terminology ("Fact Table", "[Normalization](../database-normalization/index)", etc) is covered in that document. Summary tables for data warehouse "reports" ------------------------------------------- Summary tables are a performance necessity for large tables. MariaDB and MySQL do not provide any automated way to create such, so I am providing techniques here. (Other vendors provide something similar with "materialized views".) When you have millions or billions of rows, it takes a long time to summarize the data to present counts, totals, averages, etc, in a size that is readily digestible by humans. By computing and saving subtotals as the data comes in, one can make "reports" run much faster. (I have seen 10x to 1000x speedups.) The subtotals go into a "summary table". This document guides you on efficiency in both creating and using such tables. General structure of a summary table ------------------------------------ A summary table includes two sets of columns: * Main KEY: date + some dimension(s) * Subtotals: COUNT(\*), SUM(...), ...; but not AVG() The "date" might be a DATE (a 3-byte native datatype), or an hour, or some other time interval. A 3-byte MEDIUMINT UNSIGNED 'hour' can be derived from a DATETIME or TIMESTAMP via ``` FLOOR(UNIX_TIMESTAMP(dt) / 3600) FROM_UNIXTIME(hour * 3600) ``` The "dimensions" (a DW term) are some of the columns of the "Fact" table. Examples: Country, Make, Product, Category, Host Non-dimension examples: Sales, Quantity, TimeSpent There would be one or more indexes, usually starting with some dimensions and ending with the date field. By ending with the date, one can efficiently get a range of days/weeks/etc. even when each row summarizes only one day. There will typically be a "few" summary tables. Often one summary table can serve multiple purposes sufficiently efficiently. As a rule of thumb, a summary table will have one-tenth the number of rows as the Fact table. (This number is very loose.) Example ------- Let's talk about a large chain of car dealerships. The Fact table has all the sales with columns such as datetime, salesman\_id, city, price, customer\_id, make, model, model\_year. One Summary table might focus on sales: ``` PRIMARY KEY(city, datetime), Aggregations: ct, sum_price # Core of INSERT..SELECT: DATE(datetime) AS date, city, COUNT(*) AS ct, SUM(price) AS sum_price # Reporting average price for last month, broken down by city: SELECT city, SUM(sum_price) / SUM(ct) AS 'AveragePrice' FROM SalesSummary WHERE datetime BETWEEN ... GROUP BY city; # Monthly sales, nationwide, from same summary table: SELECT MONTH(datetime) AS 'Month', SUM(ct) AS 'TotalSalesCount' SUM(sum_price) AS 'TotalDollars' FROM SalesSummary WHERE datetime BETWEEN ... GROUP BY MONTH(datetime); # This might benefit from a secondary INDEX(datetime) ``` When to augment the summary table(s)? ------------------------------------- "Augment" in this section means to add new rows into the summary table or increment the counts in existing rows. Plan A: "While inserting" rows into the Fact table, augment the summary table(s). This is simple, and workable for a smaller DW database (under 10 Fact table rows per second). For larger DW databases, Plan A likely to be too costly to be practical. Plan B: "Periodically", via cron or an EVENT. Plan C: "As needed". That is, when someone asks for a report, the code first updates the summary tables that will be needed. Plan D: "Hybrid" of B and C. C, by itself, can led to long delays for the report. By also doing B, those delays can be kept low. Plan E: (This is not advised.) "Rebuild" the entire summary table from the entire Fact table. The cost of this is prohibitive for large tables. However, Plan E may be needed when you decide to change the columns of a Summary Table, or discover a flaw in the computations. To lessen the impact of an entire build, adapt the chunking techniques in [Deleting in chunks](../big-deletes/index#deleting_in_chunks) . Plan F: "Staging table". This is primarily for very high speed ingestion. It is mentioned briefly in this blog, and discussed more thoroughly in the companion blog: High Speed Ingestion Summarizing while Inserting (one row at a time) ----------------------------------------------- ``` INSERT INTO Fact ...; INSERT INTO Summary (..., ct, foo, ...) VALUES (..., 1, foo, ...) ON DUPLICATE KEY UPDATE ct = ct+1, sum_foo = sum_foo + VALUES(foo), ...; ``` IODKU (Insert On Duplicate Key Update) will update an existing row or create a new row. It knows which to do based on the Summary table's PRIMARY KEY. Caution: This approach is costly, and will not scale to an ingestion rate of over, say, 10 rows per second (Or maybe 50/second on SSDs). More discussion later. Summarizing periodically vs as-needed ------------------------------------- If your reports need to be up-to-the-second, you need "as needed" or "hybrid". If your reports have less urgency (eg, weekly reports that don't include 'today'), then "periodically" might be best. For a daily summaries, augmenting the summary tables could be done right after midnight. But, beware of data coming "late". For both "periodic" and "as needed", you need a definitive way of keeping track of where you "left off". Case 1: You insert into the Fact table first and it has an AUTO\_INCREMENT id: Grab MAX(id) as the upper bound for summarizing and put it either into some other secure place (an extra table), or put it into the row(s) in the Summary table as you insert them. (Caveat: AUTO\_INCREMENT ids do not work well in multi-master, including Galera, setups.) Case 2: If you are using a 'staging' table, there is no issue. (More on staging tables later.) Summarizing while batch inserting --------------------------------- This applies to multi-row (batch) INSERT and LOAD DATA. The Fact table needs an AUTO\_INCREMENT id, and you need to be able to find the exact range of ids inserted. (This may be impractical in any multi-master setup.) Then perform bulk summarization using ``` FROM Fact WHERE id BETWEEN min_id and max_id ``` Summarizing when using a staging table -------------------------------------- Load the data (via INSERTs or [LOAD DATA) en masse into a "staging table". Then perform batch summarization from the Staging table. And batch copy from the Staging table to the Fact table. Note that the Staging table is handy for batching "normalization" during ingestion. See also [[data-warehousing-high-speed-ingestion|High Speed Ingestion](../load-data-infile/index) Summary table: PK or not? ------------------------- Let's say your summary table has a DATE, `dy`, and a dimension, `foo`. The question is: Should (foo, dy) be the PRIMARY KEY? Or a non-UNIQUE index? Case 1: PRIMARY KEY (foo, dy) and summarization is in lock step with, say, changes in `dy`. This case is clean and simple -- until you get to endcases. How will you handle the case of data arriving 'late'? Maybe you will need to recalculate some chunks of data? If so, how? Case 2: (foo, dy) is a non-UNIQUE INDEX. This case is clean and simple, but it can clutter the summary table because multiple rows can occur for a given (foo, dy) pair. The report will always have to [SUM()](../sum/index) up values because it cannot assume there is only one row, even when it is reporting on a single `foo` for a single `dy`. This forced-SUM is not really bad -- you should do it anyway; that way all your reports are written with one pattern. Case 3: PRIMARY KEY (foo, dy) and summarization can happen anytime. Since you should be using InnoDB, there needs to be an explicit PRIMARY KEY. One approach when you do not have a 'natural' PK is this: ``` id INT UNSIGNED AUTO_INCREMENT NOT NULL, ... PRIMARY KEY(foo, dy, id), -- `id` added to make unique INDEX(id) -- sufficient to keep AUTO_INCREMENT happy ``` This case pushes the complexity onto the summarization by doing a IODKU. Advice? Avoid Case 1; too messy. Case 2 is ok if the extra rows are not too common. Case 3 may be the closest to "once size fits all". Averages, etc. -------------- When summarizing, include `COUNT(*) AS ct and SUM(foo) AS sum_foo`. When reporting, the "average" is computed as SUM(sum\_foo) / SUM(ct). That is mathematically correct. Exception... Let's say you are looking at weather temperatures. And you monitoring station gets the temp periodically, but unreliably. That is, the number of readings for a day varies. Further, you decide that the easiest way to compensate for the inconsistency is to do something like: Compute the avg temp for each day, then average those across the month (or other timeframe). Formula for Standard Deviation: ``` SQRT( SUM(sum_foo2)/SUM(ct) - POWER(SUM(sum_foo)/SUM(ct), 2) ) ``` Where sum\_foo2 is SUM(foo \* foo) from the summary table. sum\_foo and sum\_foo2 should be FLOAT. FLOAT gives you about 7 significant digits, which is more than enough for things like average and standard deviation. FLOAT occupies 4 bytes. DOUBLE would give you more precision, but occupies 8 bytes. INT and BIGINT are not practical because they may lead to complaints about overflow. Staging table ------------- The idea here is to first load a set of Fact records into a "staging table", with the following characteristics (at least): * The table is repeatedly populated and truncated * Inserts could be individual or batched, and from one or many clients * SELECTs will be table scans, so no indexes needed * Inserting will be fast (InnoDB may be the fastest) * Normalization can be done in bulk, hence efficiently * Copying to the Fact table will be fast * Summarization can be done in bulk, hence efficiently * "Bursty" ingestion is smoothed by this process * Flip-flop a pair of Staging tables If you have bulk inserts (Batch INSERT or LOAD DATA) then consider doing the normalization and summarization immediately after each bulk insert. More details: High Speed Ingestion Extreme design -------------- Here is a more complex way to design the system, with the goal of even more scaling. * Use master-slave setup: ingest into master; report from slave(s). * Feed ingestion through a staging table (as described above) * Single-source of data: ENGINE=MEMORY; multiple sources: InnoDB * [binlog\_format = ROW](../replication-and-binary-log-server-system-variables/index#binlog_format) * Use [binlog\_ignore\_db](../replication-and-binary-log-server-system-variables/index#binlog_ignore_db) to avoid replicating staging -- necessitating putting it in a separate database. * Do the summarization from Staging * Load Fact via INSERT INTO Fact ... SELECT FROM Staging ... Explanation and comments: * ROW + ignore\_db avoids replicating Staging, yet replicates the INSERTs based on it. Hence, it lightens the write load on the Slaves * If using MEMORY, remember that it is volatile -- recover from a crash by starting the ingestion over. * To aid with debugging, TRUNCATE or re-CREATE Staging at the start of the next cycle. * Staging needs no indexes -- all operations read all rows from it. Stats on the system that this 'extreme design' came from: Fact Table: 450GB, 100M rows/day (batch of 4M/hour), 60 day retention (60+24 partitions), 75B/row, 7 summary tables, under 10 minutes to ingest and summarize the hourly batch. The INSERT..SELECT handled over 20K rows/sec going into the Fact table. Spinning drives (not SSD) with RAID-10. "Left Off" ---------- One technique involves summarizing some of the data, then recording where you "left off", so that next time, you can start there. There are some subtle issues with "left off" that you should be cautious of. If you use a DATETIME or TIMESTAMP as "left off", beware of multiple rows with the same value. * Plan A: Use a compound "left off" (eg, TIMESTAMP + ID). This is messy, error prone, etc. * Plan B: WHERE ts >= $left\_off AND ts < $max\_ts -- avoids dups, but has other problems (below) * Separate threads could COMMIT TIMESTAMPs out of order. If you use an AUTO\_INCREMENT as "left off" beware of: * In InnoDB, separate threads could COMMIT ids in the 'wrong' order. * Multi-master (including Galera and InnoDB Cluster), could lead to ordering issues. So, nothing works, at least not in a multi-threaded environment? If you can live with an occasional hiccup (skipped record), then maybe this is 'not a problem' for you. The "Flip-Flop Staging" is a safe alternative, optionally combined with the "Extreme Design". Flip-flop staging ----------------- If you have many threads simultaneously INSERTing into one staging table, then here is an efficient way to handle a large load: Have a process that flips that staging table with another, identical, staging table, and performs bulk normalization, Fact insertion, and bulk summarization. The flipping step uses a fast, atomic, RENAME. Here is a sketch of the code: ``` # Prep for flip: CREATE TABLE new LIKE Staging; # Swap (flip) Staging tables: RENAME TABLE Staging TO old, new TO Staging; # Normalize new `foo`s: # (autocommit = 1) INSERT IGNORE INTO Foos SELECT fpp FROM old LEFT JOIN Foos ... # Prep for possible deadlocks, etc while... START TRANSACTION; # Add to Fact: INSERT INTO Fact ... FROM old JOIN Foos ... # Summarize: INSERT INTO Summary ... FROM old ... GROUP BY ... COMMIT; end-while # Cleanup: DROP TABLE old; ``` Meanwhile, ingestion can continue writing to `Staging`. The ingestion INSERTs will conflict with the RENAME, but will be resolved gracefully and silently and quickly. How fast should you flip-flop? Probably the best scheme is to * Have a job that flip-flops in a tight loop (no delay, or a small delay, between iterations), and * Have a CRON that serves only as a "keep-alive" to restart the job if it dies. If Staging is 'big', an iteration will take longer, but run more efficiently. Hence, it is self-regulating. In a [Galera](../galera/index) (or InnoDB Cluster?) environment, each node could be receiving input. If can afford to loose a few rows, have `Staging` be a non-replicated MEMORY table. Otherwise, have one `Staging` per node and be InnoDB; it will be more secure, but slower and not without problems. In particular, if a node dies completely, you somehow need to process its `Staging` table. Multiple summary tables ----------------------- * Look at the reports you will need. * Design a summary table for each. * Then look at the summary tables -- you are likely to find some similarities. * Merge similar ones. To look at what a report needs, look at the WHERE clause that would provide the data. Some examples, assuming data about service records for automobiles: The GROUP BY to gives a clue of what the report might be about. 1. WHERE make = ? AND model\_year = ? GROUP BY service\_date, service\_type 2. WHERE make = ? AND model = ? GROUP BY service\_date, service\_type 3. WHERE service\_type = ? GROUP BY make, model, service\_date 4. WHERE service\_date between ? and ? GROUP BY make, model, model\_year You need to allow for 'ad hoc' queries? Well, look at all the ad hoc queries -- they all have a date range, plus nail down one or two other things. (I rarely see something as ugly as '%CL%' for nailing down another dimension.) So, start by thinking of date plus one or two other dimensions as the 'key' into a new summary table. Then comes the question of what data might be desired -- counts, sums, etc. Eventually you have a small set of summary tables. Then build a front end to allow them to pick only from those possibilities. It should encourage use of the existing summary tables, not not be truly 'open ended'. Later, another 'requirement' may surface. So, build another summary table. Of course, it may take a day to initially populate it. Games on summary tables ----------------------- Does one ever need to summarize a summary table? Yes, but only in extreme situations. Usually a 'weekly' report can be derived from a 'daily' summary table; building a separate weekly summary table not being worth the effort. Would one ever PARTITION a Summary Table? Yes, in extreme situations, such as the table being large, and * Need to purge old data (unlikely), or * Recent' data is usually requested, and the index(es) fail to prevent table scans (rare). ("Partition pruning" to the rescue.) See also -------- Rick James graciously allowed us to use this article in the Knowledge Base. [Rick James' site](http://mysql.rjweb.org/) has other useful tips, how-tos, optimizations, and debugging tips. Original source: <http://mysql.rjweb.org/doc.php/summarytables> Examples * <http://dba.stackexchange.com/a/144723/1876> * <http://stackoverflow.com/a/39403194/1766831> * <http://stackoverflow.com/a/40310314/1766831> Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb ATAN2 ATAN2 ===== Syntax ------ ``` ATAN(Y,X), ATAN2(Y,X) ``` Description ----------- Returns the arc tangent of the two variables X and Y. It is similar to calculating the arc tangent of Y / X, except that the signs of both arguments are used to determine the quadrant of the result. Examples -------- ``` SELECT ATAN(-2,2); +---------------------+ | ATAN(-2,2) | +---------------------+ | -0.7853981633974483 | +---------------------+ SELECT ATAN2(PI(),0); +--------------------+ | ATAN2(PI(),0) | +--------------------+ | 1.5707963267948966 | +--------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Obsolete Replication Information Obsolete Replication Information ================================= This section is for replication-related items that are obsolete. The information in these articles is old or outdated, but rather than throwing it away, we're preserving it here. | Title | Description | | --- | --- | | [MariaDB 5.2 Replication Feature Preview](../mariadb-52-replication-feature-preview/index) | OBSOLETE: Previewing MariaDB 5.3 replication features | | [LOAD DATA FROM MASTER (removed)](../load-data-from-master-removed/index) | Removed statement for loading the master with the slave's data | | [LOAD TABLE FROM MASTER (removed)](../load-table-from-master-removed/index) | Removed statement for loading a slave table from the master | | [XtraDB option --innodb-release-locks-early](../xtradb-option-innodb-release-locks-early/index) | Feature included only in the 5.2 replication preview | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb sysbench Benchmark Setup sysbench Benchmark Setup ======================== For our automated MariaDB/MySQL sysbench benchmark tests, we use sysbench from `lp:sysbench`. This page describes the basic parameters and configuration we use. You can find the automation wrapper scripts we use for running sysbench in [lp:mariadb-tools](../mariadb-tools/index) Current general parameters -------------------------- ``` table_open_cache = 512 thread_cache = 512 query_cache_size = 0 query_cache_type = 0 ``` Current InnoDB parameters ------------------------- ``` innodb_data_home_dir = /data/mysql/ innodb_data_file_path = ibdata1:128M:autoextend innodb_log_group_home_dir = /data/mysql/ innodb_buffer_pool_size = 1024M innodb_additional_mem_pool_size = 32M innodb_log_file_size = 256M innodb_log_buffer_size = 16M innodb_flush_log_at_trx_commit = 1 innodb_lock_wait_timeout = 50 innodb_doublewrite = 0 innodb_flush_method = O_DIRECT innodb_thread_concurrency = 0 innodb_max_dirty_pages_pct = 80 ``` Compile ------- Install MariaDB or MySQL to /usr/local and make a symlink to /usr/local/mysql. Please use non-debug version! On Mac OS X we currently need automake1.10. ``` ./autogen.sh ./configure \ --without-drizzle \ --with-mysql-includes=/usr/local/mysql/include/mysql \ --with-mysql-libs=/usr/local/mysql/lib/mysql make optionally: make install ``` Start and prepare database to use --------------------------------- ``` mysqladmin -uroot drop sbtest mysqladmin -uroot create sbtest ``` ### Tests We use the latest sysbench with Lua scripting support. Therefore the test names differ from sysbench <= 0.4. To get reasonable results we use a run time of 5 minutes. We run the tests with 1, 4, 8, 16, 32, 64, and 128 threads. ``` NUM_THREADS="1 4 8 16 32 64 128" SYSBENCH_TESTS="delete.lua \ insert.lua \ oltp_complex_ro.lua \ oltp_complex_rw.lua \ oltp_simple.lua \ select.lua \ update_index.lua \ update_non_index.lua" NUM_THREADS=1 TEST_DIR=${HOME}/work/monty_program/sysbench/sysbench/tests/db ./sysbench \ --test=${TEST_DIR}/oltp_simple.lua \ --oltp-table-size=2000000 \ --max-time=300 \ --max-requests=0 \ --mysql-table-engine=InnoDB \ --mysql-user=root \ --mysql-engine-trx=yes \ --num-threads=$NUM_THREADS \ prepare ./sysbench \ --test=${TEST_DIR}/oltp_simple.lua \ --oltp-table-size=2000000 \ --max-time=300 \ --max-requests=0 \ --mysql-table-engine=InnoDB \ --mysql-user=root \ --mysql-engine-trx=yes \ --num-threads=$NUM_THREADS \ run ``` Custom added tests ------------------ We created a couple of custom tests for SysBench: * select\_random\_ranges.lua * select\_random\_points.lua Both of these have been added to the latest SysBench v0.5 repository. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Spider mysql Database Tables Spider mysql Database Tables ============================= The [Spider storage engine](../spider/index) installs the following system tables in the `mysql` database. | Title | Description | | --- | --- | | [mysql.spider\_link\_failed\_log Table](../mysqlspider_link_failed_log-table/index) | The mysql.spider\_link\_failed\_log table. | | [mysql.spider\_link\_mon\_servers Table](../mysqlspider_link_mon_servers-table/index) | The mysql.spider\_link\_mon\_servers table. | | [mysql.spider\_tables Table](../mysqlspider_tables-table/index) | The mysql.spider\_tables table. | | [mysql.spider\_table\_crd Table](../mysqlspider_table_crd-table/index) | The mysql.spider\_table\_crd table. | | [mysql.spider\_table\_position\_for\_recovery Table](../mysqlspider_table_position_for_recovery-table/index) | The mysql.spider\_table\_position\_for\_recovery table. | | [mysql.spider\_table\_sts Table](../mysqlspider_table_sts-table/index) | The mysql.spider\_table\_sts table. | | [mysql.spider\_xa Table](../mysqlspider_xa-table/index) | The mysql.spider\_xa table. | | [mysql.spider\_xa\_failed\_log Table](../mysqlspider_xa_failed_log-table/index) | The mysql.spider\_xa\_failed\_log table. | | [mysql.spider\_xa\_member Table](../mysqlspider_xa_member-table/index) | The mysql.spider\_xa\_member table. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb MariaDB ColumnStore software upgrade 1.1.7 GA to 1.2.3 GA MariaDB ColumnStore software upgrade 1.1.7 GA to 1.2.3 GA ========================================================= MariaDB ColumnStore software upgrade 1.1.7 GA to 1.2.3 GA --------------------------------------------------------- This upgrade also applies to 1.2.0 Alpha to 1.2.3 GA upgrades ### Changes in 1.2.1 and later #### libjemalloc dependency ColumnStore 1.2.3 onwards requires libjemalloc to be installed. For Ubuntu & Debian based distributions this is installed using the package "libjemalloc1" in the standard repositories. For CentOS the package is in RedHat's EPEL repository: ``` sudo yum -y install epel-release sudo yum install jemalloc ``` #### Non-distributed is the default distribution mode in postConfigure The default distribution mode has changed from 'distributed' to 'non-distributed'. During an upgrade, however, the default is to use the distribution mode used in the original installation. The options '-d' and '-n' can always be used to override the default. #### Non-root user sudo setup Root-level permissions are no longer required to install or upgrade ColumnStore for some types of installations. Installations requiring some level of sudo access, and the instructions, are listed here: [https://mariadb.com/kb/en/library/preparing-for-columnstore-installation-121/#update-sudo-configuration-if-needed-by-root-user](../library/preparing-for-columnstore-installation-121/index#update-sudo-configuration-if-needed-by-root-user) #### Running the mysql\_upgrade script As part of the upgrade process to 1.2.3, the user is required to run the mysql\_upgrade script on all of the following nodes. * All User Modules on a system configured with separate User and Performance Modules * All Performance Modules on a system configured with separate User and Performance Modules and Local Query Feature is enabled * All Performance Modules on a system configured with combined User and Performance Modules mysql\_upgrade should be run once the upgrade has been completed. This is an example of how it run on a root user install: ``` /usr/local/mariadb/columnstore/mysql/bin/mysql_upgrade --defaults-file=/usr/local/mariadb/columnstore/mysql/my.cnf --force ``` This is an example of how it run on a non-root user install, assuming ColumnStore is installed under the user's home directory: ``` $HOME/mariadb/columnstore/mysql/bin/mysql_upgrade --defaults-file=$HOME/mariadb/columnstore/mysql/my.cnf --force ``` ### Setup In this section, we will refer to the directory ColumnStore is installed in as <CSROOT>. If you installed the RPM or DEB package, then your <CSROOT> will be /usr/local. If you installed it from the tarball, <CSROOT> will be where you unpacked it. #### Columnstore.xml / my.cnf Configuration changes made manually are not automatically carried forward during the upgrade. These modifications will need to be made again manually after the upgrade is complete. After the upgrade process the configuration files will be saved at: * <CSROOT>/mariadb/columnstore/etc/Columnstore.xml.rpmsave * <CSROOT>/mariadb/columnstore/mysql/my.cnf.rpmsave #### MariaDB root user database password If you have specified a root user database password (which is good practice), then you must configure a .my.cnf file with user credentials for the upgrade process to use. Create a .my.cnf file in the user home directory with 600 file permissions with the following content (updating PASSWORD as appropriate): ``` [mysqladmin] user = root password = PASSWORD ``` ### Choosing the type of upgrade Note, softlinks may cause a problem during the upgrade if you use the RPM or DEB packages. If you have linked a directory above /usr/local/mariadb/columnstore, the softlinks will be deleted and the upgrade will fail. In that case you will need to upgrade using the binary tarball instead. If you have only linked the data directories (ie /usr/local/MariaDB/columnstore/data\*), the RPM/DEB package upgrade will work. #### Root User Installs ##### Upgrading MariaDB ColumnStore using the tarball of RPMs (distributed mode) Upgrade MariaDB ColumnStore as user root on the server designated as PM1: **Download the package mariadb-columnstore-1.2.3-1-centos#.x86\_64.rpm.tar.gz to the PM1 server where you are installing MariaDB ColumnStore.** **Shutdown the MariaDB ColumnStore system:** ``` # mcsadmin shutdownsystem y ``` * Unpack the tarball, which will generate a set of RPMs that will reside in the /root/ directory. ``` # tar -zxf mariadb-columnstore-1.2.3-1-centos#.x86_64.rpm.tar.gz ``` * Uninstall the old packages, then install the new packages. The MariaDB ColumnStore software will be installed in /usr/local/. ``` # rpm -e --nodeps $(rpm -qa | grep '^mariadb-columnstore') # rpm -ivh mariadb-columnstore-*1.2.3*rpm ``` * Run postConfigure using the upgrade option ``` # /usr/local/mariadb/columnstore/bin/postConfigure -u ``` * Run the mysql\_upgrade script on the nodes documented above for a root user install [https://mariadb.com/kb/en/library/mariadb-columnstore-software-upgrade-117-ga-to-123-ga/#running-the-mysql\_upgrade-script](../library/mariadb-columnstore-software-upgrade-117-ga-to-123-ga/index#running-the-mysql_upgrade-script) ##### Upgrading MariaDB ColumnStore using RPM Package Repositories (non-distributed mode) The system can be upgraded when it was previously installed from the Package Repositories. This will need to be run on each module in the system. Additional information can be found in this document on how to setup and install using the 'yum' package repo command: [https://mariadb.com/kb/en/library/installing-mariadb-ax-from-the-package-repositories](../library/installing-mariadb-ax-from-the-package-repositories) Upgrade MariaDB ColumnStore as user root on the server designated as PM1: **Shutdown the MariaDB ColumnStore system:** ``` # mcsadmin shutdownsystem y ``` * Uninstall MariaDB ColumnStore Packages ``` # yum remove mariadb-columnstore* ``` * Install MariaDB ColumnStore Packages ``` # yum --enablerepo=mariadb-columnstore clean metadata # yum install mariadb-columnstore* ``` NOTE: On all modules except for PM1, start the columnstore service ``` # /usr/local/mariadb/columnstore/bin/columnstore start ``` * Run postConfigure using the upgrade and non-distributed options ``` # /usr/local/mariadb/columnstore/bin/postConfigure -u -n ``` * Run the mysql\_upgrade script on the nodes documented above for a root user install [https://mariadb.com/kb/en/library/mariadb-columnstore-software-upgrade-117-ga-to-123-ga/#running-the-mysql\_upgrade-script](../library/mariadb-columnstore-software-upgrade-117-ga-to-123-ga/index#running-the-mysql_upgrade-script) ##### Upgrading MariaDB ColumnStore using the binary tarball (distributed mode) Upgrade MariaDB ColumnStore as user root on the server designated as PM1: * Download the package into the /usr/local directory mariadb-columnstore-1.2.3-1.x86\_64.bin.tar.gz * Shutdown the MariaDB ColumnStore system: ``` # mcsadmin shutdownsystem y ``` * Run pre-uninstall script ``` # /usr/local/mariadb/columnstore/bin/pre-uninstall ``` * Unpack the tarball in the /usr/local/ directory. ``` # tar -zxvf mariadb-columnstore-1.2.3-1.x86_64.bin.tar.gz ``` * Run post-install scripts ``` # /usr/local/mariadb/columnstore/bin/post-install ``` * Run postConfigure using the upgrade option ``` # /usr/local/mariadb/columnstore/bin/postConfigure -u ``` * Run the mysql\_upgrade script on the nodes documented above for a root user install [https://mariadb.com/kb/en/library/mariadb-columnstore-software-upgrade-117-ga-to-123-ga/#running-the-mysql\_upgrade-script](../library/mariadb-columnstore-software-upgrade-117-ga-to-123-ga/index#running-the-mysql_upgrade-script) ##### Upgrading MariaDB ColumnStore using the DEB tarball (distributed mode) Upgrade MariaDB ColumnStore as user root on the server designated as PM1: * Download the package into the /root directory mariadb-columnstore-1.2.3-1.amd64.deb.tar.gz * Shutdown the MariaDB ColumnStore system: ``` # mcsadmin shutdownsystem y ``` * Unpack the tarball, which contains DEBs. ``` # tar -zxf mariadb-columnstore-1.2.3-1.amd64.deb.tar.gz ``` * Remove and install all MariaDB ColumnStore debs ``` # cd /root/ # dpkg -r $(dpkg --list | grep 'mariadb-columnstore' | awk '{print $2}') # dpkg --install mariadb-columnstore-*1.2.3-1*deb ``` * Run postConfigure using the upgrade option ``` # /usr/local/mariadb/columnstore/bin/postConfigure -u ``` * Run the mysql\_upgrade script on the nodes documented above for a root user install [https://mariadb.com/kb/en/library/mariadb-columnstore-software-upgrade-117-ga-to-123-ga/#running-the-mysql\_upgrade-script](../library/mariadb-columnstore-software-upgrade-117-ga-to-123-ga/index#running-the-mysql_upgrade-script) ##### Upgrading MariaDB ColumnStore using DEB Package Repositories (non-distributed mode) The system can be upgraded when it was previously installed from the Package Repositories. This will need to be run on each module in the system Additional information can be found in this document on how to setup and install using the 'apt-get' package repo command: [https://mariadb.com/kb/en/library/installing-mariadb-ax-from-the-package-repositories](../library/installing-mariadb-ax-from-the-package-repositories) Upgrade MariaDB ColumnStore as user root on the server designated as PM1: **Shutdown the MariaDB ColumnStore system:** ``` # mcsadmin shutdownsystem y ``` * Uninstall MariaDB ColumnStore Packages ``` # apt-get remove mariadb-columnstore* ``` * Install MariaDB ColumnStore Packages ``` # apt-get update # sudo apt-get install mariadb-columnstore* ``` NOTE: On all modules except for PM1, start the columnstore service ``` # /usr/local/mariadb/columnstore/bin/columnstore start ``` * Run postConfigure using the upgrade and non-distributed options ``` # /usr/local/mariadb/columnstore/bin/postConfigure -u -n ``` * Run the mysql\_upgrade script on the nodes documented above for a root user install [https://mariadb.com/kb/en/library/mariadb-columnstore-software-upgrade-117-ga-to-123-ga/#running-the-mysql\_upgrade-script](../library/mariadb-columnstore-software-upgrade-117-ga-to-123-ga/index#running-the-mysql_upgrade-script) #### Non-Root User Installs ##### Upgrade MariaDB ColumnStore from the binary tarball without sudo access (non-distributed mode) This upgrade method applies when root/sudo access is not an option. The uninstall script for 1.1.7 requires root access to perform some operations. These operations are the following: * removing /etc/profile.d/columnstore{Alias,Env}.sh to remove aliases and environment variables from all users. * running '<CSROOT>/mysql/columnstore/bin/syslogSetup.sh uninstall' to remove ColumnStore from the logging system * removing the columnstore startup script * remove /etc/ld.so.conf.d/columnstore.conf to ColumnStore directories from the ld library search path Because you are upgrading ColumnStore and not uninstalling it, they are not necessary. If at some point you wish to uninstall it, you (or your sysadmin) will have to perform those operations by hand. The upgrade instructions: * Download the binary tarball to the current installation location on all nodes. See <https://downloads.mariadb.com/ColumnStore/> * Shutdown the MariaDB ColumnStore system: ``` $ mcsadmin shutdownsystem y ``` * Copy Columnstore.xml to Columnstore.xml.rpmsave, and my.cnf to my.cnf.rpmsave ``` $ cp <CSROOT>/mariadb/columnstore/etc/Columnstore{.xml,.xml.rpmsave} $ cp <CSROOT>/mariadb/columnstore/mysql/my{.cnf,.cnf.rpmsave} ``` * On all nodes, untar the new files in the same location as the old ones ``` $ tar zxf columnstore-1.2.3-1.x86_64.bin.tar.gz ``` * On all nodes, run post-install, specifying where ColumnStore is installed ``` $ <CSROOT>/mariadb/columnstore/bin/post-install --installdir=<CSROOT>/mariadb/columnstore ``` * On all nodes except for PM1, start the columnstore service ``` $ <CSROOT>/mariadb/columnstore/bin/columnstore start ``` * On PM1 only, run postConfigure, specifying the upgrade, non-distributed installation mode, and the location of the installation ``` $ <CSROOT>/mariadb/columnstore/bin/postConfigure -u -n -i <CSROOT>/mariadb/columnstore ``` * Run the mysql\_upgrade script on the nodes documented above for a non-root user install [https://mariadb.com/kb/en/library/mariadb-columnstore-software-upgrade-117-ga-to-123-ga/#running-the-mysql\_upgrade-script](../library/mariadb-columnstore-software-upgrade-117-ga-to-123-ga/index#running-the-mysql_upgrade-script) ##### Upgrade MariaDB ColumnStore from the binary tarball (distributed mode) Upgrade MariaDB ColumnStore as user USER on the server designated as PM1: * Download the package into the user's home directory mariadb-columnstore-1.2.3-1.x86\_64.bin.tar.gz * Shutdown the MariaDB ColumnStore system: ``` $ mcsadmin shutdownsystem y ``` * Run the pre-uninstall script; this will require sudo access as you are running a script from 1.1.7. ``` $ <CSROOT>/mariadb/columnstore/bin/pre-uninstall --installdir=<CSROOT>/mariadb/columnstore ``` * Make the sudo changes as noted at the beginning of this document * Unpack the tarball in the same place as the original installation ``` $ tar -zxvf mariadb-columnstore-1.2.3-1.x86_64.bin.tar.gz ``` * Run post-install scripts ``` $ <CSROOT>/mariadb/columnstore/bin/post-install --installdir=<CSROOT>/mariadb/columnstore ``` * Run postConfigure using the upgrade option ``` $ <CSROOT>/mariadb/columnstore/bin/postConfigure -u -i <CSROOT>/mariadb/columnstore ``` * Run the mysql\_upgrade script on the nodes documented above for a non-root user install [https://mariadb.com/kb/en/library/mariadb-columnstore-software-upgrade-117-ga-to-123-ga/#running-the-mysql\_upgrade-script](../library/mariadb-columnstore-software-upgrade-117-ga-to-123-ga/index#running-the-mysql_upgrade-script) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb mysql.columns_priv Table mysql.columns\_priv Table ========================= The `mysql.columns_priv` table contains information about column-level privileges. The table can be queried and although it is possible to directly update it, it is best to use [GRANT](../grant/index) for setting privileges. Note that the MariaDB privileges occur at many levels. A user may be granted a privilege at the column level, but may still not have permission on a table level, for example. See [privileges](../grant/index) for a more complete view of the MariaDB privilege system. The [INFORMATION\_SCHEMA.COLUMN\_PRIVILEGES](../information-schema-column_privileges-table/index) table derives its contents from `mysql.columns_priv`. **MariaDB starting with [10.4](../what-is-mariadb-104/index)**In [MariaDB 10.4](../what-is-mariadb-104/index) and later, this table uses the [Aria](../aria/index) storage engine. **MariaDB until [10.3](../what-is-mariadb-103/index)**In [MariaDB 10.3](../what-is-mariadb-103/index) and before, this table uses the [MyISAM](../myisam-storage-engine/index) storage engine. The `mysql.columns_priv` table contains the following fields: | Field | Type | Null | Key | Default | Description | | --- | --- | --- | --- | --- | --- | | `Host` | `char(60)` | NO | PRI | | Host (together with `User`, `Db` , `Table_name` and`Column_name` makes up the unique identifier for this record. | | `Db` | `char(64)` | NO | PRI | | Database name (together with `User`, `Host` , `Table_name` and`Column_name` makes up the unique identifier for this record. | | `User` | `char(80)` | NO | PRI | | User (together with `Host`, `Db` , `Table_name` and`Column_name` makes up the unique identifier for this record. | | `Table_name` | `char(64)` | NO | PRI | | Table name (together with `User`, `Db` , `Host` and`Column_name` makes up the unique identifier for this record. | | `Column_name` | `char(64)` | NO | PRI | | Column name (together with `User`, `Db` , `Table_name` and`Host` makes up the unique identifier for this record. | | `Timestamp` | `timestamp` | NO | | `CURRENT_TIMESTAMP` | | | `Column_priv` | `set('Select', 'Insert', 'Update', 'References')` | NO | | | The privilege type. See [Column Privileges](../grant/index#column-privileges) for details. | The [Acl\_column\_grants](../server-status-variables/index#acl_column_grants) status variable, added in [MariaDB 10.1.4](https://mariadb.com/kb/en/mariadb-1014-release-notes/), indicates how many rows the `mysql.columns_priv` table contains. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Authentication Plugin - mysql_native_password Authentication Plugin - mysql\_native\_password =============================================== The `mysql_native_password` authentication plugin is the default authentication plugin that will be used for an account created when no authentication plugin is explicitly mentioned and [old\_passwords=0](../server-system-variables/index#old_passwords) is set. It uses the password hashing algorithm introduced in MySQL 4.1, which is also used by the [PASSWORD()](../password/index) function when [old\_passwords=0](../server-system-variables/index#old_passwords) is set. This hashing algorithm is based on [SHA-1](https://en.wikipedia.org/wiki/SHA-1). It is not recommended to use the `mysql_native_password` authentication plugin for new installations that require **high password security**. If someone is able to both listen to the connection protocol and get a copy of the mysql.user table, then the person would be able to use this information to connect to the MariaDB server. The [ed25519](../authentication-plugin-ed25519/index) authentication plugin is a more modern authentication plugin that provides simple password authentication using a more secure algorithm. Installing the Plugin --------------------- The `mysql_native_password` authentication plugin is statically linked into the server, so no installation is necessary. Creating Users -------------- The easiest way to create a user account with the `mysql_native_password` authentication plugin is to make sure that [old\_passwords=0](../server-system-variables/index#old_passwords) is set, and then create a user account via [CREATE USER](../create-user/index) that does not specify an authentication plugin, but does specify a password via the [IDENTIFIED BY](../create-user/index#identified-by-password) clause. For example: ``` SET old_passwords=0; CREATE USER username@hostname IDENTIFIED BY 'mariadb'; ``` If [SQL\_MODE](../sql-mode/index) does not have `NO_AUTO_CREATE_USER` set, then you can also create the user account via [GRANT](../grant/index). For example: ``` SET old_passwords=0; GRANT SELECT ON db.* TO username@hostname IDENTIFIED BY 'mariadb'; ``` You can also create the user account by providing a password hash via the [IDENTIFIED BY PASSWORD](../create-user/index#identified-by-password-password_hash) clause, and MariaDB will validate whether the password hash is one that is compatible with `mysql_native_password`. For example: ``` SET old_passwords=0; SELECT PASSWORD('mariadb'); +-------------------------------------------+ | PASSWORD('mariadb') | +-------------------------------------------+ | *54958E764CE10E50764C2EECBB71D01F08549980 | +-------------------------------------------+ CREATE USER username@hostname IDENTIFIED BY PASSWORD '*54958E764CE10E50764C2EECBB71D01F08549980'; ``` Similar to all other [authentication plugins](../authentication-plugins/index), you could also specify the name of the plugin in the [IDENTIFIED VIA](../create-user/index#identified-viawith-authentication_plugin) clause while providing the password hash as the `USING` clause. For example: ``` CREATE USER username@hostname IDENTIFIED VIA mysql_native_password USING '*54958E764CE10E50764C2EECBB71D01F08549980'; ``` Changing User Passwords ----------------------- You can change a user account's password with the [SET PASSWORD](../set-password/index) statement while providing the plain-text password as an argument to the [PASSWORD()](../password/index) function. For example: ``` SET PASSWORD = PASSWORD('new_secret') ``` You can also change the user account's password with the [ALTER USER](../alter-user/index) statement. You would have to make sure that [old\_passwords=0](../server-system-variables/index#old_passwords) is set, and then you would have to specify a password via the [IDENTIFIED BY](../alter-user/index#identified-by-password) clause. For example: ``` SET old_passwords=0; ALTER USER username@hostname IDENTIFIED BY 'new_secret'; ``` Client Authentication Plugins ----------------------------- For clients that use the `libmysqlclient` or [MariaDB Connector/C](../mariadb-connector-c/index) libraries, MariaDB provides one client authentication plugin that is compatible with the `mysql_native_password` authentication plugin: * `mysql_native_password` When connecting with a [client or utility](../clients-utilities/index) to a server as a user account that authenticates with the `mysql_native_password` authentication plugin, you may need to tell the client where to find the relevant client authentication plugin by specifying the `--plugin-dir` option. For example: ``` mysql --plugin-dir=/usr/local/mysql/lib64/mysql/plugin --user=alice ``` However, the `mysql_native_password` client authentication plugin is generally statically linked into client libraries like `libmysqlclient` or [MariaDB Connector/C](../mariadb-connector-c/index), so this is not usually necessary. ### `mysql_native_password` The `mysql_native_password` client authentication plugin hashes the password before sending it to the server. Support in Client Libraries --------------------------- The `mysql_native_password` authentication plugin is one of the conventional authentication plugins, so all client libraries should support it. Known Old Issues (Only Relevant for Old Installations) ------------------------------------------------------ ### Mismatches Between Password and authentication\_string Columns For compatibility reasons,the `mysql_native_password` authentication plugin tries to read the password hash from both the `Password` and `authentication_string` columns in the [mysql.user](../mysqluser-table/index) table. This has caused issues in the past if one of the columns had a different value than the other. Starting with [MariaDB 10.2.19](https://mariadb.com/kb/en/mariadb-10219-release-notes/) and [MariaDB 10.3.11](https://mariadb.com/kb/en/mariadb-10311-release-notes/), [CREATE USER](../create-user/index), [ALTER USER](../alter-user/index), [GRANT](../grant/index), and [SET PASSWORD](../set-password/index) will set both columns whenever an account's password is changed. See [MDEV-16774](https://jira.mariadb.org/browse/MDEV-16774) for more information. See Also -------- * [ed25519](../authentication-plugin-ed25519/index) secure connection plugin * [History of MySQL and MariaDB authentication protocols](https://mariadb.org/history-of-mysql-mariadb-authentication-protocols) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb mysqlshow mysqlshow ========= **MariaDB starting with [10.4.6](https://mariadb.com/kb/en/mariadb-1046-release-notes/)**From [MariaDB 10.4.6](https://mariadb.com/kb/en/mariadb-1046-release-notes/), `mariadb-show` is a symlink to `mysqlshow`. **MariaDB starting with [10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/)**From [MariaDB 10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/), `mysqlshow` is the symlink, and `mariadb-show` the binary name. Shows the structure of a MariaDB database (databases, tables, columns and indexes). You can also use [SHOW DATABASES](../show-databases/index), [SHOW TABLES](../show-tables/index), [SHOW COLUMNS](../show-columns/index), [SHOW INDEX](../show-index/index) and [SHOW TABLE STATUS](../show-table-status/index), as well as the [Information Schema](../information_schema/index) tables ([TABLES](../information-schema-tables-table/index), [COLUMNS](../information-schema-columns-table/index), [STATISTICS](../information-schema-statistics-table/index)), to get similar functionality. Using mysqlshow --------------- ``` mysqlshow [OPTIONS] [database [table [column]]] ``` The output displays only the names of those databases, tables, or columns for which you have some privileges. If no database is given then all matching databases are shown. If no table is given, then all matching tables in database are shown. If no column is given, then all matching columns and column types in table are shown. If the last argument contains a shell or SQL wildcard (\*,?,% or \_) then only what's matched by the wildcard is shown. If a database name contains any underscores, those should be escaped with a backslash (some Unix shells require two) to get a list of the proper tables or columns. “\*” and “?” characters are converted into SQL “%” and “\_” wildcard characters. This might cause some confusion when you try to display the columns for a table with a “\_” in the name, because in this case, mysqlshow shows you only the table names that match the pattern. This is easily fixed by adding an extra “%” last on the command line as a separate argument. ### Options `mysqlshow` supports the following options: | Option | Description | | --- | --- | | `-c name`, `--character-sets-dir=name` | Directory for [character set](../data-types-character-sets-and-collations/index) files. | | `-C`, `--compress` | Use compression in server/client protocol if both support it. | | `--count` | Show number of rows per table (may be slow for non-[MyISAM](../myisam/index) tables). | | `-# [name]`, `--debug[=name]` | Output debug log. Typical is `d:t:o,filename`, the default is `d:t:o`. | | `--debug-check` | Check memory and open file usage at exit. | | `--debug-info` | Print some debug info at exit. | | `--default-auth=name` | Default authentication client-side plugin to use. | | `--default-character-set=name` | Set the default [character set](../data-types-character-sets-and-collations/index). | | `--defaults-extra-file=name` | Read the file *name* after the global files are read. Must be given as the first option. | | `--defaults-file=name` | Only read default options from the given file *name*. Must be given as the first option. | | `--defaults-group-suffix=suffix` | In addition to the given groups, also read groups with this suffix. | | `-?`, `--help` | Display help and exit. | | `-h name`, `--host=name` | Connect to the MariaDB server on the given host. | | `-k`, `--keys` | Show indexes for table. | | `--no-defaults` | Don't read default options from any option file. Must be given as the first option. | | `-p[password]`, `--password[=password]` | Password to use when connecting to server. If password is not given, it's solicited on the command line. Specifying a password on the command line should be considered insecure. You can use an option file to avoid giving the password on the command line. | | `-W`, `--pipe` | On Windows, connect to the server via a named pipe. This option applies only if the server supports named-pipe connections. | | `--plugin-dir=name` | Directory for client-side plugins. | | `-P num`, `--port=num` | Port number to use for connection or 0 for default to, in order of preference, my.cnf, $MYSQL\_TCP\_PORT, /etc/services, built-in default (3306). | | `--print-defaults` | Print the program argument list and exit. Must be given as the first option. | | `--protocol=name` | The protocol to use for connection (tcp, socket, pipe, memory). | | `--shared-memory-base-name=name` | On Windows, the shared-memory name to use, for connections made using shared memory to a local server. The default value is `MYSQL`. The shared-memory name is case sensitive. The server must be started with the `--shared-memory` option to enable shared-memory connections. | | `-t`, `--show-table-type` | Show table type column, as in [SHOW FULL TABLES](../show-tables/index). The type is BASE TABLE or VIEW. | | `-S name`, `--socket=name` | For connections to localhost, the Unix socket file to use, or, on Windows, the name of the named pipe to use. | | `--ssl` | Enables [TLS](../data-in-transit-encryption/index). TLS is also enabled even without setting this option when certain other TLS options are set. Starting with [MariaDB 10.2](../what-is-mariadb-102/index), the `--ssl` option will not enable [verifying the server certificate](../secure-connections-overview/index#server-certificate-verification) by default. In order to verify the server certificate, the user must specify the `--ssl-verify-server-cert` option. | | `--ssl-ca=name` | Defines a path to a PEM file that should contain one or more X509 certificates for trusted Certificate Authorities (CAs) to use for [TLS](../data-in-transit-encryption/index). This option requires that you use the absolute path, not a relative path. See [Secure Connections Overview: Certificate Authorities (CAs)](../secure-connections-overview/index#certificate-authorities-cas) for more information. This option implies the `--ssl` option. | | `--ssl-capath=name` | Defines a path to a directory that contains one or more PEM files that should each contain one X509 certificate for a trusted Certificate Authority (CA) to use for [TLS](../data-in-transit-encryption/index). This option requires that you use the absolute path, not a relative path. The directory specified by this option needs to be run through the `[openssl rehash](https://www.openssl.org/docs/man1.1.1/man1/rehash.html)` command. See [Secure Connections Overview: Certificate Authorities (CAs)](../secure-connections-overview/index#certificate-authorities-cas) for more information. This option is only supported if the client was built with OpenSSL. If the client was built with yaSSL, GnuTLS, or Schannel, then this option is not supported. See [TLS and Cryptography Libraries Used by MariaDB](../tls-and-cryptography-libraries-used-by-mariadb/index) for more information about which libraries are used on which platforms. This option implies the `--ssl` option. | | `--ssl-cert=name` | Defines a path to the X509 certificate file to use for [TLS](../data-in-transit-encryption/index). This option requires that you use the absolute path, not a relative path. This option implies the `--ssl` option. | | `--ssl-cipher=name` | List of permitted ciphers or cipher suites to use for [TLS](../data-in-transit-encryption/index). This option implies the `--ssl` option. | | `--ssl-key=name` | Defines a path to a private key file to use for [TLS](../data-in-transit-encryption/index). This option requires that you use the absolute path, not a relative path. This option implies the `--ssl` option. | | `--ssl-crl=name` | Defines a path to a PEM file that should contain one or more revoked X509 certificates to use for [TLS](../data-in-transit-encryption/index). This option requires that you use the absolute path, not a relative path. See [Secure Connections Overview: Certificate Revocation Lists (CRLs)](../secure-connections-overview/index#certificate-revocation-lists-crls) for more information. This option is only supported if the client was built with OpenSSL or Schannel. If the client was built with yaSSL or GnuTLS, then this option is not supported. See [TLS and Cryptography Libraries Used by MariaDB](../tls-and-cryptography-libraries-used-by-mariadb/index) for more information about which libraries are used on which platforms. This option implies the `--ssl` option. | | `--ssl-crlpath=name` | Defines a path to a directory that contains one or more PEM files that should each contain one revoked X509 certificate to use for [TLS](../data-in-transit-encryption/index). This option requires that you use the absolute path, not a relative path. The directory specified by this option needs to be run through the `[openssl rehash](https://www.openssl.org/docs/man1.1.1/man1/rehash.html)` command. See [Secure Connections Overview: Certificate Revocation Lists (CRLs)](../secure-connections-overview/index#certificate-revocation-lists-crls) for more information. This option is only supported if the client was built with OpenSSL. If the client was built with yaSSL, GnuTLS, or Schannel, then this option is not supported. See [TLS and Cryptography Libraries Used by MariaDB](../tls-and-cryptography-libraries-used-by-mariadb/index) for more information about which libraries are used on which platforms. This option implies the `--ssl` option. | | `--ssl-verify-server-cert` | Enables (or disables) [server certificate verification](../secure-connections-overview/index#server-certificate-verification). This option is disabled by default. | | `-i`, `--status` | Shows a lot of extra information about each table. See the [INFORMATION\_SCHEMA.TABLES](../information-schema-tables-table/index) table for more details on the returned information. | | `--tls-version=name` | This option accepts a comma-separated list of TLS protocol versions. A TLS protocol version will only be enabled if it is present in this list. All other TLS protocol versions will not be permitted. See [Secure Connections Overview: TLS Protocol Versions](../secure-connections-overview/index#tls-protocol-versions) for more information. This option was added in [MariaDB 10.4.6](https://mariadb.com/kb/en/mariadb-1046-release-notes/). | | `-u`, `--user=name` | User for login if not current user. | | `-v`, `--verbose` | More verbose output; you can use this multiple times to get even more verbose output. | | `-V`, `--version` | Output version information and exit. | ### Option Files In addition to reading options from the command-line, `mysqlshow` can also read options from [option files](../configuring-mariadb-with-option-files/index). If an unknown option is provided to `mysqlshow` in an option file, then it is ignored. The following options relate to how MariaDB command-line tools handles option files. They must be given as the first argument on the command-line: | Option | Description | | --- | --- | | `--print-defaults` | Print the program argument list and exit. | | `--no-defaults` | Don't read default options from any option file. | | `--defaults-file=#` | Only read default options from the given file #. | | `--defaults-extra-file=#` | Read this file after the global files are read. | | `--defaults-group-suffix=#` | In addition to the default option groups, also read option groups with this suffix. | In [MariaDB 10.2](../what-is-mariadb-102/index) and later, `mysqlshow` is linked with [MariaDB Connector/C](../about-mariadb-connector-c/index). However, MariaDB Connector/C does not yet handle the parsing of option files for this client. That is still performed by the server option file parsing code. See [MDEV-19035](https://jira.mariadb.org/browse/MDEV-19035) for more information. #### Option Groups `mysqlshow` reads options from the following [option groups](../configuring-mariadb-with-option-files/index#option-groups) from [option files](../configuring-mariadb-with-option-files/index): | Group | Description | | --- | --- | | `[mysqlshow]` | Options read by `mysqlshow`, which includes both MariaDB Server and MySQL Server. | | `[mariadb-show]` | Options read by `mysqlshow`. Available starting with [MariaDB 10.4.6](https://mariadb.com/kb/en/mariadb-1046-release-notes/). | | `[client]` | Options read by all MariaDB and MySQL [client programs](../clients-utilities/index), which includes both MariaDB and MySQL clients. For example, `mysqldump`. | | `[client-server]` | Options read by all MariaDB [client programs](../clients-utilities/index) and the MariaDB Server. This is useful for options like socket and port, which is common between the server and the clients. | | `[client-mariadb]` | Options read by all MariaDB [client programs](../clients-utilities/index). | Examples -------- Getting a list of databases: ``` bin/mysqlshow +--------------------+ | Databases | +--------------------+ | information_schema | | test | +--------------------+ ``` Getting a list of tables in the `test` database: ``` bin/mysqlshow test Database: test +---------+ | Tables | +---------+ | author | | book | | city | | country | +---------+ ``` Getting a list of columns in the `test`.`book` table: ``` bin/mysqlshow test book Database: test Table: book +-----------+-----------------------+-------------------+------+-----+---------+----------------+--------------------------------+---------+ | Field | Type | Collation | Null | Key | Default | Extra | Privileges | Comment | +-----------+-----------------------+-------------------+------+-----+---------+----------------+--------------------------------+---------+ | id | mediumint(8) unsigned | | NO | PRI | | auto_increment | select,insert,update,references | | | title | varchar(200) | latin1_swedish_ci | NO | | | | select,insert,update,references | | | author_id | smallint(5) unsigned | | NO | MUL | | | select,insert,update,references | | +-----------+-----------------------+-------------------+------+-----+---------+----------------+--------------------------------+---------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb InnoDB File-Per-Table Tablespaces InnoDB File-Per-Table Tablespaces ================================= When you create a table using the [InnoDB storage engine](../xtradb-and-innodb/index), data written to that table is stored on the file system in a data file called a tablespace. Tablespace files contain both the data and indexes. When [innodb\_file\_per\_table=ON](../innodb-system-variables/index#innodb_file_per_table) is set, InnoDB uses one tablespace file per InnoDB table. These tablespace files have the `.ibd` extension. When [innodb\_file\_per\_table=OFF](../innodb-system-variables/index#innodb_file_per_table) is set, InnoDB stores all tables in the [InnoDB system tablespace](../innodb-system-tablespaces/index). InnoDB versions in MySQL 5.7 and above also support an additional type of tablespace called [general tablespaces](https://dev.mysql.com/doc/refman/5.7/en/general-tablespaces.html) that are created with [CREATE TABLESPACE](https://dev.mysql.com/doc/refman/5.7/en/create-tablespace.html). However, InnoDB versions in MariaDB Server do not support general tablespaces or [CREATE TABLESPACE](../create-tablespace/index). File-Per-Table Tablespace Locations ----------------------------------- By default, InnoDB's file-per-table tablespaces are created in the system's data directory, which is defined by the [datadir](../server-system-variables/index#datadir) system variable. The system variable [innodb\_data\_home\_dir](../innodb-system-variables/index#innodb_data_home_dir) will not change the location of file-per-table tablespaces. In the event that you have a specific tablespace that you need stored in a dedicated path, you can set the location using the [DATA DIRECTORY](../create-table/index#data-directoryindex-directory) table option when you create the table. For instance, ``` CREATE TABLE test.t1 ( id INT PRIMARY KEY AUTO_INCREMENT, name VARCHAR(50) ) ENGINE=InnoDB DATA DIRECTORY = "/data/contact"; ``` MariaDB then creates a database directory on the configured path and the file-per-table tablespace will be created inside that directory. On Unix-like operating systems, you can see the file using the ls command: ``` # ls -al /data/contact/test drwxrwx--- 2 mysql mysql 4096 Dec 8 18:46 . drwxr-xr-x 3 mysql mysql 4096 Dec 8 18:46 .. -rw-rw---- 1 mysql mysql 98304 Dec 8 20:41 t1.ibd ``` Note, the system user that runs the MariaDB Server process (which is usually `mysql`) must have write permissions on the given path. Copying Transportable Tablespaces --------------------------------- InnoDB's file-per-table tablespaces are transportable, which means that you can copy a file-per-table tablespace from one MariaDB Server to another server. You may find this useful in cases where you need to transport full tables between servers and don't want to use backup tools like [mariabackup](../mariabackup/index) or [mysqldump](../mysqldump/index). In fact, this process can even be used with [mariabackup](../mariabackup/index) in some cases, such as when [restoring partial backups](../partial-backup-and-restore-with-mariabackup/index) or when [restoring individual tables or partitions from a backup](../restoring-individual-tables-and-partitions-with-mariabackup/index). ### Copying Transportable Tablespaces for Non-partitioned Tables You can copy the transportable tablespace of a non-partitioned table from one server to another by exporting the tablespace file from the original server, and then importing the tablespace file into the new server. #### Exporting Transportable Tablespaces for Non-partitioned Tables You can export a non-partitioned table by locking the table and copying the table's `.ibd` and `.cfg` files from the relevant [tablespace location](#file-per-table-tablespace-locations) for the table to a backup location. For example, the process would go like this: * First, use the [FLUSH TABLES ... FOR EXPORT](../flush-tables-for-export/index) statement on the target table: ``` FLUSH TABLES test.t1 FOR EXPORT; ``` This forces the server to close the table and provides your connection with a read lock on the table. * Then, while your connection still holds the lock on the table, copy the tablespace file and the metadata file to a safe directory: ``` # cp /data/contacts/test/t1.ibd /data/saved-tablespaces/ # cp /data/contacts/test/t1.cfg /data/saved-tablespaces/ ``` * Then, once you've copied the files, you can release the lock with [UNLOCK TABLES](../lock-tables-and-unlock-tables/index): ``` UNLOCK TABLES; ``` #### Importing Transportable Tablespaces for Non-partitioned Tables You can import a non-partitioned table by discarding the table's original tablespace, copying the table's `.ibd` and `.cfg` files from the backup location to the relevant [tablespace location](#file-per-table-tablespace-locations) for the table, and then telling the server to import the tablespace. For example, the process would go like this: * First, on the destination server, you need to create a copy of the table. Use the same [CREATE TABLE](../create-table/index) statement that was used to create the table on the original server: ``` CREATE TABLE test.t1 ( id INT PRIMARY KEY AUTO_INCREMENT, name VARCHAR(50) ) ENGINE=InnoDB; ``` * Then, use [ALTER TABLE ... DISCARD TABLESPACE](../alter-table/index#discard-tablespace) to discard the new table's tablespace: ``` ALTER TABLE test.t1 DISCARD TABLESPACE; ``` * Then, copy the `.ibd` and `.cfg` files from the original server to the relevant directory on the target MariaDB Server: ``` # scp /data/tablespaces/t1.ibd target-server.com:/var/lib/mysql/test/ # scp /data/tablespaces/t1.cfg target-server.com:/var/lib/mysql/test/ ``` File-per-table tablespaces can be imported with just the `.ibd` file in many cases. If you do not have the tablespace's `.cfg` file for whatever reason, then it is usually worth trying to import the tablespace with just the `.ibd` file. * Then, once the files are in the proper directory on the target server, use [ALTER TABLE ... IMPORT TABLESPACE](../alter-table/index#import-tablespace) to import the new table's tablespace: ``` ALTER TABLE test.t1 IMPORT TABLESPACE; ``` ### Copying Transportable Tablespaces for Partitioned Tables Currently, MariaDB does not directly support the transport of tablespaces from partitioned tables. See [MDEV-10568](https://jira.mariadb.org/browse/MDEV-10568) for more information about that. It is still possible to transport partitioned tables if we use a workaround. You can copy the transportable tablespaces of a partitioned table from one server to another by exporting the tablespace file of each partition from the original server, and then importing the tablespace file of each partition into the new server. #### Exporting Transportable Tablespaces for Partitioned Tables You can export a partitioned table by locking the table and copying the `.ibd` and `.cfg` files of each partition from the relevant [tablespace location](#file-per-table-tablespace-locations) for the partition to a backup location. For example, the process would go like this: * First, let's create a test table with some data on the original server: ``` CREATE TABLE test.t2 ( employee_id INT, name VARCHAR(50), ) ENGINE=InnoDB PARTITION BY RANGE (employee_id) ( PARTITION p0 VALUES LESS THAN (6), PARTITION p1 VALUES LESS THAN (11), PARTITION p2 VALUES LESS THAN (16), PARTITION p3 VALUES LESS THAN MAXVALUE ); INSERT INTO test.t2 (name, employee_id) VALUES ('Geoff Montee', 1), ('Chris Calendar', 6), ('Kyle Joiner', 11), ('Will Fong', 16); ``` * Then, we need to export the partitioned tablespace from the original server, which follows the same process as exporting non-partitioned tablespaces. That means that we need to use the [FLUSH TABLES ... FOR EXPORT](../flush-tables-for-export/index) statement on the target table: ``` FLUSH TABLES test.t2 FOR EXPORT; ``` This forces the server to close the table and provides your connection with a read lock on the table. * Then, if we grep the database directory in the data directory for the newly created `t2` table, we can see a number of `.ibd` and `.cfg` files for the table: ``` # ls -l /var/lib/mysql/test/ | grep t2 total 428 -rw-rw---- 1 mysql mysql 827 Dec 5 16:08 t2.frm -rw-rw---- 1 mysql mysql 48 Dec 5 16:08 t2.par -rw-rw---- 1 mysql mysql 579 Dec 5 18:47 t2#P#p0.cfg -rw-r----- 1 mysql mysql 98304 Dec 5 16:43 t2#P#p0.ibd -rw-rw---- 1 mysql mysql 579 Dec 5 18:47 t2#P#p1.cfg -rw-rw---- 1 mysql mysql 98304 Dec 5 16:08 t2#P#p1.ibd -rw-rw---- 1 mysql mysql 579 Dec 5 18:47 t2#P#p2.cfg -rw-rw---- 1 mysql mysql 98304 Dec 5 16:08 t2#P#p2.ibd -rw-rw---- 1 mysql mysql 579 Dec 5 18:47 t2#P#p3.cfg -rw-rw---- 1 mysql mysql 98304 Dec 5 16:08 t2#P#p3.ibd ``` * Then, while our connection still holds the lock on the table, we need to copy the tablespace files and the metadata files to a safe directory: ``` $ mkdir /tmp/backup $ sudo cp /var/lib/mysql/test/*.ibd /tmp/backup $ sudo cp /var/lib/mysql/test/*.cfg /tmp/backup ``` * Then, once we've copied the files, we can release the lock with [UNLOCK TABLES](../lock-tables-and-unlock-tables/index): ``` UNLOCK TABLES; ``` #### Importing Transportable Tablespaces for Partitioned Tables You can import a partitioned table by creating a placeholder table, discarding the placeholder table's original tablespace, copying the partition's `.ibd` and `.cfg` files from the backup location to the relevant [tablespace location](#file-per-table-tablespace-locations) for the placeholder table, and then telling the server to import the tablespace. At that point, the server can exchange the tablespace for the placeholder table with the one for the partition. For example, the process would go like this: * First, we need to copy the saved tablespace files from the original server to the target server: ``` $ scp /tmp/backup/t2* user@target-host:/tmp/backup ``` * Then, we need to import the partitioned tablespaces onto the target server. The import process for partitioned tables is more complicated than the import process for non-partitioned tables. To start with, if it doesn't already exist, then we need to create a partitioned table on the target server that matches the partitioned table on the original server: ``` CREATE TABLE test.t2 ( id INT PRIMARY KEY AUTO_INCREMENT, name VARCHAR(50), employee_id INT ) ENGINE=InnoDB PARTITION BY RANGE (employee_id) ( PARTITION p0 VALUES LESS THAN (6), PARTITION p1 VALUES LESS THAN (11), PARTITION p2 VALUES LESS THAN (16), PARTITION p3 VALUES LESS THAN MAXVALUE ); ``` * Then, using this table as a model, we need to create a placeholder of this table with the same structure that does not use partitioning. This can be done with a [CREATE TABLE... AS SELECT](../create-table/index#create-select) statement: ``` CREATE TABLE test.t2_placeholder AS SELECT * FROM test.t2 WHERE NULL; ``` This statement will create a new table called `t2_placeholder` that has the same schema structure as `t2`, but it does not use partitioning and it contains no rows. ##### For Each Partition From this point forward, the rest of our steps need to happen for each individual partition. For each partition, we need to do the following process: * First, we need to use [ALTER TABLE ... DISCARD TABLESPACE](../alter-table/index#discard-tablespace) to discard the placeholder table's tablespace: ``` ALTER TABLE test.t2_placeholder DISCARD TABLESPACE; ``` * Then, copy the `.ibd` and `.cfg` files for the next partition to the relevant directory for the `t2_placeholder` table on the target MariaDB Server: ``` # cp /tmp/backup/t2#P#p0.cfg /var/lib/mysql/test/t2_placeholder.cfg # cp /tmp/backup/t2#P#p0.ibd /var/lib/mysql/test/t2_placeholder.ibd # chown mysql:mysql /var/lib/mysql/test/t2_placeholder* ``` File-per-table tablespaces can be imported with just the `.ibd` file in many cases. If you do not have the tablepace's `.cfg` file for whatever reason, then it is usually worth trying to import the tablespace with just the `.ibd` file. * Then, once the files are in the proper directory on the target server, we need to use [ALTER TABLE ... IMPORT TABLESPACE](../alter-table/index#import-tablespace) to import the new table's tablespace: ``` ALTER TABLE test.t2_placeholder IMPORT TABLESPACE; ``` The placeholder table now contains data from the `p0` partition on the source server. ``` SELECT * FROM test.t2_placeholder; +-------------+--------------+ | employee_id | name | +-------------+--------------+ | 1 | Geoff Montee | +-------------+--------------+ ``` * Then, it's time to transfer the partition from the placeholder to the target table. This can be done with an [ALTER TABLE... EXCHANGE PARTITION](../alter-table/index#exchange-partition) statement: ``` ALTER TABLE test.t2 EXCHANGE PARTITION p0 WITH TABLE test.t2_placeholder; ``` The target table now contains the first partition from the source table. ``` SELECT * FROM test.t2; +-------------+--------------+ | employee_id | name | +-------------+--------------+ | 1 | Geoff Montee | +-------------+--------------+ ``` * Repeat this procedure for each partition you want to import. For each partition, we need to discard the placeholder table's tablespace, and then import the partitioned table's tablespace into the placeholder table, and then exchange the tablespaces between the placeholder table and the partition of our target table. When this process is complete for all partitions, the target table will contain the imported data: ``` SELECT * FROM test.t2; +-------------+----------------+ | employee_id | name | +-------------+----------------+ | 1 | Geoff Montee | | 6 | Chris Calendar | | 11 | Kyle Joiner | | 16 | Will Fong | +-------------+----------------+ ``` * Then, we can remove the placeholder table from the database: ``` DROP TABLE test.t2_placeholder; ``` ### Known Problems with Copying Transportable Tablespaces #### Differing Storage Formats for Temporal Columns [MariaDB 10.1.2](https://mariadb.com/kb/en/mariadb-1012-release-notes/) added the [mysql56\_temporal\_format](../server-system-variables/index#mysql56_temporal_format) system variable, which enables a new MySQL 5.6-compatible storage format for the [TIME](../time/index), [DATETIME](../datetime/index) and [TIMESTAMP](../timestamp/index) data types. If a file-per-tablespace file contains columns that use one or more of these temporal data types and if the tablespace file's original table was created with a certain storage format for these columns, then the tablespace file can only be imported into tables that were also created with the same storage format for these columns as the original table. Otherwise, you will see errors like the following: ``` ALTER TABLE dt_test IMPORT TABLESPACE; ERROR 1808 (HY000): Schema mismatch (Column dt precise type mismatch.) ``` See [MDEV-15225](https://jira.mariadb.org/browse/MDEV-15225) for more information. See the pages for the [TIME](../time/index), [DATETIME](../datetime/index) and [TIMESTAMP](../timestamp/index) data types to determine how to update the storage format for temporal columns in tables that were created before [MariaDB 10.1.2](https://mariadb.com/kb/en/mariadb-1012-release-notes/) or that were created with [mysql56\_temporal\_format=OFF](../server-system-variables/index#mysql56_temporal_format). #### Differing ROW\_FORMAT Values InnoDB file-per-table tablespaces can use different [row formats](../xtradbinnodb-storage-formats/index). A specific row format can be specified when creating a table either by setting the [ROW\_FORMAT](../create-table/index#row_format) table option or by the setting the [innodb\_default\_row\_format](../innodb-system-variables/index#innodb_default_row_format) system variable. See [Setting a Table's Row Format](../innodb-storage-formats/index#setting-a-tables-row-format) for more information on how to set an InnoDB table's row format. If a file-per-tablespace file was created with a certain row format, then the tablespace file can only be imported into tables that were created with the same row format as the original table. Otherwise, you will see errors like the following: ``` ALTER TABLE t0 IMPORT TABLESPACE; ERROR 1808 (HY000): Schema mismatch (Expected FSP_SPACE_FLAGS=0x21, .ibd file contains 0x0.) ``` The error message is a bit more descriptive in [MariaDB 10.2.17](https://mariadb.com/kb/en/mariadb-10217-release-notes/) and later: ``` ALTER TABLE t0 IMPORT TABLESPACE; ERROR 1808 (HY000): Schema mismatch (Table flags don't match, server table has 0x1 and the meta-data file has 0x0; .cfg file uses ROW_FORMAT=REDUNDANT) ``` Be sure to check a tablespace's row format before moving it from one server to another. Keep in mind that the default row format can change between major versions of MySQL or MariaDB. See [Checking a Table's Row Format](../innodb-storage-formats/index#checking-a-tables-row-format) for information on how to check an InnoDB table's row format. See [MDEV-15049](https://jira.mariadb.org/browse/MDEV-15049) and [MDEV-16851](https://jira.mariadb.org/browse/MDEV-16851) for more information. #### Foreign Key Constraints DISCARD on a table with foreign key constraints is only possible after disabling [foreign\_key\_checks](../server-system-variables/index#foreign_key_checks): ``` SET SESSION foreign_key_checks=0; ALTER TABLE t0 DISCARD TABLESPACE; ``` IMPORT on the other hand does not enforce foreign key constraints. So when importing tablespaces, referential integrity can only be guaranteed to import all tables bound by foreign key constraint at the same time, from an EXPORT of those tables taken with the same transactional state. Tablespace Encryption --------------------- MariaDB supports data-at-rest encryption for the InnoDB storage engine. When enabled, the Server encrypts data before writing it to the tablespace and decrypts reads from the tablespace before returning result-sets. This means that a malicious user attempting to exfiltrate sensitive data won't be able to import the tablespace onto a different server as shown above without the encryption key. For more information on data encryption, see [Encrypting Data for InnoDB](../encrypting-data-for-innodb-xtradb/index). See Also -------- * [Geoff Montee:Importing InnoDB Partitions in MySQL 5.6 and MariaDB 10.0/10.1](http://www.geoffmontee.com/importing-innodb-partitions-in-mysql-5-6-and-mariadb-10-010-1/) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Preparing and Installing MariaDB ColumnStore 1.2.X Preparing and Installing MariaDB ColumnStore 1.2.X =================================================== | Title | Description | | --- | --- | | [Preparing for ColumnStore Installation - 1.2.0](../preparing-for-columnstore-installation-120/index) | Prerequisite With the 1.2.0 version of MariaDB ColumnStore, there should ... | | [Preparing for ColumnStore Installation - 1.2.1](../preparing-for-and-installing-columnstore-version-121/index) | Prerequisite With version 1.2.1 of MariaDB ColumnStore, there should be no... | | [Preparing for ColumnStore Installation - 1.2.2](../preparing-for-columnstore-installation-122/index) | Prerequisite With version 1.2.2 of MariaDB ColumnStore, there should be no... | | [MariaDB ColumnStore Cluster Test Tool](../mariadb-columnstore-cluster-test-tool/index) | Introduction MariaDB ColumnStore Cluster Test Tool is used to validate tha... | | [Installing and Configuring a Single Server ColumnStore System - 1.2.x](../installing-and-configuring-a-single-server-columnstore-system-12x/index) | Preparing to Install Review the Preparing for Installations Document and ... | | [Installing and Configuring a Multi Server ColumnStore System - 1.2.X](../installing-and-configuring-a-multi-server-columnstore-system-12x/index) | Preparing to Install Review the Preparing for ColumnStore Installation 1.2... | | [Custom Installation of Multi-Server ColumnStore Cluster](../custom-installation-of-multi-server-columnstore-cluster/index) | If you choose not to do the quick install and chose to customize the vario... | | [Preparing for ColumnStore Installation - 1.2.5](../preparing-for-columnstore-installation-125/index) | Prerequisite With version 1.2.5 of MariaDB ColumnStore, there should be no... | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb Using Compound Statements Outside of Stored Programs Using Compound Statements Outside of Stored Programs ==================================================== Compound statements can also be used outside of [stored programs](../stored-routines/index). ``` delimiter | IF @have_innodb THEN CREATE TABLE IF NOT EXISTS innodb_index_stats ( database_name VARCHAR(64) NOT NULL, table_name VARCHAR(64) NOT NULL, index_name VARCHAR(64) NOT NULL, last_update TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP, stat_name VARCHAR(64) NOT NULL, stat_value BIGINT UNSIGNED NOT NULL, sample_size BIGINT UNSIGNED, stat_description VARCHAR(1024) NOT NULL, PRIMARY KEY (database_name, table_name, index_name, stat_name) ) ENGINE=INNODB DEFAULT CHARSET=utf8 COLLATE=utf8_bin STATS_PERSISTENT=0; END IF| Query OK, 0 rows affected, 2 warnings (0.00 sec) ``` Note, that using compound statements this way is subject to following limitations: * Only [BEGIN](../begin-end/index), [IF](../if-statement/index), [CASE](../case-statement/index), [LOOP](../loop/index), [WHILE](../while/index), [REPEAT](../repeat-loop/index) statements may start a compound statement outside of stored programs. * [BEGIN](../begin-end/index) must use the `BEGIN NOT ATOMIC` syntax (otherwise it'll be confused with [BEGIN](../start-transaction/index) that starts a transaction). * A compound statement might not start with a label. * A compound statement is parsed completely—note "2 warnings" in the above example, even if the condition was false (InnoDB was, indeed, disabled), and the [CREATE TABLE](../create-table/index) statement was not executed, it was still parsed and the parser produced "Unknown storage engine" warning. Inside a compound block first three limitations do not apply, one can use anything that can be used inside a stored program — including labels, condition handlers, variables, and so on: ``` BEGIN NOT ATOMIC DECLARE foo CONDITION FOR 1146; DECLARE x INT DEFAULT 0; DECLARE CONTINUE HANDLER FOR SET x=1; INSERT INTO test.t1 VALUES ("hndlr1", val, 2); END| ``` Example how to use `IF`: ``` IF (1>0) THEN BEGIN NOT ATOMIC SELECT 1; END ; END IF;; ``` Example of how to use `WHILE` loop: ``` DELIMITER | BEGIN NOT ATOMIC DECLARE x INT DEFAULT 0; WHILE x <= 10 DO SET x = x + 1; SELECT x; END WHILE; END| DELIMITER ; ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb INSTALL PLUGIN INSTALL PLUGIN ============== Syntax ------ ``` INSTALL PLUGIN [IF NOT EXISTS] plugin_name SONAME 'plugin_library' ``` Description ----------- This statement installs an individual [plugin](../mariadb-plugins/index) from the specified library. To install the whole library (which could be required), use [INSTALL SONAME](../install-soname/index). See also [Installing a Plugin](../plugin-overview/index#installing-a-plugin). `plugin_name` is the name of the plugin as defined in the plugin declaration structure contained in the library file. Plugin names are not case sensitive. For maximal compatibility, plugin names should be limited to ASCII letters, digits, and underscore, because they are used in C source files, shell command lines, M4 and Bourne shell scripts, and SQL environments. `plugin_library` is the name of the shared library that contains the plugin code. The file name extension can be omitted (which makes the statement look the same on all architectures). The shared library must be located in the plugin directory (that is, the directory named by the [plugin\_dir](../server-system-variables/index#plugin_dir) system variable). The library must be in the plugin directory itself, not in a subdirectory. By default, `plugin_dir` is plugin directory under the directory named by the `pkglibdir` configuration variable, but it can be changed by setting the value of `plugin_dir` at server startup. For example, set its value in a `my.cnf` file: ``` [mysqld] plugin_dir=/path/to/plugin/directory ``` If the value of [plugin\_dir](../server-system-variables/index#plugin_dir) is a relative path name, it is taken to be relative to the MySQL base directory (the value of the basedir system variable). `INSTALL PLUGIN` adds a line to the `mysql.plugin` table that describes the plugin. This table contains the plugin name and library file name. `INSTALL PLUGIN` causes the server to read option (`my.cnf`) files just as during server startup. This enables the plugin to pick up any relevant options from those files. It is possible to add plugin options to an option file even before loading a plugin (if the loose prefix is used). It is also possible to uninstall a plugin, edit `my.cnf`, and install the plugin again. Restarting the plugin this way enables it to the new option values without a server restart. `INSTALL PLUGIN` also loads and initializes the plugin code to make the plugin available for use. A plugin is initialized by executing its initialization function, which handles any setup that the plugin must perform before it can be used. To use `INSTALL PLUGIN`, you must have the [INSERT privilege](../grant/index) for the `mysql.plugin` table. At server startup, the server loads and initializes any plugin that is listed in the `mysql.plugin` table. This means that a plugin is installed with `INSTALL PLUGIN` only once, not every time the server starts. Plugin loading at startup does not occur if the server is started with the `--skip-grant-tables` option. When the server shuts down, it executes the de-initialization function for each plugin that is loaded so that the plugin has a chance to perform any final cleanup. If you need to load plugins for a single server startup when the `--skip-grant-tables` option is given (which tells the server not to read system tables), use the `--plugin-load` [mysqld option](../mysqld-options-full-list/index). **MariaDB starting with [10.4.0](https://mariadb.com/kb/en/mariadb-1040-release-notes/)**#### IF NOT EXISTS When the `IF NOT EXISTS` clause is used, MariaDB will return a note instead of an error if the specified plugin already exists. See [SHOW WARNINGS](../show-warnings/index). Examples -------- ``` INSTALL PLUGIN sphinx SONAME 'ha_sphinx.so'; ``` The extension can also be omitted: ``` INSTALL PLUGIN innodb SONAME 'ha_xtradb'; ``` From [MariaDB 10.4.0](https://mariadb.com/kb/en/mariadb-1040-release-notes/): ``` INSTALL PLUGIN IF NOT EXISTS example SONAME 'ha_example'; Query OK, 0 rows affected (0.104 sec) INSTALL PLUGIN IF NOT EXISTS example SONAME 'ha_example'; Query OK, 0 rows affected, 1 warning (0.000 sec) SHOW WARNINGS; +-------+------+------------------------------------+ | Level | Code | Message | +-------+------+------------------------------------+ | Note | 1968 | Plugin 'example' already installed | +-------+------+------------------------------------+ ``` See Also -------- * [List of Plugins](../list-of-plugins/index) * [Plugin Overview](../plugin-overview/index) * [INFORMATION\_SCHEMA.PLUGINS Table](../plugins-table-information-schema/index) * [mysql\_plugin](../mysql_plugin/index) * [SHOW PLUGINS](../show-plugins/index) * [INSTALL SONAME](../install-soname/index) * [UNINSTALL PLUGIN](../uninstall-plugin/index) * [UNINSTALL SONAME](../uninstall-soname/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Information Schema ROCKSDB_INDEX_FILE_MAP Table Information Schema ROCKSDB\_INDEX\_FILE\_MAP Table ================================================== The [Information Schema](../information_schema/index) `ROCKSDB_INDEX_FILE_MAP` table is included as part of the [MyRocks](../myrocks/index) storage engine. The `PROCESS` [privilege](../grant/index) is required to view the table. It contains the following columns: | Column | Description | | --- | --- | | `COLUMN_FAMILY` | | | `INDEX_NUMBER` | | | `SST_NAME` | | | `NUM_ROWS` | | | `DATA_SIZE` | | | `ENTRY_DELETES` | | | `ENTRY_SINGLEDELETES` | | | `ENTRY_MERGES` | | | `ENTRY_OTHERS` | | | `DISTINCT_KEYS_PREFIX` | | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Information Schema PROFILING Table Information Schema PROFILING Table ================================== The [Information Schema](../information_schema/index) `PROFILING` table contains information about statement resource usage. Profiling information is only recorded if the `[profiling](../server-system-variables/index#profiling)` session variable is set to 1. It contains the following columns: | Column Name | Description | | --- | --- | | `QUERY_ID` | Query\_ID. | | `SEQ` | Sequence number showing the display order for rows with the same `QUERY_ID`. | | `STATE` | Profiling state. | | `DURATION` | Time in seconds that the statement has been in the current state. | | `CPU_USER` | User CPU usage in seconds. | | `CPU_SYSTEM` | System CPU usage in seconds. | | `CONTEXT_VOLUNTARY` | Number of voluntary context switches. | | `CONTEXT_INVOLUNTARY` | Number of involuntary context switches. | | `BLOCK_OPS_IN` | Number of block input operations. | | `BLOCK_OPS_OUT` | Number of block output operations. | | `MESSAGES_SENT` | Number of communications sent. | | `MESSAGES_RECEIVED` | Number of communications received. | | `PAGE_FAULTS_MAJOR` | Number of major page faults. | | `PAGE_FAULTS_MINOR` | Number of minor page faults. | | `SWAPS` | Number of swaps. | | `SOURCE_FUNCTION` | Function in the source code executed by the profiled state. | | `SOURCE_FILE` | File in the source code executed by the profiled state. | | `SOURCE_LINE` | Line in the source code executed by the profiled state. | It contains similar information to the `[SHOW PROFILE](../show-profile/index) and [SHOW PROFILES](../show-profiles/index)` statements. Profiling is enabled per session. When a session ends, its profiling information is lost. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Installing MariaDB with yum/dnf Installing MariaDB with yum/dnf =============================== On RHEL, CentOS, Fedora, and other similar Linux distributions, it is highly recommended to install the relevant [RPM packages](../rpm/index) from MariaDB's repository using [yum](https://en.wikipedia.org/wiki/Yum_(software)) or [dnf](https://en.wikipedia.org/wiki/DNF_(software)). Starting with RHEL 8 and Fedora 22, `yum` has been replaced by `dnf`, which is the next major version of `yum`. However, `yum` commands still work on many systems that use `dnf`. This page walks you through the simple installation steps using `yum`. Adding the MariaDB YUM repository --------------------------------- We currently have YUM repositories for the following Linux distributions: * Red Hat Enterprise Linux (RHEL) 6 * Red Hat Enterprise Linux (RHEL) 7 * CentOS 6 * CentOS 7 * Fedora 27 * Fedora 28 * Fedora 29 ### Using the MariaDB Package Repository Setup Script If you want to install MariaDB with `yum`, then you can configure `yum` to install from MariaDB Corporation's MariaDB Package Repository by using the [MariaDB Package Repository setup script](../mariadb-package-repository-setup-and-usage/index). MariaDB Corporation provides a MariaDB Package Repository for several Linux distributions that use `yum` to manage packages. This repository contains software packages related to MariaDB Server, including the server itself, [clients and utilities](../clients-utilities/index), [client libraries](../client-libraries/index), [plugins](../plugins/index), and [Mariabackup](../mariabackup/index). The MariaDB Package Repository setup script automatically configures your system to install packages from the MariaDB Package Repository. To use the script, execute the following command: ``` curl -sS https://downloads.mariadb.com/MariaDB/mariadb_repo_setup | sudo bash ``` Note that this script also configures a repository for [MariaDB MaxScale](../maxscale/index) and a repository for MariaDB Tools, which currently only contains [Percona XtraBackup](../percona-xtrabackup/index) and its dependencies. See [MariaDB Package Repository Setup and Usage](../mariadb-package-repository-setup-and-usage/index) for more information. ### Using the MariaDB Repository Configuration Tool If you want to install MariaDB with `yum`, then you can configure `yum` to install from MariaDB Foundation's MariaDB Repository by using the [MariaDB Repository Configuration Tool](https://downloads.mariadb.org/mariadb/repositories/). The MariaDB Foundation provides a MariaDB repository for several Linux distributions that use `yum` to manage packages. This repository contains software packages related to MariaDB Server, including the server itself, [clients and utilities](../clients-utilities/index), [client libraries](../client-libraries/index), [plugins](../plugins/index), and [Mariabackup](../mariabackup/index). The MariaDB Repository Configuration Tool can easily generate the appropriate configuration file to add the repository for your distribution. Once you have the appropriate repository configuration section for your distribution, add it to a file named `MariaDB.repo` under `/etc/yum.repos.d/`. For example, if you wanted to use the repository to install [MariaDB 10.3](../what-is-mariadb-103/index) on CentOS 7, then you could use the following `yum` repository configuration in `/etc/yum.repos.d/MariaDB.repo`: ``` [mariadb] name = MariaDB baseurl = http://yum.mariadb.org/10.3/centos7-amd64 gpgkey=https://yum.mariadb.org/RPM-GPG-KEY-MariaDB gpgcheck=1 ``` The example file above includes a `gpgkey` line to automatically fetch the GPG public key that is used to verify the digital signatures of the packages in our repositories. This allows the the `yum`, `dnf`, and `rpm` utilities to verify the integrity of the packages that they install. ### Pinning the MariaDB Repository to a Specific Minor Release If you wish to pin the `yum` repository to a specific minor release, or if you would like to do a `yum downgrade` to a specific minor release, then you can create a `yum` repository configuration with a `baseurl` option set to that specific minor release. The MariaDB Foundation archives repositories of old minor releases at the following URL: * <http://archive.mariadb.org/> So if you can't find the repository of a specific minor release at `yum.mariadb.org`, then it would be a good idea to check the archive. For example, if you wanted to pin your repository to [MariaDB 10.3.14](https://mariadb.com/kb/en/mariadb-10314-release-notes/) on CentOS 7, then you could use the following `yum` repository configuration in `/etc/yum.repos.d/MariaDB.repo`: ``` [mariadb] name = MariaDB-10.3.14 baseurl=http://yum.mariadb.org/10.3.14/centos7-amd64 # alternative: baseurl=http://archive.mariadb.org/mariadb-10.3.14/yum/centos7-amd64 gpgkey=https://yum.mariadb.org/RPM-GPG-KEY-MariaDB gpgcheck=1 ``` Note that if you change an existing repository configuration, then you need to execute the following: ``` sudo yum clean all ``` Updating the MariaDB YUM repository to a New Major Release ---------------------------------------------------------- MariaDB's `yum` repository can be updated to a new major release. How this is done depends on how you originally configured the repository. ### Updating the Major Release with the MariaDB Package Repository Setup Script If you configured `yum` to install from MariaDB Corporation's MariaDB Package Repository by using the [MariaDB Package Repository setup script](../mariadb-package-repository-setup-and-usage/index), then you can update the major release that the repository uses by running the script again. ### Updating the Major Release with the MariaDB Repository Configuration Tool If you configured `yum` to install from MariaDB Foundation's MariaDB Repository by using the [MariaDB Repository Configuration Tool](https://downloads.mariadb.org/mariadb/repositories/), then you can update the major release that the repository uses by updating the `yum` repository configuration file in-place. For example, if you wanted to change the repository from [MariaDB 10.2](../what-is-mariadb-102/index) to [MariaDB 10.3](../what-is-mariadb-103/index), and if the repository configuration file was at `/etc/yum.repos.d/MariaDB.repo`, then you could execute the following: ``` sudo sed -i 's/10.2/10.3/' /etc/yum.repos.d/MariaDB.repo ``` After that, the repository should refer to [MariaDB 10.3](../what-is-mariadb-103/index). If the `yum` repository is pinned to a specific minor release, then the above `sed` command can result in an invalid repository configuration. In that case, the recommended options are: * Edit the `MariaDB.repo` repository file manually. * Or delete the `MariaDB.repo` repository file, and then install the repository of the new version with the more robust [MariaDB Package Repository setup script](../mariadb-package-repository-setup-and-usage/index). Importing the MariaDB GPG Public Key ------------------------------------ Before MariaDB can be installed, you also have to import the GPG public key that is used to verify the digital signatures of the packages in our repositories. This allows the `yum`, `dnf` and `rpm` utilities to verify the integrity of the packages that they install. The id of our GPG public key is `0xcbcb082a1bb943db`. The short form of the id is `0x1BB943DB`. The full key fingerprint is: ``` 1993 69E5 404B D5FC 7D2F E43B CBCB 082A 1BB9 43DB ``` `yum` should prompt you to import the GPG public key the first time that you install a package from MariaDB's repository. However, if you like, the [rpm](https://linux.die.net/man/8/rpm) utility can be used to manually import this key instead. For example: ``` sudo rpm --import https://yum.mariadb.org/RPM-GPG-KEY-MariaDB ``` Once the GPG public key is imported, you are ready to install packages from the repository. Installing MariaDB Packages with YUM ------------------------------------ After the `yum` repository is configured, you can install MariaDB by executing the [yum](https://linux.die.net/man/8/yum) command. The specific command that you would use would depend on which specific packages that you want to install. ### Installing the Most Common Packages with YUM **MariaDB starting with [10.4](../what-is-mariadb-104/index)**In [MariaDB 10.4](../what-is-mariadb-104/index) and later, to Install the most common packages, execute the following command: ``` sudo yum install MariaDB-server galera-4 MariaDB-client MariaDB-shared MariaDB-backup MariaDB-common ``` **MariaDB until [10.3](../what-is-mariadb-103/index)**In [MariaDB 10.3](../what-is-mariadb-103/index) and before, to Install the most common packages, execute the following command: ``` sudo yum install MariaDB-server galera MariaDB-client MariaDB-shared MariaDB-backup MariaDB-common ``` ### Installing MariaDB Server with YUM To Install MariaDB Server, execute the following command: ``` sudo yum install MariaDB-server ``` ### Installing MariaDB Galera Cluster with YUM The process to install MariaDB Galera Cluster with the MariaDB `yum` repository is practically the same as installing standard MariaDB Server. In [MariaDB 10.1](../what-is-mariadb-101/index) and later, Galera Cluster support has been included in the standard MariaDB Server packages, so you will need to install the `MariaDB-server` package, as you normally would. In [MariaDB 10.4](../what-is-mariadb-104/index) and later, you also need to install the `galera-4` package to obtain the [Galera](../galera/index) 4 wsrep provider library. In [MariaDB 10.3](../what-is-mariadb-103/index) and before, you also need to install the `galera` package to obtain the [Galera](../galera/index) 3 wsrep provider library. **MariaDB starting with [10.4](../what-is-mariadb-104/index)**In [MariaDB 10.4](../what-is-mariadb-104/index) and later, to install MariaDB Galera Cluster, you could execute the following command: ``` sudo yum install MariaDB-server MariaDB-client galera-4 ``` **MariaDB until [10.3](../what-is-mariadb-103/index)**In [MariaDB 10.3](../what-is-mariadb-103/index) and before, to install MariaDB Galera Cluster, you could execute the following command: ``` sudo yum install MariaDB-server MariaDB-client galera ``` If you haven't yet imported the MariaDB GPG public key, then `yum` will prompt you to import it after it downloads the packages, but before it prompts you to install them. See [MariaDB Galera Cluster](../galera/index) for more information on MariaDB Galera Cluster. ### Installing MariaDB Clients and Client Libraries with YUM In [MariaDB 10.2](../what-is-mariadb-102/index) and later, [MariaDB Connector/C](../about-mariadb-connector-c/index) has been included as the client library. However, the package name for the client library has not been changed. To Install the clients and client libraries, execute the following command: ``` sudo yum install MariaDB-client MariaDB-shared ``` ### Installing Mariabackup with YUM To install [Mariabackup](../mariabackup/index), execute the following command: ``` sudo yum install MariaDB-backup ``` ### Installing Plugins with YUM Some [plugins](../plugins/index) may also need to be installed. For example, to install the [cracklib\_password\_check](../cracklib-password-check-plugin/index) password validation plugin, execute the following command: ``` sudo yum install MariaDB-cracklib-password-check ``` ### Installing Debug Info Packages with YUM **MariaDB starting with [5.5.64](https://mariadb.com/kb/en/mariadb-5564-release-notes/)**The MariaDB `yum` repository first added [debuginfo](https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/Developer_Guide/intro.debuginfo.html) packages in [MariaDB 5.5.64](https://mariadb.com/kb/en/mariadb-5564-release-notes/), [MariaDB 10.1.39](https://mariadb.com/kb/en/mariadb-10139-release-notes/), [MariaDB 10.2.23](https://mariadb.com/kb/en/mariadb-10223-release-notes/), [MariaDB 10.3.14](https://mariadb.com/kb/en/mariadb-10314-release-notes/), and [MariaDB 10.4.4](https://mariadb.com/kb/en/mariadb-1044-release-notes/). The MariaDB `yum` repository also contains [debuginfo](https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/Developer_Guide/intro.debuginfo.html) packages. These package may be needed when [debugging a problem](../how-to-produce-a-full-stack-trace-for-mysqld/index). #### Installing Debug Info for the Most Common Packages with YUM To install [debuginfo](https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/Developer_Guide/intro.debuginfo.html) for the most common packages, execute the following command: ``` sudo yum install MariaDB-server-debuginfo MariaDB-client-debuginfo MariaDB-shared-debuginfo MariaDB-backup-debuginfo MariaDB-common-debuginfo ``` #### Installing Debug Info for MariaDB Server with YUM To install [debuginfo](https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/Developer_Guide/intro.debuginfo.html) for MariaDB Server, execute the following command: ``` sudo yum install MariaDB-server-debuginfo ``` #### Installing Debug Info for MariaDB Clients and Client Libraries with YUM In [MariaDB 10.2](../what-is-mariadb-102/index) and later, [MariaDB Connector/C](../about-mariadb-connector-c/index) has been included as the client library. However, the package name for the client library has not been changed. To install [debuginfo](https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/Developer_Guide/intro.debuginfo.html) for the clients and client libraries, execute the following command: ``` sudo yum install MariaDB-client-debuginfo MariaDB-shared-debuginfo ``` #### Installing Debug Info for Mariabackup with YUM To install [debuginfo](https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/Developer_Guide/intro.debuginfo.html) for [Mariabackup](../mariabackup/index), execute the following command: ``` sudo yum install MariaDB-backup-debuginfo ``` #### Installing Debug Info for Plugins with YUM For some [plugins](../plugins/index), [debuginfo](https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/Developer_Guide/intro.debuginfo.html) may also need to be installed. For example, to install [debuginfo](https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/Developer_Guide/intro.debuginfo.html) for the [cracklib\_password\_check](../cracklib-password-check-plugin/index) password validation plugin, execute the following command: ``` sudo yum install MariaDB-cracklib-password-check-debuginfo ``` ### Installing Older Versions from the Repository The MariaDB `yum` repository contains the last few versions of MariaDB. To show what versions are available, use the following command: ``` yum list --showduplicates MariaDB-server ``` In the output you will see the available versions. For example: ``` $ yum list --showduplicates MariaDB-server Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile * base: centos.mirrors.ovh.net * extras: centos.mirrors.ovh.net * updates: centos.mirrors.ovh.net Available Packages MariaDB-server.x86_64 10.3.10-1.el7.centos mariadb MariaDB-server.x86_64 10.3.11-1.el7.centos mariadb MariaDB-server.x86_64 10.3.12-1.el7.centos mariadb mariadb-server.x86_64 1:5.5.60-1.el7_5 base ``` The MariaDB `yum` repository in this example contains [MariaDB 10.3.10](https://mariadb.com/kb/en/mariadb-10310-release-notes/), [MariaDB 10.3.11](https://mariadb.com/kb/en/mariadb-10311-release-notes/), and [MariaDB 10.3.12](https://mariadb.com/kb/en/mariadb-10312-release-notes/). The CentOS base `yum` repository also contains [MariaDB 5.5.60](https://mariadb.com/kb/en/mariadb-5560-release-notes/). To install an older version of a package instead of the latest version we just need to specify the package name, a dash, and then the version number. And we only need to specify enough of the version number for it to be unique from the other available versions. However, when installing an older version of a package, if `yum` has to install dependencies, then it will automatically choose to install the latest versions of those packages. To ensure that all MariaDB packages are on the same version in this scenario, it is necessary to specify them all. The packages that the MariaDB-server package depend on are: MariaDB-client, MariaDB-shared, and MariaDB-common. Therefore, to install [MariaDB 10.3.11](https://mariadb.com/kb/en/mariadb-10311-release-notes/) from this `yum` repository, we would do the following: ``` sudo yum install MariaDB-server-10.3.11 MariaDB-client-10.3.11 MariaDB-shared-10.3.11 MariaDB-backup-10.3.11 MariaDB-common-10.3.11 ``` The rest of the install and setup process is as normal. After Installation ------------------ After the installation is complete, you can [start MariaDB](../starting-and-stopping-mariadb-automatically/index). If you are using [MariaDB Galera Cluster](../galera/index), then keep in mind that the first node will have to be [bootstrapped](../getting-started-with-mariadb-galera-cluster/index#bootstrapping-a-new-cluster). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb ANALYZE FORMAT=JSON ANALYZE FORMAT=JSON =================== `ANALYZE FORMAT=JSON` is a mix of the [EXPLAIN FORMAT=JSON](../explain-formatjson/index) and [ANALYZE](../analyze-statement/index) statement features. The `ANALYZE FORMAT=JSON $statement` will execute `$statement`, and then print the output of `EXPLAIN FORMAT=JSON`, amended with data from the query execution. Basic Execution Data -------------------- You can get the following also from tabular `ANALYZE` statement form: * **`r_rows`** is provided for any node that reads rows. It shows how many rows were read, on average * **`r_filtered`** is provided whenever there is a condition that is checked. It shows the percentage of rows left after checking the condition. Advanced Execution Data ----------------------- The most important data not available in the regular tabula `ANALYZE` statement are: * **`r_loops`** field. This shows how many times the node was executed. Most query plan elements have this field. * **`r_total_time_ms`** field. It shows how much time in total was spent executing this node. If the node has subnodes, their execution time is included. * **`r_buffer_size`** field. Query plan nodes that make use of buffers report the size of buffer that was was used. Data About Individual Query Plan Nodes -------------------------------------- * **`filesort`** node reports whether sorting was done with `LIMIT n` parameter, and how many rows were in the sort result. * **`block-nl-join`** node has `r_loops` field, which allows to tell whether `Using join buffer` was efficient * **`range-checked-for-each-record`** reports counters that show the result of the check. * **`expression-cache`** is used for subqueries, and it reports how many times the cache was used, and what cache hit ratio was. * **`union_result`** node has `r_rows` so one can see how many rows were produced after UNION operation * and so forth Use Cases --------- See [Examples of ANALYZE FORMAT=JSON](../analyze-formatjson-examples/index). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Migrating from InfiniDB 4.x to MariaDB ColumnStore Migrating from InfiniDB 4.x to MariaDB ColumnStore ================================================== Overview -------- The columnar disk storage format is unchanged between InfiniDB 4.X and MariaDB ColumnStore allowing for relatively straightforward data migration utilizing backup and restore logic. This document outlines an approach to perform the migration that can be adapted to your particular needs. The examples in this document assume a root install with the packages installed in /usr/local. For non-root system, just substitute /usr/local with $HOME, which is the non-root user home directory. Single Server Install --------------------- ### Backup Data in InfiniDB Suspend writes if this is a live system: ``` # cc suspendDatabaseWrites y ``` ##### Backup Front-End schemas Use mysqldump to create schema files from appropriate databases: ``` /usr/local/Calpont/mysql/bin/mysqldump --defaults-file=/usr/local/Calpont/mysql/my.cnf --skip-lock-tables --no-data loans > loans_schema.sql ``` Update schema file to utilize correct engine and add schema sync only comment: ``` # sed "s/ENGINE=InfiniDB/ENGINE=columnstore COMMENT='schema sync only'/gI" loans_schema.sql > loans_schema_columnstore.sql ``` ##### Backup Back-End data Take a backup of the columnar data files pm1 which are stored in the data<N> directories. The exact folder list can be confirmed by looking at the SystemConfig section of the configuration file /usr/local/Calpont/etc/Calpont.xml. Each data<n> directory corresponds to a specific DBRoot containing the actual columnar data in the 000.dir and system metadata under systemFiles/dbrm. In addition you may also want to take a copy of the data directory if this contains custom scripts for bulk loading: ``` cp -r /usr/local/Calpont/data? . ``` ### Restoring Backup into ColumnStore: ##### Restore Front-End schemas First install a new fresh install of ColumnStore then create the schema using the mysqldump file: ``` # mcsmysql Welcome to the MariaDB monitor. Commands end with ; or \g. Your MariaDB connection id is 5 Server version: 10.1.19-MariaDB Columnstore 1.0.5-1 Copyright (c) 2000, 2016, Oracle, MariaDB Corporation Ab and others. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. MariaDB [(none)]> create database loans; Query OK, 1 row affected (0.00 sec) MariaDB [(none)]> use loans Database changed MariaDB [loans]> source loans_schema_columnstore.sql Query OK, 0 rows affected (0.00 sec) ... MariaDB [loans]> exit ``` ##### Restore Back-End data Now replace the data<N> directories with the backup on pm1 as appropriate for each directory: ``` # mcsadmin shutdownSystem y # cd /usr/local/mariadb/columnstore/ # mv data1 data1.bkp # mv /backupdir/data1 . # cd data1/systemFiles/dbrm/ # mv BRM_saves_current BRM_saves_current.bkp # cp ../../../data1.bkp/systemFiles/dbrm/BRM_saves_current . # mcsadmin startSystem ``` The system should start cleanly and the data should now be accessible in the database. Multi Server Install - Combined UM/PM ------------------------------------- ### Backup Data in InfiniDB Suspend writes if this is a live system, enter on pm1: ``` # cc suspendDatabaseWrites y ``` ##### Backup Front-End schemas Use mysqldump to create schema files from appropriate databases from pm1 ``` /usr/local/Calpont/mysql/bin/mysqldump --defaults-file=/usr/local/Calpont/mysql/my.cnf --skip-lock-tables --no-data loans > loans_schema.sql ``` Update schema file to utilize correct engine and add schema sync only comment: ``` # sed "s/ENGINE=InfiniDB/ENGINE=columnstore COMMENT='schema sync only'/gI" loans_schema.sql > loans_schema_columnstore.sql ``` ##### Backup Back-End data Take a backup of the columnar data files from each PM which are stored in the data<N> directories of each PM server. The exact folder list can be confirmed by looking at the SystemConfig section of the configuration file /usr/local/Calpont/etc/Calpont.xml. Each data<n> directory corresponds to a specific DBRoot containing the actual columnar data in the 000.dir and system metadata under systemFiles/dbrm. In addition you may also want to take a copy of the data directory if this contains custom scripts for bulk loading: ``` cp -r /usr/local/Calpont/data? . ``` ### Restoring Backup into ColumnStore ##### Restore Front-End schemas First install a new fresh install of ColumnStore then create the schema using the mysqldump file: ``` # mcsmysql Welcome to the MariaDB monitor. Commands end with ; or \g. Your MariaDB connection id is 5 Server version: 10.1.19-MariaDB Columnstore 1.0.5-1 Copyright (c) 2000, 2016, Oracle, MariaDB Corporation Ab and others. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. MariaDB [(none)]> create database loans; Query OK, 1 row affected (0.00 sec) MariaDB [(none)]> use loans Database changed MariaDB [loans]> source loans_schema_columnstore.sql Query OK, 0 rows affected (0.00 sec) ... MariaDB [loans]> exit ``` ##### Restore Back-end Data Now replace the data<N> directories with the backup on each PM as appropriate for each directory: ``` # mcsadmin shutdownSystem y # cd /usr/local/mariadb/columnstore/ # mv data1 data1.bkp # mv /backupdir/data1 . # cd data1/systemFiles/dbrm/ # mv BRM_saves_current BRM_saves_current.bkp # cp ../../../data1.bkp/systemFiles/dbrm/BRM_saves_current . # mcsadmin startSystem ``` The system should start cleanly and the data should now be accessible in the database. Multi Server Install - Separate UM/PM ------------------------------------- ### Backup Data in InfiniDB Suspend writes if this is a live system, enter on pm1: ``` # cc suspendDatabaseWrites y ``` ##### Backup Front-End schemas On um1: Use mysqldump to create schema files from appropriate databases from pm1 ``` /usr/local/Calpont/mysql/bin/mysqldump --defaults-file=/usr/local/Calpont/mysql/my.cnf --skip-lock-tables --no-data loans > loans_schema.sql ``` Update schema file to utilize correct engine and add schema sync only comment: ``` # sed "s/ENGINE=InfiniDB/ENGINE=columnstore COMMENT='schema sync only'/gI" loans_schema.sql > loans_schema_columnstore.sql ``` ##### Backup Back-End data Take a backup of the columnar data files from each PM which are stored in the data<N> directories of each PM server. The exact folder list can be confirmed by looking at the SystemConfig section of the configuration file /usr/local/Calpont/etc/Calpont.xml. Each data<n> directory corresponds to a specific DBRoot containing the actual columnar data in the 000.dir and system metadata under systemFiles/dbrm. In addition you may also want to take a copy of the data directory if this contains custom scripts for bulk loading: ``` cp -r /usr/local/Calpont/data? . ``` ### Restoring Backup into ColumnStore ##### Restore Front-End schemas On um1: First install a new fresh install of ColumnStore then create the schema using the mysqldump file: ``` # mcsmysql Welcome to the MariaDB monitor. Commands end with ; or \g. Your MariaDB connection id is 5 Server version: 10.1.19-MariaDB Columnstore 1.0.5-1 Copyright (c) 2000, 2016, Oracle, MariaDB Corporation Ab and others. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. MariaDB [(none)]> create database loans; Query OK, 1 row affected (0.00 sec) MariaDB [(none)]> use loans Database changed MariaDB [loans]> source loans_schema_columnstore.sql Query OK, 0 rows affected (0.00 sec) ... MariaDB [loans]> exit ``` ##### Restore Back-end Data Now replace the data<N> directories with the backup on each PM as appropriate for each directory: ``` # mcsadmin shutdownSystem y # cd /usr/local/mariadb/columnstore/ # mv data1 data1.bkp # mv /backupdir/data1 . # cd data1/systemFiles/dbrm/ # mv BRM_saves_current BRM_saves_current.bkp # cp ../../../data1.bkp/systemFiles/dbrm/BRM_saves_current . # mcsadmin startSystem ``` The system should start cleanly and the data should now be accessible in the database. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb SFORMAT SFORMAT ======= **MariaDB starting with [10.7.0](https://mariadb.com/kb/en/mariadb-1070-release-notes/)**SFORMAT was added in [MariaDB 10.7.0](https://mariadb.com/kb/en/mariadb-1070-release-notes/). Description ----------- The `SFORMAT` function takes an input string and a formatting specification and returns the string formatted using the rules the user passed in the specification. It use the [fmtlib library](https://fmt.dev/) for Python-like (as well as Rust, C++20, etc) string formatting. Only fmtlib 7.0.0+ is supported. There is no native support for temporal and decimal values: * TIME\_RESULT is handled as STRING\_RESULT * DECIMAL\_RESULT as REAL\_RESULT Examples -------- ``` SELECT SFORMAT("The answer is {}.", 42); +----------------------------------+ | SFORMAT("The answer is {}.", 42) | +----------------------------------+ | The answer is 42. | +----------------------------------+ CREATE TABLE test_sformat(mdb_release char(6), mdev int, feature char(20)); INSERT INTO test_sformat VALUES('10.7.0', 25015, 'Python style sformat'), ('10.7.0', 4958, 'UUID'); SELECT * FROM test_sformat; +-------------+-------+----------------------+ | mdb_release | mdev | feature | +-------------+-------+----------------------+ | 10.7.0 | 25015 | Python style sformat | | 10.7.0 | 4958 | UUID | +-------------+-------+----------------------+ SELECT SFORMAT('MariaDB Server {} has a preview for MDEV-{} which is about {}', mdb_release, mdev, feature) AS 'Preview Release Examples' FROM test_sformat; +----------------------------------------------------------------------------------------+ | Preview Release Examples | +----------------------------------------------------------------------------------------+ | MariaDB Server 10.7.0 has a preview for MDEV-25015 which is about Python style sformat | | MariaDB Server 10.7.0 has a preview for MDEV-4958 which is about UUID | +----------------------------------------------------------------------------------------+ ``` See Also -------- * [10.7 preview feature: Python-like string formatting](https://mariadb.org/10-7-preview-feature-sformat/) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Upgrading Galera Cluster Upgrading Galera Cluster ========================= | Title | Description | | --- | --- | | [Upgrading Between Minor Versions with Galera Cluster](../upgrading-between-minor-versions-with-galera-cluster/index) | Upgrading between minor versions of MariaDB with Galera Cluster, e.g. from ... | | [Upgrading from MariaDB 10.3 to MariaDB 10.4 with Galera Cluster](../upgrading-from-mariadb-103-to-mariadb-104-with-galera-cluster/index) | How to upgrade from MariaDB 10.3 to MariaDB 10.4 in a Galera Cluster deployment. | | [Upgrading from MariaDB 10.2 to MariaDB 10.3 with Galera Cluster](../upgrading-from-mariadb-102-to-mariadb-103-with-galera-cluster/index) | How to upgrade from MariaDB 10.2 to MariaDB 10.3 in a Galera Cluster deployment. | | [Upgrading from MariaDB 10.1 to MariaDB 10.2 with Galera Cluster](../upgrading-from-mariadb-101-to-mariadb-102-with-galera-cluster/index) | How to upgrade from MariaDB 10.1 to MariaDB 10.2 in a Galera Cluster deployment. | | [Upgrading from MariaDB Galera Cluster 10.0 to MariaDB 10.1 with Galera Cluster](../upgrading-galera-cluster-upgrading-from-mariadb-galera-cluster-100-to-maria/index) | How to upgrade from MariaDB Galera Cluster 10.0 to MariaDB 10.1 in a Galera Cluster deployment. | | [Upgrading from MariaDB Galera Cluster 5.5 to MariaDB Galera Cluster 10.0](../upgrading-from-mariadb-galera-cluster-55-to-mariadb-galera-cluster-100/index) | How to upgrade from MariaDB Galera Cluster 5.5 to MariaDB Galera Cluster 10.0 | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb ColumnStore User Module ColumnStore User Module ======================= The User Module manages and controls the operation of end user queries. It maintains the state of each query, issues requests to one or more Performance Modules to process the query, and resolves the query by aggregating the various result-sets from all participating Performance Modules into the one returned to the end user. Usage ----- The primary purpose of the User Module is to handle concurrency scaling. It never directly touches database files and doesn't require visibility to them. It uses a machine's RAM in a transitory manner to assemble partial query results into a complete answer that's returned to the user. It is responsible for the following core functions: * Transforming the MariaDB query plan into a ColumnStore Job List. * Performing InfiniDB Object ID lookups from the MariaDB ColumnStore system catalog. * Inspecting the Extent Map to reduce I/O. It accomplishes this through the elimination of unnecessary extents. For more information, see [Storage Architecture](../columnstore-storage-architecture/index). * Issuing instructions (sometimes called 'primitive operation'), to Performance Modules. * Executing hash joins as needed, depending on the size of smaller tables in the join. Helps manage distributed hash joins by sending needed hash maps to the Performance Modules. * Executing cross-table-scope functions and expressions that occur after a hash join. * Receiving data from the Performance Modules, re-transmitting it back to them where necessary. * Executing follow-up steps for all aggregation and distinct processing. * Returning data to the MariaDB interface. Processes --------- The User Module contains several processes, including `[mysqld](#mariadb-server)`, [ExeMgr](#execution-manager), and [distribution managers](#distribution-managers). ### MariaDB Server The User Module runs `mysqld`. This is the MariaDB Server running with ColumnStore. It performs the same tasks as a normal MariaDB Server deployment: validating connections, parsing SQL statements, SQL plan generation, and final result-set distribution. Additionally, this server converts MariaDB Server query plans into ColumnStore query plan format. This format is essentially a parse tree, but adds execution hints from the optimizer to assist the User Module in converting the parse tree to a Job List. ### Execution Manager The ExeMgr listens on a TCP/IP port for query parse trees from the MariaDB Server. It's responsible for converting these query parse trees into a Job List. Job Lists represent the sequence of instructions necessary to answer the query. The ExeMgr walks the query parse tree and iteratively generates the job steps, optimizing and re-optimizing the Job List as it goes. The major categories of job steps are the application of a column filter, processing table joins, and the projection of returned columns. Each operation in the query plan executes in parallel by the Job List itself and has the capability of running entirely on the User Module, entirely on the Performance Module or in some combination. Each node uses the Extent Map to determine which Performance Modules to send work orders. For more information on Extent Maps, see [Storage Architecture](../columnstore-storage-architecture/index). ### Distribution Managers In addition to these, the User Module also runs processes for DMLProc, DDLPrc and cpimport. DMLProc and DDLProc distribute DML and DDL statements to the appropriate Performance Modules. When cpimport runs on the User Module, it distributes source files to the Performance Modules. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb SET NAMES SET NAMES ========= Syntax ------ ``` SET NAMES {'charset_name' [COLLATE 'collation_name'] | DEFAULT} ``` Description ----------- Sets the [character\_set\_client](../server-system-variables/index#character_set_client), [character\_set\_connection](../server-system-variables/index#character_set_connection), [character\_set\_results](../server-system-variables/index#character_set_results) and, implicitly, the [collation\_connection](../server-system-variables/index#collation_connection) session system variables to the specified character set and collation. This determines which [character set](../character-sets/index) the client will use to send statements to the server, and the server will use for sending results back to the client. `ucs2`, `utf16`, and `utf32` are not valid character sets for `SET NAMES`, as they cannot be used as client character sets. The collation clause is optional. If not defined (or if `DEFAULT` is specified), the [default collation for the character set](../supported-character-sets-and-collations/index) will be used. Quotes are optional for the character set or collation clauses. Examples -------- ``` SELECT VARIABLE_NAME, SESSION_VALUE FROM INFORMATION_SCHEMA.SYSTEM_VARIABLES WHERE VARIABLE_NAME LIKE 'character_set_c%' OR VARIABLE_NAME LIKE 'character_set_re%' OR VARIABLE_NAME LIKE 'collation_c%'; +--------------------------+-----------------+ | VARIABLE_NAME | SESSION_VALUE | +--------------------------+-----------------+ | CHARACTER_SET_RESULTS | utf8 | | CHARACTER_SET_CONNECTION | utf8 | | CHARACTER_SET_CLIENT | utf8 | | COLLATION_CONNECTION | utf8_general_ci | +--------------------------+-----------------+ SET NAMES big5; SELECT VARIABLE_NAME, SESSION_VALUE FROM INFORMATION_SCHEMA.SYSTEM_VARIABLES WHERE VARIABLE_NAME LIKE 'character_set_c%' OR VARIABLE_NAME LIKE 'character_set_re%' OR VARIABLE_NAME LIKE 'collation_c%'; +--------------------------+-----------------+ | VARIABLE_NAME | SESSION_VALUE | +--------------------------+-----------------+ | CHARACTER_SET_RESULTS | big5 | | CHARACTER_SET_CONNECTION | big5 | | CHARACTER_SET_CLIENT | big5 | | COLLATION_CONNECTION | big5_chinese_ci | +--------------------------+-----------------+ SET NAMES 'latin1' COLLATE 'latin1_bin'; SELECT VARIABLE_NAME, SESSION_VALUE FROM INFORMATION_SCHEMA.SYSTEM_VARIABLES WHERE VARIABLE_NAME LIKE 'character_set_c%' OR VARIABLE_NAME LIKE 'character_set_re%' OR VARIABLE_NAME LIKE 'collation_c%'; +--------------------------+---------------+ | VARIABLE_NAME | SESSION_VALUE | +--------------------------+---------------+ | CHARACTER_SET_RESULTS | latin1 | | CHARACTER_SET_CONNECTION | latin1 | | CHARACTER_SET_CLIENT | latin1 | | COLLATION_CONNECTION | latin1_bin | +--------------------------+---------------+ SET NAMES DEFAULT; SELECT VARIABLE_NAME, SESSION_VALUE FROM INFORMATION_SCHEMA.SYSTEM_VARIABLES WHERE VARIABLE_NAME LIKE 'character_set_c%' OR VARIABLE_NAME LIKE 'character_set_re%' OR VARIABLE_NAME LIKE 'collation_c%'; +--------------------------+-------------------+ | VARIABLE_NAME | SESSION_VALUE | +--------------------------+-------------------+ | CHARACTER_SET_RESULTS | latin1 | | CHARACTER_SET_CONNECTION | latin1 | | CHARACTER_SET_CLIENT | latin1 | | COLLATION_CONNECTION | latin1_swedish_ci | +--------------------------+-------------------+ ``` See Also -------- * [SET CHARACTER SET](../set-character-set/index) * [Character Sets and Collations](../character-sets/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb Performance Schema setup_timers Table Performance Schema setup\_timers Table ====================================== Description ----------- The `setup_timers` table shows the currently selected event timers. It contains the following columns: | Column | Description | | --- | --- | | `NAME` | Type of instrument the timer is used for. | | `TIMER_NAME` | Timer applying to the instrument type. Can be modified. | The `TIMER_NAME` value can be changed to choose a different timer, and can be any non-NULL value in the [performance\_timers.TIMER\_NAME](../performance-schema-performance_timers-table/index) column. If you modify the table, monitoring is immediately affected, and currently monitored events would use a combination of old and new timers, which is probably undesirable. It is best to reset the Performance Schema statistics if you make changes to this table. Example ------- ``` SELECT * FROM setup_timers; +-----------+-------------+ | NAME | TIMER_NAME | +-----------+-------------+ | idle | MICROSECOND | | wait | CYCLE | | stage | NANOSECOND | | statement | NANOSECOND | +-----------+-------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Dynamic Column API Dynamic Column API ================== This page describes the client-side API for reading and writing [Dynamic Columns](../dynamic-columns/index) blobs. Normally, you should use [Dynamic column functions](../dynamic-columns/index#dynamic-columns-functions) which are run inside the MariaDB server and allow one to access Dynamic Columns content without any client-side libraries. If you need to read/write dynamic column blobs **on the client** for some reason, this API enables that. Where to get it --------------- The API is a part of `libmysql` C client library. In order to use it, you need to include this header file ``` #include <mysql/ma_dyncol.h> ``` and link against `libmysql`. Data structures --------------- ### DYNAMIC\_COLUMN `DYNAMIC_COLUMN` represents a packed dynamic column blob. It is essentially a string-with-length and is defined as follows: ``` /* A generic-purpose arbitrary-length string defined in MySQL Client API */ typedef struct st_dynamic_string { char *str; size_t length,max_length,alloc_increment; } DYNAMIC_STRING; ... typedef DYNAMIC_STRING DYNAMIC_COLUMN; ``` ### DYNAMIC\_COLUMN\_VALUE Dynamic columns blob stores {name, value} pairs. `DYNAMIC_COLUMN_VALUE` structure is used to represent the value in accessible form. ``` struct st_dynamic_column_value { DYNAMIC_COLUMN_TYPE type; union { long long long_value; unsigned long long ulong_value; double double_value; struct { MYSQL_LEX_STRING value; CHARSET_INFO *charset; } string; struct { decimal_digit_t buffer[DECIMAL_BUFF_LENGTH]; decimal_t value; } decimal; MYSQL_TIME time_value; } x; }; typedef struct st_dynamic_column_value DYNAMIC_COLUMN_VALUE; ``` Every value has a type, which is determined by the `type` member. | type | structure field | | --- | --- | | `DYN_COL_NULL` | - | | `DYN_COL_INT` | `value.x.long_value` | | `DYN_COL_UINT` | `value.x.ulong_value` | | `DYN_COL_DOUBLE` | `value.x.double_value` | | `DYN_COL_STRING` | `value.x.string.value`, `value.x.string.charset` | | `DYN_COL_DECIMAL` | `value.x.decimal.value` | | `DYN_COL_DATETIME` | `value.x.time_value` | | `DYN_COL_DATE` | `value.x.time_value` | | `DYN_COL_TIME` | `value.x.time_value` | | `DYN_COL_DYNCOL` | `value.x.string.value` | Notes * Values with type `DYN_COL_NULL` do not ever occur in dynamic columns blobs. * Type `DYN_COL_DYNCOL` means that the value is a packed dynamic blob. This is how nested dynamic columns are done. * Before storing a value to `value.x.decimal.value`, one must call `mariadb_dyncol_prepare_decimal()` to initialize the space for storage. ### enum\_dyncol\_func\_result `enum enum_dyncol_func_result` is used as return value. | value | name | meaning | | --- | --- | --- | | 0 | `ER_DYNCOL_OK` | OK | | 0 | `ER_DYNCOL_NO` | (the same as ER\_DYNCOL\_OK but for functions which return a YES/NO) | | 1 | `ER_DYNCOL_YES` | YES response or success | | 2 | `ER_DYNCOL_TRUNCATED` | Operation succeeded but the data was truncated | | -1 | `ER_DYNCOL_FORMAT` | Wrong format of the encoded string | | -2 | `ER_DYNCOL_LIMIT` | A limit of implementation reached | | -3 | `ER_DYNCOL_RESOURCE` | Out of resources | | -4 | `ER_DYNCOL_DATA` | Incorrect input data | | -5 | `ER_DYNCOL_UNKNOWN_CHARSET` | Unknown character set | Result codes that are less than zero represent error conditions. Function reference ------------------ Functions come in pairs: * `xxx()` operates on the old (pre-MariaDB-10.0.1) dynamic column blob format where columns were identified by numbers. * `xxx_named()` can operate on both old or new data format. If it modifies the blob, it will convert it to the new data format. You should use `xxx_named()` functions, unless you need to keep the data compatible with MariaDB versions before 10.0.1. ### mariadb\_dyncol\_create\_many Create a packed dynamic blob from arrays of values and names. ``` enum enum_dyncol_func_result mariadb_dyncol_create_many(DYNAMIC_COLUMN *str, uint column_count, uint *column_numbers, DYNAMIC_COLUMN_VALUE *values, my_bool new_string); enum enum_dyncol_func_result mariadb_dyncol_create_many_named(DYNAMIC_COLUMN *str, uint column_count, MYSQL_LEX_STRING *column_keys, DYNAMIC_COLUMN_VALUE *values, my_bool new_string); ``` where | | | | | --- | --- | --- | | `str` | `OUT` | Packed dynamic blob will be put here | | `column_count` | `IN` | Number of columns | | `column_numbers` | `IN` | Column numbers array (old format) | | `column_keys` | `IN` | Column names array (new format) | | `values` | `IN` | Column values array | | `new_string` | `IN` | If TRUE then the `str` will be reinitialized (not freed) before usage | ### mariadb\_dyncol\_update\_many Add or update columns in a dynamic columns blob. To delete a column, update its value to a "non-value" of type `DYN_COL_NULL` ``` enum enum_dyncol_func_result mariadb_dyncol_update_many(DYNAMIC_COLUMN *str, uint column_count, uint *column_numbers, DYNAMIC_COLUMN_VALUE *values); enum enum_dyncol_func_result mariadb_dyncol_update_many_named(DYNAMIC_COLUMN *str, uint column_count, MYSQL_LEX_STRING *column_keys, DYNAMIC_COLUMN_VALUE *values); ``` | | | | | --- | --- | --- | | `str` | `IN/OUT` | Dynamic columns blob to be modified. | | `column_count` | `IN` | Number of columns in following arrays | | `column_numbers` | `IN` | Column numbers array (old format) | | `column_keys` | `IN` | Column names array (new format) | | `values` | `IN` | Column values array | ### mariadb\_dyncol\_exists Check if column with given name exists in the blob ``` enum enum_dyncol_func_result mariadb_dyncol_exists(DYNAMIC_COLUMN *str, uint column_number); enum enum_dyncol_func_result mariadb_dyncol_exists_named(DYNAMIC_COLUMN *str, MYSQL_LEX_STRING *column_key); ``` | | | | | --- | --- | --- | | `str` | `IN` | Packed dynamic columns string. | | `column_number` | `IN` | Column number (old format) | | `column_key` | `IN` | Column name (new format) | The function returns YES/NO or Error code ### mariadb\_dyncol\_column\_count Get number of columns in a dynamic column blob ``` enum enum_dyncol_func_result mariadb_dyncol_column_count(DYNAMIC_COLUMN *str, uint *column_count); ``` | | | | | --- | --- | --- | | `str` | `IN` | Packed dynamic columns string. | | `column_count` | `OUT` | Number of not NULL columns in the dynamic columns string | ### mariadb\_dyncol\_list List columns in a dynamic column blob. ``` enum enum_dyncol_func_result mariadb_dyncol_list(DYNAMIC_COLUMN *str, uint *column_count, uint **column_numbers); enum enum_dyncol_func_result mariadb_dyncol_list_named(DYNAMIC_COLUMN *str, uint *column_count, MYSQL_LEX_STRING **column_keys); ``` | | | | | --- | --- | --- | | `str` | `IN` | Packed dynamic columns string. | | `column_count` | `OUT` | Number of columns in following arrays | | `column_numbers` | `OUT` | Column numbers array (old format). Caller should free this array. | | `column_keys` | `OUT` | Column names array (new format). Caller should free this array. | ### mariadb\_dyncol\_get Get a value of one column ``` enum enum_dyncol_func_result mariadb_dyncol_get(DYNAMIC_COLUMN *org, uint column_number, DYNAMIC_COLUMN_VALUE *value); enum enum_dyncol_func_result mariadb_dyncol_get_named(DYNAMIC_COLUMN *str, MYSQL_LEX_STRING *column_key, DYNAMIC_COLUMN_VALUE *value); ``` | | | | | --- | --- | --- | | `str` | `IN` | Packed dynamic columns string. | | `column_number` | `IN` | Column numbers array (old format) | | `column_key` | `IN` | Column names array (new format) | | `value` | `OUT` | Value of the column | If the column is not found NULL returned as a value of the column. ### mariadb\_dyncol\_unpack Get value of all columns ``` enum enum_dyncol_func_result mariadb_dyncol_unpack(DYNAMIC_COLUMN *str, uint *column_count, MYSQL_LEX_STRING **column_keys, DYNAMIC_COLUMN_VALUE **values); ``` | | | | | --- | --- | --- | | `str` | `IN` | Packed dynamic columns string to unpack. | | `column_count` | `OUT` | Number of columns in following arrays | | `column_keys` | `OUT` | Column names array (should be free by caller) | | `values` | `OUT` | Values of the columns array (should be free by caller) | ### mariadb\_dyncol\_has\_names Check whether the dynamic columns blob uses new data format (the one where columns are identified by names) ``` my_bool mariadb_dyncol_has_names(DYNAMIC_COLUMN *str); ``` | | | | | --- | --- | --- | | `str` | `IN` | Packed dynamic columns string. | ### mariadb\_dyncol\_check Check whether dynamic column blob has correct data format. ``` enum enum_dyncol_func_result mariadb_dyncol_check(DYNAMIC_COLUMN *str); ``` | | | | | --- | --- | --- | | `str` | `IN` | Packed dynamic columns string. | ### mariadb\_dyncol\_json Get contents od a dynamic columns blob in a JSON form ``` enum enum_dyncol_func_result mariadb_dyncol_json(DYNAMIC_COLUMN *str, DYNAMIC_STRING *json); ``` | | | | | --- | --- | --- | | `str` | `IN` | Packed dynamic columns string. | | `json` | `OUT` | JSON representation | ### mariadb\_dyncol\_val\_TYPE Get dynamic column value as one of the base types ``` enum enum_dyncol_func_result mariadb_dyncol_val_str(DYNAMIC_STRING *str, DYNAMIC_COLUMN_VALUE *val, CHARSET_INFO *cs, my_bool quote); enum enum_dyncol_func_result mariadb_dyncol_val_long(longlong *ll, DYNAMIC_COLUMN_VALUE *val); enum enum_dyncol_func_result mariadb_dyncol_val_double(double *dbl, DYNAMIC_COLUMN_VALUE *val); ``` | | | | | --- | --- | --- | | `str` or `ll` or `dbl` | `OUT` | value of the column | | `val` | `IN` | Value | ### mariadb\_dyncol\_prepare\_decimal Initialize `DYNAMIC_COLUMN_VALUE` before value of `value.x.decimal.value` can be set ``` void mariadb_dyncol_prepare_decimal(DYNAMIC_COLUMN_VALUE *value); ``` | | | | | --- | --- | --- | | `value` | `OUT` | Value of the column | This function links `value.x.decimal.value` to `value.x.decimal.buffer`. ### mariadb\_dyncol\_value\_init Initialize a `DYNAMIC_COLUMN_VALUE` structure to a safe default. ``` #define mariadb_dyncol_value_init(V) (V)->type= DYN_COL_NULL ``` ### mariadb\_dyncol\_column\_cmp\_named Compare two column names (currently, column names are compared with memcmp()) ``` int mariadb_dyncol_column_cmp_named(const MYSQL_LEX_STRING *s1, const MYSQL_LEX_STRING *s2); ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb UNCOMPRESSED_LENGTH UNCOMPRESSED\_LENGTH ==================== Syntax ------ ``` UNCOMPRESSED_LENGTH(compressed_string) ``` Description ----------- Returns the length that the compressed string had before being compressed with `[COMPRESS()](../compress/index)`. `UNCOMPRESSED_LENGTH()` returns `NULL` or an incorrect result if the string is not compressed. Until [MariaDB 10.3.1](https://mariadb.com/kb/en/mariadb-1031-release-notes/), returns `MYSQL_TYPE_LONGLONG`, or [bigint(10)](../bigint/index), in all cases. From [MariaDB 10.3.1](https://mariadb.com/kb/en/mariadb-1031-release-notes/), returns `MYSQL_TYPE_LONG`, or [int(10)](../int/index), when the result would fit within 32-bits. Examples -------- ``` SELECT UNCOMPRESSED_LENGTH(COMPRESS(REPEAT('a',30))); +-----------------------------------------------+ | UNCOMPRESSED_LENGTH(COMPRESS(REPEAT('a',30))) | +-----------------------------------------------+ | 30 | +-----------------------------------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Performance Schema host_cache Table Performance Schema host\_cache Table ==================================== The `host_cache` table contains host and IP information from the host\_cache, used for avoiding DNS lookups for new client connections. The host\_cache table contains the following columns: | Column | Description | | --- | --- | | `IP` | Client IP address. | | `HOST` | IP's resolved DNS host name, or `NULL` if unknown. | | `HOST_VALIDATED` | YES if the IP-to-host DNS lookup was successful, and the `HOST` column can be used to avoid DNS calls, or NO if unsuccessful, in which case DNS lookup is performed for each connect until either successful or a permanent error. | | `SUM_CONNECT_ERRORS` | Number of connection errors. Counts only protocol handshake errors for hosts that passed validation. These errors count towards [max\_connect\_errors](../server-system-variables/index#max_connect_errors). | | `COUNT_HOST_BLOCKED_ERRORS` | Number of blocked connections because `SUM_CONNECT_ERRORS` exceeded the [max\_connect\_errors](../server-system-variables/index#max_connect_errors) system variable. | | `COUNT_NAMEINFO_TRANSIENT_ERRORS` | Number of transient errors during IP-to-host DNS lookups. | | `COUNT_NAMEINFO_PERMANENT_ERRORS` | Number of permanent errors during IP-to-host DNS lookups. | | `COUNT_FORMAT_ERRORS` | Number of host name format errors, for example a numeric host column. | | `COUNT_ADDRINFO_TRANSIENT_ERRORS` | Number of transient errors during host-to-IP reverse DNS lookups. | | `COUNT_ADDRINFO_PERMANENT_ERRORS` | Number of permanent errors during host-to-IP reverse DNS lookups. | | `COUNT_FCRDNS_ERRORS` | Number of forward-confirmed reverse DNS errors, which occur when IP-to-host DNS lookup does not match the originating IP address. | | `COUNT_HOST_ACL_ERRORS` | Number of errors occurring because no user from the host is permitted to log in. These attempts return [error code](../mariadb-error-codes/index) `1130 ER_HOST_NOT_PRIVILEGED` and do not proceed to username and password authentication. | | `COUNT_NO_AUTH_PLUGIN_ERRORS` | Number of errors due to requesting an authentication plugin that was not available. This can be due to the plugin never having been loaded, or the load attempt failing. | | `COUNT_AUTH_PLUGIN_ERRORS` | Number of errors reported by an authentication plugin. Plugins can increment `COUNT_AUTHENTICATION_ERRORS` or `COUNT_HANDSHAKE_ERRORS` instead, but, if specified or the error is unknown, this column is incremented. | | `COUNT_HANDSHAKE_ERRORS` | Number of errors detected at the wire protocol level. | | `COUNT_PROXY_USER_ERRORS` | Number of errors detected when a proxy user is proxied to a user that does not exist. | | `COUNT_PROXY_USER_ACL_ERRORS` | Number of errors detected when a proxy user is proxied to a user that exists, but the proxy user doesn't have the PROXY privilege. | | `COUNT_AUTHENTICATION_ERRORS` | Number of errors where authentication failed. | | `COUNT_SSL_ERRORS` | Number of errors due to TLS problems. | | `COUNT_MAX_USER_CONNECTIONS_ERRORS` | Number of errors due to the per-user quota being exceeded. | | `COUNT_MAX_USER_CONNECTIONS_PER_HOUR_ERRORS` | Number of errors due to the per-hour quota being exceeded. | | `COUNT_DEFAULT_DATABASE_ERRORS` | Number of errors due to the user not having permission to access the specified default database, or it not existing. | | `COUNT_INIT_CONNECT_ERRORS` | Number of errors due to statements in the [init\_connect](../server-system-variables/index#init_connect) system variable. | | `COUNT_LOCAL_ERRORS` | Number of local server errors, such as out-of-memory errors, unrelated to network, authentication, or authorization. | | `COUNT_UNKNOWN_ERRORS` | Number of unknown errors that cannot be allocated to another column. | | `FIRST_SEEN` | Timestamp of the first connection attempt by the IP. | | `LAST_SEEN` | Timestamp of the most recent connection attempt by the IP. | | `FIRST_ERROR_SEEN` | Timestamp of the first error seen from the IP. | | `LAST_ERROR_SEEN` | Timestamp of the most recent error seen from the IP. | The `host_cache` table, along with the `host_cache`, is cleared with [FLUSH HOSTS](../flush/index), [TRUNCATE TABLE](../truncate-table/index) `host_cache` or by setting the [host\_cache\_size](../server-system-variables/index#host_cache_size) system variable at runtime. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Full Backup and Restore with Mariabackup Full Backup and Restore with Mariabackup ======================================== When using Mariabackup, you have the option of performing a full or an incremental backup. Full backups create a complete backup of the database server in an empty directory while incremental backups update a previous backup with whatever changes to the data have occurred since the backup. This page documents how to perform full backups. Backing up the Database Server ------------------------------ In order to back up the database, you need to run Mariabackup with the `[--backup](../mariabackup-options/index#-backup)` option to tell it to perform a backup and with the `[--target-dir](../mariabackup-options/index#-target-dir)` option to tell it where to place the backup files. When taking a full backup, the target directory must be empty or it must not exist. To take a backup, run the following command: ``` $ mariabackup --backup \ --target-dir=/var/mariadb/backup/ \ --user=mariabackup --password=mypassword ``` The time the backup takes depends on the size of the databases or tables you're backing up. You can cancel the backup if you need to, as the backup process does not modify the database. Mariabackup writes the backup files the target directory. If the target directory doesn't exist, then it creates it. If the target directory exists and contains files, then it raises an error and aborts. Here is an example backup directory: ``` $ ls /var/mariadb/backup/ aria_log.0000001 mysql xtrabackup_checkpoints aria_log_control performance_schema xtrabackup_info backup-my.cnf test xtrabackup_logfile ibdata1 xtrabackup_binlog_info ``` Preparing the Backup for Restoration ------------------------------------ The data files that Mariabackup creates in the target directory are not point-in-time consistent, given that the data files are copied at different times during the backup operation. If you try to restore from these files, InnoDB notices the inconsistencies and crashes to protect you from corruption Before you can restore from a backup, you first need to **prepare** it to make the data files consistent. You can do so with the `[--prepare](../mariabackup-options/index#-prepare)` option. ``` $ mariabackup --prepare \ --target-dir=/var/mariadb/backup/ ``` Restoring the Backup -------------------- Once the backup is complete and you have prepared the backup for restoration (previous step), you can restore the backup using either the `[--copy-back](../mariabackup-options/index#-copy-back)` or the `[--move-back](../mariabackup-options/index#-move-back)` options. The `[--copy-back](../mariabackup-options/index#-copy-back)` option allows you to keep the original backup files. The `[--move-back](../mariabackup-options/index#-move-back)` option actually moves the backup files to the `[datadir](../server-system-variables/index#datadir)`, so the original backup files are lost. * First, [stop the MariaDB Server process](../starting-and-stopping-mariadb/index). * Then, ensure that the `[datadir](../server-system-variables/index#datadir)` is empty. * Then, run Mariabackup with one of the options mentioned above: ``` $ mariabackup --copy-back \ --target-dir=/var/mariadb/backup/ ``` * Then, you may need to fix the file permissions. When Mariabackup restores a database, it preserves the file and directory privileges of the backup. However, it writes the files to disk as the user and group restoring the database. As such, after restoring a backup, you may need to adjust the owner of the data directory to match the user and group for the MariaDB Server, typically `mysql` for both. For example, to recursively change ownership of the files to the `mysql` user and group, you could execute: ``` $ chown -R mysql:mysql /var/lib/mysql/ ``` * Finally, [start the MariaDB Server process](../starting-and-stopping-mariadb/index). ### Restoring with Other Tools Once a full backup is prepared, it is a fully functional MariaDB data directory. Therefore, as long as the MariaDB Server process is stopped on the target server, you can technically restore the backup using any file copying tool, such as `cp` or `rysnc`. For example, you could also execute the following to restore the backup: ``` $ rsync -avrP /var/mariadb/backup /var/lib/mysql/ $ chown -R mysql:mysql /var/lib/mysql/ $ rm /var/lib/mysql/ib_logfile* ``` When using Mariabackup from versions prior to [MariaDB 10.2.10](https://mariadb.com/kb/en/mariadb-10210-release-notes/), you would also have to remove any pre-existing [InnoDB redo log](../xtradbinnodb-redo-log/index) files. For example: ``` $ rm /var/lib/mysql/ib_logfile* ``` See [Mariabackup Internal Details: Redo Log Files](../mariabackup-overview/index#redo-log-files) for more information. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb > > = Syntax ------ ``` > ``` Description ----------- Greater than operator. Evaluates both SQL expressions and returns 1 if the left value is greater than the right value and 0 if it is not, or `NULL` if either expression is NULL. If the expressions return different data types, (for instance, a number and a string), performs type conversion. When used in row comparisons these two queries return the same results: ``` SELECT (t1.a, t1.b) > (t2.x, t2.y) FROM t1 INNER JOIN t2; SELECT (t1.a > t2.x) OR ((t1.a = t2.x) AND (t1.b > t2.y)) FROM t1 INNER JOIN t2; ``` Examples -------- ``` SELECT 2 > 2; +-------+ | 2 > 2 | +-------+ | 0 | +-------+ SELECT 'b' > 'a'; +-----------+ | 'b' > 'a' | +-----------+ | 1 | +-----------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb ST_POINTONSURFACE ST\_POINTONSURFACE ================== **MariaDB starting with [10.1.2](https://mariadb.com/kb/en/mariadb-1012-release-notes/)**ST\_POINTONSURFACE() was introduced in [MariaDB 10.1.2](https://mariadb.com/kb/en/mariadb-1012-release-notes/) Syntax ------ ``` ST_PointOnSurface(g) PointOnSurface(g) ``` Description ----------- Given a geometry, returns a [POINT](../point/index) guaranteed to intersect a surface. However, see [MDEV-7514](https://jira.mariadb.org/browse/MDEV-7514). ST\_PointOnSurface() and PointOnSurface() are synonyms. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Creating User-Defined Functions Creating User-Defined Functions =============================== [User-defined functions](../user-defined-functions/index) allow MariaDB to be extended with a new function that works like a native (built-in) MariaDB function such as [ABS()](../abs/index) or [CONCAT()](../concat/index). There are alternative ways to add a new function: writing a native function (which requires modifying and compiling the server source code), or writing a stored function. Statements making use of user-defined functions are not safe for replication. Functions are written in C or C++, and to make use of them, the operating system must support dynamic loading. Each new SQL function requires corresponding functions written in C/C++. In the list below, at least the main function - x() - and one other, are required. *x* should be replaced by the name of the function you are creating. All functions need to be thread-safe, so not global or static variables that change can be allocated. Memory is allocated in *x\_init()/ and freed in* x\_deinit()*.* Simple Functions ---------------- ### x() Required for all UDFs; this is where the results are calculated. | C/C++ type | SQL type | | --- | --- | | char \* | [STRING](../string-data-types/index) | | long long | [INTEGER](../integer/index) | | double | [REAL](../data-types-numeric-data-types/index) | DECIMAL functions return string values, and so should be written accordingly. It is not possible to create ROW functions. ### x\_init() Initialization function for x(). Can be used for the following: * Check the number of arguments to X() (the SQL equivalent). * Verify the argument types, or to force arguments to be of a particular type after the function is called. * Specify whether the result can be NULL. * Specify the maximum result length. * For REAL functions, specify the maximum number of decimals for the result. * Allocate any required memory. ### x\_deinit() De-initialization function for x(). Used to de-allocate memory that was allocated in x\_init(). ### Description Each time the SQL function *X()* is called: * MariaDB will first call the C/C++ initialization function, *x\_init()*, assuming it exists. All setup will be performed, and if it returns an error, the SQL statement is aborted and no further functions are called. * If there is no *x\_init()* function, or it has been called and did not return an error, *x()* is then called once per row. * After all rows have finished processing, *x\_deinit()* is called, if present, to clean up by de-allocating any memory that was allocated in *x\_init()*. * See [User-defined Functions Calling Sequences](../user-defined-functions-calling-sequences/index) for more details on the functions. Aggregate Functions ------------------- The following functions are required for aggregate functions, such as [AVG()](../avg/index) and [SUM()](../sum/index). When using [CREATE FUNCTION](../create-function-udf/index), the [AGGREGATE](../create-function-udf/index#aggregate) keyword is required. ### x\_clear() Used to reset the current aggregate, but without inserting the argument as the initial aggregate value for the new group. ### x\_add() Used to add the argument to the current aggregate. ### x\_remove() Starting from [MariaDB 10.4](../what-is-mariadb-104/index), improves the support of [window functions](../window-functions/index) (so it is not obligatory to add it) and should remove the argument from the current aggregate. ### Description Each time the aggregate SQL function *X()* is called: * MariaDB will first call the C/C++ initialization function, *x\_init()*, assuming it exists. All setup will be performed, and if it returns an error, the SQL statement is aborted and no further functions are called. * If there is no *x\_init()* function, or it has been called and did not return an error, *x()* is then called once per row. * After all rows have finished processing, *x\_deinit()* is called, if present, to clean up by de-allocating any memory that was allocated in *x\_init()*. * MariaDB will first call the C/C++ initialization function, *x\_init()*, assuming it exists. All setup will be performed, and if it returns an error, the SQL statement is aborted and no further functions are called. * The table is sorted according to the [GROUP BY](../group-by/index) expression. * *x\_clear()* is called for the first row of each new group. * *x\_add()* is called once per row for each row in the same group. * *x()* is called when the group changes, or after the last row, to get the aggregate result. * The latter three steps are repeated until all rows have been processed. * After all rows have finished processing, *x\_deinit()* is called, if present, to clean up by de-allocating any memory that was allocated in *x\_init()*. Examples -------- For an example, see `sql/udf_example.cc` in the source tree. For a collection of existing UDFs see <https://github.com/mysqludf>. See Also -------- * [Stored Functions](../stored-functions/index) * [Stored Aggregate Functions](../stored-aggregate-functions/index) * [User-defined Functions Calling Sequences](../user-defined-functions-calling-sequences/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb PERIOD_DIFF PERIOD\_DIFF ============ Syntax ------ ``` PERIOD_DIFF(P1,P2) ``` Description ----------- Returns the number of months between periods P1 and P2. P1 and P2 can be in the format `YYMM` or `YYYYMM`, and are not date values. If P1 or P2 contains a two-digit year, values from 00 to 69 are converted to from 2000 to 2069, while values from 70 are converted to 1970 upwards. Examples -------- ``` SELECT PERIOD_DIFF(200802,200703); +----------------------------+ | PERIOD_DIFF(200802,200703) | +----------------------------+ | 11 | +----------------------------+ SELECT PERIOD_DIFF(6902,6803); +------------------------+ | PERIOD_DIFF(6902,6803) | +------------------------+ | 11 | +------------------------+ SELECT PERIOD_DIFF(7002,6803); +------------------------+ | PERIOD_DIFF(7002,6803) | +------------------------+ | -1177 | +------------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Slow Query Log Extended Statistics Slow Query Log Extended Statistics ================================== Overview -------- * Added extra logging to slow log of 'Thread\_id, Schema, Query Cache hit, Rows sent and Rows examined' * Added optional logging to slow log, through log\_slow\_verbosity, of query plan statistics * Added new session variables log\_slow\_rate\_limit, log\_slow\_verbosity, log\_slow\_filter * Added log-slow-file as synonym for 'slow-log-file', as most slow-log variables starts with 'log-slow' * Added log-slow-time as synonym for long-query-time. New Session Variables --------------------- ### log\_slow\_verbosity You can set the verbosity of what's logged to the slow query log by setting the the [log\_slow\_verbosity](../server-system-variables/index#log_slow_verbosity) variable to a combination of the following values: * `Query_plan` + For select queries, log information about the query plan. This includes "Full\_scan", "Full\_join", "Tmp\_table", "Tmp\_table\_on\_disk", "Filesort", "Filesort\_on\_disk" and number of "Merge\_passes during sorting" * `explain` (Starting from 10.0.5) + EXPLAIN output is logged in the slow query log. See [explain-in-the-slow-query-log](../explain-in-the-slow-query-log/index) for details. * `Innodb` + Reserved for future use. The default value is ' ', to be compatible with MySQL 5.1. Multiple options are separated by ','. log\_slow\_verbosity is not supported when log\_output='TABLE'. ### log\_slow\_filter You can define which queries to log to the slow query log by setting the variable [log\_slow\_filter](../server-system-variables/index#log_slow_filter) to a combination of the following values: * `admin` + Log administrative statements (create, optimize, drop etc...) * `filesort` + Log statement if it uses filesort * `filesort_on_disk` + Log statement if it uses filesort that needs temporary tables on disk * `full_join` + Log statements that doesn't uses indexes to join tables * `full_scan` + Log statements that uses full table scans * `query_cache` + Log statements that are resolved by the query cache * `query_cache_miss` + Log statements that are not resolved by the query cache * `tmp_table` + Log statements that uses in memory temporary tables * `tmp_table_on_disk` + Log statements that uses temporary tables on disk Multiple options are separated by ','. If you don't specify any options everything will be logged. ### log\_slow\_rate\_limit The [log\_slow\_rate\_limit](../server-system-variables/index#log_slow_rate_limit) variable limits logging to the slow query log by not logging every query (only one query / log\_slow\_rate\_limit is logged). This is mostly useful when debugging and you get too much information to the slow query log. Note that in any case, only queries that takes longer than **log\_slow\_time** or **long\_query\_time**' are logged (as before). This addition is based on the [microslow](http://www.percona.com/percona-builds/Percona-SQL-5.0/Percona-SQL-5.0-5.0.87-b20/patches/microslow_innodb.patch) patch from [Percona](http://www.percona.com/). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb TINYTEXT TINYTEXT ======== Syntax ------ ``` TINYTEXT [CHARACTER SET charset_name] [COLLATE collation_name] ``` Description ----------- A [TEXT](../text/index) column with a maximum length of 255 (`28 - 1`) characters. The effective maximum length is less if the value contains multi-byte characters. Each TINYTEXT value is stored using a one-byte length prefix that indicates the number of bytes in the value. See Also -------- * [TEXT](../text/index) * [BLOB and TEXT Data Types](../blob-and-text-data-types/index) * [Data Type Storage Requirements](../data-type-storage-requirements/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Server System Variables Server System Variables ======================= About the Server System Variables --------------------------------- MariaDB has many system variables that can be changed to suit your needs. The full list of server variables are listed in the contents on this page, and most are described on this page, but some are described elsewhere: * [Aria System Variables](../aria-system-variables/index) * [CONNECT System Variables](../connect-system-variables/index) * [Galera System Variables](../mariadb-galera-cluster-configuration-variables/index) * [Global Transaction ID System Variables](../gtid/index#system-variables-for-global-transaction-id) * [HandlerSocket Plugin System Variables](../handlersocket-configuration-options/index) * [InnoDB System Variables](../innodb-system-variables/index) * [Mroonga System Variables](../mroonga-system-variables/index) * [MyRocks System Variables](../myrocks-system-variables/index) * [MyISAM System Variables](../myisam-server-system-variables/index) * [Performance Schema System Variables](../performance-schema-system-variables/index) * [Replication and Binary Log System Variables](../replication-and-binary-log-server-system-variables/index) * [S3 Storage Engine System Variables](../s3-storage-engine-system-variables/index) * [Server\_Audit System Variables](../server_audit-system-variables/index) * [Spider System Variables](../spider-server-system-variables/index) * [SQL\_ERROR\_LOG Plugin System Variables](../sql_error_log-plugin-system-variables/index) * [SSL System Variables](../ssl-server-system-variables/index) * [Threadpool System Variables](../thread-pool-system-and-status-variables/index) * [TokuDB System Variables](../tokudb-system-variables/index) See also the [Full list of MariaDB options, system and status variables](../full-list-of-mariadb-options-system-and-status-variables/index). Most of these can be set with [command line options](../mysqld-options-full-list/index) and many of them can be changed at runtime. Variables that can be changed at runtime are described as "Dynamic" below, and elsewhere in the documentation. There are a few ways to see the full list of server system variables: * While in the mysql client, run: ``` SHOW VARIABLES; ``` * See [SHOW VARIABLES](../show-variables/index) for instructions on using this command. * From your shell, run mysqld like so: ``` mysqld --verbose --help ``` * View the Information Schema [GLOBAL\_VARIABLES](../information-schema-global_variables-and-session_variables-tables/index), [SESSION\_VARIABLES](../information-schema-global_variables-and-session_variables-tables/index), and [SYSTEM\_VARIABLES](../information-schema-system_variables-table/index) tables. Setting Server System Variables ------------------------------- There are several ways to set server system variables: * Specify them on the command line: ``` shell> ./mysqld_safe --aria_group_commit="hard" ``` * Specify them in your my.cnf file (see [Configuring MariaDB with my.cnf](../configuring-mariadb-with-mycnf/index) for more information): ``` aria_group_commit = "hard" ``` * Set them from the mysql client using the [SET](../set/index) command. Only variables that are dynamic can be set at runtime in this way. Note that variables set in this way will not persist after a restart. ``` SET GLOBAL aria_group_commit="hard"; ``` By convention, server variables have usually been specified with an underscore in the configuration files, and a dash on the command line. You can however specify underscores as dashes - they are interchangeable. Variables that take a numeric size can either be specified in full, or with a suffix for easier readability. Valid suffixes are: | Suffix | Description | Value | | --- | --- | --- | | K | kilobytes | 1024 | | M | megabytes | 10242 | | G | gigabytes | 10243 | | T | terabytes | 10244 (from [MariaDB 10.3.3](https://mariadb.com/kb/en/mariadb-1033-release-notes/)) | | P | petabytes | 10245 (from [MariaDB 10.3.3](https://mariadb.com/kb/en/mariadb-1033-release-notes/)) | | E | exabytes | 10246 (from [MariaDB 10.3.3](https://mariadb.com/kb/en/mariadb-1033-release-notes/)) | The suffix can be upper or lower-case. List of Server System Variables ------------------------------- #### `alter_algorithm` * **Description:** The implied `ALGORITHM` for [ALTER TABLE](../alter-table/index) if no `ALGORITHM` clause is specified. The deprecated variable [old\_alter\_table](#old_alter_table) is an alias for this. + `COPY` corresponds to the pre-MySQL 5.1 approach of creating an intermediate table, copying data one row at a time, and renaming and dropping tables. + `INPLACE` requests that the operation be refused if it cannot be done natively inside a the storage engine. + `DEFAULT` (the default) chooses `INPLACE` if available, and falls back to `COPY`. + `NOCOPY` refuses to copy a table. + `INSTANT` refuses an operation that would involve any other than metadata changes. * **Commandline:** `--alter-algorithm=default` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `enumerated` * **Default Value:** `DEFAULT` * **Valid Values:** `DEFAULT`, `COPY`, `INPLACE`, `NOCOPY`, `INSTANT` * **Introduced:** [MariaDB 10.3.7](https://mariadb.com/kb/en/mariadb-1037-release-notes/) #### `analyze_sample_percentage` * **Description:** Percentage of rows from the table [ANALYZE TABLE](../analyze-table/index) will sample to collect table statistics. Set to 0 to let MariaDB decide what percentage of rows to sample. * **Commandline:** `--analyze-sample-percentage=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `100.000000` * **Range:** `0` to `100` * **Introduced:** [MariaDB 10.4.3](https://mariadb.com/kb/en/mariadb-1043-release-notes/) #### `autocommit` * **Description:** If set to 1, the default, all queries are committed immediately. The [LOCK IN SHARE MODE](../lock-in-share-mode/index) and [FOR UPDATE](../for-update/index) clauses therefore have no effect. If set to 0, they are only committed upon a [COMMIT](../transactions-commit-statement/index) statement, or rolled back with a [ROLLBACK](../rollback-statement/index) statement. If autocommit is set to 0, and then changed to 1, all open transactions are immediately committed. * **Commandline:** `--autocommit[=#]` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `1` --- #### `automatic_sp_privileges` * **Description:** When set to 1, the default, when a stored routine is created, the creator is automatically granted permission to [ALTER](../alter-procedure/index) (which includes dropping) and to EXECUTE the routine. If set to 0, the creator is not automatically granted these privileges. * **Commandline:** `--automatic-sp-privileges`, `--skip-automatic-sp-privileges` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `1` --- #### `back_log` * **Description:** Connections take a small amount of time to start, and this setting determines the number of outstanding connection requests MariaDB can have, or the size of the listen queue for incoming TCP/IP requests. Requests beyond this will be refused. Increase if you expect short bursts of connections. Cannot be set higher than the operating system limit (see the Unix listen() man page). If not set, set to `0`, or the `--autoset-back-log` option is used, will be autoset to the lower of `900` and (50 + [max\_connections](#max_connections)/5). * **Commandline:** `--back-log=#` * **Scope:** Global * **Dynamic:** No * **Type:** number * **Default Value:** + The lower of `900` and (50 + [max\_connections](#max_connections)/5) --- #### `basedir` * **Description:** Path to the MariaDB installation directory. Other paths are usually resolved relative to this base directory. * **Commandline:** `--basedir=path` or `-b path` * **Scope:** Global * **Dynamic:** No * **Type:** directory name --- #### `big_tables` * **Description:** If this system variable is set to 1, then temporary tables will be saved to disk intead of memory. + This system variable's original intention was to allow result sets that were too big for memory-based temporary tables and to avoid the resulting 'table full' errors. + This system variable is no longer needed, because the server can automatically convert large memory-based temporary tables into disk-based temporary tables when they exceed the value of the `[tmp\_memory\_table\_size](#tmp_memory_table_size)` system variable. + To prevent memory-based temporary tables from being used at all, set the `[tmp\_memory\_table\_size](#tmp_memory_table_size)` system variable to `0`. + In [MariaDB 5.5](../what-is-mariadb-55/index) and earlier, `[sql\_big\_tables](#sql_big_tables)` is a synonym. + In [MariaDB 10.5](../what-is-mariadb-105/index), this system variable is deprecated. * **Commandline:** `--big-tables` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `0` * **Deprecated:** [MariaDB 10.5.0](https://mariadb.com/kb/en/mariadb-1050-release-notes/) --- #### `bind_address` * **Description:** By default, the MariaDB server listens for TCP/IP connections on all addresses. You can specify an alternative when the server starts using this option; either a host name, an IPv4 or an IPv6 address, "::" or "\*" (all addresses). In some systems, such as Debian and Ubuntu, the bind\_address is set to 127.0.0.1, which binds the server to listen on localhost only. `bind_address` has always been available as a [mysqld option](../mysqld-options/index); from [MariaDB 10.3.3](https://mariadb.com/kb/en/mariadb-1033-release-notes/) its also available as a system variable. Before [MariaDB 10.6.0](https://mariadb.com/kb/en/mariadb-1060-release-notes/) "::" implied listening additionally on IPv4 addresses like "\*". From 10.6.0 onwards it refers to IPv6 stictly. See also [Configuring MariaDB for Remote Client Access](../configuring-mariadb-for-remote-client-access/index). * **Commandline:** `--bind-address=addr` * **Scope:** Global * **Dynamic:** No * **Data Type:** `string` * **Default Value:** (Empty string) * **Valid Values:** Host name, IPv4, IPv6, ::, \* * **Introduced:** [MariaDB 10.3.3](https://mariadb.com/kb/en/mariadb-1033-release-notes/) (as a system variable) --- #### `bulk_insert_buffer_size` * **Description:** Size in bytes of the per-thread cache tree used to speed up bulk inserts into [MyISAM](../myisam/index) and [Aria](../aria/index) tables. A value of 0 disables the cache tree. * **Commandline:** `--bulk-insert-buffer-size=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `8388608` * **Range - 32 bit:** `0` to `4294967295` * **Range - 64 bit:** `0` to `18446744073709547520` --- #### `character_set_client` * **Description:** Determines the [character set](../data-types-character-sets-and-collations/index) for queries arriving from the client. It can be set per session by the client, although the server can be configured to ignore client requests with the `--skip-character-set-client-handshake` option. If the client does not request a character set, or requests a character set that the server does not support, the global value will be used. utf16, utf32 and ucs2 cannot be used as client character sets. From [MariaDB 10.6](../what-is-mariadb-106/index), the `utf8` [character set](../character-sets/index) (and related collations) is by default an alias for `utf8mb3` rather than the other way around. It can be set to imply `utf8mb4` by changing the value of the [old\_mode](index#old_mode) system variable. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `string` * **Default Value:** `utf8mb3` (>= [MariaDB 10.6](../what-is-mariadb-106/index)), `utf8` (<= [MariaDB 10.5](../what-is-mariadb-105/index)) --- #### `character_set_connection` * **Description:** [Character set](../data-types-character-sets-and-collations/index) used for number to string conversion, as well as for literals that don't have a character set introducer. From [MariaDB 10.6](../what-is-mariadb-106/index), the `utf8` [character set](../character-sets/index) (and related collations) is by default an alias for `utf8mb3` rather than the other way around. It can be set to imply `utf8mb4` by changing the value of the [old\_mode](index#old_mode) system variable. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `string` * **Default Value:** `utf8mb3` (>= [MariaDB 10.6](../what-is-mariadb-106/index)), `utf8` (<= [MariaDB 10.5](../what-is-mariadb-105/index)) --- #### `character_set_database` * **Description:** [Character set](../data-types-character-sets-and-collations/index) used by the default database, and set by the server whenever the default database is changed. If there's no default database, character\_set\_database contains the same value as [character\_set\_server](#character_set_server). This variable is dynamic, but should not be set manually, only by the server. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `string` * **Default Value:** `latin1` --- #### `character_set_filesystem` * **Description:** The [character set](../data-types-character-sets-and-collations/index) for the filesystem. Used for converting file names specified as a string literal from [character\_set\_client](#character_set_client) to character\_set\_filesystem before opening the file. By default set to `binary`, so no conversion takes place. This could be useful for statements such as [LOAD\_FILE()](../load_file/index) or [LOAD DATA INFILE](../load-data-infile/index) on system where multi-byte file names are use. * **Commandline:** `--character-set-filesystem=name` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `string` * **Default Value:** `binary` --- #### `character_set_results` * **Description:** [Character set](../data-types-character-sets-and-collations/index) used for results and error messages returned to the client. From [MariaDB 10.6](../what-is-mariadb-106/index), the `utf8` [character set](../character-sets/index) (and related collations) is by default an alias for `utf8mb3` rather than the other way around. It can be set to imply `utf8mb4` by changing the value of the [old\_mode](index#old_mode) system variable. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `string` * **Default Value:** `utf8mb3` (>= [MariaDB 10.6](../what-is-mariadb-106/index)), `utf8` (<= [MariaDB 10.5](../what-is-mariadb-105/index)) --- #### `character_set_server` * **Description:** Default [character set](../data-types-character-sets-and-collations/index) used by the server. See [character\_set\_database](#character_set_database) for character sets used by the default database. Defaults may be different on some systems, see for example [Differences in MariaDB in Debian](../differences-in-mariadb-in-debian/index). * **Commandline:** `--character-set-server` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `string` * **Default Value:** `latin1` --- #### `character_set_system` * **Description:** [Character set](../data-types-character-sets-and-collations/index) used by the server to store identifiers, always set to utf8, or its synonym utf8mb3 starting with [MariaDB 10.6](../what-is-mariadb-106/index). From [MariaDB 10.6](../what-is-mariadb-106/index), the `utf8` [character set](../character-sets/index) (and related collations) is by default an alias for `utf8mb3` rather than the other way around. It can be set to imply `utf8mb4` by changing the value of the [old\_mode](index#old_mode) system variable. * **Scope:** Global * **Dynamic:** No * **Data Type:** `string` * **Default Value:** `utf8mb3` (>= [MariaDB 10.6](../what-is-mariadb-106/index)), `utf8` (<= [MariaDB 10.5](../what-is-mariadb-105/index)) --- #### `character_sets_dir` * **Description:** Directory where the [character sets](../data-types-character-sets-and-collations/index) are installed. * **Commandline:** `--character-sets-dir=path` * **Scope:** Global * **Dynamic:** No * **Type:** directory name --- #### `check_constraint_checks` * **Description:** If set to `0`, will disable [constraint checks](../constraint/index), for example when loading a table that violates some constraints that you plan to fix later. * **Commandline:** `--check-constraint-checks=[0|1]` * **Scope:** Global, Session * **Dynamic:** Yes * **Type:** boolean * **Default:** ON * **Introduced:** [MariaDB 10.2.1](https://mariadb.com/kb/en/mariadb-1021-release-notes/) --- #### `collation_connection` * **Description:** Collation used for the connection [character set](../data-types-character-sets-and-collations/index). * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `string` --- #### `collation_database` * **Description:** [Collation used](../data-types-character-sets-and-collations/index) for the default database. Set by the server if the default database changes, if there is no default database the value from the `collation_server` variable is used. This variable is dynamic, but should not be set manually, only by the server. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `string` --- #### `collation_server` * **Description:** Default [collation](../data-types-character-sets-and-collations/index) used by the server. This is set to the default collation for a given character set automatically when [character\_set\_server](#character_set_server) is changed, but it can also be set manually. Defaults may be different on some systems, see for example [Differences in MariaDB in Debian](../differences-in-mariadb-in-debian/index). * **Commandline:** `--collation-server=name` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `string` * **Default Value:** `latin1_swedish_ci` --- #### `completion_type` * **Description:** The transaction completion type. If set to `NO_CHAIN` or `0` (the default), there is no effect on commits and rollbacks. If set to `CHAIN` or `1`, a [COMMIT](../transactions-commit-statement/index) statement is equivalent to COMMIT AND CHAIN, while a [ROLLBACK](../rollback-statement/index) is equivalent to ROLLBACK AND CHAIN, so a new transaction starts straight away with the same isolation level as transaction that's just finished. If set to `RELEASE` or `2`, a [COMMIT](../transactions-commit-statement/index) statement is equivalent to COMMIT RELEASE, while a [ROLLBACK](../rollback-statement/index) is equivalent to ROLLBACK RELEASE, so the server will disconnect after the transaction completes. Note that the transaction completion type only applies to explicit commits, not implicit commits. * **Commandline:** `--completion-type=name` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `enumerated` * **Default Value:** `NO_CHAIN` * **Valid Values:** `0`, `1`, `2`, `NO_CHAIN`, `CHAIN`, `RELEASE` --- #### `concurrent_insert` * **Description:** If set to `AUTO` or `1`, the default, MariaDB allows [concurrent INSERTs](../concurrent-inserts/index) and SELECTs for [MyISAM](../myisam/index) tables with no free blocks in the data (deleted rows in the middle). If set to `NEVER` or `0`, concurrent inserts are disabled. If set to `ALWAYS` or `2`, concurrent inserts are permitted for all MyISAM tables, even those with holes, in which case new rows are added at the end of a table if the table is being used by another thread. If the [--skip-new](../mysqld-options/index#-skip-new) option is used when starting the server, concurrent\_insert is set to `NEVER`. Changing the variable only affects new opened tables. Use [FLUSH TABLES](../flush/index) If you want it to also affect cached tables. See [Concurrent Inserts](../concurrent-inserts/index) for more. * **Commandline:** `--concurrent-insert[=value]` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `enumerated` * **Default Value:** `AUTO` * **Valid Values:** `0`, `1`, `2`, `AUTO`, `NEVER`, `ALWAYS` --- #### `connect_timeout` * **Description:** Time in seconds that the server waits for a connect packet before returning a 'Bad handshake'. Increasing may help if clients regularly encounter 'Lost connection to MySQL server at 'X', system error: error\_number' type-errors. * **Commandline:** `--connect-timeout=#` * **Scope:** Global * **Dynamic:** Yes * **Type:** numeric * **Default Value:** `10` --- #### `core_file` * **Description:** Write a core-file on crashes. The file name and location are system dependent. On Linux it is usually called `core.${PID}`, and it is usually written to the data directory. However, this can be changed. + See [Enabling Core Dumps](../enabling-core-dumps/index) for more information. + Previously this system variable existed only as an [option](../mysqld-options/index), but it was also made into a read-only system variable starting with [MariaDB 10.3.9](https://mariadb.com/kb/en/mariadb-1039-release-notes/), [MariaDB 10.2.17](https://mariadb.com/kb/en/mariadb-10217-release-notes/) and [MariaDB 10.1.35](https://mariadb.com/kb/en/mariadb-10135-release-notes/). + On Windows >= [MariaDB 10.4.3](https://mariadb.com/kb/en/mariadb-1043-release-notes/), this option is set by default. + Note that the option accepts no arguments; specifying `--core-file` sets the value to `ON`. It cannot be disabled in the case of Windows >= [MariaDB 10.4.3](https://mariadb.com/kb/en/mariadb-1043-release-notes/). * **Commandline:** `--core-file` * **Scope:** Global * **Dynamic:** No * **Type:** boolean * **Default Value:** + Windows >= [MariaDB 10.4.3](https://mariadb.com/kb/en/mariadb-1043-release-notes/): `ON` + All other systems: `OFF` * **Introduced:** [MariaDB 10.3.9](https://mariadb.com/kb/en/mariadb-1039-release-notes/), [MariaDB 10.2.17](https://mariadb.com/kb/en/mariadb-10217-release-notes/), [MariaDB 10.1.35](https://mariadb.com/kb/en/mariadb-10135-release-notes/) --- #### `datadir` * **Description:** Directory where the data is stored. * **Commandline:** `--datadir=path` or `-h path` * **Scope:** Global * **Dynamic:** No * **Type:** directory name --- #### `date_format` * **Description:** Unused. --- #### `datetime_format` * **Description:** Unused. --- #### `debug/debug_dbug` * **Description:** Available in debug builds only (built with -DWITH\_DEBUG=1). Used in debugging through the DBUG library to write to a trace file. Just using `--debug` will write a trace of what mysqld is doing to the default trace file. * **Commandline:** `-#`, `--debug[=debug_options]` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `string` * **Default Value:** + <= [MariaDB 10.4](../what-is-mariadb-104/index): `d:t:i:o,/tmp/mysqld.trace` (Unix) or `d:t:i:O,\mysqld.trace` (Windows) + >= [MariaDB 10.5](../what-is-mariadb-105/index): `d:t:i:o,/tmp/mariadbd.trace` (Unix) or `d:t:i:O,\mariadbd.trace` (Windows) * **Debug Options:** See the option flags on the [mysql\_debug](../mysql_debug/index) page --- #### `debug_no_thread_alarm` * **Description:** Disable system thread alarm calls. Disabling it may be useful in debugging or testing, never do it in production. * **Commandline:** `--debug-no-thead-alarm=#` * **Scope:** Global * **Dynamic:** No * **Data Type:** `boolean` * **Default Value:** `OFF` * **Introduced:** MariaDB --- #### `debug_sync` * **Description:** Used in debugging to show the interface to the [Debug Sync facility](../the-debug-sync-facility/index). MariaDB needs to be configured with -DENABLE\_DEBUG\_SYNC=1 for this variable to be available. * **Scope:** Session * **Dynamic:** Yes * **Data Type:** `string` * **Default Value:** `OFF` or `ON - current signal *signal name*` --- #### `default_password_lifetime` * **Description:** This defines the global [password expiration policy](../user-password-expiry/index). 0 means automatic password expiration is disabled. If the value is a positive integer N, the passwords must be changed every N days. This behavior can be overridden using the password expiration options in [ALTER USER](../alter-user/index). * **Commandline:** `--default-password-lifetime=#` * **Scope:** Global * **Dynamic:** Yes * **Type:** numeric * **Default Value:** `0` * **Range:** `0` to `4294967295` * **Introduced:** [MariaDB 10.4.3](https://mariadb.com/kb/en/mariadb-1043-release-notes/) --- #### `default_regex_flags` * **Description:** Introduced to address remaining incompatibilities between [PCRE](../pcre-regular-expressions/index) and the old regex library. Accepts a comma-separated list of zero or more of the following values: | | | | | --- | --- | --- | | Value | Pattern equivalent | Meaning | | DOTALL | (?s) | . matches anything including NL | | DUPNAMES | (?J) | Allow duplicate names for subpatterns | | EXTENDED | (?x) | Ignore white space and # comments | | EXTRA | (?X) | extra features (e.g. error on unknown escape character) | | MULTILINE | (?m) | ^ and $ match newlines within data | | UNGREEDY | (?U) | Invert greediness of quantifiers | * **Commandline:** `--default-regex-flags=value` * **Scope:** Global, Session * **Dynamic:** Yes * **Type:** enumeration * **Default Value:** empty * **Valid Values:** `DOTALL`, `DUPNAMES`, `EXTENDED`, `EXTRA`, `MULTILINE`, `UNGREEDY` --- #### `default_storage_engine` * **Description:** The default [storage engine](../mariadb-storage-engines/index). The default storage engine must be enabled at server startup or the server won't start. * **Commandline:** `--default-storage-engine=name` * **Scope:** Global, Session * **Dynamic:** Yes * **Type:** enumeration * **Default Value:** `InnoDB` --- #### `default_table_type` * **Description:** A synonym for [default\_storage\_engine](#default_storage_engine). Removed in [MariaDB 5.5](../what-is-mariadb-55/index). * **Commandline:** `--default-table-type=name` * **Scope:** Global, Session * **Dynamic:** Yes * **Removed:** MariaDB/MySQL 5.5 --- #### `default_tmp_storage_engine` * **Description:** Default storage engine that will be used for tables created with [CREATE TEMPORARY TABLE](../create-table/index) where no engine is specified. For internal temporary tables see [aria\_used\_for\_temp\_tables](../aria-system-variables/index#aria_used_for_temp_tables)). The storage engine used must be active or the server will not start. See [default\_storage\_engine](#default_storage_engine) for the default for non-temporary tables. Defaults to NULL, in which case the value from [default\_storage\_engine](#default_storage_engine) is used. [ROCKSDB](../myrocks/index) temporary tables cannot be created. Before [MariaDB 10.7](../what-is-mariadb-107/index), attempting to do so would silently fail, and a MyISAM table would instead be created. From [MariaDB 10.7](../what-is-mariadb-107/index), an error is returned. * **Commandline:** `--default-tmp-storage-engine=name` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `enumeration` * **Default Value:** NULL --- #### `default_week_format` * **Description:** Default mode for the [WEEK()](../week/index) function. See that page for details on the different modes * **Commandline:** `--default-week-format=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `0` * **Range:** `0` to `7` --- #### `delay_key_write` * **Description:** Specifies how MyISAM tables handles [CREATE TABLE](../create-table/index) DELAY\_KEY\_WRITE. If set to `ON`, the default, any DELAY KEY WRITEs are honored. The key buffer is then flushed only when the table closes, speeding up writes. MyISAM tables should be automatically checked upon startup in this case, and --external locking should not be used, as it can lead to index corruption. If set to `OFF`, DELAY KEY WRITEs are ignored, while if set to `ALL`, all new opened tables are treated as if created with DELAY KEY WRITEs enabled. * **Commandline:** `--delay-key-write[=name]` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `enumeration` * **Default Value:** `ON` * **Valid Values:** `ON`, `OFF`, `ALL` --- #### `delayed_insert_limit` * **Description:** After this many rows have been inserted with [INSERT DELAYED](../insert-delayed/index), the handler will check for and execute any waiting [SELECT](../select/index) statements. * **Commandline:** `--delayed-insert-limit=#` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `100` * **Range:** `1` to `4294967295` --- #### `delayed_insert_timeout` * **Description:** Time in seconds that the [INSERT DELAYED](../insert-delayed/index) handler will wait for INSERTs before terminating. * **Commandline:** `--delayed-insert-timeout=#` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `300` --- #### `delayed_queue_size` * **Description:** Number of rows, per table, that can be queued when performing [INSERT DELAYED](../insert-delayed/index) statements. If the queue becomes full, clients attempting to perform INSERT DELAYED's will wait until the queue has room available again. * **Commandline:** `--delayed-queue-size=#` * **Scope:** Global * **Dynamic:** Yes * **Type:** numeric * **Default Value:** `1000` * **Range:** `1 to 4294967295` --- #### `disconnect_on_expired_password` * **Description:** When a user password has expired (see [User Password Expiry](../user-password-expiry/index)), this variable controls how the server handles clients that are not aware of the sandbox mode. If enabled, the client is not permitted to connect, otherwise the server puts the client in a sandbox mode. * **Commandline:** `--disconnect-on-expired-password[={0|1}]` * **Scope:** Global * **Dynamic:** Yes * **Type:** boolean * **Default Value:** `OFF` * **Introduced:** [MariaDB 10.4.3](https://mariadb.com/kb/en/mariadb-1043-release-notes/) --- #### `div_precision_increment` * **Description:** The precision of the result of the decimal division will be the larger than the precision of the dividend by that number. By default it's `4`, so `SELECT 2/15` would return 0.1333 and `SELECT 2.0/15` would return 0.13333. After setting div\_precision\_increment to `6`, for example, the same operation would return 0.133333 and 0.1333333 respectively. From [MariaDB 10.1.46](https://mariadb.com/kb/en/mariadb-10146-release-notes/), [MariaDB 10.2.33](https://mariadb.com/kb/en/mariadb-10233-release-notes/), [MariaDB 10.3.24](https://mariadb.com/kb/en/mariadb-10324-release-notes/), [MariaDB 10.4.14](https://mariadb.com/kb/en/mariadb-10414-release-notes/) and [MariaDB 10.5.5](https://mariadb.com/kb/en/mariadb-1055-release-notes/), `div_precision_increment` is taken into account in intermediate calculations. Previous versions did not, and the results were dependent on the optimizer, and therefore unpredictable. In [MariaDB 10.1.46](https://mariadb.com/kb/en/mariadb-10146-release-notes/), [MariaDB 10.1.47](https://mariadb.com/kb/en/mariadb-10147-release-notes/), [MariaDB 10.2.33](https://mariadb.com/kb/en/mariadb-10233-release-notes/), [MariaDB 10.2.34](https://mariadb.com/kb/en/mariadb-10234-release-notes/), [MariaDB 10.2.35](https://mariadb.com/kb/en/mariadb-10235-release-notes/), [MariaDB 10.3.24](https://mariadb.com/kb/en/mariadb-10324-release-notes/), [MariaDB 10.3.25](https://mariadb.com/kb/en/mariadb-10325-release-notes/), [MariaDB 10.4.14](https://mariadb.com/kb/en/mariadb-10414-release-notes/), [MariaDB 10.4.15](https://mariadb.com/kb/en/mariadb-10415-release-notes/), [MariaDB 10.5.5](https://mariadb.com/kb/en/mariadb-1055-release-notes/) and [MariaDB 10.5.6](https://mariadb.com/kb/en/mariadb-1056-release-notes/) only, the fix truncated decimal values after every division, resulting in lower precision in some cases for those versions only. From [MariaDB 10.1.48](https://mariadb.com/kb/en/mariadb-10148-release-notes/), [MariaDB 10.2.35](https://mariadb.com/kb/en/mariadb-10235-release-notes/), [MariaDB 10.3.26](https://mariadb.com/kb/en/mariadb-10326-release-notes/), [MariaDB 10.4.16](https://mariadb.com/kb/en/mariadb-10416-release-notes/) and [MariaDB 10.5.7](https://mariadb.com/kb/en/mariadb-1057-release-notes/), a different fix was implemented. Instead of truncating decimal values after every division, they are instead truncated for comparison purposes only. For example Versions other than [MariaDB 10.1.46](https://mariadb.com/kb/en/mariadb-10146-release-notes/), [MariaDB 10.1.47](https://mariadb.com/kb/en/mariadb-10147-release-notes/), [MariaDB 10.2.33](https://mariadb.com/kb/en/mariadb-10233-release-notes/), [MariaDB 10.2.34](https://mariadb.com/kb/en/mariadb-10234-release-notes/), [MariaDB 10.2.35](https://mariadb.com/kb/en/mariadb-10235-release-notes/), [MariaDB 10.3.24](https://mariadb.com/kb/en/mariadb-10324-release-notes/), [MariaDB 10.3.25](https://mariadb.com/kb/en/mariadb-10325-release-notes/), [MariaDB 10.4.14](https://mariadb.com/kb/en/mariadb-10414-release-notes/), [MariaDB 10.4.15](https://mariadb.com/kb/en/mariadb-10415-release-notes/), [MariaDB 10.5.5](https://mariadb.com/kb/en/mariadb-1055-release-notes/) and [MariaDB 10.5.6](https://mariadb.com/kb/en/mariadb-1056-release-notes/): ``` SELECT (55/23244*1000); +-----------------+ | (55/23244*1000) | +-----------------+ | 2.3662 | +----------------- ``` [MariaDB 10.1.46](https://mariadb.com/kb/en/mariadb-10146-release-notes/), [MariaDB 10.1.47](https://mariadb.com/kb/en/mariadb-10147-release-notes/), [MariaDB 10.2.33](https://mariadb.com/kb/en/mariadb-10233-release-notes/), [MariaDB 10.2.34](https://mariadb.com/kb/en/mariadb-10234-release-notes/), [MariaDB 10.2.35](https://mariadb.com/kb/en/mariadb-10235-release-notes/), [MariaDB 10.3.24](https://mariadb.com/kb/en/mariadb-10324-release-notes/), [MariaDB 10.3.25](https://mariadb.com/kb/en/mariadb-10325-release-notes/), [MariaDB 10.4.14](https://mariadb.com/kb/en/mariadb-10414-release-notes/), [MariaDB 10.4.15](https://mariadb.com/kb/en/mariadb-10415-release-notes/), [MariaDB 10.5.5](https://mariadb.com/kb/en/mariadb-1055-release-notes/) and [MariaDB 10.5.6](https://mariadb.com/kb/en/mariadb-1056-release-notes/) only: ``` SELECT (55/23244*1000); +-----------------+ | (55/23244*1000) | +-----------------+ | 2.4000 | +-----------------+ ``` This is because the intermediate result, `SELECT 55/23244` takes into account `div_precision_increment` and results were truncated after every division in those versions only. * **Commandline:** `--div-precision-increment=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `4` * **Range:** `0` to `30` --- #### `encrypt_tmp_disk_tables` * **Description:** Enables automatic encryption of all internal on-disk temporary tables that are created during query execution if `[aria\_used\_for\_temp\_tables=ON](../aria-system-variables/index#aria_used_for_temp_tables)` is set. See [Data at Rest Encryption](../data-at-rest-encryption/index) and [Enabling Encryption for Internal On-disk Temporary Tables](../encrypting-data-for-aria/index#enabling-encryption-for-internal-on-disk-temporary-tables). * **Commandline:** `--encrypt-tmp-disk-tables[={0|1}]` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `OFF` --- #### `encrypt_tmp_files` * **Description:** Enables automatic encryption of temporary files, such as those created for filesort operations, binary log file caches, etc. See [Data at Rest Encryption](../data-at-rest-encryption/index). * **Commandline:** `--encrypt-tmp-files[={0|1}]` * **Scope:** Global * **Dynamic:** No * **Data Type:** `boolean` * **Default Value:** `OFF` --- #### `encryption_algorithm` * **Description:** Which encryption algorithm to use for table encryption. `aes_cbc` is the recommended one. See [Table and Tablespace Encryption](../table-and-tablespace-encryption/index). * **Commandline:** `--encryption-algorithm=value` * **Scope:** Global * **Dynamic:** No * **Data Type:** `enum` * **Default Value:** `none` * **Valid Values:** `none`, `aes_ecb`, `aes_cbc`, `aes_ctr` * **Introduced:** [MariaDB 10.1.3](https://mariadb.com/kb/en/mariadb-1013-release-notes/) * **Removed:** [MariaDB 10.1.4](https://mariadb.com/kb/en/mariadb-1014-release-notes/) --- #### `enforce_storage_engine` * **Description:** Force the use of a particular storage engine for new tables. Used to avoid unwanted creation of tables using another engine. For example, setting to [InnoDB](../innodb/index) will prevent any [MyISAM](../myisam/index) tables from being created. If another engine is specified in a [CREATE TABLE](../create-table/index) statement, the outcome depends on whether the `NO_ENGINE_SUBSTITUTION` [SQL\_MODE](../sql-mode/index) has been set or not. If set, the query will fail, while if not set, a warning will be returned and the table created according to the engine specified by this variable. The variable has a session scope, but is only modifiable by a user with the SUPER privilege. * **Commandline:** None * **Scope:** Session * **Dynamic:** Yes * **Data Type:** `string` * **Default Value:** `none` --- #### `engine_condition_pushdown` * **Description:** Deprecated in [MariaDB 5.5](../what-is-mariadb-55/index) and removed and replaced by the [optimizer\_switch](#optimizer_switch) `engine_condition_pushdown={on|off}` flag in [MariaDB 10.0](../what-is-mariadb-100/index).. Specifies whether the engine condition pushdown optimization is enabled. Since [MariaDB 10.1.1](https://mariadb.com/kb/en/mariadb-1011-release-notes/), engine condition pushdown is enabled for all engines that support it. * **Commandline:** `--engine-condition-pushdown` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `OFF` * **Deprecated:** [MariaDB 5.5](../what-is-mariadb-55/index) * **Removed:** [MariaDB 10.0](../what-is-mariadb-100/index) --- #### `eq_range_index_dive_limit` * **Description:** Limit used for speeding up queries listed by long nested INs. The optimizer will use existing index statistics instead of doing index dives for equality ranges if the number of equality ranges for the index is larger than or equal to this number. If set to `0` (unlimited, the default), index dives are always used. * **Commandline:** `--eq-range-index-dive-limit=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `200` (>= [MariaDB 10.4.3](https://mariadb.com/kb/en/mariadb-1043-release-notes/)), `0` (<= [MariaDB 10.4.2](https://mariadb.com/kb/en/mariadb-1042-release-notes/)) * **Range:** `0` to `4294967295` * **Introduced:** [MariaDB 10.3.10](https://mariadb.com/kb/en/mariadb-10310-release-notes/), [MariaDB 10.2.18](https://mariadb.com/kb/en/mariadb-10218-release-notes/) --- #### `error_count` * **Description:** Read-only variable denoting the number of errors from the most recent statement in the current session that generated errors. See [SHOW\_ERRORS()](../show-errors/index). * **Scope:** Session * **Dynamic:** Yes * **Data Type:** `numeric` --- #### `event_scheduler` * **Description:** Status of the [Event](../events/index) Scheduler. Can be set to `ON` or `OFF`, while `DISABLED` means it cannot be set at runtime. Setting the variable will cause a load of events if they were not loaded at startup. * **Commandline:** `--event-scheduler[=value]` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `enumeration` * **Default Value:** `OFF` * **Valid Values:** `ON` (or `1`), `OFF` (or `0`), `DISABLED` --- #### `expensive_subquery_limit` * **Description:** Number of rows to be examined for a query to be considered expensive, that is, maximum number of rows a subquery may examine in order to be executed during optimization and used for constant optimization. * **Commandline:** `--expensive-subquery-limit=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `100` * **Range:** `0` upwards --- #### `explicit_defaults_for_timestamp` * **Description:** This option causes [CREATE TABLE](../create-table/index) to create all [TIMESTAMP](../timestamp/index) columns as [NULL](../null-values/index) with the DEFAULT NULL attribute, Without this option, TIMESTAMP columns are NOT NULL and have implicit DEFAULT clauses. * **Commandline:** `--explicit-defaults-for-timestamp=[={0|1}]` * **Scope:** Global, Session * **Dynamic:** No * **Data Type:** `boolean` * **Default Value:**`ON` (>= [MariaDB 10.10](../what-is-mariadb-1010/index)), `OFF` (<= [MariaDB 10.9](../what-is-mariadb-109/index)) --- #### `external_user` * **Description:** External user name set by the plugin used to authenticate the client. `NULL` if native MariaDB authentication is used. * **Scope:** Session * **Dynamic:** No * **Data Type:** `string` * **Default Value:** `NULL` --- #### `flush` * **Description:** Usually, MariaDB writes changes to disk after each SQL statement, and the operating system handles synchronizing (flushing) it to disk. If set to `ON`, the server will synchronize all changes to disk after each statement. * **Commandline:** `--flush` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `OFF` --- #### `flush_time` * **Description:** Interval in seconds that tables are closed to synchronize (flush) data to disk and free up resources. If set to 0, the default, there is no automatic synchronizing tables and closing of tables. This option should not be necessary on systems with sufficient resources. * **Commandline:** `--flush_time=#` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `0` --- #### `foreign_key_checks` * **Description:** If set to 1 (the default) [foreign key constraints](../foreign-keys/index) (including ON UPDATE and ON DELETE behavior) [InnoDB](../innodb/index) tables are checked, while if set to 0, they are not checked. `0` is not recommended for normal use, though it can be useful in situations where you know the data is consistent, but want to reload data in a different order from that that specified by parent/child relationships. Setting this variable to 1 does not retrospectively check for inconsistencies introduced while set to 0. * **Commandline:** None * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `1` --- #### `ft_boolean_syntax` * **Description:** List of operators supported by an IN BOOLEAN MODE [full-text search](../full-text-indexes/index). If you wish to change, note that each character must be ASCII and non-alphanumeric, the full string must be 14 characters and the first or second character must be a space. Positions 10, 13 and 14 are reserved for future extensions. Also, no duplicates are permitted except for the phrase quoting characters in positions 11 and 12, which may be the same. * **Commandline:** `--ft-boolean-syntax=name` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `string` * **Default Value:** `+ -><()*:""&|` --- #### `ft_max_word_len` * **Description:** Maximum length for a word to be included in the [MyISAM](../myisam/index) [full-text index](../full-text-indexes/index). If this variable is changed, the full-text index must be rebuilt in order for the new value to take effect. The quickest way to do this is by issuing a `REPAIR TABLE table_name QUICK` statement. See [innodb\_ft\_max\_token\_size](../innodb-system-variables/index#innodb_ft_max_token_size) for the [InnoDB](../innodb/index) equivalent. * **Commandline:** `--ft-max-word-len=#` * **Scope:** Global * **Dynamic:** No * **Data Type:** `numeric` * **Default Value:** `84` * **Minimum Value:** `10` --- #### `ft_min_word_len` * **Description:** Minimum length for a word to be included in the [MyISAM](../myisam/index) [full-text index](../full-text-indexes/index). If this variable is changed, the full-text index must be rebuilt in order for the new value to take effect. The quickest way to do this is by issuing a `REPAIR TABLE table_name QUICK` statement. See [innodb\_ft\_min\_token\_size](../innodb-system-variables/index#innodb_ft_min_token_size) for the [InnoDB](../innodb/index) equivalent. * **Commandline:** `--ft-min-word-len=#` * **Scope:** Global * **Dynamic:** No * **Data Type:** `numeric` * **Default Value:** `4` * **Minimum Value:** `1` --- #### `ft_query_expansion_limit` * **Description:** For [full-text searches](../full-text-indexes/index), denotes the numer of top matches when using WITH QUERY EXPANSION. * **Commandline:** `--ft-query-expansion-limit=#` * **Scope:** Global * **Dynamic:** No * **Data Type:** `numeric` * **Default Value:** `20` * **Range:** `0` to `1000` --- #### `ft_stopword_file` * **Description:** File containing a list of [stopwords](../stopwords/index) for use in [MyISAM](../myisam/index) [full-text searches](../full-text-indexes/index). Unless an absolute path is specified the file will be looked for in the data directory. The file is not parsed for comments, so all words found become stopwords. By default, a built-in list of words (built from `storage/myisam/ft_static.c file`) is used. Stopwords can be disabled by setting this variable to `''` (an empty string). If this variable is changed, the full-text index must be rebuilt. The quickest way to do this is by issuing a `REPAIR TABLE table_name QUICK` statement. See [innodb\_ft\_server\_stopword\_table](../innodb-system-variables/index#innodb_ft_server_stopword_table) for the [InnoDB](../innodb/index) equivalent. * **Commandline:** `--ft-stopword-file=file_name` * **Scope:** Global * **Dynamic:** No * **Data Type:** `file name` * **Default Value:** `(built-in)` --- #### `general_log` * **Description:** If set to 0, the default unless the --general-log option is used, the [general query log](../general-query-log/index) is disabled, while if set to 1, the general query log is enabled. See [log\_output](#log_output) for how log files are written. If that variable is set to `NONE`, no logs will be written even if general\_query\_log is set to `1`. * **Commandline:** `--general-log` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `0` --- #### `general_log_file` * **Description:** Name of the [general query log](../general-query-log/index) file. If this is not specified, the name is taken from the [log-basename](../mysqld-options/index#-log-basename) setting or from your system hostname with `.log` as a suffix. * **Commandline:** `--general-log-file=file_name` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `file name` * **Default Value:** `*host\_name*.log` --- #### `group_concat_max_len` * **Description:** Maximum length in bytes of the returned result for a [GROUP\_CONCAT()](../group_concat/index) function. * **Commandline:** `--group-concat-max-len=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** + `1048576` (1M) >= [MariaDB 10.2.4](https://mariadb.com/kb/en/mariadb-1024-release-notes/) + `1024` (1K) <= [MariaDB 10.2.3](https://mariadb.com/kb/en/mariadb-1023-release-notes/) * **Range - 32-bit:** `4` to `4294967295` * **Range - 64-bit:** `4` to `18446744073709547520` --- . #### `have_compress` * **Description:** If the zlib compression library is accessible to the server, this will be set to `YES`, otherwise it will be `NO`. The [COMPRESS()](../compress/index) and [UNCOMPRESS()](../uncompress/index) functions will only be available if set to `YES`. * **Scope:** Global * **Dynamic:** No --- #### `have_crypt` * **Description:** If the crypt() system call is available this variable will be set to `YES`, otherwise it will be set to `NO`. If set to `NO`, the [ENCRYPT()](../encrypt/index) function cannot be used. * **Scope:** Global * **Dynamic:** No --- #### `have_csv` * **Description:** If the server supports [CSV tables](../csv/index), will be set to `YES`, otherwise will be set to `NO`. Removed in [MariaDB 10.0](../what-is-mariadb-100/index), use the [Information Schema PLUGINS](../information-schema-plugins-table/index) table or [SHOW ENGINES](../show-engines/index) instead. * **Scope:** Global * **Dynamic:** No * **Removed:** [MariaDB 10.0](../what-is-mariadb-100/index) --- #### `have_dynamic_loading` * **Description:** If the server supports dynamic loading of [plugins](../mariadb-plugins/index), will be set to `YES`, otherwise will be set to `NO`. * **Scope:** Global * **Dynamic:** No --- #### `have_geometry` * **Description:** If the server supports spatial data types, will be set to `YES`, otherwise will be set to `NO`. * **Scope:** Global * **Dynamic:** No --- #### `have_ndbcluster` * **Description:** If the server supports NDBCluster ([disabled in MariaDB](../ndb-disabled-in-mariadb/index)). * **Scope:** Global * **Dynamic:** No * **Removed:** [MariaDB 10.0](../what-is-mariadb-100/index) --- #### `have_partitioning` * **Description:** If the server supports partitioning, will be set to `YES`, unless the `--skip-partition` option is used, in which case will be set to `DISABLED`. Will be set to `NO` otherwise. Removed in [MariaDB 10.0](../what-is-mariadb-100/index) - [SHOW PLUGINS](../show-plugins/index) should be used instead. * **Scope:** Global * **Dynamic:** No * **Removed:** [MariaDB 10.0](../what-is-mariadb-100/index) --- #### `have_profiling` * **Description:** If statement profiling is available, will be set to `YES`, otherwise will be set to `NO`. See [SHOW PROFILES()](../show-profiles/index) and [SHOW PROFILE()](../show-profile/index). * **Scope:** Global * **Dynamic:** No --- #### `have_query_cache` * **Description:** If the server supports the [query cache](../the-query-cache/index), will be set to `YES`, otherwise will be set to `NO`. * **Scope:** Global * **Dynamic:** No --- #### `have_rtree_keys` * **Description:** If RTREE indexes (used for [spatial indexes](../spatial-index/index)) are available, will be set to `YES`, otherwise will be set to `NO`. * **Scope:** Global * **Dynamic:** No --- #### `have_symlink` * **Description:** This system variable can be used to determine whether the server supports symbolic links (note that it has no meaning on Windows). + If symbolic links are supported, then the value will be `YES`. + If symbolic links are not supported, then the value will be `NO`. + If symbolic links are disabled with the [--symbolic-links](../mysqld-options/index#-symbolic-links) option and the `skip` [option prefix](../mysqld-options/index#option-prefixes) (i.e. --skip-symbolic-links), then the value will be `DISABLED`. + Symbolic link support is required for the [INDEX DIRECTORY](../create-table/index#data-directoryindex-directory) and [DATA DIRECTORY](../create-table/index#data-directoryindex-directory) table options. * **Scope:** Global * **Dynamic:** No --- #### `histogram_size` * **Description:** Number of bytes used for a [histogram](../histogram-based-statistics/index), or, from [MariaDB 10.7](../what-is-mariadb-107/index) when [histogram\_type](#histogram_type) is set to `JSON_HB`, number of buckets. If set to 0, no histograms are created by [ANALYZE](../analyze-table/index). * **Commandline:** `--histogram-size=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `254` (>= [MariaDB 10.4.3](https://mariadb.com/kb/en/mariadb-1043-release-notes/)), `0` (<= [MariaDB 10.4.2](https://mariadb.com/kb/en/mariadb-1042-release-notes/)) * **Range:** `0` to `255` --- #### `histogram_type` * **Description:** Specifies the type of [histograms](../histogram-based-statistics/index) created by [ANALYZE](../analyze-table/index). + `SINGLE_PREC_HB` - single precision height-balanced. + `DOUBLE_PREC_HB` - double precision height-balanced. + `JSON_HB` - JSON histograms (from [MariaDB 10.7](../what-is-mariadb-107/index)) * **Commandline:** `--histogram-type=value` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `enumeration` * **Default Value:** `DOUBLE_PREC_HB` (>= [MariaDB 10.4.3](https://mariadb.com/kb/en/mariadb-1043-release-notes/)), `SINGLE_PREC_HB`(<= [MariaDB 10.4.2](https://mariadb.com/kb/en/mariadb-1042-release-notes/)) * **Valid Values:** + `SINGLE_PREC_HB`, `DOUBLE_PREC_HB` (<= [MariaDB 10.6](../what-is-mariadb-106/index)) + `SINGLE_PREC_HB`, `DOUBLE_PREC_HB`, `JSON_HB` (>= [MariaDB 10.7](../what-is-mariadb-107/index)) --- #### `host_cache_size` * **Description:** Number of host names that will be cached to avoid resolving. Setting to `0` disables the cache. Changing the value while the server is running causes an implicit [FLUSH HOSTS](../flush/index), clearing the host cache and truncating the [performance\_schema.host\_cache](../performance-schema-host_cache-table/index) table. If you are connecting from a lot of different machines you should consider increasing. * **Commandline:** `--host-cache-size=#`. * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `128` * **Range:** `0` to `65536` --- #### `hostname` * **Description:** When the server starts, this variable is set to the server host name. * **Scope:** Global * **Dynamic:** No * **Data Type:** `string` --- #### `identity` * **Description:** A synonym for [last\_insert\_id](#last_insert_id) variable. --- #### `idle_readonly_transaction_timeout` * **Description:** Time in seconds that the server waits for idle read-only transactions before killing the connection. If set to `0`, the default, connections are never killed. See also [idle\_transaction\_timeout](#idle_transaction_timeout), [idle\_write\_transaction\_timeout](#idle_write_transaction_timeout) and [Transaction Timeouts](../transaction-timeouts/index). * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `0` * **Range:** `0` to `31536000` * **Introduced:** [MariaDB 10.3.0](https://mariadb.com/kb/en/mariadb-1030-release-notes/) --- #### `idle_transaction_timeout` * **Description:** Time in seconds that the server waits for idle transactions before killing the connection. If set to `0`, the default, connections are never killed. See also [idle\_readonly\_transaction\_timeout](#idle_readonly_transaction_timeout), [idle\_write\_transaction\_timeout](#idle_write_transaction_timeout) and [Transaction Timeouts](../transaction-timeouts/index). * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `0` * **Range:** `0` to `31536000` * **Introduced:** [MariaDB 10.3.0](https://mariadb.com/kb/en/mariadb-1030-release-notes/) --- #### `idle_write_transaction_timeout` * **Description:** Time in seconds that the server waits for idle read-write transactions before killing the connection. If set to `0`, the default, connections are never killed. See also [idle\_transaction\_timeout](#idle_transaction_timeout), [idle\_readonly\_transaction\_timeout](#idle_readonly_transaction_timeout) and [Transaction Timeouts](../transaction-timeouts/index). Called `idle_readwrite_transaction_timeout` until [MariaDB 10.3.2](https://mariadb.com/kb/en/mariadb-1032-release-notes/). * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `0` * **Range:** `0` to `31536000` * **Introduced:** [MariaDB 10.3.0](https://mariadb.com/kb/en/mariadb-1030-release-notes/) --- #### `ignore_db_dirs` * **Description:** Tells the server that this directory can never be a database. That means two things - firstly it is ignored by the [SHOW DATABASES](../show-databases/index) command and [INFORMATION\_SCHEMA](../information-schema/index) tables. And secondly, USE, CREATE DATABASE and SELECT statements will return an error if the database from the ignored list specified. Use this option several times if you need to ignore more than one directory. To make the list empty set the void value to the option as --ignore-db-dir=. If the option or configuration is specified multiple times, viewing this value will list the ignore directories separated by a period. * **Commandline:** `--ignore-db-dirs=dir`. * **Scope:** Global * **Dynamic:** No * **Data Type:** `string` --- #### `in_predicate_conversion_threshold` * **Description:** The minimum number of scalar elements in the value list of an IN predicate that triggers its conversion to an IN subquery. Set to 0 to disable the conversion. See [Conversion of Big IN Predicates Into Subqueries](../conversion-of-big-in-predicates-into-subqueries/index). * **Commandline:** `--in-predicate-conversion-threshold=#` * **Scope:** Global, Session * **Dynamic:** No * **Data Type:** `numeric` * **Default Value:** `1000` * **Range:** `0` to `4294967295` * **Introduced:** [MariaDB 10.3.18](https://mariadb.com/kb/en/mariadb-10318-release-notes/) (previously debug builds only) --- #### `in_transaction` * **Description:** Session-only and read-only variable that is set to `1` if a transaction is in progress, `0` if not. * **Commandline:** No * **Scope:** Session * **Dynamic:** No * **Data Type:** `boolean` * **Default Value:** `0` --- #### `init_connect` * **Description:** String containing one or more SQL statements, separated by semicolons, that will be executed by the server for each client connecting. If there's a syntax error in the one of the statements, the client will fail to connect. For this reason, the statements are not executed for users with the [SUPER](../grant/index#super) privilege or, from [MariaDB 10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/), the [CONNECTION ADMIN](../grant/index#connection-admin) privilege, who can then still connect and correct the error. See also [init\_file](#init_file). * **Commandline:** `--init-connect=name` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `string` --- #### `init_file` * **Description:** Name of a file containing SQL statements that will be executed by the server on startup. Each statement should be on a new line, and end with a semicolon. See also [init\_connect](#init_connect). * **Commandline:** `init-file=file_name` * **Scope:** Global * **Dynamic:** No * **Data Type:** `file name` --- #### `insert_id` * **Description:** Value to be used for the next statement inserting a new [AUTO\_INCREMENT](../auto_increment/index) value. * **Scope:** Session * **Dynamic:** Yes * **Data Type:** `numeric` --- #### `interactive_timeout` * **Description:** Time in seconds that the server waits for an interactive connection (one that connects with the mysql\_real\_connect() CLIENT\_INTERACTIVE option) to become active before closing it. See also [wait\_timeout](#wait_timeout). * **Commandline:** `--interactive-timeout=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `28800` * **Range: (Windows): `1` to `2147483`** * **Range: (Other): `1` to `31536000`** --- #### `join_buffer_size` * **Description:** Minimum size in bytes of the buffer used for queries that cannot use an index, and instead perform a full table scan. Increase to get faster full joins when adding indexes is not possible, although be aware of memory issues, since joins will always allocate the minimum size. Best left low globally and set high in sessions that require large full joins. In 64-bit platforms, Windows truncates values above 4GB to 4GB with a warning. See also [Block-Based Join Algorithms - Size of Join Buffers](../block-based-join-algorithms/index#size-of-join-buffers). * **Commandline:** `--join-buffer-size=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `262144` (256kB) * **Range (non-Windows):** `128` to `18446744073709547520` * **Range (Windows):** `8228` to `18446744073709547520` --- #### `join_buffer_space_limit` * **Description:** Maximum size in bytes of the query buffer, By default 1024\*128\*10. See [Block-based join algorithms](../block-based-join-algorithms/index#size-of-join-buffers). * **Commandline:** `--join-buffer-space-limit=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `2097152` * **Range:** `2048` to `99999999997952` --- #### `join_cache_level` * **Description:** Controls which of the eight block-based algorithms can be used for join operations. See [Block-based join algorithms](../block-based-join-algorithms/index) for more information. + 1 – flat (Block Nested Loop) BNL + 2 – incremental BNL + 3 – flat Block Nested Loop Hash (BNLH) + 4 – incremental BNLH + 5 – flat Batch Key Access (BKA) + 6 – incremental BKA + 7 – flat Batch Key Access Hash (BKAH) + 8 – incremental BKAH * **Commandline:** `--join-cache-level=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `2` * **Range:** `0` to `8` --- #### `keep_files_on_create` * **Description:** If a [MyISAM](../myisam/index) table is created with no DATA DIRECTORY option, the .MYD file is stored in the database directory. When set to `0`, the default, if MariaDB finds another .MYD file in the database directory it will overwrite it. Setting this variable to `1` means that MariaDB will return an error instead, just as it usually does in the same situation outside of the database directory. The same applies for .MYI files and no INDEX DIRECTORY option. Deprecated in [MariaDB 10.8.0](https://mariadb.com/kb/en/mariadb-1080-release-notes/). * **Commandline:** `--keep-files-on-create=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `OFF` --- #### `large_files_support` * **Description:** ON if the server if was compiled with large file support or not, else OFF * **Scope:** Global * **Dynamic:** No --- #### `large_page_size` * **Description:** Indicates the size of memory page if large page support (Linux only) is enabled. The page size is determined from the Hugepagesize setting in `/proc/meminfo`. See [large\_pages](#large_pages). Deprecated and unused in [MariaDB 10.5.3](https://mariadb.com/kb/en/mariadb-1053-release-notes/) since multiple page size support was added. * **Scope:** Global * **Dynamic:** No * **Data Type:** `numeric` * **Default Value:** Autosized (see description) * **Deprecated:** [MariaDB 10.5.3](https://mariadb.com/kb/en/mariadb-1053-release-notes/) --- #### `large_pages` * **Description:** Indicates whether large page support (Linux only - called huge pages) is used. This is set with `--large-pages` or disabled with `--skip-large-pages`. Large pages are used for the [innodb buffer pool](../innodb-buffer-pool/index) and for online DDL (of size 3\* [innodb\_sort\_buffer\_size](../innodb-system-variables/index#innodb_sort_buffer_size) (or 6 when encryption is used)). To use large pages, the Linux `sysctl` variable `kernel.shmmax` must be large than the llocation. Also the `sysctl` variable `vm.nr_hugepages` multipled by [large-page](#large_page_size)) must be larger than the usage. The ulimit for locked memory must be sufficient to cover the amount used (`ulimit -l` and equalivent in /etc/security/limits.conf / or in systemd [LimitMEMLOCK](../systemd/index)). If these operating system controls or insufficient free huge pages are available, the allocation of large pages will fall back to conventional memory allocation and a warning will appear in the logs. Only allocations of the default `Hugepagesize` currently occur (see `/proc/meminfo`). * **Commandline:** `--large-pages`, `--skip-large-pages` * **Scope:** Global * **Dynamic:** No * **Data Type:** `boolean` * **Default Value:** `OFF` --- #### `last_insert_id` * **Description:** Contains the same value as that returned by [LAST\_INSERT\_ID()](../last_insert_id/index). Note that setting this variable doen't update the value returned by the underlying function. * **Scope:** Session * **Dynamic:** Yes * **Data Type:** `numeric` --- #### `lc_messages` * **Description:** This system variable can be specified as a [locale](../server-locale/index) name. The language of the associated [locale](../server-locale/index) will be used for error messages. See [Server Locales](../server-locale/index) for a list of supported locales and their associated languages. + This system variable is set to `en_US` by default, which means that error messages are in English by default. + If this system variable is set to a valid [locale](../server-locale/index) name, but the server can't find an [error message file](../error-log/index#error-messages-file) for the language associated with the [locale](../server-locale/index), then the default language will be used instead. + This system variable is used along with the `[lc\_messages\_dir](#lc_messages_dir)` system variable to construct the path to the [error messages file](../error-log/index#error-messages-file). + See [Setting the Language for Error Messages](../setting-the-language-for-error-messages/index) for more information. * **Commandline:** `--lc-messages=name` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `string` * **Default Value:** `en_us` --- #### `lc_messages_dir` * **Description:** This system variable can be specified either as the path to the directory storing the server's [error message files](../error-log/index#error-messages-file) or as the path to the directory storing the specific language's [error message file](../error-log/index#error-messages-file). See [Server Locales](../server-locale/index) for a list of available locales and their related languages. + The server initially tries to interpret the value of this system variable as a path to the directory storing the server's [error message files](../error-log/index#error-messages-file). Therefore, it constructs the path to the language's [error message file](../error-log/index#error-messages-file) by concatenating the value of this system variable with the language name of the [locale](../server-locale/index) specified by the `[lc\_messages](index#lc_messages)` system variable . + If the server does not find the [error message file](../error-log/index#error-messages-file) for the language, then it tries to interpret the value of this system variable as a direct path to the directory storing the specific language's [error message file](../error-log/index#error-messages-file). + See [Setting the Language for Error Messages](../setting-the-language-for-error-messages/index) for more information. * **Commandline:** `--lc-messages-dir=path` * **Scope:** Global * **Dynamic:** No * **Data Type:** `directory name` --- #### `lc_time_names` * **Description:** The locale that determines the language used for the date and time functions [DAYNAME()](../dayname/index), [MONTHNAME()](../monthname/index) and [DATE\_FORMAT()](date-format). Locale names are language and region subtags, for example 'en\_ZA' (English - South Africa) or 'es\_US: Spanish - United States'. The default is always 'en-US' regardless of the system's locale setting. See [server locale](../server-locale/index) for a full list of supported locales. * **Commandline:** `--lc-time-names=name` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `string` * **Default Value:** `en_US` --- #### `license` * **Description:** Server license, for example `GPL`. * **Scope:** Global * **Dynamic:** No * **Data Type:** `string` --- #### `local_infile` * **Description:** If set to `1`, LOCAL is supported for [LOAD DATA INFILE](../load-data-infile/index) statements. If set to `0`, usually for security reasons, attempts to perform a LOAD DATA LOCAL will fail with an error message. * **Commandline:** `--local-infile=#` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `ON` --- #### `lock_wait_timeout` * **Description:** Timeout in seconds for attempts to acquire [metadata locks](../metadata-locking/index). Statements using metadata locks include [FLUSH TABLES WITH READ LOCK](../flush/index), [LOCK TABLES](../transactions-lock/index), HANDLER and DML and DDL operations on tables, [stored procedures](../stored-procedures/index) and [functions](../stored-functions/index), and [views](../views/index). The timeout is separate for each attempt, of which there may be multiple in a single statement. `0` (from [MariaDB 10.3.0](https://mariadb.com/kb/en/mariadb-1030-release-notes/)) means no wait. See [WAIT and NOWAIT](../wait-and-nowait/index). * **Commandline:** `--lock-wait-timeout=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** + `86400` (1 day) >= [MariaDB 10.2.4](https://mariadb.com/kb/en/mariadb-1024-release-notes/) + `31536000` (1 year) <= [MariaDB 10.2.3](https://mariadb.com/kb/en/mariadb-1023-release-notes/) * **Range:** + `0` to `31536000` (>= [MariaDB 10.3](../what-is-mariadb-103/index)) + `1` to `31536000` (<= [MariaDB 10.2](../what-is-mariadb-102/index)) --- #### `locked_in_memory` * **Description:** Indicates whether --memlock was used to lock mysqld in memory. * **Commandline:** `--memlock` * **Scope:** Global * **Dynamic:** No * **Data Type:** `boolean` * **Default Value:** `OFF` --- #### `log` * **Description:** Deprecated and removed in [MariaDB 10.0](../what-is-mariadb-100/index), use [general\_log](#general_log) instead. * **Commandline:** `-l [filename]` or `--log[=filename]` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `string` * **Default Value:** `OFF` * **Removed:** [MariaDB 10.0](../what-is-mariadb-100/index) --- #### `log_disabled_statements` * **Description:** If set, the specified type of statements (slave and/or stored procedure statements) will not be logged to the [general log](../general-query-log/index). Multiple values are comma-separated, without spaces. * **Commandline:** `--log-disabled_statements=value` * **Scope:** Global, Session * **Dynamic:** No * **Data Type:** `set` * **Default Value:** `sp` * **Valid Values:** `slave` and/or `sp`, or empty string for none * **Introduced:** [MariaDB 10.3.1](https://mariadb.com/kb/en/mariadb-1031-release-notes/) --- #### `log_error` * **Description:** Specifies the name of the [error log](../error-log/index). If [--console](../mysqld-options/index#-console) is specified later in the configuration (Windows only) or this option isn't specified, errors will be logged to stderr. If no name is provided, errors will still be logged to `hostname.err` in the `datadir` directory by default. If a configuration file sets `--log-error`, one can reset it with `--skip-log-error` (useful to override a system wide configuration file). MariaDB always writes its error log, but the destination is configurable. See [error log](../error-log/index) for details. * **Commandline:** `--log-error[=name]`, `--skip-log-error` * **Scope:** Global * **Dynamic:** No * **Data Type:** `file name` * **Default Value:** (empty string) --- #### `log_output` * **Description:** How the output for the [general query log](../general-query-log/index) and the [slow query log](../slow-query-log/index) is stored. By default written to file (`FILE`), it can also be stored in the [general\_log](../mysqlgeneral_log-table/index) and [slow\_log](../mysqlslow_log-table/index) tables in the mysql database (`TABLE`), or not stored at all (`NONE`). More than one option can be chosen at the same time, with `NONE` taking precedence if present. Logs will not be written if logging is not enabled. See [Writing logs into tables](../writing-logs-into-tables/index), and the [slow\_query\_log](#slow_query_log) and [general\_log](#general_log) server system variables. * **Commandline:** `--log-output=name` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `set` * **Default Value:** `FILE` * **Valid Values:** `TABLE`, `FILE` or `NONE` --- #### `log_queries_not_using_indexes` * **Description:** Queries that don't use an index, or that perform a full index scan where the index doesn't limit the number of rows, will be logged to the [slow query log](../slow-query-log/index) (regardless of time taken). The slow query log needs to be enabled for this to have an effect. Mapped to `log_slow_filter='not_using_index'` from [MariaDB 10.3.1](https://mariadb.com/kb/en/mariadb-1031-release-notes/). * **Commandline:** `--log-queries-not-using-indexes` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `OFF` --- #### `log_slow_admin_statements` * **Description:** Log slow [OPTIMIZE](../optimize-table/index), [ANALYZE](../analyze-table/index), [ALTER](../alter/index) and other [administrative](../slow-query-log-overview/index#logging-slow-administrative-statements) statements to the [slow log](../slow-query-log/index) if it is open. See also [log\_slow\_disabled\_statements](#log_slow_disabled_statements) and [log\_slow\_filter](#log_slow_filter). * **Commandline:** `--log-slow-admin-statements` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** + `ON` (>= [MariaDB 10.2.4](https://mariadb.com/kb/en/mariadb-1024-release-notes/)) + `OFF` (<= [MariaDB 10.2.3](https://mariadb.com/kb/en/mariadb-1023-release-notes/)) --- #### `log_slow_disabled_statements` * **Description:** If set, the specified type of statements will not be logged to the [slow query log](../slow-query-log/index). See also [log\_slow\_admin\_statements](#log_slow_admin_statements) and [log\_slow\_filter](#log_slow_filter). * **Commandline:** `--log-slow-disabled_statements=value` * **Scope:** Global, Session * **Dynamic:** No * **Data Type:** `set` * **Default Value:** `sp` * **Valid Vales:** `admin`, `call`, `slave` and/or `sp` * **Introduced:** [MariaDB 10.3.1](https://mariadb.com/kb/en/mariadb-1031-release-notes/) --- #### `log_slow_filter` * **Description:** Comma-delimited string (without spaces) containing one or more settings for filtering what is logged to the [slow query log](../slow-query-log/index). If a query matches one of the types listed in the filter, and takes longer than [long\_query\_time](#long_query_time), it will be logged(except for 'not\_using\_index' which is always logged if enabled, regardless of the time). Sets [log-slow-admin-statements](#log_slow_admin_statements) to ON. See also [log\_slow\_disabled\_statements](#log_slow_disabled_statements). + `admin` log [administrative](../slow-query-log-overview/index#logging-slow-administrative-statements) queries (create, optimize, drop etc...) + `filesort` logs queries that use a filesort. + `filesort_on_disk` logs queries that perform a a filesort on disk. + `filesort_priority_queue` (from [MariaDB 10.3.2](https://mariadb.com/kb/en/mariadb-1032-release-notes/)) + `full_join` logs queries that perform a join without indexes. + `full_scan` logs queries that perform full table scans. + `not_using_index` logs queries that don't use an index, or that perform a full index scan where the index doesn't limit the number of rows. Disregards [long\_query\_time](#long_query_time), unlike other options. [log\_queries\_not\_using\_indexes](#log_queries_not_using_indexes) maps to this option. From [MariaDB 10.3.1](https://mariadb.com/kb/en/mariadb-1031-release-notes/). + `query_cache` log queries that are resolved by the query cache. + `query_cache_miss` logs queries that are not found in the [query cache](../query-cache/index). + `tmp_table` logs queries that create an implicit temporary table. + `tmp_table_on_disk` logs queries that create a temporary table on disk. * **Commandline:** `log-slow-filter=value1[,value2...]` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `enumeration` * **Default Value:** + `admin`, `filesort`, `filesort_on_disk`, `full_join`, `full_scan`, `query_cache`, `query_cache_miss`, `tmp_table`, `tmp_table_on_disk` (<= [MariaDB 10.3.0](https://mariadb.com/kb/en/mariadb-1030-release-notes/)) + `admin`, `filesort`, `filesort_on_disk`, `filesort_priority_queue`, `full_join`, `full_scan`, `query_cache`, `query_cache_miss`, `tmp_table`, `tmp_table_on_disk` (>= [MariaDB 10.3.1](https://mariadb.com/kb/en/mariadb-1031-release-notes/)) * **Valid Values:** `admin`, `filesort`, `filesort_on_disk`, `filesort_priority_queue`, `full_join`, `full_scan`, `query_cache`, `query_cache_miss`, `tmp_table`, `tmp_table_on_disk` --- #### `log_slow_queries` * **Description:** Deprecated and removed in [MariaDB 10.0](../what-is-mariadb-100/index), use [slow\_query\_log](#slow_query_log) instead. * **Commandline:** `--log-slow-queries[=name]` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `OFF` * **Removed:** [MariaDB 10.0](../what-is-mariadb-100/index) --- #### `log_slow_rate_limit` * **Description:** The [slow query log](../slow-query-log/index) will log every this many queries. The default is `1`, or every query, while setting it to `20` would log every 20 queries, or five percent. Aims to reduce I/O usage and excessively large slow query logs. See also [Slow Query Log Extended Statistics](../slow-query-log-extended-statistics/index). * **Commandline:** `log-slow-rate-limit=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `1` * **Range:** `1` upwards --- #### `log_slow_verbosity` * **Description:** Controls information to be added to the [slow query log](../slow-query-log/index). Options are added in a comma-delimited string. See also [Slow Query Log Extended Statistics](../slow-query-log-extended-statistics/index). log\_slow\_verbosity is not supported when log\_output='TABLE'. + `query_plan` logs query execution plan information + `innodb` an unused Percona XtraDB option for logging XtraDB/InnoDB statistics. + `explain` prints EXPLAIN output in the [slow query log](../slow-query-log/index). See [EXPLAIN in the Slow Query Log](../explain-in-the-slow-query-log/index). * **Commandline:** `log-slow-verbosity=value1[,value2...]` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `enumeration` * **Default Value:** (Empty) * **Valid Values:** (Empty), `query_plan`, `innodb`, `explain` --- #### `log_tc_size` * **Description:** Defines the size in bytes of the memory-mapped file-based transaction coordinator log, which is only used if the [binary log](../binary-log/index) is disabled. If you have two or more XA-capable storage engines enabled, then a transaction coordinator log must be available. This size is defined in multiples of 4096. See [Transaction Coordinator Log](../transaction-coordinator-log/index) for more information. Also see the `[--log-tc](../mysqld-options/index#-log-tc)` server option and the `[--tc-heuristic-recover](#-tc-heuristic-recover)` option. * **Commandline:** `log-tc-size=#` * **Scope:** Global * **Dynamic:** No * **Data Type:** `numeric` * **Default Value:** `24576` * **Range:** `12288` to `18446744073709551615` --- #### `log_warnings` * **Description:** Determines which additional warnings are logged. Setting to `0` disables additional warning logging. Note that this does not prevent all warnings, there is a core set of warnings that will always be written to the error log. The additional warnings are as follows: + log\_warnings >= 1 - [Event scheduler](../event-scheduler/index) information. - System signals - Wrong usage of `--user` - Failed setrlimit() and mlockall() - Changed limits - Wrong values of lower\_case\_table\_names and stack\_size - Wrong values for command line options - Start log position and some master information when starting slaves - Slave reconnects - Killed slaves - Error reading relay logs - [Unsafe statements for statement-based replication](../unsafe-statements-for-statement-based-replication/index). If this warning occurs frequently, it is throttled to prevent flooding the log. - Disabled [plugins](../mariadb-plugins/index) that one tried to enable or use. - UDF files that didn't include the required init functions. - DNS lookup failures. + log\_warnings >= 2 - Access denied errors. - Connections aborted or closed due to errors or timeouts. - Table handler errors - Messages related to the files used to [persist replication state](../change-master-to/index#option-persistence): * Either the default `master.info` file or the file that is configured by the `[master\_info\_file](../mysqld-options/index#-master-info-file)` option. * Either the default `relay-log.info` file or the file that is configured by the `[relay\_log\_info\_file](../replication-and-binary-log-system-variables/index#relay_log_info_file)` system variable. - Information about a master's [binary log dump thread](../replication-threads/index#binary-log-dump-thread). + log\_warnings >= 3 - All errors and warnings during [MyISAM](../myisam/index) repair and auto recover. - Information about old-style language options. - Information about [progress of InnoDB online DDL](https://mariadb.org/monitoring-progress-and-temporal-memory-usage-of-online-ddl-in-innodb/). + log\_warnings >=4 - Connections aborted due to "Too many connections" errors. - Connections closed normally. - Connections aborted due to `[KILL](../data-manipulation-kill-connection-query/index)`. - Connections closed due to released connections, such as when `[completion\_type](#completion_type)` is set to `RELEASE`. + log\_warnings >=9 - Information about initializing plugins. * **Commandline:** `-W [level]` or `--log-warnings[=level]` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** + `2` (>= [MariaDB 10.2.4](https://mariadb.com/kb/en/mariadb-1024-release-notes/)) + `1` (<= [MariaDB 10.2.3](https://mariadb.com/kb/en/mariadb-1023-release-notes/)) * **Range:** `0` to `4294967295` --- #### `long_query_time` * **Description:** If a query takes longer than this many seconds to execute (microseconds can be specified too), the [Slow\_queries](../server-status-variables/index#slow_queries) status variable is incremented and, if enabled, the query is logged to the [slow query log](../slow-query-log/index). * **Commandline:** `--long-query-time=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `10.000000` * **Range:** `0` upwards --- #### `low_priority_updates` * **Description:** If set to 1 (0 is the default), for [storage engines](../storage-engines/index) that use only table-level locking ([Aria](../aria/index), [MyISAM](../myisam/index), [MEMORY](../memory-storage-engine/index) and [MERGE](../merge/index)), all INSERTs, UPDATEs, DELETEs and LOCK TABLE WRITEs will wait until there are no more SELECTs or LOCK TABLE READs pending on the relevant tables. Set this to 1 if reads are prioritized over writes. + In [MariaDB 5.5](../what-is-mariadb-55/index) and earlier, `[sql\_low\_priority\_updates](#sql_low_priority_updates)` is a synonym. * **Commandline:** `--low-priority-updates` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `0` --- #### `lower_case_file_system` * **Description:** Read-only variable describing whether the file system is case-sensitive. If set to `OFF`, file names are case-sensitive. If set to `ON`, they are not case-sensitive. * **Scope:** Global * **Dynamic:** No * **Data Type:** `boolean` * **Default Value:** `##` --- #### `lower_case_table_names` * **Description:** If set to `0` (the default on Unix-based systems), table names and aliases and database names are compared in a case-sensitive manner. If set to `1` (the default on Windows), names are stored in lowercase and not compared in a case-sensitive manner. If set to `2` (the default on Mac OS X), names are stored as declared, but compared in lowercase. This system variable's value cannot be changed after the datadir has been initialized. lower\_case\_table\_names is set when a MariaDB instance starts, and it remains constant afterwards. * **Commandline:** `--lower-case-table-names[=#]` * **Scope:** Global * **Dynamic:** No * **Data Type:** `numeric` * **Default Value:** `0` (Unix), `1` (Windows), `2` (Mac OS X) * **Range:** `0` to `2` --- #### `max_allowed_packet` * **Description:** Maximum size in bytes of a packet or a generated/intermediate string. The packet message buffer is initialized with the value from [net\_buffer\_length](#net_buffer_length), but can grow up to max\_allowed\_packet bytes. Set as large as the largest BLOB, in multiples of 1024. If this value is changed, it should be changed on the client side as well. See [slave\_max\_allowed\_packet](../replication-and-binary-log-server-system-variables/index#slave_max_allowed_packet) for a specific limit for replication purposes. * **Commandline:** `--max-allowed-packet=#` * **Scope:** Global, Session * **Dynamic:** Yes (Global), No (Session) * **Data Type:** `numeric` * **Default Value:** + `16777216` (16M) + `1073741824` (1GB) (client-side) * **Range:** `1024` to `1073741824` --- #### `max_connect_errors` * **Description:** Limit to the number of successive failed connects from a host before the host is blocked from making further connections. The count for a host is reset to zero if they successfully connect. To unblock, flush the host cache with a [FLUSH HOSTS](../flush/index) statement or [mysqladmin flush-hosts](../mysqladmin/index). * **Commandline:** `--max-connect-errors=#` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `100` * **Range:** `1` to `4294967295` --- #### `max_connections` * **Description:** The maximum number of simultaneous client connections. See also [Handling Too Many Connections](../handling-too-many-connections/index). Note that this value affects the number of file descriptors required on the operating system. Minimum was changed from `1` to `10` to avoid possible unexpected results for the user ([MDEV-18252](https://jira.mariadb.org/browse/MDEV-18252)). * **Commandline:** `--max-connections=#` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `151` * **Range:** + `10` to `100000` (>= [MariaDB 10.3.6](https://mariadb.com/kb/en/mariadb-1036-release-notes/), [MariaDB 10.2.15](https://mariadb.com/kb/en/mariadb-10215-release-notes/), [MariaDB 10.1.33](https://mariadb.com/kb/en/mariadb-10133-release-notes/)) + `1` to `100000` (<= [MariaDB 10.3.5](https://mariadb.com/kb/en/mariadb-1035-release-notes/), [MariaDB 10.2.14](https://mariadb.com/kb/en/mariadb-10214-release-notes/), [MariaDB 10.1.32](https://mariadb.com/kb/en/mariadb-10132-release-notes/)) --- #### `max_delayed_threads` * **Description:** Limits to the number of [INSERT DELAYED](../insert-delayed/index) threads. Once this limit is reached, the insert is handled as if there was no DELAYED attribute. If set to `0`, DELAYED is ignored entirely. The session value can only be set to `0` or to the same as the global value. * **Commandline:** `--max-delayed-threads=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `20` * **Range:** `0` to `16384` --- #### `max_digest_length` * **Description:** Maximum length considered for computing a statement digest, such as used by the [Performance Schema](../performance-schema/index) and query rewrite plugins. Statements that differ after this many bytes produce the same digest, and are aggregated for statistics purposes. The variable is allocated per session. Increasing will allow longer statements to be distinguished from each other, but increase memory use, while decreasing will reduce memory use, but more statements may become indistinguishable. * **Commandline:** `--max-digest-length=#` * **Scope:** Global, * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `1024` * **Range:** `0` to `1048576` --- #### `max_error_count` * **Description:** Specifies the maximum number of messages stored for display by [SHOW ERRORS](../show-errors/index) and [SHOW WARNINGS](../show-warnings/index) statements. * **Commandline:** `--max-error-count=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `64` * **Range:** `0` to `65535` --- #### `max_heap_table_size` * **Description:** Maximum size in bytes for user-created [MEMORY](../memory-storage-engine/index) tables. Setting the variable while the server is active has no effect on existing tables unless they are recreated or altered. The smaller of max\_heap\_table\_size and [tmp\_table\_size](#tmp_table_size) also limits internal in-memory tables. When the maximum size is reached, any further attempts to insert data will receive a "table ... is full" error. Temporary tables created with [CREATE TEMPORARY](../create-table/index) will not be converted to Aria, as occurs with internal temporary tables, but will also receive a table full error. * **Commandline:** `--max-heap-table-size=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `16777216` * **Range :** `16384` to `4294966272` --- #### `max_insert_delayed_threads` * **Description:** Synonym for [max\_delayed\_threads](#max_delayed_threads). --- #### `max_join_size` * **Description:** Statements will not be performed if they are likely to need to examine more than this number of rows, row combinations or do more disk seeks. Can prevent poorly-formatted queries from taking server resources. Changing this value to anything other the default will reset [sql\_big\_selects](#sql_big_selects) to 0. If sql\_big\_selects is set again, max\_join\_size will be ignored. This limit is also ignored if the query result is sitting in the [query cache](../the-query-cache/index). Previously named [sql\_max\_join\_size](#sql_max_join_size), which is still a synonym. * **Commandline:** `--max-join-size=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `18446744073709551615` * **Range:** `1` to `18446744073709551615` --- #### `max_length_for_sort_data` * **Description:** Used to decide which algorithm to choose when sorting rows. If the total size of the column data, not including columns that are part of the sort, is less than `max_length_for_sort_data`, then we add these to the sort key. This can speed up the sort as we don't have to re-read the same row again later. Setting the value too high can slow things down as there will be a higher disk activity for doing the sort. * **Commandline:** `--max-length-for-sort-data=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `1024` * **Range:** `4` to `8388608` --- #### `max_long_data_size` * **Description:** Maximum size for parameter values sent with mysql\_stmt\_send\_long\_data(). If not set, will default to the value of [max\_allowed\_packet](#max_allowed_packet). Deprecated in [MariaDB 5.5](../what-is-mariadb-55/index) and removed in [MariaDB 10.5.0](https://mariadb.com/kb/en/mariadb-1050-release-notes/); use [max\_allowed\_packet](#max_allowed_packet) instead. * **Commandline:** `--max-long-data-size=#` * **Scope:** Global * **Dynamic:** No * **Data Type:** `numeric` * **Default Value:** + `16777216` (16M) * **Range:** `1024` to `4294967295` * **Deprecated:** [MariaDB 5.5](../what-is-mariadb-55/index) * **Removed:** [MariaDB 10.5.0](https://mariadb.com/kb/en/mariadb-1050-release-notes/) --- #### `max_password_errors` * **Description:** The maximum permitted number of failed connection attempts due to an invalid password before a user is blocked from further connections. [FLUSH\_PRIVILEGES](../flush/index) will permit the user to connect again. This limit is ignored for users with the [SUPER](../grant/index#super) privilege or, from [MariaDB 10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/), the [CONNECTION ADMIN](../grant/index#connection-admin) privilege. The maximum also doesn't apply to users with a hostname of localhost, 127.0.0.1 or ::1. * **Commandline:** `--max-password-errors=#` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `4294967295` * **Range:** `1` to `4294967295` * **Introduced:** [MariaDB 10.4.2](https://mariadb.com/kb/en/mariadb-1042-release-notes/) --- #### `max_prepared_stmt_count` * **Description:** Maximum number of prepared statements on the server. Can help prevent certain forms of denial-of-service attacks. If set to `0`, no prepared statements are permitted on the server. * **Commandline:** `--max-prepared-stmt-count=#` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `16382` * **Range:** `0` to `4294967295` (>= [MariaDB 10.3.6](https://mariadb.com/kb/en/mariadb-1036-release-notes/)), `0` to `1048576` (<= [MariaDB 10.3.5](https://mariadb.com/kb/en/mariadb-1035-release-notes/)) --- #### `max_recursive_iterations` * **Description:** Maximum number of iterations when executing recursive queries, used to prevent infinite loops in [recursive CTEs](../recursive-common-table-expressions-overview/index). * **Commandline:** `--max-recursive-iterations=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `1000` (>= [MariaDB 10.6.0](https://mariadb.com/kb/en/mariadb-1060-release-notes/)), `4294967295` (<= [MariaDB 10.5](../what-is-mariadb-105/index)) * **Range:** `0` to `4294967295` * **Introduced:** [MariaDB 10.2.2](https://mariadb.com/kb/en/mariadb-1022-release-notes/) --- #### `max_rowid_filter_size` * **Description:** The maximum size of the container of a rowid filter. * **Commandline:** `--max-rowid-filter-size=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `131072` * **Range:** `1024` to `18446744073709551615` * **Introduced:** [MariaDB 10.4.3](https://mariadb.com/kb/en/mariadb-1043-release-notes/) --- #### `max_seeks_for_key` * **Description:** The optimizer assumes that the number specified here is the most key seeks required when searching with an index, regardless of the actual index cardinality. If this value is set lower than its default and maximum, indexes will tend to be preferred over table scans. * **Commandline:** `--max-seeks-for-key=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `4294967295` * **Range:** `1` to `4294967295` --- #### `max_session_mem_used` * **Description:** Amount of memory a single user session is allowed to allocate. This limits the value of the session variable [Memory\_used](../server-status-variables/index#memory_used). * **Commandline:** `--max-session-mem-used=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `9223372036854775807` (8192 PB) * **Range:** `8192` to `18446744073709551615` --- #### `max_sort_length` * **Description:** Maximum size in bytes used for sorting data values - anything exceeding this is ignored. The server uses only the first `max_sort_length` bytes of each value and ignores the rest. * **Commandline:** `--max-sort-length=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `1024` * **Range:** + `4` to `8388608` (<= [MariaDB 10.1.45](https://mariadb.com/kb/en/mariadb-10145-release-notes/), [MariaDB 10.2.32](https://mariadb.com/kb/en/mariadb-10232-release-notes/), [MariaDB 10.3.23](https://mariadb.com/kb/en/mariadb-10323-release-notes/), [MariaDB 10.4.13](https://mariadb.com/kb/en/mariadb-10413-release-notes/), [MariaDB 10.5.3](https://mariadb.com/kb/en/mariadb-1053-release-notes/)) + `8` to `8388608` (>= [MariaDB 10.1.46](https://mariadb.com/kb/en/mariadb-10146-release-notes/), [MariaDB 10.2.33](https://mariadb.com/kb/en/mariadb-10233-release-notes/), [MariaDB 10.3.24](https://mariadb.com/kb/en/mariadb-10324-release-notes/), [MariaDB 10.4.14](https://mariadb.com/kb/en/mariadb-10414-release-notes/), [MariaDB 10.5.4](https://mariadb.com/kb/en/mariadb-1054-release-notes/)) --- #### `max_sp_recursion_depth` * **Description:** Permitted number of recursive calls for a [stored procedure](../stored-procedures/index). `0`, the default, no recursion is permitted. Increasing this value increases the thread stack requirements, so you may need to increase [thread\_stack](#thread_stack) as well. This limit doesn't apply to [stored functions](../stored-functions/index). * **Commandline:** `--max-sp-recursion-depth[=#]` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `0` * **Range:** `0` to `255` --- #### `max_statement_time` * **Description:** Maximum time in seconds that a query can execute before being aborted. This includes all queries, not just [SELECT](../select/index) statements, but excludes statements in stored procedures. If set to 0, no limit is applied. See [Aborting statements that take longer than a certain time to execute](../aborting-statements-that-take-longer-than-a-certain-time-to-execute/index) for details and limitations. Useful when combined with [SET STATEMENT](../set-statement/index) for limiting the execution times of individual queries. * **Commandline:** `--max-statement-time[=#]` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `0.000000` * **Range:** `0` upwards --- #### `max_tmp_tables` * **Description:** Unused. --- #### `max_user_connections` * **Description:** Maximum simultaneous connections permitted for each user account. When set to `0`, there is no per user limit. Setting it to `-1` stops users without the [SUPER](../grant/index#super) privilege or, from [MariaDB 10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/), the [CONNECTION ADMIN](../grant/index#connection-admin) privilege, from connecting to the server. The session variable is always read-only and only privileged users can modify user limits. The session variable defaults to the global `max_user_connections` variable, unless the user's specific `[MAX\_USER\_CONNECTIONS](../create-user/index#max_user_connections)` resource option is non-zero. When both global variable and the user resource option are set, the user's [MAX\_USER\_CONNECTIONS](../create-user/index#max_user_connections) is used. Note: This variable does not affect users with the [SUPER](../grant/index#super) privilege or, from [MariaDB 10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/), the [CONNECTION ADMIN](../grant/index#connection-admin) privilege. * **Commandline:** `--max-user-connections=#` * **Scope:** Global, Session * **Dynamic:** Yes, (except when globally set to `0` or `-1`) * **Data Type:** `numeric` * **Default Value:** `0` * **Range:** `-1` to `4294967295` --- #### `max_write_lock_count` * **Description:** Read lock requests will be permitted for processing after this many write locks. Applies only to storage engines that use table level locks (thr\_lock), so no effect with [InnoDB](../innodb/index) or [Archive](../archive/index). * **Commandline:** `--max-write-lock-count=#` * **Scope:** Global * **Dynamic:** No * **Data Type:** `numeric` * **Default Value:** `4294967295` * **Range:** `0-4294967295` --- #### `metadata_locks_cache_size` * **Description:** Size of the metadata locks cache, used for reducing the need to create and destroy synchronization objects. It is particularly helpful on systems where this process is inefficient, such as Windows XP. * **Commandline:** `--metadata-locks-cache-size=#` * **Scope:** Global * **Dynamic:** No * **Data Type:** `numeric` * **Default Value:** `1024` * **Range:** `1` to `1048576` --- #### `metadata_locks_hash_instances` * **Description:** Number of hashes used by the set of metadata locks. The metadata locks are partitioned into separate hashes in order to reduce contention. * **Commandline:** `--metadata-locks-hash-instances=#` * **Scope:** Global * **Dynamic:** No * **Data Type:** `numeric` * **Default Value:** `8` * **Range:** `1` to `1024` --- #### `min_examined_row_limit` * **Description:** If a query examines more than this number of rows, it is logged to the [slow query log](../slow-query-log/index). If set to `0`, the default, no row limit is used. * **Commandline:** `--min-examined-row-limit=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `0` * **Range:** `0-4294967295` --- #### `mrr_buffer_size` * **Description:** Size of buffer to use when using multi-range read with range access. See [Multi Range Read optimization](../multi-range-read-optimization/index#range-access) for more information. * **Commandline:** `--mrr-buffer-size=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `262144` * **Range** `8192` to `2147483648` --- #### `multi_range_count` * **Description:** Ignored. Use [mrr\_buffer\_size](#mrr_buffer_size) instead. * **Commandline:** `--multi-range-count=#` * **Default Value:** `256` * **Removed:** [MariaDB 10.5.1](https://mariadb.com/kb/en/mariadb-1051-release-notes/) --- #### `mysql56_temporal_format` * **Description:** If set (the default), MariaDB uses the MySQL 5.6 low level formats for [TIME](../time/index), [DATETIME](../datetime/index) and [TIMESTAMP](../timestamp/index) instead of the [MariaDB 5.3](../what-is-mariadb-53/index) version. The version MySQL introduced in 5.6 requires more storage, but potentially allows negative dates and has some advantages in replication. There should be no reason to revert to the old [MariaDB 5.3](../what-is-mariadb-53/index) microsecond format. See also [MDEV-10723](https://jira.mariadb.org/browse/MDEV-10723). * **Commandline:** `--mysql56-temporal-format` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `ON` --- #### `named_pipe` * **Description:** On Windows systems, determines whether connections over named pipes are permitted. * **Commandline:** `--named-pipe` * **Scope:** Global * **Dynamic:** No * **Data Type:** `boolean` * **Default Value:** `OFF` --- #### `net_buffer_length` * **Description:** The starting size, in bytes, for the connection and thread buffers for each client thread. The size can grow to [max\_allowed\_packet](#max_allowed_packet). This variable's session value is read-only. Can be set to the expected length of client statements if memory is a limitation. * **Commandline:** `--net-buffer-length=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `16384` * **Range:** `1024` to `1048576` --- #### `net_read_timeout` * **Description:** Time in seconds the server will wait for a client connection to send more data before aborting the read. See also [net\_write\_timeout](#net_write_timeout) and [slave\_net\_timeout](../replication-and-binary-log-server-system-variables/index#slave_net_timeout) * **Commandline:** `--net-read-timeout=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `30` * **Range:** `1` upwards --- #### `net_retry_count` * **Description:** Permit this many retries before aborting when attempting to read or write on a communication port. On FreeBSD systems should be set higher as threads are sent internal interrupts.. * **Commandline:** `--net-retry-count=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `10` * **Range:** `1` to `4294967295` --- #### `net_write_timeout` * **Description:** Time in seconds to wait on writing a block to a connection before aborting the write. See also [net\_read\_timeout](#net_read_timeout) and [slave\_net\_timeout](../replication-and-binary-log-server-system-variables/index#slave_net_timeout). * **Commandline:** `--net-write-timeout=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `60` * **Range:** `1` upwards --- #### `old` * **Description:** Disabled by default, enabling it reverts index hints to those used before MySQL 5.1.17. Enabling may lead to replication errors. Deprecated and replaced by [old\_mode](#old_mode) from [MariaDB 10.9](../what-is-mariadb-109/index). * **Commandline:** `--old` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `OFF` * **Deprecated:** [MariaDB 10.9](../what-is-mariadb-109/index) --- #### `old_alter_table` * **Description:** From [MariaDB 10.3.7](https://mariadb.com/kb/en/mariadb-1037-release-notes/), an alias for [alter\_algorithm](#alter_algorithm). Prior to that, if set to `1` (`0` is default), MariaDB reverts to the non-optimized, pre-MySQL 5.1, method of processing [ALTER TABLE](../alter-table/index) statements. A temporary table is created, the data is copied over, and then the temporary table is renamed to the original. * **Commandline:** `--old-alter-table` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `enumerated` (>=[MariaDB 10.3.7](https://mariadb.com/kb/en/mariadb-1037-release-notes/)), `boolean` (<= [MariaDB 10.3.6](https://mariadb.com/kb/en/mariadb-1036-release-notes/)) * **Default Value:** See [alter\_algorithm](#alter_algorithm) (>= [MariaDB 10.3.7](https://mariadb.com/kb/en/mariadb-1037-release-notes/)), `0` (<= [MariaDB 10.3.6](https://mariadb.com/kb/en/mariadb-1036-release-notes/)) * **Valid Values:** See [alter\_algorithm](#alter_algorithm) for the full list. * **Deprecated:** [MariaDB 10.3.7](https://mariadb.com/kb/en/mariadb-1037-release-notes/) (superceded by [alter\_algorithm](#alter_algorithm)) --- #### `old_mode` * **Description:** Used for getting MariaDB to emulate behavior from an old version of MySQL or MariaDB. See [OLD Mode](../old_mode/index). Fully replaces the [old](#old) variable from [MariaDB 10.9](../what-is-mariadb-109/index). * **Commandline:** `--old-mode` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `string` * **Default Value:** `UTF8_IS_UTF8MB3` (>= [MariaDB 10.6](../what-is-mariadb-106/index)) `(empty string)` (<= [MariaDB 10.5](../what-is-mariadb-105/index)) * **Valid Values:** See [OLD Mode](../old_mode/index) for the full list. --- #### `old_passwords` * **Description:** If set to `1` (`0` is default), MariaDB reverts to using the `[mysql\_old\_password](../authentication-plugin-mysql_old_password/index)` authentication plugin by default for newly created users and passwords, instead of the `[mysql\_native\_password](../authentication-plugin-mysql_native_password/index)` authentication plugin. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `OFF` --- #### `open_files_limit` * **Description:** The number of file descriptors available to MariaDB. If you are getting the `Too many open files` error, then you should increase this limit. If set to 0, then MariaDB will calculate a limit based on the following: MAX([max\_connections](#max_connections)\*5, [max\_connections](#max_connections) +[table\_open\_cache](#table_open_cache)\*2) MariaDB sets the limit with `[setrlimit](https://linux.die.net/man/2/setrlimit)`. MariaDB cannot set this to exceed the hard limit imposed by the operating system. Therefore, you may also need to change the hard limit. There are a few ways to do so. + If you are using `[mysqld\_safe](../mysqld_safe/index)` to start `mysqld`, then see the instructions at [mysqld\_safe: Configuring the Open Files Limit](../mysqld_safe/index#configuring-the-open-files-limit). + If you are using `[systemd](../systemd/index)` to start `mysqld`, then see the instructions at [systemd: Configuring the Open Files Limit](../systemd/index#configuring-the-open-files-limit). + Otherwise, you can change the hard limit for the `mysql` user account by modifying `[/etc/security/limits.conf](https://linux.die.net/man/5/limits.conf)`. See [Configuring Linux for MariaDB: Configuring the Open Files Limit](../configuring-linux-for-mariadb/index#configuring-the-open-files-limit) for more details. * **Commandline:** `--open-files-limit=count` * **Scope:** Global * **Dynamic:** No * **Data Type:** `numeric` * **Default Value:** Autosized (see description) * **Range:** `0` to `4294967295` --- #### `optimizer_max_sel_arg_weight` * **Description:** The maximum weight of the SEL\_ARG graph. Set to 0 for no limit. * **Commandline:** `--optimizer-max-sel-arg-weight=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `32000` * **Range:** `0` to `18446744073709551615` * **Introduced:** [MariaDB 10.5.9](https://mariadb.com/kb/en/mariadb-1059-release-notes/) --- #### `optimizer_prune_level` * **Description:** If set to `1`, the default, the optimizer will use heuristics to prune less-promising partial plans from the optimizer search space. If set to `0`, heuristics are disabled and an exhaustive search is performed. * **Commandline:** `--optimizer-prune-level[=#]` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `1` --- #### `optimizer_search_depth` * **Description:** Maximum search depth by the query optimizer. Smaller values lead to less time spent on execution plans, but potentially less optimal results. If set to `0`, MariaDB will automatically choose a reasonable value. Since the better results from more optimal planning usually offset the longer time spent on planning, this is set as high as possible by default. `63` is a valid value, but its effects (switching to the original find\_best search) are deprecated. * **Commandline:** `--optimizer-search-depth[=#]` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `62` * **Range:** `0` to `63` --- #### `optimizer_selectivity_sampling_limit` * **Description:** Controls number of record samples to check condition selectivity. Only used if `[optimizer\_use\_condition\_selectivity](index#optimizer_use_condition_selectivity) > 4.` * **Commandline:** `optimizer-selectivity-sampling-limit[=#]` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `100` * **Range:** `10` upwards --- #### `optimizer_switch` * **Description:** A series of flags for controlling the query optimizer. See [Optimizer Switch](../optimizer-switch/index) for defaults, and a comparison to MySQL. * **Commandline:** `--optimizer-switch=value` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `string` * **Valid Values:** + `condition_pushdown_for_derived={on|off}` (>=[MariaDB 10.2.2](https://mariadb.com/kb/en/mariadb-1022-release-notes/)) + `condition_pushdown_for_subquery={on|off}` (>=[MariaDB 10.4.0](https://mariadb.com/kb/en/mariadb-1040-release-notes/)) + `condition_pushdown_from_having={on|off}` (>=[MariaDB 10.4.3](https://mariadb.com/kb/en/mariadb-1043-release-notes/)) + `default` - set all optimizations to their default values. + `derived_merge={on|off}` - see [Derived table merge optimization](../derived-table-merge-optimization/index) + `derived_with_keys={on|off}` - see [Derived table with key optimization](../derived-table-with-key-optimization/index) + `engine_condition_pushdown={on|off}`. Deprecated in [MariaDB 10.1.1](https://mariadb.com/kb/en/mariadb-1011-release-notes/) as engine condition pushdown is now automatically enabled for all engines that support it. + `exists_to_in={on|off}` - see [EXISTS-to-IN optimization](../exists-to-in-optimization/index) + `extended_keys={on|off}` - see [Extended Keys](../extended-keys/index) + `firstmatch={on|off}` - see [First Match Strategy](../firstmatch-strategy/index) + `index_condition_pushdown={on|off}` - see [Index Condition Pushdown](../index-condition-pushdown/index) + `index_merge={on|off}` + `index_merge_intersection={on|off}` + `index_merge_sort_intersection={on|off}` - [more details](../index_merge_sort_intersection/index) + `index_merge_sort_union={on|off}` + `index_merge_union={on|off}` + `in_to_exists={on|off}` - see [IN-TO-EXISTS transformation](../non-semi-join-subquery-optimizations/index#the-in-to-exists-transformation) + `join_cache_bka={on|off}` - see [Block-Based Join Algorithms](../block-based-join-algorithms/index) + `join_cache_hashed={on|off}` - see [Block-Based Join Algorithms](../block-based-join-algorithms/index) + `join_cache_incremental={on|off}` - see [Block-Based Join Algorithms](../block-based-join-algorithms/index) + `loosescan={on|off}` - see [LooseScan strategy](../loosescan-strategy/index) + `materialization={on|off}` - [Semi-join](../semi-join-materialization-strategy/index) and [non semi-join](../non-semi-join-subquery-optimizations/index#materialization-for-non-correlated-in-subqueries) materialization. + `mrr={on|off}` - see [Multi Range Read optimization](../multi-range-read-optimization/index) + `mrr_cost_based={on|off}` - see [Multi Range Read optimization](../multi-range-read-optimization/index) + `mrr_sort_keys={on|off}` - see [Multi Range Read optimization](../multi-range-read-optimization/index) + `not_null_range_scan={on|off}` - see [not\_null\_range\_scan optimization](../not_null_range_scan-optimization/index) ( >= [MariaDB 10.5.0](https://mariadb.com/kb/en/mariadb-1050-release-notes/)) + `optimize_join_buffer_size={on|off}` - see [Block-Based Join Algorithms](../block-based-join-algorithms/index) + `orderby_uses_equalities={on|off}` (>= [MariaDB 10.1.15](https://mariadb.com/kb/en/mariadb-10115-release-notes/), [MariaDB 10.2.1](https://mariadb.com/kb/en/mariadb-1021-release-notes/)) - if not set, the optimizer ignores equality propagation. See [MDEV-8989](https://jira.mariadb.org/browse/MDEV-8989). + `outer_join_with_cache={on|off}` - see [Block-Based Join Algorithms](../block-based-join-algorithms/index) + `partial_match_rowid_merge={on|off}` - see [Non-semi-join subquery optimizations](../non-semi-join-subquery-optimizations/index) + `partial_match_table_scan={on|off}` - see [Non-semi-join subquery optimizations](../non-semi-join-subquery-optimizations/index) + `rowid_filter={on|off}` - see [Rowid Filtering Optimization](../rowid-filtering-optimization/index) (>= [MariaDB 10.4.3](https://mariadb.com/kb/en/mariadb-1043-release-notes/) ) + `semijoin={on|off}` - see [Semi-join subquery optimizations](../semi-join-subquery-optimizations/index) + `semijoin_with_cache={on|off}` - see [Block-Based Join Algorithms](../block-based-join-algorithms/index) + `split_materialized={on|off}` + `subquery_cache={on|off}` - see [subquery cache](../subquery-cache/index). + `table_elimination={on|off}` - see [Table Elimination User Interface](../table-elimination-user-interface/index) --- #### `optimizer_trace` * **Description:** Controls [tracing of the optimizer](../optimizer-trace/index): optimizer\_trace=option=val[,option=val...], where option is one of {enabled} and val is one of {on, off, default} * **Commandline:** `--optimizer-trace=value` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `enum` * **Default Value:** `enabled=off` * **Valid Values:** `enabled={on|off|default}` * **Introduced:** [MariaDB 10.4.3](https://mariadb.com/kb/en/mariadb-1043-release-notes/) --- #### `optimizer_trace_max_mem_size` * **Description:** Limits the memory used while tracing a query by specifying the maximum allowed cumulated size, in bytes, of stored [optimizer traces](../optimizer-trace/index). * **Commandline:** `--optimizer-trace-max-mem-size=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `1048576` * **Range:** `1` to `18446744073709551615` * **Introduced:** [MariaDB 10.4.3](https://mariadb.com/kb/en/mariadb-1043-release-notes/) --- #### `optimizer_use_condition_selectivity` * **Description:** Controls which statistics can be used by the optimizer when looking for the best query execution plan. + `1` Use selectivity of predicates as in [MariaDB 5.5](../what-is-mariadb-55/index). + `2` Use selectivity of all range predicates supported by indexes. + `3` Use selectivity of all range predicates estimated without [histogram](../histogram-based-statistics/index). + `4` Use selectivity of all range predicates estimated with [histogram](../histogram-based-statistics/index). + `5` Additionally use selectivity of certain non-range predicates calculated on record sample. * **Commandline:** `--optimizer-use-condition-selectivity=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `4` (>= [MariaDB 10.4.1](https://mariadb.com/kb/en/mariadb-1041-release-notes/)), `1` (<= [MariaDB 10.4.0](https://mariadb.com/kb/en/mariadb-1040-release-notes/)) * **Range:** `1` to `5` --- #### `pid_file` * **Description:** Full path of the process ID file. * **Commandline:** `--pid-file=file_name` * **Scope:** Global * **Dynamic:** No * **Data Type:** `file name` --- #### `plugin_dir` * **Description:** Path to the [plugin](../mariadb-plugins/index) directory. For security reasons, either make sure this directory can only be read by the server, or set [secure\_file\_priv](#secure_file_priv). * **Commandline:** `--plugin-dir=path` * **Scope:** Global * **Dynamic:** No * **Data Type:** `directory name` * **Default Value:** `BASEDIR/lib/plugin` --- #### `plugin_maturity` * **Description:** The lowest acceptable [plugin](../mariadb-plugins/index) maturity. MariaDB will not load plugins less mature than the specified level. * **Commandline:** `--plugin-maturity=level` * **Scope:** Global * **Dynamic:** No * **Type:** enum * **Default Value:** One less than the server maturity (>= [MariaDB 10.3.3](https://mariadb.com/kb/en/mariadb-1033-release-notes/)), `unknown` (<= [MariaDB 10.3.2](https://mariadb.com/kb/en/mariadb-1032-release-notes/)) * **Valid Values:** `unknown`, `experimental`, `alpha`, `beta`, `gamma`, `stable` --- #### `port` * **Description:** Port to listen for TCP/IP connections. If set to `0`, will default to, in order of preference, my.cnf, the MYSQL\_TCP\_PORT [environment variable](../mariadb-environment-variables/index), /etc/services, built-in default (3306). * **Commandline:** `--port=#`, `-P` * **Scope:** Global * **Dynamic:** No * **Data Type:** `numeric` * **Default Value:** `3306` * **Range:** `0` to `65535` --- #### `preload_buffer_size` * **Description:** Size in bytes of the buffer allocated when indexes are preloaded. * **Commandline:** `--preload-buffer-size=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `32768` * **Range:** `1024` to `1073741824` --- #### `profiling` * **Description:** If set to `1` (`0` is default), statement profiling will be enabled. See [SHOW PROFILES()](../show-profiles/index) and [SHOW PROFILE()](../show-profile/index). * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `OFF` --- #### `profiling_history_size` * **Description:** Number of statements about which profiling information is maintained. If set to `0`, no profiles are stored. See [SHOW PROFILES](../show-profiles/index). * **Commandline:** `--profiling-history-size=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `15` * **Range:** `0` to `100` --- #### `progress_report_time` * **Description:** Time in seconds between sending [progress reports](../progress-reporting/index) to the client for time-consuming statements. If set to `0`, progress reporting will be disabled. * **Commandline:** `--progress-report-time=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `5` * **Range:** `0` to `4294967295` --- #### `protocol_version` * **Description:** The version of the client/server protocol used by the MariaDB server. * **Commandline:** None * **Scope:** Global * **Dynamic:** No * **Data Type:** `numeric` * **Default Value:** `10` * **Range:** `0` to `4294967295` --- #### `proxy_protocol_networks` * **Description:** Enable [proxy protocol](../proxy-protocol-support/index) for these source networks. The syntax is a comma separated list of IPv4 and IPv6 networks. If the network doesn't contain a mask, it is considered to be a single host. "\*" represents all networks and must be the only directive on the line. String "localhost" represents non-TCP local connections (Unix domain socket, Windows named pipe or shared memory). See [Proxy Protocol Support](../proxy-protocol-support/index). * **Commandline:** `--proxy-protocol-networks=value` * **Scope:** Global * **Dynamic:** Yes (>= [MariaDB 10.3.6](https://mariadb.com/kb/en/mariadb-1036-release-notes/)), No (<= [MariaDB 10.3.5](https://mariadb.com/kb/en/mariadb-1035-release-notes/)) * **Data Type:** `string` * **Default Value:** (empty) * **Introduced:** [MariaDB 10.3.1](https://mariadb.com/kb/en/mariadb-1031-release-notes/) --- #### `proxy_user` * **Description:** Set to the proxy user account name if the current client is a proxy, else `NULL`. * **Scope:** Session * **Dynamic:** No * **Data Type:** `string` --- #### `pseudo_slave_mode` * **Description:** For internal use by the server. * **Scope:** Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `OFF` --- #### `pseudo_thread_id` * **Description:** For internal use only. * **Scope:** Session * **Dynamic:** Yes * **Data Type:** `numeric` --- #### `query_alloc_block_size` * **Description:** Size in bytes of the extra blocks allocated during query parsing and execution (after [query\_prealloc\_size](#query_prealloc_size) is used up). * **Commandline:** `--query-alloc-block-size=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `16384` * **Range - 32 bit:** `1024` to `4294967295` * **Range - 64 bit:** `1024` to `18446744073709547520` --- #### `query_cache_limit` * **Description:** Size in bytes for which results larger than this are not stored in the [query cache](../the-query-cache/index). * **Commandline:** `--query-cache-limit=#` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `1048576` (1MB) * **Range:** `0` to `4294967295` --- #### `query_cache_min_res_unit` * **Description:** Minimum size in bytes of the blocks allocated for [query cache](../the-query-cache/index) results. * **Commandline:** `--query-cache-min-res-unit=#` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `4096` (4KB) * **Range - 32 bit:** `1024` to `4294967295` * **Range - 64 bit:** `1024` to `18446744073709547520` --- #### `query_cache_size` * **Description:** Size in bytes available to the [query cache](../the-query-cache/index). About 40KB is needed for query cache structures, so setting a size lower than this will result in a warning. `0`, the default before [MariaDB 10.1.7](https://mariadb.com/kb/en/mariadb-1017-release-notes/), effectively disables the query cache. **Warning:** Starting from [MariaDB 10.1.7](https://mariadb.com/kb/en/mariadb-1017-release-notes/), [query\_cache\_type](#query_cache_type) is automatically set to ON if the server is started with the query\_cache\_size set to a non-zero (and non-default) value. This will happen even if [query\_cache\_type](#query_cache_type) is explicitly set to OFF in the configuration. * **Commandline:** `--query-cache-size=#` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `1M` (although frequently given a default value in some setups) * **Valid Values:** `0` upwards in units of 1024. --- #### `query_cache_strip_comments` * **Description:** If set to `1` (`0` is default), the server will strip any comments from the query before searching to see if it exists in the [query cache](../the-query-cache/index). Multiple space, line feeds, tab and other white space characters will also be removed. * **Commandline:** `query-cache-strip-comments` * **Scope:** Session, Global * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `OFF` --- #### `query_cache_type` * **Description:** If set to `0`, the [query cache](../the-query-cache/index) is disabled (although a buffer of [query\_cache\_size](#query_cache_size) bytes is still allocated). If set to `1` all SELECT queries will be cached unless SQL\_NO\_CACHE is specified. If set to `2` (or `DEMAND`), only queries with the SQL CACHE clause will be cached. Note that if the server is started with the query cache disabled, it cannot be enabled at runtime. **Warning:** Starting from [MariaDB 10.1.7](https://mariadb.com/kb/en/mariadb-1017-release-notes/), query\_cache\_type is automatically set to ON if the server is started with the [query\_cache\_size](#query_cache_size) set to a non-zero (and non-default) value. This will happen even if [query\_cache\_type](#query_cache_type) is explicitly set to OFF in the configuration. * **Commandline:** `--query-cache-type=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `enumeration` * **Default Value:** `OFF` * **Valid Values:** `0` or `OFF`, `1` or `ON`, `2` or `DEMAND` --- #### `query_cache_wlock_invalidate` * **Description:** If set to `0`, the default, results present in the [query cache](../the-query-cache/index) will be returned even if there's a write lock on the table. If set to `1`, the client will first have to wait for the lock to be released. * **Commandline:** `--query-cache-wlock-invalidate` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `OFF` --- #### `query_prealloc_size` * **Description:** Size in bytes of the persistent buffer for query parsing and execution, allocated on connect and freed on disconnect. Increasing may be useful if complex queries are being run, as this will reduce the need for more memory allocations during query operation. See also [query\_alloc\_block\_size](#query_alloc_block_size). * **Commandline:** `--query-prealloc-size=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `24576` * **Range:** `1024` to `4294967295` --- #### `rand_seed1` * **Description:** `rand_seed1` and `rand_seed2` facilitate replication of the [RAND()](../rand/index) function. The master passes the value of these to the slaves so that the random number generator is seeded in the same way, and generates the same value, on the slave as on the master. Until [MariaDB 10.1.4](https://mariadb.com/kb/en/mariadb-1014-release-notes/), the variable value could not be viewed, with the [SHOW VARIABLES](../show-variables/index) output always displaying zero. * **Commandline:** None * **Scope:** Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** Varies * **Range:** `0` to `18446744073709551615` --- #### `rand_seed2` * **Description:** See [rand\_seed1](#rand_seed1). --- #### `range_alloc_block_size` * **Description:** Size in bytes of blocks allocated during range optimization. The unit size in 1024. * **Commandline:** `--range-alloc-block-size=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `4096` * **Range - 32 bit:** `4096` to `4294967295` * **Range - 64 bit:** `4096` to `18446744073709547520` --- #### `read_buffer_size` * **Description:** Each thread performing a sequential scan (for MyISAM, Aria and MERGE tables) allocates a buffer of this size in bytes for each table scanned. Increase if you perform many sequential scans. If not in a multiple of 4KB, will be rounded down to the nearest multiple. Also used in ORDER BY's for caching indexes in a temporary file (not temporary table), for caching results of nested queries, for bulk inserts into partitions, and to determine the memory block size of [MEMORY](../memory-storage-engine/index) tables. * **Commandline:** `--read-buffer-size=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `131072` * **Range:** `8200 to 2147479552` --- #### `read_only` * **Description:** When set to `1` (`0` is default), no updates are permitted except from users with the [SUPER](../grant/index#super) privilege or, from [MariaDB 10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/), the [READ ONLY ADMIN](../grant/index#read_only-admin) privilege, or replica servers updating from a primary. The `read_only` variable is useful for replica servers to ensure no updates are accidentally made outside of what are performed on the primary. Inserting rows to log tables, updates to temporary tables and [OPTIMIZE TABLE](../optimize-table/index) or [ANALYZE TABLE](../analyze-table/index) statements are excluded from this limitation. If `read_only` is set to `1`, then the [SET PASSWORD](../set-password/index) statement is limited only to users with the [SUPER](../grant/index#super) privilege (<= [MariaDB 10.5.1](https://mariadb.com/kb/en/mariadb-1051-release-notes/)) or [READ ONLY ADMIN](../grant/index#read_only-admin) privilege (>= [MariaDB 10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/)). Attempting to set this variable to `1` will fail if the current session has table locks or transactions pending, while if other sessions hold table locks, the statement will wait until these locks are released before completing. While the attempt to set `read_only` is waiting, other requests for table locks or transactions will also wait until `read_only` has been set. See [Read-Only Replicas](../read-only-replicas/index) for more. * **Commandline:** `--read-only` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `OFF` --- #### `read_rnd_buffer_size` * **Description:** Size in bytes of the buffer used when reading rows from a [MyISAM](../myisam/index) table in sorted order after a key sort. Larger values improve ORDER BY performance, although rather increase the size by SESSION where the need arises to avoid excessive memory use. * **Commandline:** `--read-rnd-buffer-size=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `262144` * **Range:** `8200` to `2147483647` --- - - #### `require_secure_transport` * **Description:** When this option is enabled, connections attempted using insecure transport will be rejected. Secure transports are SSL/TLS, Unix sockets or named pipes. Note that [per-account requirements](../securing-connections-for-client-and-server/index#requiring-tls) take precedence. * **Commandline:** `--require-secure-transport[={0|1}]` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `OFF` * **Introduced:** [MariaDB 10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/) --- #### `rowid_merge_buff_size` * **Description:** The maximum size in bytes of the memory available to the Rowid-merge strategy. See [Non-semi-join subquery optimizations](../non-semi-join-subquery-optimizations/index#optimizer-control) for more information. * **Commandline:** `--rowid-merge-buff-size=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `8388608` * **Range:** `0` to `2147483647` --- #### `rpl_recovery_rank` * **Description:** Unused. * **Removed:** [MariaDB 10.1.2](https://mariadb.com/kb/en/mariadb-1012-release-notes/) --- #### `safe_show_database` * **Description:** This variable was removed in [MariaDB 5.5](../what-is-mariadb-55/index), and has been replaced by the more flexible [SHOW DATABASES](../show-databases/index) privilege. * **Commandline:** `--safe-show-database` (until MySQL 4.1.1) * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `boolean` * **Removed:** [MariaDB 5.5](../what-is-mariadb-55/index) --- #### `secure_auth` * **Description:** Connections will be blocked if they use the the `[mysql\_old\_password](../authentication-plugin-mysql_old_password/index)` authentication plugin. The server will also fail to start if the privilege tables are in the old, pre-MySQL 4.1 format. * **Commandline:** `--secure-auth` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `ON` --- #### `secure_file_priv` * **Description:** [LOAD DATA](../load-data-infile/index), [SELECT ... INTO](../select/index#into) and [LOAD FILE()](../load_file/index) will only work with files in the specified path. If not set, the default, or set to empty string, the statements will work with any files that can be accessed. * **Commandline:** `--secure-file-priv=path` * **Scope:** Global * **Dynamic:** No * **Data Type:** `path name` * **Default Value:** None --- #### `secure_timestamp` * **Description:** Restricts direct setting of a session timestamp. Possible levels are: + YES - timestamp cannot deviate from the system clock + REPLICATION - replication thread can adjust timestamp to match the master's + SUPER - a user with this privilege and a replication thread can adjust timestamp + NO - historical behavior, anyone can modify session timestamp * **Commandline:** `--secure-timestamp=value` * **Scope:** Global * **Dynamic:** No * **Data Type:** `enum` * **Default Value:** `NO` * **Introduced:** [MariaDB 10.3.7](https://mariadb.com/kb/en/mariadb-1037-release-notes/) --- #### `session_track_schema` * **Description:** Whether to track changes to the default schema within the current session. * **Commandline:** `--session-track-schema={0|1}` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `ON` * **Introduced:** [MariaDB 10.2.2](https://mariadb.com/kb/en/mariadb-1022-release-notes/) --- #### `session_track_state_change` * **Description:** Whether to track changes to the session state. * **Commandline:** `--session-track-state-change={0|1}` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `OFF` * **Introduced:** [MariaDB 10.2.2](https://mariadb.com/kb/en/mariadb-1022-release-notes/) --- #### `session_track_system_variables` * **Description:** Comma-separated list of session system variables for which to track changes. In [MariaDB 10.2](../what-is-mariadb-102/index), by default no variables are tracked. For compatibility with MySQL defaults, this variable should be set to "autocommit, character\_set\_client, character\_set\_connection, character\_set\_results, time\_zone" (the default from [MariaDB 10.3.1](https://mariadb.com/kb/en/mariadb-1031-release-notes/)). The `*` character tracks all session variables. * **Commandline:** `--session-track-system-variables=value` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `string` * **Default Value:** `autocommit, character_set_client, character_set_connection, character_set_results, time_zone` (>= [MariaDB 10.3.1](https://mariadb.com/kb/en/mariadb-1031-release-notes/)), empty string (<= [MariaDB 10.3.0](https://mariadb.com/kb/en/mariadb-1030-release-notes/)) * **Introduced:** [MariaDB 10.2.2](https://mariadb.com/kb/en/mariadb-1022-release-notes/) --- #### `session_track_transaction_info` * **Description:** Track changes to the transaction attributes. OFF to disable; STATE to track just transaction state (Is there an active transaction? Does it have any data? etc.); CHARACTERISTICS to track transaction state and report all statements needed to start a transaction with the same characteristics (isolation level, read only/read write,snapshot - but not any work done / data modified within the transaction). * **Commandline:** `--session-track-transaction-info=value` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `enum` * **Default Value:** `OFF` * **Valid Values:** `OFF`, `STATE`, `CHARACTERISTICS` * **Introduced:** [MariaDB 10.2.2](https://mariadb.com/kb/en/mariadb-1022-release-notes/) --- #### `shared_memory` * **Description:** Windows only, determines whether the server permits shared memory connections. See also [shared\_memory\_base\_name](#shared_memory_base_name). * **Scope:** Global * **Dynamic:** No --- #### `shared_memory_base_name` * **Description:** Windows only, specifies the name of the shared memory to use for shared memory connection. Mainly used when running more than one instance on the same physical machine. By default the name is `MYSQL` and is case sensitive. See also [shared\_memory](#shared_memory). * **Scope:** Global * **Dynamic:** No * **Data Type:** `string` * **Default Value:** `MYSQL` --- #### `skip_external_locking` * **Description:** If this system variable is set, then some kinds of external table locks will be disabled for some [storage engines](../storage-engines/index). + If this system variable is set, then the [MyISAM](../myisam-storage-engine/index) storage engine will not use file-based locks. Otherwise, it will use the `[fcntl()](https://linux.die.net/man/2/fcntl)` function with the `F_SETLK` option to get file-based locks on Unix, and it will use the `[LockFileEx()](https://docs.microsoft.com/en-us/windows/desktop/api/fileapi/nf-fileapi-lockfileex)` function to get file-based locks on Windows. + If this system variable is set, then the [Aria](../aria/index) storage engine will not lock a table when it decrements the table's in-file counter that keeps track of how many connections currently have the table open. See [MDEV-19393](https://jira.mariadb.org/browse/MDEV-19393) for more information. * **Commandline:** `--skip-external-locking` * **Scope:** Global * **Dynamic:** No * **Data Type:** `boolean` * **Default Value:** `1` --- #### `skip_name_resolve` * **Description:** If set to 1 (0 is the default), only IP addresses are used for connections. Host names are not resolved. All host values in the GRANT tables must be IP addresses (or localhost). * **Commandline:** `--skip-name-resolve` * **Scope:** Global * **Dynamic:** No * **Data Type:** `boolean` * **Default Value:** `0` --- #### `skip_networking` * **Description:** If set to 1, (0 is the default), the server does not listen for TCP/IP connections. All interaction with the server will be through socket files (Unix) or named pipes or shared memory (Windows). It's recommended to use this option if only local clients are permitted to connect to the server. * **Commandline:** `--skip-networking` * **Scope:** Global * **Dynamic:** No * **Data Type:** `boolean` * **Default Value:** `0` --- #### `skip_show_database` * **Description:** If set to 1, (0 is the default), only users with the [SHOW DATABASES](../show-databases/index) privilege can use the SHOW DATABASES statement to see all database names. * **Commandline:** `--skip-show-database` * **Scope:** Global * **Dynamic:** No * **Data Type:** `boolean` * **Default Value:** `0` --- #### `slow_launch_time` * **Description:** Time in seconds. If a thread takes longer than this to launch, the `slow_launch_threads` [server status variable](../server-status-variables/index) is incremented. * **Commandline:** `--slow-launch-time=#` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `2` --- #### `slow_query_log` * **Description:** If set to 0, the default unless the --slow-query-log option is used, the [slow query log](../slow-query-log/index) is disabled, while if set to 1 (both global and session variables), the slow query log is enabled. * **Commandline:** `--slow-query-log` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `0` * **See also:** See [log\_output](#log_output) to see how log files are written. If that variable is set to `NONE`, no logs will be written even if slow\_query\_log is set to `1`. --- #### `slow_query_log_file` * **Description:** Name of the [slow query log](../slow-query-log/index) file. * **Commandline:** `--slow-query-log-file=file_name` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `file name` * **Default Value:** `*host\_name*-slow.log` --- #### `socket` * **Description:** On Unix-like systems, this is the name of the socket file used for local client connections, by default `/tmp/mysql.sock`, often changed by the distribution, for example `/var/lib/mysql/mysql.sock`. On Windows, this is the name of the named pipe used for local client connections, by default `MySQL`. On Windows, this is not case-sensitive. * **Commandline:** `--socket=name` * **Scope:** Global * **Dynamic:** No * **Data Type:** `file name` * **Default Value:** `/tmp/mysql.sock` (Unix), `MySQL` (Windows) --- #### `sort_buffer_size` * **Description:** Each session performing a sort allocates a buffer with this amount of memory. Not specific to any storage engine. If the status variable [sort\_merge\_passes](../server-status-variables/index#sort_merge_passes) is too high, you may need to look at improving your query indexes, or increasing this. Consider reducing where there are many small sorts, such as OLTP, and increasing where needed by session. 16k is a suggested minimum. * **Commandline:** `--sort-buffer-size=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `number` * **Default Value:** `2M (2097152)` (some distributions increase the default) --- #### `sql_auto_is_null` * **Description:** If set to 1, the query `SELECT * FROM table_name WHERE auto_increment_column IS NULL` will return an auto-increment that has just been successfully inserted, the same as the LAST\_INSERT\_ID() function. Some ODBC programs make use of this IS NULL comparison. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `0` --- #### `sql_big_selects` * **Description:** If set to 0, MariaDB will not perform large SELECTs. See [max\_join\_size](#max_join_size) for details. If max\_join\_size is set to anything but DEFAULT, sql\_big\_selects is automatically set to 0. If sql\_big\_selects is again set, max\_join\_size will be ignored. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `1` --- #### `sql_big_tables` * **Description:** Old variable, which if set to 1, allows large result sets by saving all temporary sets to disk, avoiding 'table full' errors. No longer needed, as the server now handles this automatically. + This is a synonym for `[big\_tables](#big_tables)`. * **Commandline:** `--sql-big-tables` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `0` * **Removed:** [MariaDB 10.0](../what-is-mariadb-100/index) --- #### `sql_buffer_result` * **Description:** If set to 1 (0 is default), results from SELECT statements are always placed into temporary tables. This can help the server when it takes a long time to send the results to the client by allowing the table locks to be freed early. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `0` --- #### `sql_if_exists` * **Description:** If set to 1, adds an implicit IF EXISTS to ALTER, RENAME and DROP of TABLES, VIEWS, FUNCTIONS and PACKAGES. This variable is mainly used in replication to tag DDLs that can be ignored on the slave if the target table doesn't exist. * **Commandline:** `--sql-if-exists[={0|1}]` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `OFF` * **Introduced:** [MariaDB 10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/) --- #### `sql_log_off` * **Description:** If set to 1 (0 is the default), no logging to the [general query log](../general-query-log/index) is done for the client. Only clients with the SUPER privilege can update this variable. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `0` --- #### `sql_log_update` * **Description:** Removed. Use [sql\_log\_bin](#sql_log_bin) instead. * **Removed:** MariaDB/MySQL 5.5 --- #### `sql_low_priority_updates` * **Description:** If set to 1 (0 is the default), for [storage engines](../storage-engines/index) that use only table-level locking ([Aria](../aria/index), [MyISAM](../myisam/index), [MEMORY](../memory-storage-engine/index) and [MERGE](../merge/index)), all INSERTs, UPDATEs, DELETEs and LOCK TABLE WRITEs will wait until there are no more SELECTs or LOCK TABLE READs pending on the relevant tables. Set this to 1 if reads are prioritized over writes. + This is a synonym for `[low\_priority\_updates](#low_priority_updates)`. * **Commandline:** `--sql-low-priority-updates` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `0` * **Removed:** [MariaDB 10.0](../what-is-mariadb-100/index) --- #### `sql_max_join_size` * **Description:** Synonym for [max\_join\_size](#max_join_size), the preferred name. * **Deprecated:** [MariaDB 5.5](../what-is-mariadb-55/index) * **Removed:** [MariaDB 10.0](../what-is-mariadb-100/index) --- #### `sql_mode` * **Description:** Sets the [SQL Mode](../sql-mode/index). Multiple modes can be set, separated by a comma. * **Commandline:** `--sql-mode=value[,value[,value...]]` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `string` * **Default Value:** + `STRICT_TRANS_TABLES,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION` * **Valid Values:** See [SQL Mode](../sql-mode/index) for the full list. --- #### `sql_notes` * **Description:** If set to 1, the default, [warning\_count](#warning_count) is incremented each time a Note warning is encountered. If set to 0, Note warnings are not recorded. [mysqldump](../mysqldump/index) has outputs to set this variable to 0 so that no unnecessary increments occur when data is reloaded. * **Commandline:** None * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `1` --- #### `sql_quote_show_create` * **Description:** If set to 1, the default, the server will quote identifiers for [SHOW CREATE DATABASE](../show-create-database/index), [SHOW CREATE TABLE](../show-create-table/index) and [SHOW CREATE VIEW](../show-create-view/index) statements. Quoting is disabled if set to 0. Enable to ensure replications works when identifiers require quoting. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `1` --- #### `sql_safe_updates` * **Description:** If set to 1, UPDATEs and DELETEs must be executed by using an index (simply mentioning an indexed column in a WHERE clause is not enough, optimizer must actually use it) or they must mention an indexed column and specify a LIMIT clause. Otherwise a statement will be aborted. Prevents the common mistake of accidentally deleting or updating every row in a table. Until [MariaDB 10.3.11](https://mariadb.com/kb/en/mariadb-10311-release-notes/), could not be set as a command-line option or in my.cnf. * **Commandline:** `--sql-safe-updates[={0|1}]` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `OFF` --- #### `sql_select_limit` * **Description:** Maximum number of rows that can be returned from a SELECT query. Default is the maximum number of rows permitted per table by the server, usually 232-1 or 264-1. Can be restored to the default value after being changed by assigning it a value of DEFAULT. * **Commandline:** None * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `18446744073709551615` --- #### `sql_warnings` * **Description:** If set to 1, single-row INSERTs will produce a string containing warning information if a warning occurs. * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `OFF (0)` --- #### `storage_engine` * **Description:** See [default\_storage\_engine](#default_storage_engine). * **Deprecated:** [MariaDB 5.5](../what-is-mariadb-55/index) --- #### `standard_compliant_cte` * **Description:** Allow only standard-compliant [common table expressions](../common-table-expressions/index). Prior to [MariaDB 10.2.4](https://mariadb.com/kb/en/mariadb-1024-release-notes/), this variable was named `standards_compliant_cte`. * **Commandline:** `--standard-compliant-cte={0|1}` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `ON` * **Introduced:** [MariaDB 10.2.2](https://mariadb.com/kb/en/mariadb-1022-release-notes/) --- #### `stored_program_cache` * **Description:** Limit to the number of [stored routines](../stored-programs-and-views/index) held in the stored procedures and stored functions caches. Each time a stored routine is executed, this limit is first checked, and if the number held in the cache exceeds this, that cache is flushed and memory freed. * **Commandline:** `--stored-program-cache=#` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `256` * **Range:** `256` to `524288` --- #### `strict_password_validation` * **Description:** When [password validation](../password-validation/index) plugins are enabled, reject passwords that cannot be validated (passwords specified as a hash). This excludes direct updates to the privilege tables. * **Commandline:** `--strict-password-validation` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `ON` --- #### `sync_frm` * **Description:** If set to 1, the default, each time a non-temporary table is created, its .frm definition file is synced to disk. Fractionally slower, but safer in case of a crash. * **Commandline:** `--sync-frm` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `TRUE` --- #### `system_time_zone` * **Description:** The system time zone is determined when the server starts. The system [time zone](../time-zones/index) is usually read from the operating system's environment. See [Time Zones: System Time Zone](../time-zones/index#system-time-zone) for the various ways to change the system time zone. This variable is not the same as the `[time\_zone](#time_zone)` system variable, which is the variable that actually controls a session's active time zone. The system time zone is used for a session when `time_zone` is set to the special value `SYSTEM`. * **Scope:** Global * **Dynamic:** No * **Data Type:** `string` --- #### `table_definition_cache` * **Description:** Number of table definitions that can be cached. Table definitions are taken from the .frm files, and if there are a large number of tables increasing the cache size can speed up table opening. Unlike the [table\_open\_cache](#table_open_cache), as the table\_definition\_cache doesn't use file descriptors, and is much smaller. * **Commandline:** `--table-definition-cache=#` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `400` * **Range:** + `400` to `2097152` (>= [MariaDB 10.4.2](https://mariadb.com/kb/en/mariadb-1042-release-notes/), [MariaDB 10.3.13](https://mariadb.com/kb/en/mariadb-10313-release-notes/), [MariaDB 10.2.22](https://mariadb.com/kb/en/mariadb-10222-release-notes/), [MariaDB 10.1.38](https://mariadb.com/kb/en/mariadb-10138-release-notes/)) + `400` to `524288` (<= [MariaDB 10.4.1](https://mariadb.com/kb/en/mariadb-1041-release-notes/), [MariaDB 10.3.12](https://mariadb.com/kb/en/mariadb-10312-release-notes/), [MariaDB 10.2.21](https://mariadb.com/kb/en/mariadb-10221-release-notes/), [MariaDB 10.1.37](https://mariadb.com/kb/en/mariadb-10137-release-notes/)) --- #### `table_lock_wait_timeout` * **Description:** Unused, and removed. * **Commandline:** `--table-lock-wait-timeout=#` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `50` * **Range:** `1` to `1073741824` * **Removed:** [MariaDB 5.5](../what-is-mariadb-55/index) --- #### `table_open_cache` * **Description:** Maximum number of open tables cached in one table cache instance. See [Optimizing table\_open\_cache](../optimizing-table_open_cache/index) for suggestions on optimizing. Increasing table\_open\_cache increases the number of file descriptors required. * **Commandline:** `--table-open-cache=#` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `2000` * **Range:** + `1` to `1048576` (1024K) --- #### `table_open_cache_instances` * **Description:** This system variable specifies the maximum number of table cache instances. MariaDB Server initially creates just a single instance. However, whenever it detects contention on the existing instances, it will automatically create a new instance. When the number of instances has been increased due to contention, it does not decrease again. The default value of this system variable is `8`, which is expected to handle up to 100 CPU cores. If your system is larger than this, then you may benefit from increasing the value of this system variable. + Depending on the ratio of actual available file handles, and `[table\_open\_cache](index#table_open_cache)` size, the max. instance count may be auto adjusted to a lower value on server startup. + The implementation and behavior of this feature is different than the same feature in MySQL 5.6. + See [Optimizing table\_open\_cache: Automatic Creation of New Table Open Cache Instances](../optimizing-table_open_cache/index#automatic-creation-of-new-table-open-cache-instances) for more information. * **Scope:** Global * **Dynamic:** No * **Data Type:** `numeric` * **Default Value:** `8` (>= [MariaDB 10.2.2](https://mariadb.com/kb/en/mariadb-1022-release-notes/)) * **Range:** `1` to `64` * **Introduced:** [MariaDB 10.2.2](https://mariadb.com/kb/en/mariadb-1022-release-notes/) --- #### `table_type` * **Description:** Removed and replaced by [storage\_engine](#storage_engine). Use [default\_storage\_engine](#default_storage_engine) instead. --- #### `tcp_keepalive_interval` * **Description:** The interval, in seconds, between when successive keep-alive packets are sent if no acknowledgement is received. If set to 0, the system dependent default is used. * **Commandline:** `--tcp-keepalive-interval=#` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `0` * **Range:** `0` to `2147483` * **Introduced:** [MariaDB 10.3.3](https://mariadb.com/kb/en/mariadb-1033-release-notes/) --- #### `tcp_keepalive_probes` * **Description:** The number of unacknowledged probes to send before considering the connection dead and notifying the application layer. If set to 0, a system dependent default is used. * **Commandline:** `--tcp-keepalive-probes=#` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `0` * **Range:** `0` to `2147483` * **Introduced:** [MariaDB 10.3.3](https://mariadb.com/kb/en/mariadb-1033-release-notes/) --- #### `tcp_keepalive_time` * **Description:** Timeout, in seconds, with no activity until the first TCP keep-alive packet is sent. If set to 0, a system dependent default is used. * **Commandline:** `--tcp-keepalive-time=#` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `0` * **Range:** `0` to `2147483` * **Introduced:** [MariaDB 10.3.3](https://mariadb.com/kb/en/mariadb-1033-release-notes/) --- #### `tcp_nodelay` * **Description:** Set the TCP\_NODELAY option (disable Nagle's algorithm) on socket. * **Commandline:** `--tcp-nodelay={0|1}` * **Scope:** Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `1` * **Introduced:** [MariaDB 10.4.0](https://mariadb.com/kb/en/mariadb-1040-release-notes/) --- #### `thread_cache_size` * **Description:** Number of threads server caches for re-use. If this limit hasn't been reached, when a client disconnects, its threads are put into the cache, and re-used where possible. In [MariaDB 10.2.0](https://mariadb.com/kb/en/mariadb-1020-release-notes/) and newer the threads are freed after 5 minutes of idle time. Normally this setting has little effect, as the other aspects of the thread implementation are more important, but increasing it can help servers with high volumes of connections per second so that most can use a cached, rather than a new, thread. The cache miss rate can be calculated as the [server status variables](../server-status-variables/index) threads\_created/connections. If the [thread pool](../thread-pool/index) is active, `thread_cache_size` is ignored. If `thread_cache_size` is set to greater than the value of [max\_connections](#max_connections), `thread_cache_size` will be set to the [max\_connections](#max_connections) value. * **Commandline:** `--thread-cache-size=#` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `256` (adjusted if thread pool is active) * **Range:** `0` to `16384` --- #### `thread_concurrency` * **Description:** Allows applications to give the system a hint about the desired number of threads. Specific to Solaris only, invokes thr\_setconcurrency(). Deprecated and has no effect from [MariaDB 5.5](../what-is-mariadb-55/index). * **Commandline:** `--thread-concurrency=#` * **Scope:** Global * **Dynamic:** No * **Data Type:** `numeric` * **Default Value:** `10` * **Range:** `1` to `512` * **Deprecated:** [MariaDB 5.5](../what-is-mariadb-55/index) * **Removed:** [MariaDB 10.5.1](https://mariadb.com/kb/en/mariadb-1051-release-notes/) --- #### `thread_stack` * **Description:** Stack size for each thread. If set too small, limits recursion depth of stored procedures and complexity of SQL statements the server can handle in memory. Also affects limits in the crash-me test. * **Commandline:** `--thread-stack=#` * **Scope:** Global * **Dynamic:** No * **Data Type:** `numeric` * **Default Value:** + `299008` * **Range:** `131072` to `18446744073709551615` --- #### `time_format` * **Description:** Unused. --- #### `time_zone` * **Description:** The global value determines the default [time zone](../time-zones/index) for sessions that connect. The session value determines the session's active [time zone](../time-zones/index). When it is set to `SYSTEM`, the session's time zone is determined by the `[system\_time\_zone](#system_time_zone)` system variable. * **Commandline:** `--default-time-zone=string` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `string` * **Default Value:** `SYSTEM` --- #### `timed_mutexes` * **Description:** Determines whether [InnoDB](../innodb/index) mutexes are timed. `OFF`, the default, disables mutex timing, while `ON` enables it. See also [SHOW ENGINE](../show-engine/index) for more on mutex statistics. Deprecated and has no effect. * **Commandline:** `--timed-mutexes` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `OFF` * **Deprecated:** [MariaDB 5.5.39](https://mariadb.com/kb/en/mariadb-5539-release-notes/) * **Removed:** [MariaDB 10.5.1](https://mariadb.com/kb/en/mariadb-1051-release-notes/) --- #### `timestamp` * **Description:** Sets the time for the client. This will affect the result returned by the [NOW()](../now/index) function, not the [SYSDATE()](../sysdate/index) function, unless the server is started with the [--sysdate-is-now](../mysqld-options/index#-sysdate-is-now) option, in which case SYSDATE becomes an alias of NOW, and will also be affected. Also used to get the original timestamp when restoring rows from the [binary log](../binary-log/index). * **Scope:** Session * **Dynamic:** Yes * **Valid Values:** `timestamp_value` (Unix epoch timestamp, not MariaDB timestamp), `DEFAULT` --- #### `tmp_disk_table_size` * **Description:** Max size for data for an internal temporary on-disk [MyISAM](../myisam/index) or [Aria](../aria/index) table. These tables are created as part of complex queries when the result doesn't fit into the memory engine. You can set this variable if you want to limit the size of temporary tables created in your temporary directory [tmpdir](#tmpdir). * **Commandline:** `--tmp-disk-table-size=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `18446744073709551615` (max unsigned integer, no limit) * **Range:** `1024` to `18446744073709551615` * **Introduced:** [MariaDB 10.2.7](https://mariadb.com/kb/en/mariadb-1027-release-notes/) --- #### `tmp_memory_table_size` * **Description:** An alias for [tmp\_table\_size](#tmp_table_size). * **Commandline:** `--tmp-memory-table-size=#` * **Introduced:** [MariaDB 10.2.7](https://mariadb.com/kb/en/mariadb-1027-release-notes/) --- #### `tmp_table_size` * **Description:** The largest size for temporary tables in memory (not [MEMORY](../memory-storage-engine/index) tables) although if [max\_heap\_table\_size](#max_heap_table_size) is smaller the lower limit will apply. You can see if it's necessary to increase by comparing the [status variables](../server-status-variables/index) `Created_tmp_disk_tables` and `Created_tmp_tables` to see how many temporary tables out of the total created needed to be converted to disk. Often complex GROUP BY queries are responsible for exceeding the limit. Defaults may be different on some systems, see for example [Differences in MariaDB in Debian](../differences-in-mariadb-in-debian/index). From [MariaDB 10.2.7](https://mariadb.com/kb/en/mariadb-1027-release-notes/), [tmp\_memory\_table\_size](#tmp_memory_table_size) is an alias. * **Commandline:** `--tmp-table-size=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `16777216` (16MB) * **Range:** + `1024` to `4294967295` (< [MariaDB 10.5](../what-is-mariadb-105/index)) + `0` to `4294967295` (>= [MariaDB 10.5.0](https://mariadb.com/kb/en/mariadb-1050-release-notes/)) --- #### `tmpdir` * **Description:** Directory for storing temporary tables and files. Can specify a list (separated by semicolons in Windows, and colons in Unix) that will then be used in round-robin fashion. This can be used for load balancing across several disks. Note that if the server is a [replication](../replication/index) replica, and [slave\_load\_tmpdir](../replication-and-binary-log-system-variables/index#slave_load_tmpdir), which overrides `tmpdir` for replicas, is not set, you should not set `tmpdir` to a directory that is cleared when the machine restarts, or else replication may fail. * **Commandline:** `--tmpdir=path` or `-t path` * **Scope:** Global * **Dynamic:** No * **Type:** directory name/s * **Default:** + `$TMPDIR` (environment variable) if set + otherwise `$TEMP` if set and on Windows + otherwise `$TMP` if set and on Windows + otherwise `P_tmpdir` (`"/tmp"`) or `C:\TEMP` (unless overridden during buid time) --- #### `transaction_alloc_block_size` * **Description:** Size in bytes to increase the memory pool available to each transaction when the available pool is not large enough. See [transaction\_prealloc\_size](#transaction_prealloc_size). * **Commandline:** `--transaction-alloc-block-size=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Type:** numeric * **Default Value:** `8192` * **Range:** `1024` to `4294967295` * **Block Size:** `1024` --- #### `transaction_prealloc_size` * **Description:** Initial size of a memory pool available to each transaction for various memory allocations. If the memory pool is not large enough for an allocation, it is increased by [transaction\_alloc\_block\_size](#transaction_alloc_block_size) bytes, and truncated back to transaction\_prealloc\_size bytes when the transaction is completed. If set large enough to contain all statements in a transaction, extra malloc() calls are avoided. * **Commandline:** `--transaction-prealloc-size=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Type:** numeric * **Default Value:** `4096` * **Range:** `1024` to `4294967295` * **Block Size:** `1024` --- #### `tx_isolation` * **Description:** The transaction isolation level. See also [SET TRANSACTION ISOLATION LEVEL](../set-transaction-isolation-level/index). * **Commandline:** `--transaction-isolation=name` * **Scope:** Global, Session * **Dynamic:** Yes * **Type:** enumeration * **Default Value:** `REPEATABLE-READ` * **Valid Values:** `READ-UNCOMMITTED`, `READ-COMMITTED`, `REPEATABLE-READ`, `SERIALIZABLE` --- #### `tx_read_only` * **Description:** Default transaction access mode. If set to `OFF`, the default, access is read/write. If set to `ON`, access is read-only. The `SET TRANSACTION` statement can also change the value of this variable. See [SET TRANSACTION](../set-transaction/index) and [START TRANSACTION](../start-transaction/index). * **Commandline:** `--transaction-read-only=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Type:** boolean * **Default Value:** `OFF` --- #### `unique_checks` * **Description:** If set to 0, storage engines can (but are not required to) assume that duplicate keys are not present in input data. If set to 0, inserting duplicates into a `UNIQUE` index can succeed, causing the table to become corrupted. Set to 0 to speed up imports of large tables to InnoDB. * **Scope:** Global, Session * **Dynamic:** Yes * **Type:** boolean * **Default Value:** `1` --- #### `updatable_views_with_limit` * **Description:** Determines whether view updates can be made with an UPDATE or DELETE statement with a LIMIT clause if the view does not contain all primary or not null unique key columns from the underlying table. `0` prohibits this, while `1` permits it while issuing a warning (the default). * **Commandline:** `--updatable-views-with-limit=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Type:** boolean * **Default Value:** `1` --- #### `use_stat_tables` * **Description:** Controls the use of [engine-independent table statistics](../engine-independent-table-statistics/index). + `never`: The optimizer will not use data from statistics tables. + `complementary`: The optimizer uses data from statistics tables if the same kind of data is not provided by the storage engine. + `preferably`: Prefer the data from statistics tables, if it's not available there, use the data from the storage engine. + `complementary_for_queries`: Same as `complementary`, but for queries only (to avoid needlessly collecting for [ANALYZE TABLE](../analyze-table/index)). From [MariaDB 10.4.1](https://mariadb.com/kb/en/mariadb-1041-release-notes/). + `preferably_for_queries`: Same as `preferably`, but for queries only (to avoid needlessly collecting for [ANALYZE TABLE](../analyze-table/index)). From [MariaDB 10.4.1](https://mariadb.com/kb/en/mariadb-1041-release-notes/). * **Commandline:** `--use-stat-tables=mode` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `enum` * **Default Value:** `preferably_for_queries` (>= [MariaDB 10.4.1](https://mariadb.com/kb/en/mariadb-1041-release-notes/)), `never` (<= [MariaDB 10.4.0](https://mariadb.com/kb/en/mariadb-1040-release-notes/)) --- #### `version` * **Description:** Server version number. It may also include a suffix with configuration or build information. `-debug` indicates debugging support was enabled on the server, and `-log` indicates at least one of the binary log, general log or [slow query log](../slow-query-log/index) are enabled, for example `10.0.1-MariaDB-mariadb1precise-log`. From [MariaDB 10.2.1](https://mariadb.com/kb/en/mariadb-1021-release-notes/), this variable can be set at startup in order to fake the server version. * **Commandline:** `-V`, `--version[=name]` (>= [MariaDB 10.2.1](https://mariadb.com/kb/en/mariadb-1021-release-notes/)), `--version` (<= [MariaDB 10.2.0](https://mariadb.com/kb/en/mariadb-1020-release-notes/)) * **Scope:** Global * **Dynamic:** No * **Type:** string --- #### `version_comment` * **Description:** Value of the COMPILATION\_COMMENT option specified by CMake when building MariaDB, for example `mariadb.org binary distribution`. * **Scope:** Global * **Dynamic:** No * **Type:** string --- #### `version_compile_machine` * **Description:** The machine type or architecture MariaDB was built on, for example `i686`. * **Scope:** Global * **Dynamic:** No * **Type:** string --- #### `version_compile_os` * **Description:** Operating system that MariaDB was built on, for example `debian-linux-gnu`. * **Scope:** Global * **Dynamic:** No * **Type:** string --- #### `version_malloc_library` * **Description:** Version of the used malloc library. * **Commandline:** No * **Scope:** Global * **Dynamic:** No * **Type:** string --- #### `version_source_revision` * **Description:** Source control revision id for MariaDB source code, enabling one to see exactly which version of the source was used for a build. * **Commandline:** None * **Scope:** Global * **Dynamic:** No * **Type:** string * **Introduced:** [MariaDB 10.3.2](https://mariadb.com/kb/en/mariadb-1032-release-notes/) --- #### `wait_timeout` * **Description:** Time in seconds that the server waits for a connection to become active before closing it. The session value is initialized when a thread starts up from either the global value, if the connection is non-interactive, or from the [interactive\_timeout](#interactive_timeout) value, if the connection is interactive. * **Commandline:** `--wait-timeout=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Type:** numeric * **Default Value:** `28800` * **Range: (Windows): `1` to `2147483`** * **Range: (Other): `1` to `31536000`** --- #### `warning_count` * **Description:** Read-only variable indicating the number of warnings, errors and notes resulting from the most recent statement that generated messages. See [SHOW WARNINGS](../show-warnings/index) for more. Note warnings will only be recorded if [sql\_notes](#sql_notes) is true (the default). * **Scope:** Session * **Dynamic:** No * **Type:** numeric --- Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb Simple Password Check Plugin Simple Password Check Plugin ============================ `simple_password_check` is a [password validation](../password-validation-plugin-api/index) plugin. It can check whether a password contains at least a certain number of characters of a specific type. When first installed, a password is required to be at least eight characters, and requires at least one digit, one uppercase character, one lowercase character, and one character that is neither a digit nor a letter. Note that passwords can be directly set as a hash, bypassing the password validation, if the [strict\_password\_validation](../server-system-variables/index#strict_password_validation) variable is `OFF` (it is `ON` by default). Installing the Plugin --------------------- Although the plugin's shared library is distributed with MariaDB by default, the plugin is not actually installed by MariaDB by default. There are two methods that can be used to install the plugin with MariaDB. The first method can be used to install the plugin without restarting the server. You can install the plugin dynamically by executing `[INSTALL SONAME](../install-soname/index)` or `[INSTALL PLUGIN](../install-plugin/index)`. For example: ``` INSTALL SONAME 'simple_password_check'; ``` The second method can be used to tell the server to load the plugin when it starts up. The plugin can be installed this way by providing the `[--plugin-load](../mysqld-options/index#-plugin-load)` or the `[--plugin-load-add](../mysqld-options/index#-plugin-load-add)` options. This can be specified as a command-line argument to `[mysqld](../mysqld-options/index)` or it can be specified in a relevant server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index). For example: ``` [mariadb] ... plugin_load_add = simple_password_check ``` Uninstalling the Plugin ----------------------- You can uninstall the plugin dynamically by executing `[UNINSTALL SONAME](../uninstall-soname/index)` or `[UNINSTALL PLUGIN](../uninstall-plugin/index)`. For example: ``` UNINSTALL SONAME 'simple_password_check'; ``` If you installed the plugin by providing the `[--plugin-load](../mysqld-options/index#-plugin-load)` or the `[--plugin-load-add](../mysqld-options/index#-plugin-load-add)` options in a relevant server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index), then those options should be removed to prevent the plugin from being loaded the next time the server is restarted. Example ------- When creating a new password, if the criteria are not met, the following error is returned: ``` SET PASSWORD FOR 'bob'@'%.loc.gov' = PASSWORD('abc'); ERROR 1819 (HY000): Your password does not satisfy the current policy requirements ``` Known Issues ------------ ### Issues with PAM Authentication Plugin Prior to [MariaDB 10.4.0](https://mariadb.com/kb/en/mariadb-1040-release-notes/), all [password validation plugins](../password-validation-plugins/index) are incompatible with the `[pam](../pam-authentication-plugin/index)` authentication plugin. See [Authentication Plugin - PAM: Conflicts with Password Validation](../authentication-plugin-pam/index#conflicts-with-password-validation) for more information. Versions -------- | Version | Status | Introduced | | --- | --- | --- | | 1.0 | Stable | [MariaDB 10.1.18](https://mariadb.com/kb/en/mariadb-10118-release-notes/) | | 1.0 | Gamma | [MariaDB 10.1.13](https://mariadb.com/kb/en/mariadb-10113-release-notes/) | | 1.0 | Beta | [MariaDB 10.1.11](https://mariadb.com/kb/en/mariadb-10111-release-notes/) | | 1.0 | Alpha | [MariaDB 10.1.2](https://mariadb.com/kb/en/mariadb-1012-release-notes/) | System Variables ---------------- #### `simple_password_check_digits` * **Description:** A password must contain at least this many digits. * **Commandline:** `--simple-password-check-digits=#` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `1` * **Range:** `0` to `1000` --- #### `simple_password_check_letters_same_case` * **Description:** A password must contain at least this many upper-case and this many lower-case letters. * **Commandline:** `--simple-password-check-letters-same-case=#` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `1` * **Range:** `0` to `1000` --- #### `simple_password_check_minimal_length` * **Description:** A password must contain at least this many characters. * **Commandline:** `--simple-password-check-minimal-length=#` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `8` * **Range:** `0` to `1000` --- #### `simple_password_check_other_characters` * **Description:** A password must contain at least this many characters that are neither digits nor letters. * **Commandline:** `--simple-password-check-other-characters=#` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `1` * **Range:** `0` to `1000` --- Options ------- #### `simple_password_check` * **Description:** Controls how the server should treat the plugin when the server starts up. + Valid values are: - `OFF` - Disables the plugin without removing it from the `[mysql.plugins](../mysqlplugin-table/index)` table. - `ON` - Enables the plugin. If the plugin cannot be initialized, then the server will still continue starting up, but the plugin will be disabled. - `FORCE` - Enables the plugin. If the plugin cannot be initialized, then the server will fail to start with an error. - `FORCE_PLUS_PERMANENT` - Enables the plugin. If the plugin cannot be initialized, then the server will fail to start with an error. In addition, the plugin cannot be uninstalled with `[UNINSTALL SONAME](../uninstall-soname/index)` or `[UNINSTALL PLUGIN](../uninstall-plugin/index)` while the server is running. + See [Plugin Overview: Configuring Plugin Activation at Server Startup](../plugin-overview/index#configuring-plugin-activation-at-server-startup) for more information. * **Commandline:** `--simple-password-check=value` * **Data Type:** `enumerated` * **Default Value:** `ON` * **Valid Values:** `OFF`, `ON`, `FORCE`, `FORCE_PLUS_PERMANENT` --- See Also -------- * [Password Validation](../password-validation/index) * [cracklib\_password\_check plugin](../cracklib_password_check/index) - use the Cracklib password-strength checking library Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb UPPER UPPER ===== Syntax ------ ``` UPPER(str) ``` Description ----------- Returns the string `str` with all characters changed to uppercase according to the current character set mapping. The default is latin1 (cp1252 West European). ``` SELECT UPPER(surname), givenname FROM users ORDER BY surname; +----------------+------------+ | UPPER(surname) | givenname | +----------------+------------+ | ABEL | Jacinto | | CASTRO | Robert | | COSTA | Phestos | | MOSCHELLA | Hippolytos | +----------------+------------+ ``` `UPPER()` is ineffective when applied to binary strings (`[BINARY](../binary/index)`, `[VARBINARY](../varbinary/index)`, `[BLOB](../blob/index)`). The description of `[LOWER](../lower/index)()` shows how to perform lettercase conversion of binary strings. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb ALTER FUNCTION ALTER FUNCTION ============== Syntax ------ ``` ALTER FUNCTION func_name [characteristic ...] characteristic: { CONTAINS SQL | NO SQL | READS SQL DATA | MODIFIES SQL DATA } | SQL SECURITY { DEFINER | INVOKER } | COMMENT 'string' ``` Description ----------- This statement can be used to change the characteristics of a stored function. More than one change may be specified in an `ALTER FUNCTION` statement. However, you cannot change the parameters or body of a stored function using this statement; to make such changes, you must drop and re-create the function using [DROP FUNCTION](../drop-function/index) and [CREATE FUNCTION](../create-function/index). You must have the `ALTER ROUTINE` privilege for the function. (That privilege is granted automatically to the function creator.) If binary logging is enabled, the `ALTER FUNCTION` statement might also require the `SUPER` privilege, as described in [Binary Logging of Stored Routines](../binary-logging-of-stored-routines/index). Example ------- ``` ALTER FUNCTION hello SQL SECURITY INVOKER; ``` See Also -------- * [CREATE FUNCTION](../create-function/index) * [SHOW CREATE FUNCTION](../show-create-function/index) * [DROP FUNCTION](../drop-function/index) * [SHOW FUNCTION STATUS](../show-function-status/index) * [Information Schema ROUTINES Table](../information-schema-routines-table/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Installing MariaDB AX / MariaDB ColumnStore from the Package Repositories - 1.2.X Installing MariaDB AX / MariaDB ColumnStore from the Package Repositories - 1.2.X ================================================================================= Introduction ============ Installing MariaDB AX and MariaDB ColumnStore individual packages can be done from the yum, apt-get, and zypper Repositories based on the OS. MariaDB AX packages which consist of: * MariaDB ColumnStore Platform * MariaDB ColumnStore API (Bulk Write SDK) * MariaDB ColumnStore Data-Adapters * MariaDB ColumnStore Tools * MariaDB Maxscale * MariaDB Connectors + MariaDB Maxscale CDC Connector + MariaDB ODBC Connector + MariaDB Java-client Connector jar file You can install packages from the Repositories for Single-Server installs and for Multi-Server installs utilizing the Non-Distributed feature where the packages are installed on all the servers in the cluster before the configuration and setup is performed. NOTE: Document shows installing the latest GA version of each package by using 'latest' in the download paths. You can also install other version by entering the specific release ID, like 1.2.2-1. MariaDB AX Packages =================== This section shows how to setup and install all associated packages for MariaDB AX. Start by doing the MariaDB Connector Packages. Go to that section and install the connectors first. CentOS 6 -------- ### Adding the MariaDB AX YUM repository Add new file with repository information, /etc/yum.repos.d/mariadb-columnstore.repo ``` [mariadb-columnstore] name=MariaDB ColumnStore baseurl=https://downloads.mariadb.com/MariaDB/mariadb-columnstore/latest/yum/centos/6/x86_64/ gpgkey=https://downloads.mariadb.com/MariaDB/mariadb-columnstore/RPM-GPG-KEY-MariaDB-ColumnStore gpgcheck=1 ``` Add new file with repository information, /etc/yum.repos.d/mariadb-columnstore-tools.repo ``` [mariadb-columnstore-tools] name=MariaDB ColumnStore Tools baseurl=https://downloads.mariadb.com/MariaDB/mariadb-columnstore-tools/latest/yum/centos/6/x86_64/ gpgkey=https://downloads.mariadb.com/MariaDB/mariadb-columnstore/RPM-GPG-KEY-MariaDB-ColumnStore gpgcheck=1 ``` Add new file with repository information, /etc/yum.repos.d/mariadb-maxscale.repo ``` [mariadb-maxscale] name=MariaDB MaxScale baseurl=https://downloads.mariadb.com/MaxScale/latest/centos/6/x86_64 gpgkey=https://downloads.mariadb.com/MaxScale/MariaDB-MaxScale-GPG-KEY gpgcheck=1 ``` ### Installing MariaDB AX With the repo file in place you can now install MariaDB ColumnStore like so: ``` sudo yum --enablerepo=mariadb-columnstore clean metadata sudo yum groups mark remove "MariaDB ColumnStore" sudo yum groupinstall "MariaDB ColumnStore" sudo yum --enablerepo=mariadb-columnstore-tools clean metadata sudo yum install mariadb-columnstore-tools sudo yum --enablerepo=mariadb-maxscale clean metadata sudo yum install maxscale maxscale-cdc-connector ``` CentOS 7 -------- ### Adding the MariaDB AX YUM repository Add new file with repository information, /etc/yum.repos.d/mariadb-columnstore.repo ``` [mariadb-columnstore] name=MariaDB ColumnStore baseurl=https://downloads.mariadb.com/MariaDB/mariadb-columnstore/latest/yum/centos/7/x86_64/ gpgkey=https://downloads.mariadb.com/MariaDB/mariadb-columnstore/RPM-GPG-KEY-MariaDB-ColumnStore gpgcheck=1 ``` Add new file with repository information, /etc/yum.repos.d/mariadb-columnstore-api.repo ``` [mariadb-columnstore-api] name=MariaDB ColumnStore API baseurl=https://downloads.mariadb.com/MariaDB/mariadb-columnstore-api/latest/yum/centos/7/x86_64/ gpgkey=https://downloads.mariadb.com/MariaDB/mariadb-columnstore/RPM-GPG-KEY-MariaDB-ColumnStore gpgcheck=1 ``` ### Adding the MariaDB ColumnStore Tools YUM repository Add new file with repository information, /etc/yum.repos.d/mariadb-columnstore-tools.repo ``` [mariadb-columnstore-tools] name=MariaDB ColumnStore Tools baseurl=https://downloads.mariadb.com/MariaDB/mariadb-columnstore-tools/latest/yum/centos/7/x86_64/ gpgkey=https://downloads.mariadb.com/MariaDB/mariadb-columnstore/RPM-GPG-KEY-MariaDB-ColumnStore gpgcheck=1 ``` Add new file with repository information, /etc/yum.repos.d/mariadb-maxscale.repo ``` [mariadb-maxscale] name=MariaDB MaxScale baseurl=https://downloads.mariadb.com/MaxScale/latest/centos/7/x86_64 gpgkey=https://downloads.mariadb.com/MaxScale/MariaDB-MaxScale-GPG-KEY gpgcheck=1 ``` ### Adding the MariaDB ColumnStore Data Adapters YUM repository Add new file with repository information, /etc/yum.repos.d/mariadb-columnstore-data-adapters.repo ``` [mariadb-columnstore-data-adapters] name=MariaDB ColumnStore Data Adapters baseurl=https://downloads.mariadb.com/MariaDB/data-adapters/mariadb-streaming-data-adapters/latest/yum/centos/7/x86_64/ gpgkey=https://downloads.mariadb.com/MariaDB/mariadb-columnstore/RPM-GPG-KEY-MariaDB-ColumnStore gpgcheck=1 ``` ### Installing MariaDB AX With the repo file in place you can now install MariaDB ColumnStore like so: ``` sudo yum --enablerepo=mariadb-columnstore clean metadata sudo yum groups mark remove "MariaDB ColumnStore" sudo yum groupinstall "MariaDB ColumnStore" sudo yum --enablerepo=mariadb-columnstore-api clean metadata sudo yum install epel-release sudo yum install mariadb-columnstore-api* sudo yum --enablerepo=mariadb-columnstore-tools clean metadata sudo yum install mariadb-columnstore-tools sudo yum --enablerepo=mariadb-maxscale clean metadata sudo yum install maxscale maxscale-cdc-connector sudo yum --enablerepo=mariadb-columnstore-data-adapters clean metadata sudo yum install mariadb-columnstore-data-adapters-maxscale-cdc-adapter sudo yum install mariadb-columnstore-data-adapters-avro-kafka-adapter ``` SUSE 12 ------- ### Adding the MariaDB ColumnStore ZYPPER repository Add new file with repository information, /etc/zypp/repos.d/mariadb-columnstore.repo ``` [mariadb-columnstore] name=mariadb-columnstore enabled=1 autorefresh=0 baseurl=https://downloads.mariadb.com/MariaDB/mariadb-columnstore/latest/yum/sles/12/x86_64 type=rpm-md ``` Add new file with repository information, /etc/zypp/repos.d/mariadb-columnstore-tools.repo ``` [mariadb-columnstore-tools] name=mariadb-columnstore-tools enabled=1 autorefresh=0 baseurl=https://downloads.mariadb.com/MariaDB/mariadb-columnstore-tools/latest/yum/sles/12/x86_64 type=rpm-md ``` Add new file with repository information, /etc/zypp/repos.d/mariadb-maxscale.repo ``` [mariadb-maxscale] name=mariadb-maxscale enabled=1 autorefresh=0 baseurl=https://downloads.mariadb.com/MaxScale/latest/sles/12/x86_64 type=rpm-md ``` Download the MariaDB ColumnStore and MaxScale keys ``` rpm --import https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key rpm --import https://downloads.mariadb.com/MaxScale/MariaDB-MaxScale-GPG-KEY ``` ### Installing MariaDB ColumnStore With the repo file in place you can now install MariaDB ColumnStore like so: ``` sudo zypper refresh sudo zypper install mariadb-columnstore* sudo zypper install mariadb-columnstore-tools sudo zypper install maxscale maxscale-cdc-connector ``` Debian 8 -------- ### Adding the MariaDB ColumnStore APT-GET repository Install package: ``` sudo apt-get install apt-transport-https ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore.list ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore/latest/repo/debian8 jessie main ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-api.list ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore-api/latest/repo/debian8 jessie main ``` Add new file with repository information, /etc/apt/sources.list.d/debian-backports.list ``` deb http://httpredir.debian.org/debian jessie-backports main contrib non-free ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-tools.list ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore-tools/latest/repo/debian8 jessie main ``` Add new file with repository information, /etc/apt/sources.list.d/mariadb-maxscale.list ``` deb https://downloads.mariadb.com/MaxScale/latest/debian jessie main ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-data-adapters.list ``` deb https://downloads.mariadb.com/MariaDB/data-adapters/mariadb-streaming-data-adapters/latest/repo/debian8 jessie main ``` Download the MariaDB ColumnStore key ``` wget -qO - https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` Download the MariaDB MaxScale key ``` sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 28C12247 ``` ### Installing MariaDB ColumnStore With the repo file in place you can now install MariaDB ColumnStore like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore* sudo apt-get install mariadb-columnstore-api* sudo apt-get install mariadb-columnstore-tools sudo apt-get install maxscale maxscale-cdc-connector sudo apt-get install mariadb-columnstore-maxscale-cdc-adapters sudo apt-get install mariadb-columnstore-kafka-avro-adapters ``` Debian 9 -------- ### Adding the MariaDB ColumnStore APT-GET repository Install package: ``` sudo apt-get install apt-transport-https dirmngr ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore.list ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore/latest/repo/debian9 stretch main ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-api.list ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore-api/latest/repo/debian9 stretch main ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-tools.list ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore-tools/latest/repo/debian9 stretch main ``` Add new file with repository information, /etc/apt/sources.list.d/mariadb-maxscale.list ``` deb https://downloads.mariadb.com/MaxScale/latest/debian stretch main ``` ``` deb https://downloads.mariadb.com/MariaDB/data-adapters/mariadb-streaming-data-adapters/latest/repo/debian9 stretch main ``` Download the MariaDB ColumnStore key ``` wget -qO - https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` Download the MariaDB MaxScale key ``` sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 28C12247 ``` ### Installing MariaDB ColumnStore With the repo file in place you can now install MariaDB ColumnStore like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore* sudo apt-get install mariadb-columnstore-api* sudo apt-get install mariadb-columnstore-tools sudo apt-get install maxscale maxscale-cdc-connector sudo apt-get install mariadb-columnstore-maxscale-cdc-adapters sudo apt-get install mariadb-columnstore-kafka-avro-adapters ``` Ubuntu 16 --------- ### Adding the MariaDB ColumnStore APT-GET repository Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore.list ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore/latest/repo/ubuntu16 xenial main ``` ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore-api/latest/repo/ubuntu16 xenial main ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-tools.list ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore-tools/latest/repo/ubuntu16 xenial main ``` Add new file with repository information, /etc/apt/sources.list.d/mariadb-maxscale.list ``` deb https://downloads.mariadb.com/MaxScale/latest/ubuntu xenial main ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-data-adapters.list ``` deb https://downloads.mariadb.com/MariaDB/data-adapters/mariadb-streaming-data-adapters/latest/repo/ubuntu16 xenial main ``` Download the MariaDB ColumnStore key ``` wget -qO - https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` Download the MariaDB MaxScale key ``` sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 28C12247 ``` ### Installing MariaDB ColumnStore With the repo file in place you can now install MariaDB ColumnStore like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore* sudo apt-get install mariadb-columnstore-api* sudo apt-get install mariadb-columnstore-tools sudo apt-get install maxscale maxscale-cdc-connector sudo apt-get install mariadb-columnstore-maxscale-cdc-adapters sudo apt-get install mariadb-columnstore-kafka-avro-adapters ``` Ubuntu 18 --------- ### Adding the MariaDB ColumnStore APT-GET repository Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore.list ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore/latest/repo/ubuntu18 bionic main ``` ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore-api/latest/repo/ubuntu18 bionic main ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-tools.list ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore-tools/latest/repo/ubuntu18 bionic main ``` Add new file with repository information, /etc/apt/sources.list.d/mariadb-maxscale.list ``` deb https://downloads.mariadb.com/MaxScale/latest/ubuntu bionic main ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-data-adapters.list ``` deb https://downloads.mariadb.com/MariaDB/data-adapters/mariadb-streaming-data-adapters/latest/repo/ubuntu18 bionic main ``` Download the MariaDB ColumnStore key ``` wget -qO - https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` Download the MariaDB MaxScale key ``` sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 28C12247 ``` ### Installing MariaDB ColumnStore With the repo file in place you can now install MariaDB ColumnStore like so: ``` sudo apt-get update sudo add-apt-repository universe sudo apt-get install mariadb-columnstore* sudo apt-get install mariadb-columnstore-api* sudo apt-get install mariadb-columnstore-tools sudo apt-get install maxscale maxscale-cdc-connector sudo apt-get install mariadb-columnstore-maxscale-cdc-adapters sudo apt-get install mariadb-columnstore-kafka-avro-adapters ``` MariaDB ColumnStore Packages ============================ Before install, make sure you go through the preparation guide to complete the system setup before installs the packages [https://mariadb.com/kb/en/library/preparing-for-columnstore-installation-11x/](../library/preparing-for-columnstore-installation-11x/index) CentOS 6 -------- ### Adding the MariaDB ColumnStore YUM repository Add new file with repository information, /etc/yum.repos.d/mariadb-columnstore.repo ``` [mariadb-columnstore] name=MariaDB ColumnStore baseurl=https://downloads.mariadb.com/MariaDB/mariadb-columnstore/latest/yum/centos/6/x86_64/ gpgkey=https://downloads.mariadb.com/MariaDB/mariadb-columnstore/RPM-GPG-KEY-MariaDB-ColumnStore gpgcheck=1 ``` ### Installing MariaDB ColumnStore With the repo file in place you can now install MariaDB ColumnStore like so: ``` sudo yum --enablerepo=mariadb-columnstore clean metadata sudo yum groups mark remove "MariaDB ColumnStore" sudo yum groupinstall "MariaDB ColumnStore" ``` You can also install this way: ``` sudo yum --enablerepo=mariadb-columnstore clean metadata sudo yum install mariadb-columnstore* ``` CentOS 7 -------- ### Adding the MariaDB ColumnStore YUM repository Add new file with repository information, /etc/yum.repos.d/mariadb-columnstore.repo ``` [mariadb-columnstore] name=MariaDB ColumnStore baseurl=https://downloads.mariadb.com/MariaDB/mariadb-columnstore/latest/yum/centos/7/x86_64/ gpgkey=https://downloads.mariadb.com/MariaDB/mariadb-columnstore/RPM-GPG-KEY-MariaDB-ColumnStore gpgcheck=1 ``` ### Installing MariaDB ColumnStore With the repo file in place you can now install MariaDB ColumnStore like so: ``` sudo yum --enablerepo=mariadb-columnstore clean metadata sudo yum groups mark remove "MariaDB ColumnStore" sudo yum groupinstall "MariaDB ColumnStore" ``` You can also install this way: ``` sudo yum --enablerepo=mariadb-columnstore clean metadata sudo yum install mariadb-columnstore* ``` SUSE 12 ------- ### Adding the MariaDB ColumnStore ZYPPER repository Add new file with repository information, /etc/zypp/repos.d/mariadb-columnstore.repo ``` [mariadb-columnstore] name=mariadb-columnstore enabled=1 autorefresh=0 baseurl=https://downloads.mariadb.com/MariaDB/mariadb-columnstore/latest/yum/sles/12/x86_64 type=rpm-md ``` Download the MariaDB ColumnStore key ``` rpm --import https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key ``` ### Installing MariaDB ColumnStore With the repo file in place you can now install MariaDB ColumnStore like so: ``` sudo zypper refresh sudo zypper install mariadb-columnstore* ``` Debian 8 -------- ### Adding the MariaDB ColumnStore APT-GET repository Install package: ``` sudo apt-get install apt-transport-https ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore.list ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore/latest/repo/debian8 jessie main ``` Download the MariaDB ColumnStore key ``` wget -qO - https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` ### Installing MariaDB ColumnStore With the repo file in place you can now install MariaDB ColumnStore like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore* ``` Debian 9 -------- ### Adding the MariaDB ColumnStore APT-GET repository Install package: ``` sudo apt-get install apt-transport-https dirmngr ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore.list ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore/latest/repo/debian9 stretch main ``` Download the MariaDB ColumnStore key ``` wget -qO - https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` ### Installing MariaDB ColumnStore With the repo file in place you can now install MariaDB ColumnStore like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore* ``` Ubuntu 16 --------- ### Adding the MariaDB ColumnStore APT-GET repository Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore.list ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore/latest/repo/ubuntu16 xenial main ``` Download the MariaDB ColumnStore key ``` wget -qO - https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` ### Installing MariaDB ColumnStore With the repo file in place you can now install MariaDB ColumnStore like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore* ``` Ubuntu 18 --------- ### Adding the MariaDB ColumnStore APT-GET repository Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore.list ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore/latest/repo/ubuntu18 bionic main ``` Download the MariaDB ColumnStore key ``` wget -qO - https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` ### Installing MariaDB ColumnStore With the repo file in place you can now install MariaDB ColumnStore like so: ``` sudo apt-get update sudo add-apt-repository universe sudo apt-get install mariadb-columnstore* ``` ### After installation After the installation completes, follow the configuration and startup steps in the Single-Node and Multi-Node Installation guides using the [Non-Distributed Install feature](../library/installing-and-configuring-a-multi-server-columnstore-system-11x/index#non-distributed-install). MariaDB ColumnStore API (Bulk Write SDK) Package ================================================ Additional information on the ColumnStore API (Bulk Write SDK): [https://mariadb.com/kb/en/library/columnstore-bulk-write-sdk/](../library/columnstore-bulk-write-sdk/index) CentOS 7 -------- ### Adding the MariaDB ColumnStore API YUM repository Add new file with repository information, /etc/yum.repos.d/mariadb-columnstore-api.repo ``` [mariadb-columnstore-api] name=MariaDB ColumnStore API baseurl=https://downloads.mariadb.com/MariaDB/mariadb-columnstore-api/latest/yum/centos/7/x86_64/ gpgkey=https://downloads.mariadb.com/MariaDB/mariadb-columnstore/RPM-GPG-KEY-MariaDB-ColumnStore gpgcheck=1 ``` ### Installing MariaDB ColumnStore API With the repo file in place you can now install MariaDB ColumnStore API like so: ``` sudo yum install epel-release sudo yum --enablerepo=mariadb-columnstore-api clean metadata sudo yum install mariadb-columnstore-api* ``` #### MariaDB ColumnStore API C++ To install only the C++ part of the API use: ``` sudo yum install epel-release sudo yum --enablerepo=mariadb-columnstore-api clean metadata sudo yum install mariadb-columnstore-api-cpp sudo yum install mariadb-columnstore-api-cpp-devel ``` #### MariaDB ColumnStore API Java To install only the Java part of the API use: ``` sudo yum install epel-release sudo yum --enablerepo=mariadb-columnstore-api clean metadata sudo yum install mariadb-columnstore-api-java ``` #### MariaDB ColumnStore API Python 2 To install only the Python 2 part of the API use: ``` sudo yum install epel-release sudo yum --enablerepo=mariadb-columnstore-api clean metadata sudo yum install mariadb-columnstore-api-python ``` #### MariaDB ColumnStore API Python 3 To install only the Python 3 part of the API use: ``` sudo yum install epel-release sudo yum --enablerepo=mariadb-columnstore-api clean metadata sudo yum install mariadb-columnstore-api-python3 ``` #### MariaDB ColumnStore API Spark To install only the Spark part of the API, and the Scala ColumnStore Exporter library use: ``` sudo yum install epel-release sudo yum --enablerepo=mariadb-columnstore-api clean metadata sudo yum install mariadb-columnstore-api-spark ``` #### MariaDB ColumnStore API PySpark To install only the PySpark part of the API the Python ColumnStore exporter use: ``` sudo yum install epel-release sudo yum --enablerepo=mariadb-columnstore-api clean metadata sudo yum install mariadb-columnstore-api-pyspark ``` #### MariaDB ColumnStore API PySpark 3 To install only the PySpark 3 part of the API the Python 3 ColumnStore exporter use: ``` sudo yum install epel-release sudo yum --enablerepo=mariadb-columnstore-api clean metadata sudo yum install mariadb-columnstore-api-pyspark3 ``` Debian 8 -------- ### Adding the MariaDB ColumnStore API APT-GET repository Install package: ``` sudo apt-get install apt-transport-https ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-api.list ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore-api/latest/repo/debian8 jessie main ``` Download the MariaDB ColumnStore key ``` wget -qO - https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` Add new file with repository information, /etc/apt/sources.list.d/debian-backports.list ``` deb http://httpredir.debian.org/debian jessie-backports main contrib non-free ``` ### Installing MariaDB ColumnStore API With the repo file in place you can now install MariaDB ColumnStore API like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-api* ``` #### MariaDB ColumnStore API C++ To install only the C++ part of the API use: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-api-cpp sudo apt-get install mariadb-columnstore-api-cpp-devel ``` #### MariaDB ColumnStore API Java To install only the Java part of the API use: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-api-java ``` #### MariaDB ColumnStore API Python 2 To install only the Python 2 part of the API use: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-api-python ``` #### MariaDB ColumnStore API Python 3 To install only the Python 3 part of the API use: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-api-python3 ``` #### MariaDB ColumnStore API Spark To install only the Spark part of the API, and the Scala ColumnStore Exporter library use: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-api-spark ``` #### MariaDB ColumnStore API PySpark To install only the PySpark part of the API the Python ColumnStore exporter use: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-api-pyspark ``` #### MariaDB ColumnStore API PySpark 3 To install only the PySpark 3 part of the API the Python 3 ColumnStore exporter use: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-api-pyspark3 ``` Debian 9 -------- ### Adding the MariaDB ColumnStore API APT-GET repository Install package: ``` sudo apt-get install apt-transport-https dirmngr ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-api.list ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore-api/latest/repo/debian9 stretch main ``` Download the MariaDB ColumnStore key ``` wget -qO - https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` ### Installing MariaDB ColumnStore API With the repo file in place you can now install MariaDB ColumnStore API like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-api* ``` #### MariaDB ColumnStore API C++ To install only the C++ part of the API use: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-api-cpp sudo apt-get install mariadb-columnstore-api-cpp-devel ``` #### MariaDB ColumnStore API Java To install only the Java part of the API use: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-api-java ``` #### MariaDB ColumnStore API Python 2 To install only the Python 2 part of the API use: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-api-python ``` #### MariaDB ColumnStore API Python 3 To install only the Python 3 part of the API use: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-api-python3 ``` #### MariaDB ColumnStore API Spark To install only the Spark part of the API, and the Scala ColumnStore Exporter library use: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-api-spark ``` #### MariaDB ColumnStore API PySpark To install only the PySpark part of the API the Python ColumnStore exporter use: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-api-pyspark ``` #### MariaDB ColumnStore API PySpark 3 To install only the PySpark 3 part of the API the Python 3 ColumnStore exporter use: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-api-pyspark3 ``` Ubuntu 16 --------- ### Adding the MariaDB ColumnStore API APT-GET repository Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-api.list ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore-api/latest/repo/ubuntu16 xenial main ``` Download the MariaDB ColumnStore key ``` wget -qO - https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` Ubuntu 18 --------- ### Adding the MariaDB ColumnStore API APT-GET repository Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-api.list ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore-api/latest/repo/ubuntu18 bionic main ``` Download the MariaDB ColumnStore key ``` wget -qO - https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` ### Installing MariaDB ColumnStore API With the repo file in place you can now install MariaDB ColumnStore API like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-api* ``` #### MariaDB ColumnStore API C++ To install only the C++ part of the API use: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-api-cpp sudo apt-get install mariadb-columnstore-api-cpp-devel ``` #### MariaDB ColumnStore API Java To install only the Java part of the API use: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-api-java ``` #### MariaDB ColumnStore API Python 2 To install only the Python 2 part of the API use: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-api-python ``` #### MariaDB ColumnStore API Python 3 To install only the Python 3 part of the API use: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-api-python3 ``` #### MariaDB ColumnStore API Spark To install only the Spark part of the API, and the Scala ColumnStore Exporter library use: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-api-spark ``` #### MariaDB ColumnStore API PySpark To install only the PySpark part of the API the Python ColumnStore exporter use: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-api-pyspark ``` #### MariaDB ColumnStore API PySpark 3 To install only the PySpark 3 part of the API the Python 3 ColumnStore exporter use: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-api-pyspark3 ``` Windows 10 ---------- Install via MSI (Windows Installer) <http://downloads.mariadb.com/MariaDB/mariadb-columnstore-api/latest/winx64-packages/> MariaDB ColumnStore Tools Package ================================= Additional information on the Backup and Restore Tool: [https://mariadb.com/kb/en/library/backup-and-restore-for-mariadb-columnstore-110-onwards/](../library/backup-and-restore-for-mariadb-columnstore-110-onwards/index) Additional information on mcsimport: [https://mariadb.com/kb/en/library/columnstore-remote-bulk-data-import-mcsimport/](../library/columnstore-remote-bulk-data-import-mcsimport/index) CentOS 6 -------- ### Adding the MariaDB ColumnStore Tools YUM repository Add new file with repository information, /etc/yum.repos.d/mariadb-columnstore-tools.repo ``` [mariadb-columnstore-tools] name=MariaDB ColumnStore Tools baseurl=https://downloads.mariadb.com/MariaDB/mariadb-columnstore-tools/latest/yum/centos/6/x86_64/ gpgkey=https://downloads.mariadb.com/MariaDB/mariadb-columnstore/RPM-GPG-KEY-MariaDB-ColumnStore gpgcheck=1 ``` **Note:** The CentOS 6 package of mariadb-columnstore-tools doesn't include mcsimport. ### Installing MariaDB ColumnStore Tools With the repo file in place you can now install MariaDB ColumnStore Tools like so: ``` sudo yum --enablerepo=mariadb-columnstore-tools clean metadata sudo yum install mariadb-columnstore-tools ``` CentOS 7 -------- ### Adding the MariaDB ColumnStore Tools YUM repository Add new file with repository information, /etc/yum.repos.d/mariadb-columnstore-tools.repo ``` [mariadb-columnstore-tools] name=MariaDB ColumnStore Tools baseurl=https://downloads.mariadb.com/MariaDB/mariadb-columnstore-tools/latest/yum/centos/7/x86_64/ gpgkey=https://downloads.mariadb.com/MariaDB/mariadb-columnstore/RPM-GPG-KEY-MariaDB-ColumnStore gpgcheck=1 ``` ### Installing MariaDB ColumnStore Tools With the repo file in place you can now install MariaDB ColumnStore Tools like so: ``` sudo yum --enablerepo=mariadb-columnstore-tools clean metadata sudo yum install mariadb-columnstore-tools ``` **Note:** The CentOS 7 package of mariadb-columnstore-tools includes mcsimport which requires mariadb-columnstore-api-cpp and its repository. SUSE 12 ------- ### Adding the MariaDB ColumnStore Tools ZYPPER repository Add new file with repository information, /etc/zypp/repos.d/mariadb-columnstore-tools.repo ``` [mariadb-columnstore-tools] name=mariadb-columnstore-tools enabled=1 autorefresh=0 baseurl=https://downloads.mariadb.com/MariaDB/mariadb-columnstore-tools/latest/yum/sles/12/x86_64 type=rpm-md ``` Download the MariaDB ColumnStore key ``` rpm --import https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key ``` ### Installing MariaDB ColumnStore With the repo file in place you can now install MariaDB ColumnStore like so: ``` sudo zypper refresh sudo zypper install mariadb-columnstore-tools ``` **Note:** The SUSE 12 package of mariadb-columnstore-tools doesn't include mcsimport. Debian 8 -------- ### Adding the MariaDB ColumnStore Tools APT-GET repository Install package: ``` sudo apt-get install apt-transport-https ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-tools.list ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore-tools/latest/repo/debian8 jessie main ``` Download the MariaDB ColumnStore key ``` wget -qO - https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` ### Installing MariaDB ColumnStore Tools With the repo file in place you can now install MariaDB ColumnStore Tools like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-tools ``` **Note:** The Debian 8 package of mariadb-columnstore-tools includes mcsimport which requires mariadb-columnstore-api-cpp and its repository. Debian 9 -------- ### Adding the MariaDB ColumnStore Tools APT-GET repository Install package: ``` sudo apt-get install apt-transport-https dirmngr ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-tools.list ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore-tools/latest/repo/debian9 stretch main ``` Download the MariaDB ColumnStore key ``` wget -qO - https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` ### Installing MariaDB ColumnStore Tools With the repo file in place you can now install MariaDB ColumnStore Tools like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-tools ``` **Note:** The Debian 9 package of mariadb-columnstore-tools includes mcsimport which requires mariadb-columnstore-api-cpp and its repository. Ubuntu 16 --------- ### Adding the MariaDB ColumnStore Tools APT-GET repository Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-tools.list ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore-tools/latest/repo/ubuntu16 xenial main ``` Download the MariaDB ColumnStore key ``` wget -qO - https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` Ubuntu 18 --------- ### Adding the MariaDB ColumnStore Tools APT-GET repository Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-tools.list ``` deb https://downloads.mariadb.com/MariaDB/mariadb-columnstore-tools/latest/repo/ubuntu18 bionic main ``` Download the MariaDB ColumnStore key ``` wget -qO - https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` ### Installing MariaDB ColumnStore Tools With the repo file in place you can now install MariaDB ColumnStore Tools like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-tools ``` **Note:** The Ubuntu 16 and 18 packages of mariadb-columnstore-tools include mcsimport which requires mariadb-columnstore-api-cpp and its repository. Windows 10 ---------- Install via MSI (Windows Installer) <http://downloads.mariadb.com/ColumnStore-Tools/latest/winx64-packages/> MariaDB MaxScale Packages ========================= CentOS 6 -------- ### Adding the MariaDB MaxScale YUM repository Add new file with repository information, /etc/yum.repos.d/mariadb-maxscale.repo ``` [mariadb-maxscale] name=MariaDB MaxScale baseurl=https://downloads.mariadb.com/MaxScale/latest/centos/6/x86_64 gpgkey=https://downloads.mariadb.com/MaxScale/MariaDB-MaxScale-GPG-KEY gpgcheck=1 ``` ### Installing MariaDB MaxScale With the repo file in place you can now install MariaDB MaxScale like so: You can also install this way: ``` sudo yum --enablerepo=mariadb-maxscale clean metadata sudo yum install maxscale maxscale-cdc-connector ``` CentOS 7 -------- ### Adding the MariaDB MaxScale YUM repository Add new file with repository information, /etc/yum.repos.d/mariadb-maxscale.repo ``` [mariadb-maxscale] name=MariaDB MaxScale baseurl=https://downloads.mariadb.com/MaxScale/latest/centos/7/x86_64 gpgkey=https://downloads.mariadb.com/MaxScale/MariaDB-MaxScale-GPG-KEY gpgcheck=1 ``` ### Installing MariaDB MaxScale You can also install this way: ``` sudo yum --enablerepo=mariadb-maxscale clean metadata sudo yum install maxscale maxscale-cdc-connector ``` SUSE 12 ------- ### Adding the MariaDB MaxScale ZYPPER repository Add new file with repository information, /etc/zypp/repos.d/mariadb-maxscale.repo ``` [mariadb-maxscale] name=mariadb-maxscale enabled=1 autorefresh=0 baseurl=https://downloads.mariadb.com/MaxScale/latest/sles/12/x86_64 type=rpm-md ``` Download the MariaDB MaxScale key ``` rpm --import https://downloads.mariadb.com/MaxScale/MariaDB-MaxScale-GPG-KEY ``` ### Installing MariaDB MaxScale With the repo file in place you can now install MariaDB MaxScale like so: ``` sudo zypper refresh sudo zypper install maxscale maxscale-cdc-connector ``` Debian 8 -------- ### Adding the MariaDB MaxScale APT-GET repository Install package: ``` sudo apt-get install apt-transport-https ``` Add new file with repository information, /etc/apt/sources.list.d/mariadb-maxscale.list ``` deb https://downloads.mariadb.com/MaxScale/latest/debian jessie main ``` Download the MariaDB MaxScale key ``` apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 28C12247 ``` ### Installing MariaDB MaxScale Additional information on setting to Maxscale: [https://mariadb.com/kb/en/mariadb-enterprise/mariadb-maxscale-14/mariadb-maxscale-installation-guide/](../mariadb-enterprise/mariadb-maxscale-14/mariadb-maxscale-installation-guide/index) With the repo file in place you can now install MariaDB MaxScale like so: ``` sudo apt-get update sudo apt-get install maxscale maxscale-cdc-connector ``` Debian 9 -------- ### Adding the MariaDB MaxScale APT-GET repository Install package: ``` sudo apt-get install apt-transport-https dirmngr ``` Add new file with repository information, /etc/apt/sources.list.d/mariadb-maxscale.list ``` deb https://downloads.mariadb.com/MaxScale/latest/debian stretch main ``` Download the MariaDB MaxScale key ``` apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 28C12247 ``` ### Installing MariaDB MaxScale With the repo file in place you can now install MariaDB MaxScale like so: ``` sudo apt-get update sudo apt-get install maxscale maxscale-cdc-connector ``` Ubuntu 16 --------- ### Adding the MariaDB MaxScale APT-GET repository Add new file with repository information, /etc/apt/sources.list.d/mariadb-maxscale.list ``` deb https://downloads.mariadb.com/MaxScale/latest/ubuntu xenial main ``` Download the MariaDB MaxScale key ``` apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 28C12247 ``` Ubuntu 18 --------- ### Adding the MariaDB MaxScale APT-GET repository Add new file with repository information, /etc/apt/sources.list.d/mariadb-maxscale.list ``` deb https://downloads.mariadb.com/MaxScale/latest/ubuntu bionic main ``` Download the MariaDB MaxScale key ``` apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 28C12247 ``` ### Installing MariaDB MaxScale With the repo file in place you can now install MariaDB MaxScale like so: ``` sudo apt-get update sudo apt-get install maxscale maxscale-cdc-connector ``` MariaDB Connector Packages ========================== ODBC Connector -------------- Additional Information on the ODBC connector: [https://mariadb.com/kb/en/library/mariadb-connector-odbc/](../library/mariadb-connector-odbc/index) How to Install the ODBC Connector: [https://mariadb.com/kb/en/library/about-mariadb-connector-odbc/](../library/about-mariadb-connector-odbc/index) Java Connector -------------- Additional information on the Java Connector: [https://mariadb.com/kb/en/library/mariadb-connector-j/](../library/mariadb-connector-j/index) How to Install the Java Connector: [https://mariadb.com/kb/en/library/getting-started-with-the-java-connector/](../library/getting-started-with-the-java-connector/index) MariaDB ColumnStore Data Adapters Packages ========================================== Additional information on the Data Adapters: [https://mariadb.com/kb/en/library/columnstore-streaming-data-adapters/](../library/columnstore-streaming-data-adapters/index) NOTE: MaxScale CDC Connector requires the MariaDB MaxScale package be installed first. The MariaDB ColumnStore Data Adapters Packages are: * Kafka Adapters * Maxscale CDC Adapters Kafka install package dependencies: * N/A Maxscale CDC install package dependencies:: * MaxScale CDC Connector * MariaDB ColumnStore API * MariaDB MaxScale CentOS 7 -------- ### Adding the MariaDB ColumnStore Data Adapters YUM repository Add new file with repository information, /etc/yum.repos.d/mariadb-columnstore-data-adapters.repo ``` [mariadb-columnstore-data-adapters] name=MariaDB ColumnStore Data Adapters baseurl=https://downloads.mariadb.com/MariaDB/data-adapters/mariadb-streaming-data-adapters/latest/yum/centos/7/x86_64/ gpgkey=https://downloads.mariadb.com/MariaDB/mariadb-columnstore/RPM-GPG-KEY-MariaDB-ColumnStore gpgcheck=1 ``` ### Installing MariaDB ColumnStore Data Adapters With the repo file in place you can now install MariaDB ColumnStore Maxscale CDC Data Adapters like so: ``` sudo yum --enablerepo=mariadb-columnstore-data-adapters clean metadata sudo yum install mariadb-columnstore-data-adapters-maxscale-cdc-adapter ``` With the repo file in place you can now install MariaDB ColumnStore Kafka Data Adapters like so: ``` sudo yum --enablerepo=mariadb-columnstore-data-adapters clean metadata sudo yum install mariadb-columnstore-data-adapters-avro-kafka-adapter ``` Debian 8 -------- ### Adding the MariaDB ColumnStore Data Adapters APT-GET repository Install package: ``` sudo apt-get install apt-transport-https ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-data-adapters.list ``` deb https://downloads.mariadb.com/MariaDB/data-adapters/mariadb-streaming-data-adapters/latest/repo/debian8 jessie main ``` Download the MariaDB ColumnStore key ``` wget -qO - https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` ### Installing MariaDB ColumnStore Data Adapters With the repo file in place you can now install MariaDB ColumnStore Maxscale CDC Data Adapters like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-maxscale-cdc-adapters ``` With the repo file in place you can now install MariaDB ColumnStore Kafka Data Adapters like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-kafka-avro-adapters ``` Debian 9 -------- ### Adding the MariaDB ColumnStore Data Adapters APT-GET repository Install package: ``` sudo apt-get install apt-transport-https dirmngr ``` Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-data-adapters.list ``` deb https://downloads.mariadb.com/MariaDB/data-adapters/mariadb-streaming-data-adapters/latest/repo/debian9 stretch main ``` Download the MariaDB ColumnStore key ``` wget -qO - https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` ### Installing MariaDB ColumnStore Data Adapters With the repo file in place you can now install MariaDB ColumnStores Maxscale CDC Data Adapters like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-maxscale-cdc-adapters ``` With the repo file in place you can now install MariaDB ColumnStores Kafka Data Adapters like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-kafka-avro-adapters ``` Ubuntu 16 --------- ### Adding the MariaDB ColumnStore Data Adapters APT-GET repository Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-data-adapters.list ``` deb https://downloads.mariadb.com/MariaDB/data-adapters/mariadb-streaming-data-adapters/latest/repo/ubuntu16 xenial main ``` Download the MariaDB ColumnStore key ``` wget -qO - https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` Ubuntu 18 --------- ### Adding the MariaDB ColumnStore Data Adapters APT-GET repository Add new file with repository information, /etc/apt/sources.list.d/mariab-columnstore-data-adapters.list ``` deb https://downloads.mariadb.com/MariaDB/data-adapters/mariadb-streaming-data-adapters/latest/repo/ubuntu18 bionic main ``` Download the MariaDB ColumnStore key ``` wget -qO - https://downloads.mariadb.com/MariaDB/mariadb-columnstore/MariaDB-ColumnStore.gpg.key | sudo apt-key add - ``` ### Installing MariaDB ColumnStore Data Adapters With the repo file in place you can now install MariaDB ColumnStore Maxscale CDC Data Adapters like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-maxscale-cdc-adapters ``` With the repo file in place you can now install MariaDB ColumnStore Kafka Data Adapters like so: ``` sudo apt-get update sudo apt-get install mariadb-columnstore-kafka-avro-adapters ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb MariaDB Installation (Version 10.1.21) via RPMs on CentOS 7 MariaDB Installation (Version 10.1.21) via RPMs on CentOS 7 =========================================================== Here are the detailed steps for installing MariaDB (version 10.1.21) via RPMs on CentOS 7. The RPM's needed for the installation are all available on the MariaDB website and are given below: * jemalloc-3.6.0-1.el7.x86\_64.rpm * MariaDB-10.1.21-centos7-x86\_64-client.rpm * MariaDB-10.1.21-centos7-x86\_64-compat.rpm * galera-25.3.19-1.rhel7.el7.centos.x86\_64.rpm * jemalloc-devel-3.6.0-1.el7.x86\_64.rpm * MariaDB-10.1.21-centos7-x86\_64-common.rpm * MariaDB-10.1.21-centos7-x86\_64-server.rpm Step by step installation: * 1) First install all of the dependencies needed. Its easy to do this via YUM packages: yum install rsync nmap lsof perl-DBI nc * 2) rpm -ivh jemalloc-3.6.0-1.el7.x86\_64.rpm * 3) rpm -ivh jemalloc-devel-3.6.0-1.el7.x86\_64.rpm * 4) rpm -ivh MariaDB-10.1.21-centos7-x86\_64-common.rpm MariaDB-10.1.21-centos7-x86\_64-compat.rpm MariaDB-10.1.21-centos7-x86\_64-client.rpm galera-25.3.19-1.rhel7.el7.centos.x86\_64.rpm MariaDB-10.1.21-centos7-x86\_64-server.rpm While installing MariaDB-10.1.21-centos7-x86\_64-common.rpm there might be a conflict with older MariaDB packages. we need to remove them and install the original rpm again. Here is the error message for dependencies: ``` # rpm -ivh MariaDB-10.1.21-centos7-x86_64-common.rpm warning: MariaDB-10.1.21-centos7-x86_64-common.rpm: Header V4 DSA/SHA1 Signature, key ID 1bb943db: NOKEY error: Failed dependencies: mariadb-libs < 1:10.1.21-1.el7.centos conflicts with MariaDB-common-10.1.21-1.el7.centos.x86_64 ``` Solution: search for this package: ``` # rpm -qa | grep mariadb-libs mariadb-libs-5.5.52-1.el7.x86_64 ``` Remove this package: ``` # rpm -ev --nodeps mariadb-libs-5.5.52-1.el7.x86_64 Preparing packages... mariadb-libs-1:5.5.52-1.el7.x86_64 ``` While installing the Galera package there might be a conflict in installation for a dependency package. Here is the error message: ``` [root@centos-2 /]# rpm -ivh galera-25.3.19-1.rhel7.el7.centos.x86_64.rpm error: Failed dependencies: libboost_program_options.so.1.53.0()(64bit) is needed by galera-25.3.19-1.rhel7.el7.centos.x86_64 The dependencies for Galera package is: libboost_program_options.so.1.53.0 ``` Solution: ``` yum install boost-devel.x86_64 ``` Another warning message while installing Galera package is as shown below: ``` warning: galera-25.3.19-1.rhel7.el7.centos.x86_64.rpm: Header V4 DSA/SHA1 Signature, key ID 1bb943db: NOKEY ``` The solution for this is to import the key: ``` #rpm --import http://yum.mariadb.org/RPM-GPG-KEY-MariaDB ``` After step 4, the installation will be completed. The last step will be to run [mysql\_secure\_installation](../mysql_secure_installation/index) to secure the production server by dis allowing remote login for root, creating root password and removing the test database. * 5) mysql\_secure\_installation Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Information Schema ROCKSDB_SST_PROPS Table Information Schema ROCKSDB\_SST\_PROPS Table ============================================ The [Information Schema](../information_schema/index) `ROCKSDB_SST_PROPS` table is included as part of the [MyRocks](../myrocks/index) storage engine. The `PROCESS` [privilege](../grant/index) is required to view the table. It contains the following columns: | Column | Description | | --- | --- | | `SST_NAME` | | | `COLUMN_FAMILY` | | | `DATA_BLOCKS` | | | `ENTRIES` | | | `RAW_KEY_SIZE` | | | `RAW_VALUE_SIZE` | | | `DATA_BLOCK_SIZE` | | | `INDEX_BLOCK_SIZE` | | | `INDEX_PARTITIONS` | | | `TOP_LEVEL_INDEX_SIZE` | | | `FILTER_BLOCK_SIZE` | | | `COMPRESSION_ALGO` | | | `CREATION_TIME` | | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb SELECT INTO DUMPFILE SELECT INTO DUMPFILE ==================== Syntax ------ ``` SELECT ... INTO DUMPFILE 'file_path' ``` Description ----------- `SELECT ... INTO DUMPFILE` is a [SELECT](../select/index) clause which writes the resultset into a single unformatted row, without any separators, in a file. The results will not be returned to the client. *file\_path* can be an absolute path, or a relative path starting from the data directory. It can only be specified as a [string literal](../string-literals/index), not as a variable. However, the statement can be dynamically composed and executed as a prepared statement to work around this limitation. This statement is binary-safe and so is particularly useful for writing [BLOB](../blob/index) values to file. It can be used, for example, to copy an image or an audio document from the database to a file. SELECT ... INTO FILE can be used to save a text file. The file must not exist. It cannot be overwritten. A user needs the [FILE](../grant/index#global-privileges) privilege to run this statement. Also, MariaDB needs permission to write files in the specified location. If the [secure\_file\_priv](../server-system-variables/index#secure_file_priv) system variable is set to a non-empty directory name, the file can only be written to that directory. Since [MariaDB 5.1](../what-is-mariadb-51/index), the [character\_set\_filesystem](../server-system-variables/index#character_set_filesystem) system variable has controlled interpretation of file names that are given as literal strings. Example ------- ``` SELECT _utf8'Hello world!' INTO DUMPFILE '/tmp/world'; SELECT LOAD_FILE('/tmp/world') AS world; +--------------+ | world | +--------------+ | Hello world! | +--------------+ ``` See Also -------- * [SELECT](../select/index) * [LOAD\_FILE()](../load_file/index) * [SELECT INTO Variable](../select-into-variable/index) * [SELECT INTO OUTFILE](../select-into-outfile/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb JSON_UNQUOTE JSON\_UNQUOTE ============= **MariaDB starting with [10.2.3](https://mariadb.com/kb/en/mariadb-1023-release-notes/)**JSON functions were added in [MariaDB 10.2.3](https://mariadb.com/kb/en/mariadb-1023-release-notes/). Syntax ------ ``` JSON_UNQUOTE(val) ``` Description ----------- Unquotes a JSON value, returning a string, or NULL if the argument is null. An error will occur if the given value begins and ends with double quotes and is an invalid JSON string literal. If the given value is not a JSON string, value is passed through unmodified. Certain character sequences have special meanings within a string. Usually, a backslash is ignored, but the escape sequences in the table below are recognised by MariaDB, unless the [SQL Mode](../sql-mode/index) is set to NO\_BACKSLASH\_ESCAPES SQL. | Escape sequence | Character | | --- | --- | | `\"` | Double quote (") | | `\b` | Backslash | | `\f` | Formfeed | | `\n` | Newline (linefeed) | | `\r` | Carriage return | | `\t` | Tab | | `\\` | Backslash (\) | | `\uXXXX` | UTF-8 bytes for Unicode value XXXX | Examples -------- ``` SELECT JSON_UNQUOTE('"Monty"'); +-------------------------+ | JSON_UNQUOTE('"Monty"') | +-------------------------+ | Monty | +-------------------------+ ``` With the default [SQL Mode](../sql-mode/index): ``` SELECT JSON_UNQUOTE('Si\bng\ting'); +-----------------------------+ | JSON_UNQUOTE('Si\bng\ting') | +-----------------------------+ | Sng ing | +-----------------------------+ ``` Setting NO\_BACKSLASH\_ESCAPES: ``` SET @@sql_mode = 'NO_BACKSLASH_ESCAPES'; SELECT JSON_UNQUOTE('Si\bng\ting'); +-----------------------------+ | JSON_UNQUOTE('Si\bng\ting') | +-----------------------------+ | Si\bng\ting | +-----------------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Upgrading MariaDB ColumnStore from 1.0.2 to 1.0.3 Upgrading MariaDB ColumnStore from 1.0.2 to 1.0.3 ================================================= MariaDB ColumnStore software upgrade 1.0.2 to 1.0.3 --------------------------------------------------- Note: Columnstore.xml modifications you manually made are not automatically carried forward on an upgrade. These modifications will need to be incorporated back into .XML once the upgrade has occurred. The previous configuration file will be saved as /usr/local/mariadb/columnstore/etc/Columnstore.xml.rpmsave. ### Choosing the type of upgrade #### Root User Installs #### Upgrading MariaDB ColumnStore using RPMs Upgrade MariaDB ColumnStore as user root on the server designated as PM1: **Download the package mariadb-columnstore-1.0.3-1-centos#.x86\_64.rpm.tar.gz to the PM1 server where you are installing MariaDB ColumnStore.** Shutdown the MariaDB ColumnStore system: ``` # mcsadmin shutdownsystem y ``` * Unpack the tarball, which will generate a set of RPMs that will reside in the /root/ directory. `tar -zxf mariadb-columnstore-1.0.3-1-centos#.x86_64.rpm.tar.gz` * Upgrade the RPMs. The MariaDB ColumnStore software will be installed in /usr/local/. ``` rpm -e --nodeps $(rpm -qa | grep '^mariadb-columnstore') rpm -ivh mariadb-columnstore-*1.0.3*rpm ``` * Run postConfigure using the upgrade option, which will utilize the configuration from the Columnstore.xml,rpmsave ``` # /usr/local/mariadb/columnstore/bin/postConfigure -u ``` For RPM Upgrade, the previous configuration file will be saved as: /usr/local/mariadb/columnstore/etc/Columnstore.xml.rpmsave ### Initial download/install of MariaDB ColumnStore binary package Upgrade MariaDB ColumnStore as user root on the server designated as PM1: * Download the package into the /usr/local directory -mariadb-columnstore-release#.x86\_64.bin.tar.gz (Binary 64-BIT)to the server where you are installing MariaDB ColumnStore. * Shutdown the MariaDB ColumnStore system: `mcsadmin shutdownsystem y` * Run pre-uninstall script `/usr/local/mariadb/columnstore/bin/pre-uninstall` * Unpack the tarball, in the /usr/local/ directory. `tar -zxvf -mariadb-columnstore-release#.x86_64.bin.tar.gz` * Run post-install scripts `/usr/local/mariadb/columnstore/bin/post-install` * Run postConfigure using the upgrade option, which will utilize the configuration from the Columnstore.xml,rpmsave `/usr/local/mariadb/columnstore/bin/postConfigure -u` ### Upgrading MariaDB ColumnStore using the DEB package A DEB upgrade would be done on a system that supports DEBs like Debian or Ubuntu systems. Upgrade MariaDB ColumnStore as user root on the server designated as PM1: * Download the package into the /root directory ``` mariadb-columnstore-release#.amd64.deb.tar.gz ``` (DEB 64-BIT) to the server where you are installing MariaDB ColumnStore. * Shutdown the MariaDB ColumnStore system: ``` mcsadmin shutdownsystem y ``` * Unpack the tarball, which will generate DEBs. ``` tar -zxf mariadb-columnstore-release#.amd64.deb.tar.gz ``` * Remove, purge and install all MariaDB ColumnStore debs ``` cd /root/ dpkg -r mariadb-columnstore*deb dpkg -P mariadb-columnstore*deb ``` * Run postConfigure using the upgrade option, which will utilize the configuration from the Columnstore.xml,rpmsave ``` /usr/local/mariadb/columnstore/bin/postConfigure -u ``` #### Non-Root User Installs ### Initial download/install of MariaDB ColumnStore binary package Upgrade MariaDB ColumnStore as user root on the server designated as PM1: * Download the package into the /home/'non-root-user" directory mariadb-columnstore-release#.x86\_64.bin.tar.gz (Binary 64-BIT)to the server where you are installing MariaDB ColumnStore. * Shutdown the MariaDB ColumnStore system: `mcsadmin shutdownsystem y` * Run pre-uninstall script `$HOME/mariadb/columnstore/bin/pre-uninstall -i /home/guest/mariadb/columnstore` * Unpack the tarball, which will generate the $HOME/ directory. `tar -zxvf -mariadb-columnstore-release#.x86_64.bin.tar.gz` * Run post-install scripts 1. $HOME/mariadb/columnstore/bin/post-install -i /home/guest/mariadb/columnstore * Run postConfigure using the upgrade option, which will utilize the configuration from the Columnstore.xml,rpmsave `$HOME/mariadb/columnstore/bin/postConfigure -u -i /home/guest/mariadb/columnstore` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb MariaDB Audit Plugin - Log Format MariaDB Audit Plugin - Log Format ================================= The audit plugin logs user access to MariaDB and its objects. The audit trail (i.e., audit log) is a set of records, written as a list of fields to a file in a plain‐text format. The fields in the log are separated by commas. The format used for the plugin's own log file is slightly different from the format used if it logs to the system log because it has its own standard format. The general format for the logging to the plugin's own file is defined like the following: ``` [timestamp],[serverhost],[username],[host],[connectionid], [queryid],[operation],[database],[object],[retcode] ``` If the [server\_audit\_output\_type](../server_audit-system-variables/index#server_audit_output_type) variable is set to `syslog` instead of the default, `file`, the audit log file format will be as follows: ``` [timestamp][syslog_host][syslog_ident]:[syslog_info][serverhost],[username],[host], [connectionid],[queryid],[operation],[database],[object],[retcode] ``` | Item logged | Description | | --- | --- | | timestamp | Time at which the event occurred. If syslog is used, the format is defined by `syslogd`. | | syslog\_host | Host from which the syslog entry was received. | | syslog\_ident | For identifying a system log entry, including the MariaDB server. | | syslog\_info | For providing information for identifying a system log entry. | | serverhost | The MariaDB server host name. | | username | Connected user. | | host | Host from which the user connected. | | connectionid | Connection ID number for the related operation. | | queryid | Query ID number, which can be used for finding the relational table events and related queries. For TABLE events, multiple lines will be added. | | operation | Recorded action type: CONNECT, QUERY, READ, WRITE, CREATE, ALTER, RENAME, DROP. | | database | Active database (as set by [USE](../use/index)). | | object | Executed query for QUERY events, or the table name in the case of TABLE events. | | retcode | Return code of the logged operation. | Various events will result in different audit records. Some events will not return a value for some fields (e.g., when the active database is not set when connecting to the server). Below is a generic example of the output for connect events, with placeholders representing data. These are events in which a user connected, disconnected, or tried unsuccessfully to connect to the server. ``` [timestamp],[serverhost],[username],[host],[connectionid],0,CONNECT,[database],,0 [timestamp],[serverhost],[username],[host],[connectionid],0,DISCONNECT,,,0 [timestamp],[serverhost],[username],[host],[connectionid],0,FAILED_CONNECT,,,[retcode] ``` Here is the one audit record generated for each query event: ``` [timestamp],[serverhost],[username],[host],[connectionid],[queryid],QUERY,[database],[object], [retcode] ``` Below are generic examples of records that are entered in the audit log for each type of table event: ``` [timestamp],[serverhost],[username],[host],[connectionid],[queryid],CREATE,[database],[object], [timestamp],[serverhost],[username],[host],[connectionid],[queryid],READ,[database],[object], [timestamp],[serverhost],[username],[host],[connectionid],[queryid],WRITE,[database],[object], [timestamp],[serverhost],[username],[host],[connectionid],[queryid],ALTER,[database],[object], [timestamp],[serverhost],[username],[host],[connectionid],[queryid],RENAME,[database], [object_old]|[database_new].[object_new], [timestamp],[serverhost],[username],[host],[connectionid],[queryid],DROP,[database],[object], ``` Starting in version 1.2.0, passwords are hidden in the log for certain types of queries. They are replaced with asterisks for `GRANT`, `CREATE USER`, `CREATE MASTER`, `CREATE SERVER`, and `ALTER SERVER` statements. Passwords, however, are not replaced for the `PASSWORD()` and `OLD_PASSWORD()` functions when they are used inside other SQL statements (i.e., SET PASSWORD`).` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb VERSION VERSION ======= Syntax ------ ``` VERSION() ``` Description ----------- Returns a string that indicates the MariaDB server version. The string uses the utf8 [character set](../data-types-character-sets-and-collations/index). Examples -------- ``` SELECT VERSION(); +----------------+ | VERSION() | +----------------+ | 10.4.7-MariaDB | +----------------+ ``` The `VERSION()` string may have one or more of the following suffixes: | Suffix | Description | | --- | --- | | -embedded | The server is an embedded server (libmysqld). | | -log | General logging, slow logging or binary (replication) logging is enabled. | | -debug | The server is compiled for debugging. | | -valgrind | The server is compiled to be instrumented with valgrind. | Changing the Version String --------------------------- Some old legacy code may break because they are parsing the `VERSION` string and expecting a MySQL string or a simple version string like Joomla til API17, see [MDEV-7780](https://jira.mariadb.org/browse/MDEV-7780). From [MariaDB 10.2](../what-is-mariadb-102/index), one can fool these applications by setting the version string from the command line or the my.cnf files with [--version=...](../server-system-variables/index#version). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb JSON_KEYS JSON\_KEYS ========== **MariaDB starting with [10.2.3](https://mariadb.com/kb/en/mariadb-1023-release-notes/)**JSON functions were added in [MariaDB 10.2.3](https://mariadb.com/kb/en/mariadb-1023-release-notes/). Syntax ------ ``` JSON_KEYS(json_doc[, path]) ``` Description ----------- Returns the keys as a JSON array from the top-level value of a JSON object or, if the optional path argument is provided, the top-level keys from the path. Excludes keys from nested sub-objects in the top level value. The resulting array will be empty if the selected object is empty. Returns NULL if any of the arguments are null, a given path does not locate an object, or if the json\_doc argument is not an object. An error will occur if JSON document is invalid, the path is invalid or if the path contains a `*` or `**` wildcard. Examples -------- ``` SELECT JSON_KEYS('{"A": 1, "B": {"C": 2}}'); +--------------------------------------+ | JSON_KEYS('{"A": 1, "B": {"C": 2}}') | +--------------------------------------+ | ["A", "B"] | +--------------------------------------+ SELECT JSON_KEYS('{"A": 1, "B": 2, "C": {"D": 3}}', '$.C'); +-----------------------------------------------------+ | JSON_KEYS('{"A": 1, "B": 2, "C": {"D": 3}}', '$.C') | +-----------------------------------------------------+ | ["D"] | +-----------------------------------------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb ABS ABS === Syntax ------ ``` ABS(X) ``` Description ----------- Returns the absolute (non-negative) value of `X`. If `X` is not a number, it is converted to a numeric type. Examples -------- ``` SELECT ABS(42); +---------+ | ABS(42) | +---------+ | 42 | +---------+ SELECT ABS(-42); +----------+ | ABS(-42) | +----------+ | 42 | +----------+ SELECT ABS(DATE '1994-01-01'); +------------------------+ | ABS(DATE '1994-01-01') | +------------------------+ | 19940101 | +------------------------+ ``` See Also -------- * [SIGN()](../sign/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb myisamchk myisamchk ========= myisamchk is a commandline tool for checking, repairing and optimizing non-partitioned [MyISAM](../myisam/index) tables. myisamchk is run from the commandline as follows: ``` myisamchk [OPTIONS] tables[.MYI] ``` The full list of options are listed below. One or more MyISAM tables can be specified. MyISAM tables have an associated .MYI index file, and the table name can either be specified with or without the .MYI extension. Referencing it with the extension allows you to use wildcards, so it's possible to run myisamchk on *all* the MyISAM tables in the database with `*.MYI`. The path to the files must also be specified if they're not in the current directory. myisamchk should not be run while anyone is accessing any of the affected tables. It is also best to make a backup before running. With no options, myisamchk simply checks your table as the default operation. The following options can be set while passed as commandline options to myisamchk, or set with a [myisamchk] section in your [my.cnf](../configuring-mariadb-with-mycnf/index) file. General Options --------------- | Option | Description | | --- | --- | | -H, --HELP | Display help and exit. Options are presented in a single list. | | -?, --help | Display help and exit. Options are grouped by type of operation. | | -debug=options, -# options | Write a debugging log. A typical debug\_options string is ´d:t:o,file\_name´. The default is ´d:t:o,/tmp/myisamchk.trace´. (Available in debug builds only) | | -t path, --tmpdir=path | Path for temporary files. Multiple paths can be specified, separated by colon (:) on Unix and semicolon (;) on Windows. They will be used in a round-robin fashion. If not set, the TMPDIR environment variable is used. | | -s, --silent | Only print errors. One can use two -s (-ss) to make myisamchk very silent. | | -v, --verbose | Print more information. This can be used with --description and --check. Use many -v for more verbosity. | | -V, --version | Print version and exit. | | -w, --wait | If table is locked, wait instead of returning an error. | | --print-defaults | Print the program argument list and exit. | | --no-defaults | Don't read default options from any option file. | | --defaults-file=filename | Only read default options from the given file *filename*, which can be the full path, or the path relative to the current directory. | | --defaults-extra-file=filename | Read the file *filename*, which can be the full path, or the path relative to the current directory, after the global files are read. | | --defaults-group-suffix=str | Also read groups with a suffix of *str*. For example, `--defaults-group-suffix=x` would read the groups [myisamchk] and [myisamchk\_x] | The following variables can also be set by using *--var\_name=value*, for example *--ft\_min\_word\_len=5* | Variable | Default Value | | --- | --- | | decode\_bits | 9 | | ft\_max\_word\_len | version-dependent | | ft\_min\_word\_len | 4 | | ft\_stopword\_file | built-in list | | key\_buffer\_size | 1044480 | | key\_cache\_block\_size | 1024 | | myisam\_block\_size | 1024 | | myisam\_sort\_buffer\_size | 134216704 | | myisam\_sort\_key\_blocks | 16 | | read\_buffer\_size | 262136 | | sort\_buffer\_size | 134216704 | | sort\_key\_blocks | 16 | | stats\_method | nulls\_unequal | | write\_buffer\_size | 262136 | Checking Tables --------------- If no option is provided, myisamchk will perform a check table. It is possible to check [MyISAM](../myisam/index) tables without shutting down or restricting access to the server by using [CHECK TABLE](../check-table/index) instead. The following check options are available: | Option | Description | | --- | --- | | -c, --check | Check table for errors. This is the default operation if you specify no option that selects an operation type explicitly. | | -e, --extend-check | Check the table VERY throughly. Only use this in extreme cases as it may be slow, and myisamchk should normally be able to find out if the table has errors even without this switch. Increasing the *key\_buffer\_size* can help speed the process up. | | -F, --fast | Check only tables that haven't been closed properly. | | -C, --check-only-changed | Check only tables that have changed since last check. | | -f, --force | Restart with '-r' (recover) if there are any errors in the table. States will be updated as with '--update-state'. | | -i, --information | Print statistics information about the table that is checked. | | -m, --medium-check | Faster than *extend-check*, but only finds 99.99% of all errors. Should be good enough for most cases. | | -U --update-state | Mark tables as crashed if you find any errors. This should be used to get the full benefit of the *--check-only-changed* option, but you shouldn´t use this option if the mysqld server is using the table and you are running it with external locking disabled. | | -T, --read-only | Don't mark table as checked. This is useful if you use myisamchk to check a table that is in use by some other application that does not use locking, such as mysqld when run with external locking disabled. | Repairing Tables ---------------- It is also possible to repair [MyISAM](../myisam/index) tables by using [REPAIR TABLE](../repair-table/index). The following repair options are available, and are applicable when using '-r' or '-o': | Option | Description | | --- | --- | | -B, --backup | Make a backup of the .MYD file as 'filename-time.BAK'. | | --correct-checksum | Correct the checksum information for table. | | -D len, --data-file-length=# | Max length of data file (when recreating data file when it's full). | | -e, --extend-check | Try to recover every possible row from the data file. Normally this will also find a lot of garbage rows; Don't use this option if you are not totally desperate. | | -f, --force | Overwrite old temporary files. Add another --force to avoid 'myisam\_sort\_buffer\_size is too small' errors. In this case we will attempt to do the repair with the given myisam\_sort\_buffer\_size and dynamically allocate as many management buffers as needed. | | -k val, --keys-used=# | Specify which keys to update. The value is a bit mask of which keys to use. Each binary bit corresponds to a table index, with the first index being bit 0. *0* disables all index updates, useful for faster inserts. Deactivated indexes can be reactivated by using *myisamchk -r*. | | --create-missing-keys | Create missing keys. This assumes that the data file is correct and that the number of rows stored in the index file is correct. Enables *--quick* | | --max-record-length=# | Skip rows larger than this if myisamchk can't allocate memory to hold them. | | -r, --recover | Can fix almost anything except unique keys that aren't unique (a rare occurrence). Usually this is the best option to try first. Increase *myisam\_sort\_buffer\_size* for better performance. | | -n, --sort-recover | Forces recovering with sorting even if the temporary file would be very large. | | -p, --parallel-recover | Uses the same technique as '-r' and '-n', but creates all the keys in parallel, in different threads. | | -o, --safe-recover | Uses old recovery method; Slower than '-r' but uses less disk space and can handle a couple of cases where '-r' reports that it can't fix the data file. Increase *key\_buffer\_size* for better performance. | | --character-sets-dir=directory\_name | Directory where the [character sets](../data-types-character-sets-and-collations/index) are installed. | | --set-collation=name | Change the collation (and by implication, the [character set](../data-types-character-sets-and-collations/index)) used by the index. | | -q, --quick | Faster repair by not modifying the data file. One can give a second '-q' to force myisamchk to modify the original datafile in case of duplicate keys. NOTE: Tables where the data file is corrupted can't be fixed with this option. | | -u, --unpack | Unpack file packed with myisampack. | Other Actions ------------- | Option | Description | | --- | --- | | -a, --analyze | Analyze distribution of keys. Will make some joins faster as the join optimizer can better choose the order in which to join the tables and which indexes to use. You can check the calculated distribution by using '--description --verbose table\_name' or [SHOW INDEX FROM table\_name](../show-index/index). | | --stats\_method=name | Specifies how index statistics collection code should treat NULLs. Possible values of *name* are "nulls\_unequal" (default), "nulls\_equal" (emulate MySQL 4.0 behavior), and "nulls\_ignored". | | -d, --description | Print some descriptive information about the table. Specifying the *--verbose* option once or twice produces additional information. | | -A [value], --set-auto-increment[=value] | Force auto\_increment to start at this or higher value. If no value is given, then sets the next auto\_increment value to the highest used value for the auto key + 1. | | -S, --sort-index | Sort the index tree blocks in high-low order. This optimizes seeks and makes table scans that use indexes faster. | | -R index\_num, --sort-records=# | Sort records according to the given index (as specified by the index number). This makes your data much more localized and may speed up range-based SELECTs and ORDER BYs using this index. It may be VERY slow to do a sort the first time! To see the index numbers, [SHOW INDEX](../show-index/index) displays table indexes in the same order that myisamchk sees them. The first index is 1. | | -b offset, --block-search=offset | Find the record to which a block at the given *offset* belongs. | For more, see [Memory and Disk Use With myisamchk](../memory-and-disk-use-with-myisamchk/index). Examples -------- Check all the MyISAM tables in the current directory: ``` myisamchk *.MYI ``` If you are not in the database directory, you can check all the tables there by specifying the path to the directory: ``` myisamchk /path/to/database_dir/*.MYI ``` Check all tables in all databases by specifying a wildcard with the path to the MariaDB data directory: ``` myisamchk /path/to/datadir/*/*.MYI ``` The recommended way to quickly check all MyISAM tables: ``` myisamchk --silent --fast /path/to/datadir/*/*.MYI ``` Check all MyISAM tables and repair any that are corrupted: ``` myisamchk --silent --force --fast --update-state \ --key_buffer_size=64M --sort_buffer_size=64M \ --read_buffer_size=1M --write_buffer_size=1M \ /path/to/datadir/*/*.MYI ``` See Also -------- * [Memory and Disk Use With myisamchk](../memory-and-disk-use-with-myisamchk/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Selectively Skipping Replication of Binlog Events Selectively Skipping Replication of Binlog Events ================================================= The terms *master* and *slave* have historically been used in replication, but the terms terms *primary* and *replica* are now preferred. The old terms are used still used in parts of the documentation, and in MariaDB commands, although [MariaDB 10.5](../what-is-mariadb-105/index) has begun the process of renaming. The documentation process is ongoing. See [MDEV-18777](https://jira.mariadb.org/browse/MDEV-18777) to follow progress on this effort. Normally, all changes that are logged as events in the [binary log](../binary-log/index) are also replicated to all slaves (though still subject to filtering by [replicate-do-db](../replication-and-binary-log-system-variables/index#replicate_do_db), [replicate-ignore-db](../replication-and-binary-log-system-variables/index#replicate_ignore_db), and similar options). However, sometimes it may be desirable to have certain events be logged into the binlog, but not be replicated to all or a subset of slaves, where the distinction between events that should be replicated or not is under the control of the application making the changes. This could be useful if an application does some replication external to the server outside of the built-in replication, or if it has some data that should not be replicated for whatever reason. This is possible with the following [system variables](../server-system-variables/index). Master Session Variable: skip\_replication ------------------------------------------ When the [skip\_replication](../replication-and-binary-log-server-system-variables/index#skip_replication) variable is set to true, changes are logged into the [binary log](../binary-log/index) with the flag `@@skip_replication` set. Such events will not be replicated by slaves that run with `--replicate-events-marked-for-skip` set different from its default of `REPLICATE`. | | | | --- | --- | | Variable Name | `skip_replication` | | Scope | Session only | | Access Type | Dynamic | | Data Type | `bool` | | Default Value | `OFF` | The `skip_replication` option only has effect if [binary logging](../binary-log/index) is enabled and [sql\_log\_bin](../replication-and-binary-log-server-system-variables/index#skip_replication) is true. Attempting to change `@@skip_replication` in the middle of a transaction will fail; this is to avoid getting half of a transaction replicated while the other half is not replicated. Be sure to end any current transaction with `COMMIT`/`ROLLBACK` before changing the variable. Slave Option: --replicate-events-marked-for-skip ------------------------------------------------ The [replicate\_events\_marked\_for\_skip](../replication-and-binary-log-server-system-variables/index#replicate_events_marked_for_skip) option tells the slave whether to replicate events that are marked with the `@@skip_replication` flag. Default is `REPLICATE`, to ensure that all changes are replicated to the slave. If set to `FILTER_ON_SLAVE`, events so marked will be skipped on the slave and not replicated. If set to `FILTER_ON_MASTER`, the filtering will be done on the master, saving on network bandwidth as the events will not be received by the slave at all. | | | | --- | --- | | Variable Name | `replicate_events_marked_for_skip` | | Scope | Global | | Access Type | Dynamic | | Data Type | enum: `REPLICATE` `|` `FILTER_ON_SLAVE` `|` `FILTER_ON_MASTER` | | Default Value | `REPLICATE` | **Note:** `replicate_events_marked_for_skip` is a dynamic variable (it can be changed without restarting the server), however the slave threads must be stopped when it is changed, otherwise an error will be thrown. When events are filtered due to `@@skip_replication`, the filtering happens on the master side; in other words, the event is never sent to the slave. If many events are filtered like this, a slave can sit a long time without receiving any events from the master. This is not a problem in itself, but must be kept in mind when inquiring on the slave about events that are filtered. For example `START SLAVE UNTIL <some position>` will stop when the first event that is **not** filtered is encountered at the given position or beyond. If the event at the given position is filtered, then the slave thread will only stop when the next non-filtered event is encountered. In effect, if an event is filtered, to the slave it appears that it was never written to the binlog on the master. Note that when events are filtered for a slave, the data in the database will be different on the slave and on the master. It is the responsibility of the application to replicate the data outside of the built-in replication or otherwise ensure consistency of operation. If this is not done, it is possible for replication to encounter, for example, `[UNIQUE](../constraint_type-unique-constraint/index)` contraint violations or other problems which will cause replication to stop and require manual intervention to fix. The session variable `@@skip_replication` can be changed without requiring special privileges. This makes it possible for normal applications to control it without requiring `SUPER` privileges. But it must be kept in mind when using slaves with `--replicate-events-marked-for-skip` set different from `REPLICATE`, as it allows any connection to do changes that are not replicated. skip\_replication and sql\_log\_bin ----------------------------------- `[@@sql\_log\_bin](../set-sql_log_bin/index)` and `@@skip_replication` are somewhat related, as they can both be used to prevent a change on the master from being replicated to the slave. The difference is that with `@@skip_replication`, changes are still written into the binlog, and replication of the events is only skipped on slaves that explicitly are configured to do so, with `--replicate-events-marked-for-skip` different from `REPLICATE`. With `@@sql_log_bin`, events are not logged into the binlog, and so are not replicated by any slave. skip\_replication and the Binlog -------------------------------- When events in the binlog are marked with the `@@skip_replication` flag, the flag will be preserved if the events are dumped by the `[mysqlbinlog](../mysqlbinlog/index)` program and re-applied against a server with the `[mysql client](../mysql-command-line-client/index)` program. Similarly, the `[BINLOG](../binlog/index)` statement will preserve the flag from the event being replayed. And a slave which runs with `--log-slave-updates` and does not filter events (`--replicate-events-marked-for-skip=REPLICATE`) will also preserve the flag in the events logged into the binlog on the slave. See Also -------- * [Using SQL\_SLAVE\_SKIP\_COUNTER](../set-global-sql_slave_skip_counter/index) - How to skip a number of events on the slave Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Plans for 10.1 Plans for 10.1 ============== **Note:** This page is obsolete. The information is old, outdated, or otherwise currently incorrect. We are keeping the page for historical reasons only. **Do not** rely on the information in this article. We manage our development plans in Jira. [This search](https://mariadb.atlassian.net/issues/?jql=project+%3D+MDEV+AND+issuetype+%3D+Task+AND+fixVersion+in+%2810.1.0%2C+10.1%29+ORDER+BY+priority+DESC) shows what we **currently** plan for 10.1. It shows all tasks with the **Fix-Version** being 10.1. Not all these tasks will really end up in 10.1, but tasks with the "red" priorities (, , and ) have a much higher chance of being done in time for 10.1. Practically, you can think of these tasks as "features that **will** be in 10.1". Tasks with the "green" priorities ( and ) probably won't be in 10.1. Think of them as "bonus features that would be **nice to have** in 10.1". Although, as you can see, some of these tasks are already Closed, that is, they are already in 10.1. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb ROW_COUNT ROW\_COUNT ========== Syntax ------ ``` ROW_COUNT() ``` Description ----------- ROW\_COUNT() returns the number of rows updated, inserted or deleted by the preceding statement. This is the same as the row count that the mysql client displays and the value from the [mysql\_affected\_rows()](../mysql_affected_rows/index) C API function. Generally: * For statements which return a result set (such as [SELECT](../select/index), [SHOW](../show/index), [DESC](../describe/index) or [HELP](../help-command/index)), returns -1, even when the result set is empty. This is also true for administrative statements, such as [OPTIMIZE](../optimize-table/index). * For DML statements other than [SELECT](../select/index) and for [ALTER TABLE](../alter/index), returns the number of affected rows. * For DDL statements (including [TRUNCATE](../truncate/index)) and for other statements which don't return any result set (such as [USE](../use/index), [DO](../do/index), [SIGNAL](../signal/index) or [DEALLOCATE PREPARE](../deallocate-drop-prepared-statement/index)), returns 0. For [UPDATE](../update/index), affected rows is by default the number of rows that were actually changed. If the CLIENT\_FOUND\_ROWS flag to [mysql\_real\_connect()](../mysql_real_connect/index) is specified when connecting to mysqld, affected rows is instead the number of rows matched by the WHERE clause. For [REPLACE](../replace/index), deleted rows are also counted. So, if REPLACE deletes a row and adds a new row, ROW\_COUNT() returns 2. For [INSERT ... ON DUPLICATE KEY](../insert-on-duplicate-key-update/index), updated rows are counted twice. So, if INSERT adds a new rows and modifies another row, ROW\_COUNT() returns 3. ROW\_COUNT() does not take into account rows that are not directly deleted/updated by the last statement. This means that rows deleted by foreign keys or triggers are not counted. **Warning:** You can use ROW\_COUNT() with prepared statements, but you need to call it after EXECUTE, not after [DEALLOCATE PREPARE](../deallocate-drop-prepared-statement/index), because the row count for allocate prepare is always 0. **Warning:** When used after a [CALL](../call/index) statement, this function returns the number of rows affected by the last statement in the procedure, not by the whole procedure. **Warning:** After [INSERT DELAYED](../insert-delayed/index), ROW\_COUNT() returns the number of the rows you tried to insert, not the number of the successful writes. This information can also be found in the [diagnostics area](../diagnostics-area/index). Statements using the ROW\_COUNT() function are not [safe for replication](../unsafe-statements-for-replication/index). Examples -------- ``` CREATE TABLE t (A INT); INSERT INTO t VALUES(1),(2),(3); SELECT ROW_COUNT(); +-------------+ | ROW_COUNT() | +-------------+ | 3 | +-------------+ DELETE FROM t WHERE A IN(1,2); SELECT ROW_COUNT(); +-------------+ | ROW_COUNT() | +-------------+ | 2 | +-------------+ ``` Example with prepared statements: ``` SET @q = 'INSERT INTO t VALUES(1),(2),(3);'; PREPARE stmt FROM @q; EXECUTE stmt; Query OK, 3 rows affected (0.39 sec) Records: 3 Duplicates: 0 Warnings: 0 SELECT ROW_COUNT(); +-------------+ | ROW_COUNT() | +-------------+ | 3 | +-------------+ ``` See Also -------- * [FOUND\_ROWS()](../found_rows/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Database Design Phase 5: Operation Database Design Phase 5: Operation ================================== This article follows on from [Database Design Phase 4: Testing](../database-design-phase-4-testing/index). The operation phase takes place when the testing is complete and the database is ready to be rolled out for everyday use. The users of the system begin to operate the system, load data, read reports and so on. Inevitably, problems come to light. The designers need to carefully manage the database's scope at this stage, as users may expect all their desires to be pandered to. Poor database designers may find themselves extending the project well beyond their initial time estimate, and the situation may also become unpleasant if the scope has not been clearly defined and agreed upon. Project owners will feel wronged if their needs are not met, and the database designers will feel overworked and underpaid. Even when scope has been well managed, there will always be new requirements, These then lead to the next stage. There are numerous strategies for implementing a rollout. The low-key approach often works well, where the relatively low number of users in the early stage make bug fixing easy. Hugely publicized rollouts often end with egg on the stakeholder's faces, as the best testers of all, the users, invariably find unforeseen bugs, which is best done away from the spotlight. Alternatively, rollouts can occur in a distributed manner, where a pilot branch or office is selected, and when the system has proven its stability, it's rolled out to the remaining branches. The following are the steps in the operation phase: 1. Hand over operation of the database to the users. 2. Make any final changes based on the problems discovered by users. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb mariadb-upgrade mariadb-upgrade =============== **MariaDB starting with [10.4.6](https://mariadb.com/kb/en/mariadb-1046-release-notes/)**From [MariaDB 10.4.6](https://mariadb.com/kb/en/mariadb-1046-release-notes/), `mariadb-upgrade` is a symlink to `mysql_upgrade`, the tool that checks and updates your tables to the latest version. **MariaDB starting with [10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/)**From [MariaDB 10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/), `mysql_upgrade` is the symlink, and `mariadb-upgrade` the binary name. See [mysql\_upgrade](../mysql_upgrade/index) for details. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Buildbot Setup for Virtual Machines Buildbot Setup for Virtual Machines ==================================== This section documents the exact steps used to set up each virtual machine used in the MariaDB Buildbot for building packages and testing. There are lots of boring details, but the information here should be useful for reference, and as a help when installing new virtual images for additional distros and versions. The articles here document how the virtual machine images were actually set up, not the most efficient way to recreate all of them. Thus, some historical artifacts remain, reflecting the order they were initially added and lessons learned along the way. For example, the steps for the earliest VMs are somewhat overly enthusiastic about using the `qemu-img create -b` option to make one vm a copy-on-write copy on top of another image. This makes it harder to modify the images afterwards, since if the base image is modified, any copy-on-write vm on top of it needs to be re-created. The descriptions do not go into painful detail about the installation procedure. Generally the .iso for the distro was downloaded, and the default, non-graphical installer started. Installing Linux these days is quite easy, and generally just defaults were picked. With respect to harddisk partitioning, generally an 8Gb image was configured, of which 1/2 Gb was reserved for swap and the rest for a single root partition "/". For details on setting up a host server to run these VMs, see [Buildbot Setup for VM host](../buildbot-setup-for-vm-host/index). | Title | Description | | --- | --- | | [Buildbot Setup for Virtual Machines - General Principles](../buildbot-setup-for-virtual-machines-general-principles/index) | The installations are kept minimal, picking mostly default options. This h... | ### [Buildbot Setup for Virtual Machines - Ubuntu](../buildbot-setup-for-virtual-machines-ubuntu/index) | Title | Description | | --- | --- | | [Buildbot Setup for Virtual Machines - Ubuntu 14.04 "trusty"](../buildbot-setup-for-virtual-machines-ubuntu-1404-trusty/index) | Base install qemu-img create -f qcow2 /kvm/vms/vm-trusty-amd64-seri | | [Buildbot Setup for Virtual Machines - Ubuntu 13.10 "saucy"](../buildbot-setup-for-virtual-machines-ubuntu-1310-saucy/index) | Base install qemu-img create -f qcow2 /kvm/vms/vm-saucy-amd64-seria | | [Buildbot Setup for Virtual Machines - Ubuntu 13.04 "raring"](../buildbot-setup-for-virtual-machines-ubuntu-1304-raring/index) | Base install qemu-img create -f qcow2 /kvm/vms/vm-raring-amd64-seri | | [Buildbot Setup for Virtual Machines - Ubuntu 12.10 "quantal"](../buildbot-setup-for-virtual-machines-ubuntu-1210-quantal/index) | Base install qemu-img create -f qcow2 /kvm/vms/vm-quantal-amd64-ser | | [Buildbot Setup for Virtual Machines - Ubuntu 12.04 "precise"](../buildbot-setup-for-virtual-machines-ubuntu-1204-precise/index) | Base install qemu-img create -f qcow2 /kvm/vms/vm-precise-amd64-ser | | [Buildbot Setup for Virtual Machines - Ubuntu 11.10 "oneiric"](../buildbot-setup-for-virtual-machines-ubuntu-1110-oneiric/index) | Base install qemu-img create -f qcow2 /kvm/vms/vm-oneiric-amd64-ser | | [Buildbot Setup for Virtual Machines - Ubuntu 11.04 "natty"](../buildbot-setup-for-virtual-machines-ubuntu-1104-natty/index) | Base install qemu-img create -f qcow2 vm-natty-amd64-serial.qcow2 8G | | [Buildbot Setup for Virtual Machines - Ubuntu 10.10 "maverick"](../buildbot-setup-for-virtual-machines-ubuntu-1010-maverick/index) | Base install qemu-img create -f qcow2 vm-maverick-amd64-serial.qcow2 | | [Buildbot Setup for Virtual Machines - Ubuntu 10.04 (alpha), i386 and amd64](../buildbot-setup-for-virtual-machines-ubuntu-1004-alpha-i386-and-amd64/index) | Base install qemu-img create -f qcow2 vm-lucid-amd64-serial.qcow2 8G | | [Buildbot Setup for Virtual Machines - Ubuntu 9.04 i386](../buildbot-setup-for-virtual-machines-ubuntu-904-i386/index) | This vm is used to build source tarball and for Ubuntu 9.04 32-bit .deb. Fi... | | [Buildbot Setup for Virtual Machines - Ubuntu 9.04 amd64](../buildbot-setup-for-virtual-machines-ubuntu-904-amd64/index) | Base install qemu-img create -f qcow2 vm-jaunty-amd64-serial.qcow2 8 | | [Buildbot Setup for Virtual Machines - Ubuntu 8.04, 8.10, and 9.10](../buildbot-setup-for-virtual-machines-ubuntu-804-810-and-910/index) | These 6 platforms were installed together (i386 and amd64). Base installs U... | ### [Buildbot Setup for Virtual Machines - Debian](../buildbot-setup-for-virtual-machines-debian/index) | Title | Description | | --- | --- | | [Buildbot Setup for Virtual Machines - Debian 7 "wheezy"](../buildbot-setup-for-virtual-machines-debian-7-wheezy/index) | Base install qemu-img create -f qcow2 /kvm/vms/vm-wheezy-amd64-seri | | [Buildbot Setup for Virtual Machines - Debian 6 amd64](../buildbot-setup-for-virtual-machines-debian-6-amd64/index) | Create the VM: cd /kvm/vms qemu-img create -f qcow2 vm-debian6-amd64 | | [Buildbot Setup for Virtual Machines - Debian 6 i386](../buildbot-setup-for-virtual-machines-debian-6-i386/index) | Base Install cd /kvm/vms qemu-img create -f qcow2 vm-debian6-i386-se | | [Buildbot Setup for Virtual Machines - Debian 5 amd64](../buildbot-setup-for-virtual-machines-debian-5-amd64/index) | Download netinst CD image debian-503-amd64-netinst.iso cd /kvm/vms q | | [Buildbot Setup for Virtual Machines - Debian 5 i386](../buildbot-setup-for-virtual-machines-debian-5-i386/index) | Base install Download netinst CD image debian-503-i386-netinst.iso and inst... | | [Buildbot Setup for Virtual Machines - Debian 4 i386](../buildbot-setup-for-virtual-machines-debian-4-i386/index) | Create the VM: cd /kvm/vms qemu-img create -f qcow2 vm-debian4-i386- | | [Buildbot Setup for Virtual Machines - Debian 4 amd64](../buildbot-setup-for-virtual-machines-debian-4-amd64/index) | cd /kvm/vms qemu-img create -f qcow2 vm-debian4-amd64-serial.qcow2 8 | ### [Buildbot Setup for Virtual Machines - Red Hat](../buildbot-setup-for-virtual-machines-red-hat/index) | Title | Description | | --- | --- | | [Buildbot Setup for Virtual Machines - Fedora 20](../buildbot-setup-for-virtual-machines-fedora-20/index) | Base install qemu-img create -f qcow2 /kvm/vms/vm-fedora20-i386-ser | | [Buildbot Setup for Virtual Machines - Fedora 19](../buildbot-setup-for-virtual-machines-fedora-19/index) | Base install qemu-img create -f qcow2 /kvm/vms/vm-fedora19-i386-ser | | [Buildbot Setup for Virtual Machines - Fedora 18](../buildbot-setup-for-virtual-machines-fedora-18/index) | Base install qemu-img create -f qcow2 /kvm/vms/vm-fedora18-i386-ser | | [Buildbot Setup for Virtual Machines - Fedora 17](../buildbot-setup-for-virtual-machines-fedora-17/index) | Base install qemu-img create -f qcow2 /kvm/vms/vm-fedora17-i386-ser | | [Buildbot Setup for Virtual Machines - Fedora 16](../buildbot-setup-for-virtual-machines-fedora-16/index) | Base install qemu-img create -f qcow2 /kvm/vms/vm-fedora16-i386-ser | | [Buildbot Setup for Virtual Machines - CentOS 6.2](../buildbot-setup-for-virtual-machines-centos-62/index) | Base install qemu-img create -f qcow2 /kvm/vms/vm-centos6-amd64-ser | | [Buildbot Setup for Virtual Machines - Red Hat 6 x86](../buildbot-setup-for-virtual-machines-red-hat-6-x86/index) | The following steps were used to create a Red Hat 6 x86 buildslave. Initial Setup cd vms q | | [Buildbot Setup for Virtual Machines - CentOS 5 i386](../buildbot-setup-for-virtual-machines-centos-5-i386/index) | Base install cd /kvm qemu-img create -f qcow2 vms/vm-centos5-i386-ba | | [Buildbot Setup for Virtual Machines - Centos 5 amd64](../buildbot-setup-for-virtual-machines-centos-5-amd64/index) | Base install cd /kvm wget http://ftp.klid.dk/ftp/centos/5.3/isos/x86 | ### [Buildbot Setup for Virtual Machines - Additional Steps](../buildbot-setup-for-virtual-machines-additional-steps/index) | Title | Description | | --- | --- | | [Installing the Boost library needed for the OQGraph storage engine](../installing-the-boost-library-needed-for-the-oqgraph-storage-engine/index) | The OQGraph storage engine needs a newer version of Boost that what is avai... | | [Installing VM images for testing .deb upgrade between versions](../installing-vm-images-for-testing-deb-upgrade-between-versions/index) | This step creates virtual machine images used to do an important additional... | | [Install Cassandra on Fulltest VMs](../install-cassandra-on-fulltest-vms/index) | CassandraSE is no longer actively being developed and has been removed in M... | | [Install cmake on build VMs](../install-cmake-on-build-vms/index) | MariaDB 5.5 Requires cmake. Install cmake on all -build VMs (and other Unix... | | [Installing correct libraries for PAM and readline](../installing-correct-libraries-for-pam-and-readline/index) | Some additional/alternative libraries needs to be installed to handle readl... | | [Resizing a Virtual Machine Image](../resizing-a-virtual-machine-image/index) | Some KVM images end up not having enough space on them. In such cases, it i... | | [Update Debian 4 mirrors for Buildbot VMs](../update-debian-4-mirrors-for-buildbot-vms/index) | Debian 4 has become so old that the apt repository has been moved out of th... | ### Other Buildbot Setup for Virtual Machines Articles | Title | Description | | --- | --- | | [Buildbot Setup for Virtual Machines - FreeBSD 9.2](../buildbot-setup-for-virtual-machines-freebsd-92/index) | Base install qemu-img create -f qcow2 /kvm/vms/vm-freebsd92-amd64-s | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Securing MariaDB Securing MariaDB ================= This section is about securing your MariaDB installation. If you are looking for the list of security vulnerabilities fixed in MariaDB, see [Security Vulnerabilities Fixed in MariaDB](../cve/index). There are a number of issues to consider when looking at improving the security of your MariaDB installation. These include: | Title | Description | | --- | --- | | [Encryption](../securing-mariadb-encryption/index) | MariaDB supports encryption for data while at rest and while in transit. | | [Running mysqld as root](../running-mysqld-as-root/index) | MariaDB should never normally be run as root | | [mysql\_secure\_installation](../mysql_secure_installation/index) | Improve the security of a MariaDB installation. | | [SecuRich](../securich/index) | Library of security-related stored procedures. | | [SELinux](../selinux/index) | Security-Enhanced Linux (SELinux) is a Linux kernel module that provides a ... | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Spider Functions Spider Functions ================= The following [UDFs](../user-defined-functions/index) are available with the [Spider Storage Engine](../spider/index). | Title | Description | | --- | --- | | [SPIDER\_BG\_DIRECT\_SQL](../spider_bg_direct_sql/index) | Background SQL execution | | [SPIDER\_COPY\_TABLES](../spider_copy_tables/index) | Copy table data | | [SPIDER\_DIRECT\_SQL](../spider_direct_sql/index) | Execute SQL on the remote server | | [SPIDER\_FLUSH\_TABLE\_MON\_CACHE](../spider_flush_table_mon_cache/index) | Refreshing Spider monitoring server information | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Uploading Package to PPA Uploading Package to PPA ======================== After creating a Launchpad account: #### Docker build, cloning the MariaDB repository and mapping it to the docker container 1. mkdir mariadb-source 2. cd mariadb-source 3. vi Dockerfile 4. Copy the following contents to Dockerfile: ``` # MariaDB 10.3 Ubuntu 17.10 build environment # Published as mariadb-10-3-ubuntu-17.10-build-env FROM ubuntu:17.10 RUN DEBIAN_FRONTEND=noninteractive apt-get update && \ apt-get install -y --no-install-recommends \ systemd \ devscripts \ build-essential \ lsb-release \ equivs \ git \ curl \ git-buildpackage \ nano \ vim \ pristine-tar RUN curl -skO https://raw.githubusercontent.com/ottok/mariadb-10.1/ubuntu-17.10/debian/control ENV GIT_SSL_NO_VERIFY true RUN mk-build-deps -t 'apt-get -y -o Debug::pkgProblemResolver=yes --no-install-recommends' -i control ENV container docker ENV DEBIAN_FRONTEND noninteractive ENV LANG C.UTF-8 ENV LC_ALL C.UTF-8 ``` 5. Run `docker build . -t ubuntu-17.10-packaging` 6. Do git clone of the latest repository: `cd && mkdir debian-packaging && cd debian-packaging && git clone https://salsa.debian.org/mariadb-team/mariadb-10.1.git` #### Generate, publish and upload PGP key 7. Generate OpenPGP key with the following command: `$ gpg --gen-key` * select (1) RSA and RSA * Keysize: accept 2048 * Valid for: accept 0 * Type name, email and comment (comment is optional) * Type 0 * Type passphrase (twice) * Follow instructions to help generate a random key * Keep the Key ID and fingerprint text, they are needed in the next step Set generated key as default in `~/.bashrc` `$ nano ~/.bashrc` [.. add this ..] `export GPGKEY=<key_id>` Restart GPG-agent and source '/.bashrc', or restart session 8. Publish the key to the key server: `gpg --keyserver keyserver.ubuntu.com --send-keys 12345678` and substitute `12345678` with your key's id * If this gives timeout error, keep re-trying after a while 9. Upload the key's fingerprint here: Upload <https://help.launchpad.net/YourAccount/ImportingYourPGPKey> fingerprint here <https://launchpad.net/~rsurve/+editpgpkeys> 10. `gpg --export [your-key-id] > ~/debian-packaging/pub.key` 11. `gpg --export-secret-key [your-key-id] > ~/debian-packaging/secret.key` `gpg -k` ^Should show the key 12. How to upload: <https://github.com/exelearning/iteexe/wiki/How-to-upload-to-Launchpad-PPA-repository-(.deb-packages)> 13. Open `/etc/devscripts.conf` And look for this line: `DEBSIGN_MAINT` Uncomment it and add your name there `export DEBEMAIL=[your-email-id]` #### From inside the container 14. `docker run -v ~/debian-packaging/:/repo -it ubuntu-17.10-packaging bash` 15. `apt-get install devscripts` 16. `gpg --import pub.key` 17. `gpg --import secret.key` 18. `gpg -k` 19. `cd /repo/mariadb-10.1 && git fetch && git checkout pristine-tar && git checkout ubuntu-17.10` 20. `git clean -dffx && git reset --hard HEAD` 21. `export DEB_BUILD_OPTIONS="parallel=10 nocheck"` or `export DEB_BUILD_OPTIONS="parallel=5 nocheck"` 22. Go to `/repo` folder (Inside docker) and delete all the files except mariadb-10.1 folder: `rm *` 23. `gbp buildpackage` #### For re-running the set up container 24. To generate an ID, run: `docker commit <container-id>` This will generate an ID. For restarting the same container again use this ID: `docker run -v ~/debian-packaging/:/repo -it <ID> bash` 25. Last command for uploading package to PPA: `backportpackage -u <your-ppa-address> -d <ubuntu-version-to-backport-to> -S ~<a-version-suffix-name-for-this-package> <the-most-recent-dsc-file>` Example: `backportpackage -u ppa:cvicentiu/mariadb-10.0-dev2 -d bionic -S ~testtry mariadb-10.1_10.1.30-0ubuntu0.17.10.1.dsc` Run this command in the `/repo` folder, where the `.dsc` file is located It should ask for the gpg key password again * Docker tutorial available here: <https://docs.google.com/presentation/d/1euJrK7MJ9QRvwW33iwESIEo5Dyi7JWExIKFrISktFao/edit#slide=id.p4> Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb MariaDB 5.3 Optimizer Debugging MariaDB 5.3 Optimizer Debugging =============================== [MariaDB 5.3](../what-is-mariadb-53/index) has an optimizer debugging patch. The patch is pushed into [lp:maria-captains/maria/5.3-optimizer-debugging](https://code.launchpad.net/~maria-captains/maria/5.3-optimizer-debugging) The patch is wrapped in #ifdef, but there is a #define straight in mysql\_priv.h so simply compiling that tree should produce a binary with optimizer debugging enabled. The patch adds two system variables: * `@@debug_optimizer_prefer_join_prefix` * `@@debug_optimizer_dupsweedout_penalized` the variables are present as session/global variables, and are also settable via the server command line. debug\_optimizer\_prefer\_join\_prefix -------------------------------------- If this variable is non-NULL, it is assumed to specify a join prefix as a comma-separated list of table aliases: ``` set debug_optimizer_prefer_join_prefix='tbl1,tbl2,tbl3'; ``` The optimizer will try its best to build a join plan which matches the specified join prefix. It does this by comparing join prefixes it is considering with `@@debug_optimizer_prefer_join_prefix`, and multiplying cost by a million if the plan doesn't match the prefix. As a result, you can more-or-less control the join order. For example, let's take this query: ``` MariaDB [test]> explain select * from ten A, ten B, ten C; +----+-------------+-------+------+---------------+------+---------+------+------+------------------------------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+-------+------+---------------+------+---------+------+------+------------------------------------+ | 1 | SIMPLE | A | ALL | NULL | NULL | NULL | NULL | 10 | | | 1 | SIMPLE | B | ALL | NULL | NULL | NULL | NULL | 10 | Using join buffer (flat, BNL join) | | 1 | SIMPLE | C | ALL | NULL | NULL | NULL | NULL | 10 | Using join buffer (flat, BNL join) | +----+-------------+-------+------+---------------+------+---------+------+------+------------------------------------+ 3 rows in set (0.00 sec) ``` and request a join order of C,A,B: ``` MariaDB [test]> set debug_optimizer_prefer_join_prefix='C,A,B'; Query OK, 0 rows affected (0.00 sec) MariaDB [test]> explain select * from ten A, ten B, ten C; +----+-------------+-------+------+---------------+------+---------+------+------+------------------------------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+-------+------+---------------+------+---------+------+------+------------------------------------+ | 1 | SIMPLE | C | ALL | NULL | NULL | NULL | NULL | 10 | | | 1 | SIMPLE | A | ALL | NULL | NULL | NULL | NULL | 10 | Using join buffer (flat, BNL join) | | 1 | SIMPLE | B | ALL | NULL | NULL | NULL | NULL | 10 | Using join buffer (flat, BNL join) | +----+-------------+-------+------+---------------+------+---------+------+------+------------------------------------+ 3 rows in set (0.00 sec) ``` We got it. Note that this is still a *best-effort* approach: * you won't be successful in forcing join orders which the optimizer considers invalid (e.g. for "t1 LEFT JOIN t2" you won't be able to get a join order of t2,t1). * The optimizer does various plan pruning and may discard the requested join order before it has a chance to find out that it is a million-times cheaper than any other. ### Semi-joins It is possible to force the join order of joins plus semi-joins. This may cause a different strategy to be used: ``` MariaDB [test]> set debug_optimizer_prefer_join_prefix=NULL; Query OK, 0 rows affected (0.00 sec) MariaDB [test]> explain select * from ten A where a in (select B.a from ten B, ten C where C.a + A.a < 4); +----+-------------+-------+------+---------------+------+---------+------+------+----------------------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+-------+------+---------------+------+---------+------+------+----------------------------+ | 1 | PRIMARY | A | ALL | NULL | NULL | NULL | NULL | 10 | | | 1 | PRIMARY | B | ALL | NULL | NULL | NULL | NULL | 10 | Using where | | 1 | PRIMARY | C | ALL | NULL | NULL | NULL | NULL | 10 | Using where; FirstMatch(A) | +----+-------------+-------+------+---------------+------+---------+------+------+----------------------------+ 3 rows in set (0.00 sec) MariaDB [test]> set debug_optimizer_prefer_join_prefix='C,A,B'; Query OK, 0 rows affected (0.00 sec) MariaDB [test]> explain select * from ten A where a in (select B.a from ten B, ten C where C.a + A.a < 4); +----+-------------+-------+------+---------------+------+---------+------+------+-------------------------------------------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+-------+------+---------------+------+---------+------+------+-------------------------------------------------+ | 1 | PRIMARY | C | ALL | NULL | NULL | NULL | NULL | 10 | Start temporary | | 1 | PRIMARY | A | ALL | NULL | NULL | NULL | NULL | 10 | Using where; Using join buffer (flat, BNL join) | | 1 | PRIMARY | B | ALL | NULL | NULL | NULL | NULL | 10 | Using where; End temporary | +----+-------------+-------+------+---------------+------+---------+------+------+-------------------------------------------------+ 3 rows in set (0.00 sec) ``` Semi-join materialization is a somewhat special case, because "join prefix" is not exactly what you see in the EXPLAIN output. For semi-join materialization: * don't put "`<subqueryN>`" into `@@debug_optimizer_prefer_join_prefix` * instead, put all of the materialization tables into the place where you want the `<subqueryN>` line. * Attempts to control the join order inside the materialization nest will be unsuccessful. Example: we want A-C-B-AA: ``` MariaDB [test]> set debug_optimizer_prefer_join_prefix='A,C,B,AA'; Query OK, 0 rows affected (0.00 sec) MariaDB [test]> explain select * from ten A, ten AA where A.a in (select B.a from ten B, ten C); +----+-------------+-------------+--------+---------------+--------------+---------+------+------+------------------------------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+-------------+--------+---------------+--------------+---------+------+------+------------------------------------+ | 1 | PRIMARY | A | ALL | NULL | NULL | NULL | NULL | 10 | | | 1 | PRIMARY | <subquery2> | eq_ref | distinct_key | distinct_key | 5 | func | 1 | | | 1 | PRIMARY | AA | ALL | NULL | NULL | NULL | NULL | 10 | Using join buffer (flat, BNL join) | | 2 | SUBQUERY | B | ALL | NULL | NULL | NULL | NULL | 10 | | | 2 | SUBQUERY | C | ALL | NULL | NULL | NULL | NULL | 10 | | +----+-------------+-------------+--------+---------------+--------------+---------+------+------+------------------------------------+ 5 rows in set (0.00 sec) ``` but we get A-B-C-AA. debug\_optimizer\_dupsweedout\_penalized ---------------------------------------- There are four semi-join execution strategies: 1. `FirstMatch` 2. `Materialization` 3. `LooseScan` 4. `DuplicateWeedout` The first three strategies have flags in @@optimizer\_switch that can be used to disable them. The `DuplicateWeedout` strategy does not have a flag. This was done for a reason, as that strategy is the catch-all strategy and it can handle all kinds of subqueries, in all kinds of join orders. (We're slowly moving to the point where it will be possible to run with `FirstMatch` enabled and everything else disabled but we are not there yet.) Since `DuplicateWeedout` cannot be disabled, there are cases where it "gets in the way" by being chosen over the strategy you need. This is what `debug_optimizer_dupsweedout_penalized` is for. if you set: ``` MariaDB [test]> set debug_optimizer_dupsweedout_penalized=TRUE; ``` ...the costs of query plans that use `DuplicateWeedout` will be multiplied by a millon. This doesn't mean that you will get rid of `DuplicateWeedout` — due to [Bug #898747](https://bugs.launchpad.net/bugs/898747) it is still possible to have `DuplicateWeedout` used even if a cheaper plan exits. A partial remedy to this is to run with ``` MariaDB [test]> set optimizer_prune_level=0; ``` It is possible to use both `debug_optimizer_dupsweedout_penalized` and `debug_optimizer_prefer_join_prefix` at the same time. This should give you the desired strategy and join order. Further reading --------------- * See mysql-test/t/debug\_optimizer.test (in the MariaDB source code) for examples Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Doing Time with MariaDB Doing Time with MariaDB ======================= The recording of date and time in a MariaDB database is a very common requirement. For gathering temporal data, one needs to know which type of columns to use in a table. More importantly is knowing how to record chronological data and how to retrieve it in various formats. Although this is a seemingly basic topic, there are many built-in time functions that can be used for more accurate SQL statements and better formatting of data. In this article we will explore these various aspects of how to do time with MariaDB. #### About Time Since date and time are only numeric strings, they can be stored in a regular character column. However, by using temporal data type columns, you can make use of several built-in functions offered by MariaDB. Currently, there are five temporal data types available: `DATE`, `TIME`, `DATETIME`, `TIMESTAMP`, and `YEAR`. The `DATE` column type is for recording the date only and is basically in this format: `yyyy-mm-dd`. The `TIME` column type is for recording time in this format: `hhh:mm:ss`. To record a combination of date and time, there is the `DATETIME` column type: `yyyy-mm-dd hh:mm:ss`. The `TIMESTAMP` column is similar to `DATETIME`, but it's a little limited in its range of allowable time. It starts at the Unix epoc time (i.e., 1970-01-01) and ends at the end of 2037. Finally, the `YEAR` data type is for recording only the year in a column: `yy` or `yyyy`. For the examples in this article, `DATE`, `TIME`, and `DATETIME` columns will be used. The database that will be referenced is for a fictitious psychiatry practice that keeps track of its patients and billable hours in MariaDB. #### Telling Time To record the current date and time in a MariaDB table, there are a few built-in functions that may be used. First, to record the date there are the functions [CURRENT\_DATE](../current_date/index) and [CURDATE( )](../curdate/index) (depending on your style), which both produce the same results (e.g., 2017-08-01). Notice that [CURDATE( )](../curdate/index) requires parentheses and the other does not. With many functions a column name or other variables are placed inside of the parentheses to get a result. With functions like [CURDATE( )](../curdate/index), there is nothing that may go inside the parenthesis. Since these two functions retrieve the current date in the format of the `DATE` column type, they can be used to fill in a `DATE` column when inserting a row: ``` INSERT INTO billable_work (doctor_id, patient_id, session_date) VALUES('1021', '1256', CURRENT_DATE); ``` The column *session\_date* is a `DATE` column. Notice that there are no quotes around the date function. If there were it would be taken as a literal value rather than a function. Incidentally, I've skipped discussing how the table was set up. If you're not familiar with how to set up a table, you may want to read the [MariaDB Basics](../mariadb-basics/index) article. To see what was just recorded by the [INSERT](../insert/index) statement above, the following may be entered (results follow): ``` SELECT rec_id, doctor_id, patient_id, session_date FROM billable_work WHERE rec_id=LAST_INSERT_ID(); +--------+-----------+------------+--------------+ | rec_id | doctor_id | patient_id | session_date | +--------+-----------+------------+--------------+ | 2462 | 1021 | 1256 | 2017-08-23 | +--------+-----------+------------+--------------+ ``` Notice in the billable\_work table that the primary key column (i.e., `rec_id`) is an automatically generated and incremental number column (i.e., `AUTO_INCREMENT`). As long as another record is not created or the user does not exit from the mysql client or otherwise end the session, the [LAST\_INSERT\_ID( )](../last_insert_id/index) function will retrieve the value of the `rec_id` for the last record entered by the user. To record the time of an appointment for a patient in a time data type column, [CURRENT\_TIME](../current_time/index) or [CURTIME( )](../curtime/index) are used in the same way to insert the time. The following is entered to update the row created above to mark the starting time of the appointment—another [SELECT](../select/index) statement follows with the results: ``` UPDATE billable_work SET session_time=CURTIME() WHERE rec_id='2462'; SELECT patient_id, session_date, session_time FROM billable_work WHERE rec_id='2462'; +------------+--------------+--------------+ | patient_id | session_date | session_time | +------------+--------------+--------------+ | 1256 | 2017-08-23 | 10:30:23 | +------------+--------------+--------------+ ``` The column session\_time is a time column. To record the date and time together in the same column, [CURRENT\_TIMESTAMP](../current_timestamp/index) or [SYSDATE( )](../sysdate/index) or [NOW( )](../now/index) can be used. All three functions produce the same time format: `yyyy-mm-dd hh:mm:ss`. Therefore, the column's data type would have to be `DATETIME` to use them. #### How to get a Date Although MariaDB records the date in a fairly agreeable format, you may want to present the date when it's retrieved in a different format. Or, you may want to extract part of the date, such as only the day of the month. There are many functions for reformatting and selectively retrieving date and time information. To start off with, let's select a column with a data type of `DATE` and look at the functions available for retrieving each component. To extract the year, there's the [YEAR( )](../year/index) function. For extracting just the month, the [MONTH( )](../month/index) function could be called upon. And to grab the day of the month, [DAYOFMONTH( )](../dayofmonth/index) will work. Using the record entered above, here's what an SQL statement and its results would look like in which the session date is broken up into separate parts, but in a different order: ``` SELECT MONTH(session_date) AS Month, DAYOFMONTH(session_date) AS Day, YEAR(session_date) AS Year FROM billable_work WHERE rec_id='2462'; +-------+------+------+ | Month | Day | Year | +-------+------+------+ | 8 | 23 | 2017 | +-------+------+------+ ``` For those who aren't familiar with the keyword `AS`, it's used to label a column's output and may be referenced within an SQL statement. Splitting up the elements of a date can be useful in analyzing a particular element. If the bookkeeper of the fictitious psychiatry office needed to determine if the day of the week of each session was on a Saturday because the billing rate would be higher (time and a half), the [DAYOFWEEK( )](../dayofweek/index) function could be used. To spice up the examples, let's wrap the date function up in an [IF( )](../if-function/index) function that tests for the day of the week and sets the billing rate accordingly. ``` SELECT patient_id AS 'Patient ID', session_date AS 'Date of Session', IF(DAYOFWEEK(session_date)=6, 1.5, 1.0) AS 'Billing Rate' FROM billable_work WHERE rec_id='2462'; +-------------+-----------------+--------------+ | Patient ID | Date of Session | Billing Rate | +-------------+-----------------+--------------+ | 1256 | 2017-08-23 | 1.5 | +-------------+-----------------+--------------+ ``` Since we've slipped in the [IF( )](../if-function/index) function, we should explain it's format. The test condition is listed first within the parentheses. In this case, the test is checking if the session date is the sixth day of the week. Then, what MariaDB should display is given if the test passes, followed by the result if it fails. Similar to the [DAYOFWEEK( )](../dayofweek/index) function, there's also [WEEKDAY( )](../weekday/index). The only difference is that for [DAYOFWEEK( )](../dayofweek/index) the first day of the week is Sunday—with [WEEKDAY( )](../weekday/index) the first day is Monday. Both functions represent the first day with 0 and the last with `6`. Having *Saturday* and *Sunday* symbolized by `5` and `6` can be handy in constructing an IF statement that has a test component like "`WEEKDAY(*session\_date*) > 4`" to determine if a date is a weekend day. This is cleaner than testing for values of `0` and `6`. There is a function for determining the day of the year: [DAYOFYEAR( )](../dayofyear/index). It's not used often, but it is available if you ever need it. Occasionally, though, knowing the quarter of a year for a date can be useful for financial accounting. Rather than set up a formula in a script to determine the quarter, the [QUARTER( )](../quarter/index) function can do this easily. For instance, suppose an accountant wants a list of a doctor's sessions for each patient for the previous quarter. These three SQL statements could be entered in sequence to achieve the results that follow: ``` SET @LASTQTR:=IF((QUARTER(CURDATE())-1)=0, 4, QUARTER(CURDATE())-1); SET @YR:=IF(@LASTQTR=4, YEAR(NOW())-1, YEAR(NOW())); SELECT patient_id AS 'Patient ID', COUNT(session_time) AS 'Number of Sessions' FROM billable_work WHERE QUARTER(session_date) = @LASTQTR AND YEAR(session_date) = @YR AND doctor_id='1021' GROUP BY patient_id ORDER BY patient_id LIMIT 5; +------------+--------------------+ | Patient ID | Number of Sessions | +------------+--------------------+ | 1104 | 10 | | 1142 | 7 | | 1203 | 18 | | 1244 | 6 | | 1256 | 12 | +------------+--------------------+ ``` This example is the most complicated so far. But it's not too difficult to understand if we pull it apart. The first SQL statement sets up a user variable containing the previous quarter (i.e., 1, 2, 3, or 4). This variable will be needed in the other two statements. The [IF( )](../if-function/index) clause in the first statement checks if the quarter of the current date minus one is zero. It will equal zero when it's run during the first quarter of a year. During a first quarter, of course, the previous quarter is the fourth quarter of the previous year. So, if the equation equals zero, then the variable `@LASTQTR` is set to `4`. Otherwise, `@LASTQTR` is set to the value of the current quarter minus one. The second statement is necessary to ensure that the records for the correct year are selected. So, if `@LASTQTR` equals four, then `@YR` needs to equal last year. If not, `@YR` is set to the current year. With the user variables set to the correct quarter and year, the [SELECT](../select/index) statement can be entered. The [COUNT( )](../count/index) function counts the number of appointments that match the `WHERE` clause for each patient based on the [GROUP BY](../select/index#group-by) clause. The `WHERE` clause looks for sessions with a quarter that equals `@LASTQTR` and a year that equals `@YR`, as well as the doctor's identification number. In summary, what we end up with is a set of SQL statements that retrieve the desired information regardless of which quarter or year it's entered. #### What is the Time? The last section covered how to retrieve pieces of a date column. Now let's look at how to do the same with a time column. To extract just the hour of a time saved in MariaDB, the [HOUR( )](../hour/index) function could be used. For the minute and second, there's [MINUTE( )](../minute/index) and [SECOND( )](../second/index). Let's put them all together in one straightforward [SELECT](../select/index) statement: ``` SELECT HOUR(session_time) AS Hour, MINUTE(session_time) AS Minute, SECOND(session_time) AS Second FROM billable_work WHERE rec_id='2462'; +------+--------+--------+ | Hour | Minute | Second | +------+--------+--------+ | 10 | 30 | 00 | +------+--------+--------+ ``` #### Date & Time Combined All of the examples given so far have involved separate columns for date and time. The [EXTRACT( )](../extract/index) function, however, will allow a particular component to be extracted from a combined column type (i.e., `DATETIME` or `TIMESTAMP`). The format is `EXTRACT(*date\_type* FROM *date\_column*)` where *date\_type* is the component to retrieve and *date\_column* is the name of the column from which to extract data. To extract the year, the *date\_type* would be `YEAR`; for month, `MONTH` is used; and for day, there's `DAY`. To extract time elements, `HOUR` is used for hour, `MINUTE` for minute, and `SECOND` for second. Although that's all pretty simple, let's look at an example. Suppose the table billable\_work has a column called `appointment` (a `datetime` column) that contains the date and time for which the appointment was scheduled (as opposed to the time it actually started in `session_time`). To get the hour and minute for a particular date, the following SQL statement will suffice: ``` SELECT patient_name AS Patient, EXTRACT(HOUR FROM appointment) AS Hour, EXTRACT(MINUTE FROM appointment) AS Minute FROM billable_work, patients WHERE doctor_id='1021' AND EXTRACT(MONTH FROM appointment)='8' AND EXTRACT(DAY FROM appointment)='30' AND billable_work.patient_id = patients.patient_id; ``` This statement calls upon another table (`patients`) which holds patient information such as their names. It requires a connecting point between the tables (i.e., the `patient_id` from each table). If you're confused on how to form relationships between tables in a [SELECT](../select/index) statement, you may want to go back and read the [Getting Data from MariaDB](../getting-data-from-mariadb/index) article. The SQL statement above would be used to retrieve the appointments for one doctor for one day, giving results like this: ``` +-------------------+------+--------+ | Patient | Hour | Minute | +-------------------+------+--------+ | Michael Zabalaoui | 10 | 00 | | Jerry Neumeyer | 11 | 00 | | Richard Stringer | 13 | 30 | | Janice Sogard | 14 | 30 | +-------------------+------+--------+ ``` In this example, the time elements are separated and they don't include the date. With the [EXTRACT( )](../extract/index) function, however, you can also return combined date and time elements. There is `DAY_HOUR` for the day and hour; there's `DAY_MINUTE` for the day, hour, and minute; `DAY_SECOND` for day, hour, minute, and second; and `YEAR_MONTH` for year and month. There are also some time only combinations: `HOUR_MINUTE` for hour and minute; `HOUR_SECOND` for hour, minute, and second; and `MINUTE_SECOND` for minute and second. However, there's not a `MONTH_DAY` to allow the combining of the two extracts in the `WHERE` clause of the last [SELECT](../select/index) statement above. Nevertheless, we'll modify the example above and use the `HOUR_MINUTE` date\_type to retrieve the hour and minute in one resulting column. It would only require the second and third lines to be deleted and replaced with this: ``` ... EXTRACT(HOUR_MINUTE FROM appointment) AS Appointment ... +-------------------+-------------+ | Patient | Appointment | +-------------------+-------------+ | Michael Zabalaoui | 1000 | | Jerry Neumeyer | 1100 | | Richard Stringer | 1330 | | Janice Sogard | 1430 | +-------------------+-------------+ ``` The problem with this output, though, is that the times aren't very pleasing looking. For more natural date and time displays, there are a few simple date formatting functions available and there are the [DATE\_FORMAT( )](../date_format/index) and [TIME\_FORMAT( )](../time_format/index) functions. #### Fine Time Pieces The simple functions that we mentioned are used for reformatting the output of days and months. To get the date of patient sessions for August, but in a more wordier format, [MONTHNAME( )](../monthname/index) and [DAYNAME( )](../dayname/index) could be used: ``` SELECT patient_name AS Patient, CONCAT(DAYNAME(appointment), ' - ', MONTHNAME(appointment), ' ', DAYOFMONTH(appointment), ', ', YEAR(appointment)) AS Appointment FROM billable_work, patients WHERE doctor_id='1021' AND billable_work.patient_id = patients.patient_id AND appointment>'2017-08-01' AND appointment<'2017-08-31' LIMIT 1; +-------------------+-----------------------------+ | Patient | Appointment | +-------------------+-----------------------------+ | Michael Zabalaoui | Wednesday - August 30, 2017 | +-------------------+-----------------------------+ ``` In this statement the [CONCAT( )](../concat/index) splices together the results of several date functions along with spaces and other characters. The [EXTRACT( )](../extract/index) function was eliminated from the `WHERE` clause and instead a simple numeric test for sessions in August was given. Although [EXTRACT( )](../extract/index) is fairly straightforward, this all can be accomplished with less typing by using the [DATE\_FORMAT( )](../date_format/index) function. The [DATE\_FORMAT( )](../date_format/index) function has over thirty options for formatting the date to your liking. Plus, you can combine the options and add your own separators and other text. The syntax is `DATE_FORMAT(date_column, 'options & characters')`. As an example, let's reproduce the last SQL statement by using the [DATE\_FORMAT( )](../date_format/index) function for formatting the date of the appointment and for scanning for appointments in July only: ``` SELECT patient_name AS Patient, DATE_FORMAT(appointment, '%W - %M %e, %Y') AS Appointment FROM billable_work, patients WHERE doctor_id='1021' AND billable_work.patient_id = patients.patient_id AND DATE_FORMAT(appointment, '%c') = 8 LIMIT 1; ``` This produces the exact same output as above, but with a more succinct statement. The option `%W` gives the name of the day of the week. The option `%M` provides the month's name. The option `%e` displays the day of the month (`%d` would work, but it left-pads single-digit dates with zeros). Finally, `%Y` is for the four character year. All other elements within the quotes (i.e., the spaces, the dash, and the comma) are literal characters for a nicer display. With [DATE\_FORMAT( )](../date_format/index), time elements of a field also can be formatted. For instance, suppose we also wanted the hour and minute of the appointment. We would only need to change the second line of the SQL statement above (to save space, patient\_name was eliminated): ``` SELECT DATE_FORMAT(appointment, '%W - %M %e, %Y at %r') AS Appointment ... +--------------------------------------------+ | Appointment | +--------------------------------------------+ | Wednesday - August 30, 2017 at 02:11:19 AM | +--------------------------------------------+ ``` The word at was added along with the formatting option `%r` which gives the time with AM or PM at the end. Although it may be a little confusing at first, once you've learned some of the common formatting options, [DATE\_FORMAT( )](../date_format/index) is much easier to use than [EXTRACT( )](../extract/index). There are many more options to [DATE\_FORMAT( )](../date_format/index) that we haven't mentioned. For a complete list of the options available, see the [DATE\_FORMAT( ) documentation page](../date_format/index). #### Clean up Time In addition to [DATE\_FORMAT( )](../date_format/index), MariaDB has a comparable built-in function for formating only time: [TIME\_FORMAT( )](../time_format/index). The syntax is the same and uses the same options as [DATE\_FORMAT( )](../date_format/index), except only the time related formatting options apply. As an example, here's an SQL statement that a doctor might use at the beginning of each day to get a list of her appointments for the day: ``` SELECT patient_name AS Patient, TIME_FORMAT(appointment, '%l:%i %p') AS Appointment FROM billable_work, patients WHERE doctor_id='1021' AND billable_work.patient_id = patients.patient_id AND DATE_FORMAT(appointment, '%Y-%m-%d') = CURDATE(); +-------------------+-------------+ | Patient | Appointment | +-------------------+-------------+ | Michael Zabalaoui | 10:00 AM | | Jerry Neumeyer | 11:00 AM | | Richard Stringer | 01:30 PM | | Janice Sogard | 02:30 PM | +-------------------+-------------+ ``` The option `%l` provides the hours 01 through 12. The `%p` at the end indicates (with the AM or PM) whether the time is before or after noon. The `%i` option gives the minute. The colon and the space are for additional display appeal. Of course, all of this can be done exactly the same way with the [DATE\_FORMAT( )](../date_format/index) function. As for the [DATE\_FORMAT( )](../date_format/index) component in the WHERE clause here, the date is formatted exactly as it will be with [CURDATE( )](../curdate/index) (i.e., 2017-08-30) so that they may be compared properly. #### Time to End Many developers use PHP, Perl, or some other scripting language with MariaDB. Sometimes developers will solve retrieval problems with longer scripts rather than learn precisely how to extract temporal data with MariaDB. As you can see in several of the examples here (particularly the one using the [QUARTER( )](../quarter/index) function), you can accomplish a great deal within MariaDB. When faced with a potentially complicated SQL statement, try creating it in the mysql client first. Once you get what you need (under various conditions) and in the format desired, then copy the statement into your script. This practice can greatly help you improve your MariaDB statements and scripting code. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb ALTER TABLE ALTER TABLE =========== Syntax ------ ``` ALTER [ONLINE] [IGNORE] TABLE [IF EXISTS] tbl_name [WAIT n | NOWAIT] alter_specification [, alter_specification] ... alter_specification: table_option ... | ADD [COLUMN] [IF NOT EXISTS] col_name column_definition [FIRST | AFTER col_name ] | ADD [COLUMN] [IF NOT EXISTS] (col_name column_definition,...) | ADD {INDEX|KEY} [IF NOT EXISTS] [index_name] [index_type] (index_col_name,...) [index_option] ... | ADD [CONSTRAINT [symbol]] PRIMARY KEY [index_type] (index_col_name,...) [index_option] ... | ADD [CONSTRAINT [symbol]] UNIQUE [INDEX|KEY] [index_name] [index_type] (index_col_name,...) [index_option] ... | ADD FULLTEXT [INDEX|KEY] [index_name] (index_col_name,...) [index_option] ... | ADD SPATIAL [INDEX|KEY] [index_name] (index_col_name,...) [index_option] ... | ADD [CONSTRAINT [symbol]] FOREIGN KEY [IF NOT EXISTS] [index_name] (index_col_name,...) reference_definition | ADD PERIOD FOR SYSTEM_TIME (start_column_name, end_column_name) | ALTER [COLUMN] col_name SET DEFAULT literal | (expression) | ALTER [COLUMN] col_name DROP DEFAULT | ALTER {INDEX|KEY} index_name [NOT] INVISIBLE | CHANGE [COLUMN] [IF EXISTS] old_col_name new_col_name column_definition [FIRST|AFTER col_name] | MODIFY [COLUMN] [IF EXISTS] col_name column_definition [FIRST | AFTER col_name] | DROP [COLUMN] [IF EXISTS] col_name [RESTRICT|CASCADE] | DROP PRIMARY KEY | DROP {INDEX|KEY} [IF EXISTS] index_name | DROP FOREIGN KEY [IF EXISTS] fk_symbol | DROP CONSTRAINT [IF EXISTS] constraint_name | DISABLE KEYS | ENABLE KEYS | RENAME [TO] new_tbl_name | ORDER BY col_name [, col_name] ... | RENAME COLUMN old_col_name TO new_col_name | RENAME {INDEX|KEY} old_index_name TO new_index_name | CONVERT TO CHARACTER SET charset_name [COLLATE collation_name] | [DEFAULT] CHARACTER SET [=] charset_name | [DEFAULT] COLLATE [=] collation_name | DISCARD TABLESPACE | IMPORT TABLESPACE | ALGORITHM [=] {DEFAULT|INPLACE|COPY|NOCOPY|INSTANT} | LOCK [=] {DEFAULT|NONE|SHARED|EXCLUSIVE} | FORCE | partition_options | ADD PARTITION [IF NOT EXISTS] (partition_definition) | DROP PARTITION [IF EXISTS] partition_names | COALESCE PARTITION number | REORGANIZE PARTITION [partition_names INTO (partition_definitions)] | ANALYZE PARTITION partition_names | CHECK PARTITION partition_names | OPTIMIZE PARTITION partition_names | REBUILD PARTITION partition_names | REPAIR PARTITION partition_names | EXCHANGE PARTITION partition_name WITH TABLE tbl_name | REMOVE PARTITIONING | ADD SYSTEM VERSIONING | DROP SYSTEM VERSIONING index_col_name: col_name [(length)] [ASC | DESC] index_type: USING {BTREE | HASH | RTREE} index_option: [ KEY_BLOCK_SIZE [=] value | index_type | WITH PARSER parser_name | COMMENT 'string' | CLUSTERING={YES| NO} ] [ IGNORED | NOT IGNORED ] table_options: table_option [[,] table_option] ... ``` Description ----------- `ALTER TABLE` enables you to change the structure of an existing table. For example, you can add or delete columns, create or destroy indexes, change the type of existing columns, or rename columns or the table itself. You can also change the comment for the table and the storage engine of the table. If another connection is using the table, a [metadata lock](../metadata-locking/index) is active, and this statement will wait until the lock is released. This is also true for non-transactional tables. When adding a `UNIQUE` index on a column (or a set of columns) which have duplicated values, an error will be produced and the statement will be stopped. To suppress the error and force the creation of `UNIQUE` indexes, discarding duplicates, the [IGNORE](../ignore/index) option can be specified. This can be useful if a column (or a set of columns) should be UNIQUE but it contains duplicate values; however, this technique provides no control on which rows are preserved and which are deleted. Also, note that `IGNORE` is accepted but ignored in `ALTER TABLE ... EXCHANGE PARTITION` statements. This statement can also be used to rename a table. For details see [RENAME TABLE](../rename-table/index). When an index is created, the storage engine may use a configurable buffer in the process. Incrementing the buffer speeds up the index creation. [Aria](../aria/index) and [MyISAM](../myisam/index) allocate a buffer whose size is defined by [aria\_sort\_buffer\_size](../aria-system-variables/index#aria_sort_buffer_size) or [myisam\_sort\_buffer\_size](../myisam-system-variables/index#myisam_sort_buffer_size), also used for [REPAIR TABLE](../repair-table/index). [InnoDB](../innodb/index) allocates three buffers whose size is defined by [innodb\_sort\_buffer\_size](../innodb-system-variables/index#innodb_sort_buffer_size). Privileges ---------- Executing the `ALTER TABLE` statement generally requires at least the [ALTER](../grant/index#table-privileges) privilege for the table or the database.. If you are renaming a table, then it also requires the [DROP](../grant/index#table-privileges), [CREATE](../grant/index#table-privileges) and [INSERT](../grant/index#table-privileges) privileges for the table or the database as well. Online DDL ---------- Online DDL is supported with the [ALGORITHM](#algorithm) and [LOCK](#lock) clauses. See [InnoDB Online DDL Overview](../innodb-online-ddl-overview/index) for more information on online DDL with [InnoDB](../innodb/index). ### ALTER ONLINE TABLE ALTER ONLINE TABLE also works for partitioned tables. Online `ALTER TABLE` is available by executing the following: ``` ALTER ONLINE TABLE ...; ``` This statement has the following semantics: This statement is equivalent to the following: ``` ALTER TABLE ... LOCK=NONE; ``` See the [LOCK](#lock) alter specification for more information. This statement is equivalent to the following: ``` ALTER TABLE ... ALGORITHM=INPLACE; ``` See the [ALGORITHM](#algorithm) alter specification for more information. WAIT/NOWAIT ----------- **MariaDB starting with [10.3.0](https://mariadb.com/kb/en/mariadb-1030-release-notes/)**Set the lock wait timeout. See [WAIT and NOWAIT](../wait-and-nowait/index). IF EXISTS --------- The `IF EXISTS` and `IF NOT EXISTS` clauses are available for the following: ``` ADD COLUMN [IF NOT EXISTS] ADD INDEX [IF NOT EXISTS] ADD FOREIGN KEY [IF NOT EXISTS] ADD PARTITION [IF NOT EXISTS] CREATE INDEX [IF NOT EXISTS] DROP COLUMN [IF EXISTS] DROP INDEX [IF EXISTS] DROP FOREIGN KEY [IF EXISTS] DROP PARTITION [IF EXISTS] CHANGE COLUMN [IF EXISTS] MODIFY COLUMN [IF EXISTS] DROP INDEX [IF EXISTS] ``` When `IF EXISTS` and `IF NOT EXISTS` are used in clauses, queries will not report errors when the condition is triggered for that clause. A warning with the same message text will be issued and the ALTER will move on to the next clause in the statement (or end if finished). **MariaDB starting with [10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/)**If this is directive is used after `ALTER ... TABLE`, one will not get an error if the table doesn't exist. Column Definitions ------------------ See [CREATE TABLE: Column Definitions](../create-table/index#column-definitions) for information about column definitions. Index Definitions ----------------- See [CREATE TABLE: Index Definitions](../create-table/index#index-definitions) for information about index definitions. The [CREATE INDEX](../create-index/index) and [DROP INDEX](../drop-index/index) statements can also be used to add or remove an index. Character Sets and Collations ----------------------------- ``` CONVERT TO CHARACTER SET charset_name [COLLATE collation_name] [DEFAULT] CHARACTER SET [=] charset_name [DEFAULT] COLLATE [=] collation_name ``` See [Setting Character Sets and Collations](../setting-character-sets-and-collations/index) for details on setting the [character sets and collations](../character-sets/index). Alter Specifications -------------------- ### Table Options See [CREATE TABLE: Table Options](../create-table/index#table-options) for information about table options. ### ADD COLUMN ``` ... ADD COLUMN [IF NOT EXISTS] (col_name column_definition,...) ``` Adds a column to the table. The syntax is the same as in [CREATE TABLE](../create-table/index). If you are using `IF NOT_EXISTS` the column will not be added if it was not there already. This is very useful when doing scripts to modify tables. The `FIRST` and `AFTER` clauses affect the physical order of columns in the datafile. Use `FIRST` to add a column in the first (leftmost) position, or `AFTER` followed by a column name to add the new column in any other position. Note that, nowadays, the physical position of a column is usually irrelevant. See also [Instant ADD COLUMN for InnoDB](../instant-add-column-for-innodb/index). ### DROP COLUMN ``` ... DROP COLUMN [IF EXISTS] col_name [CASCADE|RESTRICT] ``` Drops the column from the table. If you are using `IF EXISTS` you will not get an error if the column didn't exist. If the column is part of any index, the column will be dropped from them, except if you add a new column with identical name at the same time. The index will be dropped if all columns from the index were dropped. If the column was used in a view or trigger, you will get an error next time the view or trigger is accessed. **MariaDB starting with [10.2.8](https://mariadb.com/kb/en/mariadb-1028-release-notes/)**Dropping a column that is part of a multi-column `UNIQUE` constraint is not permitted. For example: ``` CREATE TABLE a ( a int, b int, primary key (a,b) ); ALTER TABLE x DROP COLUMN a; [42000][1072] Key column 'A' doesn't exist in table ``` The reason is that dropping column `a` would result in the new constraint that all values in column `b` be unique. In order to drop the column, an explicit `DROP PRIMARY KEY` and `ADD PRIMARY KEY` would be required. Up until [MariaDB 10.2.7](https://mariadb.com/kb/en/mariadb-1027-release-notes/), the column was dropped and the additional constraint applied, resulting in the following structure: ``` ALTER TABLE x DROP COLUMN a; Query OK, 0 rows affected (0.46 sec) DESC x; +-------+---------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-------+---------+------+-----+---------+-------+ | b | int(11) | NO | PRI | NULL | | +-------+---------+------+-----+---------+-------+ ``` **MariaDB starting with [10.4.0](https://mariadb.com/kb/en/mariadb-1040-release-notes/)**[MariaDB 10.4.0](https://mariadb.com/kb/en/mariadb-1040-release-notes/) supports instant DROP COLUMN. DROP COLUMN of an indexed column would imply [DROP INDEX](../drop-index/index) (and in the case of a non-UNIQUE multi-column index, possibly ADD INDEX). These will not be allowed with [ALGORITHM=INSTANT](#algorithm), but unlike before, they can be allowed with [ALGORITHM=NOCOPY](#algorithm) `RESTRICT` and `CASCADE` are allowed to make porting from other database systems easier. In MariaDB, they do nothing. ### MODIFY COLUMN Allows you to modify the type of a column. The column will be at the same place as the original column and all indexes on the column will be kept. Note that when modifying column, you should specify all attributes for the new column. ``` CREATE TABLE t1 (a INT UNSIGNED AUTO_INCREMENT, PRIMARY KEY((a)); ALTER TABLE t1 MODIFY a BIGINT UNSIGNED AUTO_INCREMENT; ``` ### CHANGE COLUMN Works like `MODIFY COLUMN` except that you can also change the name of the column. The column will be at the same place as the original column and all index on the column will be kept. ``` CREATE TABLE t1 (a INT UNSIGNED AUTO_INCREMENT, PRIMARY KEY(a)); ALTER TABLE t1 CHANGE a b BIGINT UNSIGNED AUTO_INCREMENT; ``` ### ALTER COLUMN This lets you change column options. ``` CREATE TABLE t1 (a INT UNSIGNED AUTO_INCREMENT, b varchar(50), PRIMARY KEY(a)); ALTER TABLE t1 ALTER b SET DEFAULT 'hello'; ``` ### RENAME INDEX/KEY **MariaDB starting with [10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/)**From [MariaDB 10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/), it is possible to rename an index using the `RENAME INDEX` (or `RENAME KEY`) syntax, for example: ``` ALTER TABLE t1 RENAME INDEX i_old TO i_new; ``` ### RENAME COLUMN **MariaDB starting with [10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/)**From [MariaDB 10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/), it is possible to rename a column using the `RENAME COLUMN` syntax, for example: ``` ALTER TABLE t1 RENAME COLUMN c_old TO c_new; ``` ### ADD PRIMARY KEY Add a primary key. For `PRIMARY KEY` indexes, you can specify a name for the index, but it is silently ignored, and the name of the index is always `PRIMARY`. See [Getting Started with Indexes: Primary Key](../getting-started-with-indexes/index#primary-key) for more information. ### DROP PRIMARY KEY Drop a primary key. For `PRIMARY KEY` indexes, you can specify a name for the index, but it is silently ignored, and the name of the index is always `PRIMARY`. See [Getting Started with Indexes: Primary Key](../getting-started-with-indexes/index#primary-key) for more information. ### ADD FOREIGN KEY Add a foreign key. For `FOREIGN KEY` indexes, a reference definition must be provided. For `FOREIGN KEY` indexes, you can specify a name for the constraint, using the `CONSTRAINT` keyword. That name will be used in error messages. First, you have to specify the name of the target (parent) table and a column or a column list which must be indexed and whose values must match to the foreign key's values. The `MATCH` clause is accepted to improve the compatibility with other DBMS's, but has no meaning in MariaDB. The `ON DELETE` and `ON UPDATE` clauses specify what must be done when a `DELETE` (or a `REPLACE`) statements attempts to delete a referenced row from the parent table, and when an `UPDATE` statement attempts to modify the referenced foreign key columns in a parent table row, respectively. The following options are allowed: * `RESTRICT`: The delete/update operation is not performed. The statement terminates with a 1451 error (SQLSTATE '2300'). * `NO ACTION`: Synonym for `RESTRICT`. * `CASCADE`: The delete/update operation is performed in both tables. * `SET NULL`: The update or delete goes ahead in the parent table, and the corresponding foreign key fields in the child table are set to `NULL`. (They must not be defined as `NOT NULL` for this to succeed). * `SET DEFAULT`: This option is implemented only for the legacy PBXT storage engine, which is disabled by default and no longer maintained. It sets the child table's foreign key fields to their `DEFAULT` values when the referenced parent table key entries are updated or deleted. If either clause is omitted, the default behavior for the omitted clause is `RESTRICT`. See [Foreign Keys](../foreign-keys/index) for more information. ### DROP FOREIGN KEY Drop a foreign key. See [Foreign Keys](../foreign-keys/index) for more information. ### ADD INDEX Add a plain index. Plain indexes are regular indexes that are not unique, and are not acting as a primary key or a foreign key. They are also not the "specialized" `FULLTEXT` or `SPATIAL` indexes. See [Getting Started with Indexes: Plain Indexes](../getting-started-with-indexes/index#plain-indexes) for more information. ### DROP INDEX Drop a plain index. Plain indexes are regular indexes that are not unique, and are not acting as a primary key or a foreign key. They are also not the "specialized" `FULLTEXT` or `SPATIAL` indexes. See [Getting Started with Indexes: Plain Indexes](../getting-started-with-indexes/index#plain-indexes) for more information. ### ADD UNIQUE INDEX Add a unique index. The `UNIQUE` keyword means that the index will not accept duplicated values, except for NULLs. An error will raise if you try to insert duplicate values in a UNIQUE index. For `UNIQUE` indexes, you can specify a name for the constraint, using the `CONSTRAINT` keyword. That name will be used in error messages. See [Getting Started with Indexes: Unique Index](../getting-started-with-indexes/index#unique-index) for more information. ### DROP UNIQUE INDEX Drop a unique index. The `UNIQUE` keyword means that the index will not accept duplicated values, except for NULLs. An error will raise if you try to insert duplicate values in a UNIQUE index. For `UNIQUE` indexes, you can specify a name for the constraint, using the `CONSTRAINT` keyword. That name will be used in error messages. See [Getting Started with Indexes: Unique Index](../getting-started-with-indexes/index#unique-index) for more information. ### ADD FULLTEXT INDEX Add a `FULLTEXT` index. See [Full-Text Indexes](../full-text-indexes/index) for more information. ### DROP FULLTEXT INDEX Drop a `FULLTEXT` index. See [Full-Text Indexes](../full-text-indexes/index) for more information. ### ADD SPATIAL INDEX Add a SPATIAL index. See [SPATIAL INDEX](../spatial-index/index) for more information. ### DROP SPATIAL INDEX Drop a SPATIAL index. See [SPATIAL INDEX](../spatial-index/index) for more information. ### ENABLE/ DISABLE KEYS `DISABLE KEYS` will disable all non unique keys for the table for storage engines that support this (at least MyISAM and Aria). This can be used to [speed up inserts](../how-to-quickly-insert-data-into-mariadb/index) into empty tables. `ENABLE KEYS` will enable all disabled keys. ### RENAME TO Renames the table. See also [RENAME TABLE](../rename-table/index). ### ADD CONSTRAINT Modifies the table adding a [constraint](../constraint/index) on a particular column or columns. **MariaDB starting with [10.2.1](https://mariadb.com/kb/en/mariadb-1021-release-notes/)**[MariaDB 10.2.1](https://mariadb.com/kb/en/mariadb-1021-release-notes/) introduced new ways to define a constraint. Note: Before [MariaDB 10.2.1](https://mariadb.com/kb/en/mariadb-1021-release-notes/), constraint expressions were accepted in syntax, but ignored. ``` ALTER TABLE table_name ADD CONSTRAINT [constraint_name] CHECK(expression); ``` Before a row is inserted or updated, all constraints are evaluated in the order they are defined. If any constraint fails, then the row will not be updated. One can use most deterministic functions in a constraint, including [UDF's](../user-defined-functions/index). ``` CREATE TABLE account_ledger ( id INT PRIMARY KEY AUTO_INCREMENT, transaction_name VARCHAR(100), credit_account VARCHAR(100), credit_amount INT, debit_account VARCHAR(100), debit_amount INT); ALTER TABLE account_ledger ADD CONSTRAINT is_balanced CHECK((debit_amount + credit_amount) = 0); ``` The `constraint_name` is optional. If you don't provide one in the `ALTER TABLE` statement, MariaDB auto-generates a name for you. This is done so that you can remove it later using [DROP CONSTRAINT](#drop-constraint) clause. You can disable all constraint expression checks by setting the variable [check\_constraint\_checks](../server-system-variables/index#check_constraint_checks) to `OFF`. You may find this useful when loading a table that violates some constraints that you want to later find and fix in SQL. To view constraints on a table, query [information\_schema.TABLE\_CONSTRAINTS](../information-schema-table_constraints-table/index): ``` SELECT CONSTRAINT_NAME, TABLE_NAME, CONSTRAINT_TYPE FROM information_schema.TABLE_CONSTRAINTS WHERE TABLE_NAME = 'account_ledger'; +-----------------+----------------+-----------------+ | CONSTRAINT_NAME | TABLE_NAME | CONSTRAINT_TYPE | +-----------------+----------------+-----------------+ | is_balanced | account_ledger | CHECK | +-----------------+----------------+-----------------+ ``` ### DROP CONSTRAINT **MariaDB starting with [10.2.22](https://mariadb.com/kb/en/mariadb-10222-release-notes/)**`DROP CONSTRAINT` for `UNIQUE` and `FOREIGN KEY` [constraints](../constraint/index) was introduced in [MariaDB 10.2.22](https://mariadb.com/kb/en/mariadb-10222-release-notes/) and [MariaDB 10.3.13](https://mariadb.com/kb/en/mariadb-10313-release-notes/). **MariaDB starting with [10.2.1](https://mariadb.com/kb/en/mariadb-1021-release-notes/)**`DROP CONSTRAINT` for `CHECK` constraints was introduced in [MariaDB 10.2.1](https://mariadb.com/kb/en/mariadb-1021-release-notes/) Modifies the table, removing the given constraint. ``` ALTER TABLE table_name DROP CONSTRAINT constraint_name; ``` When you add a constraint to a table, whether through a [CREATE TABLE](../create-table/index#constraint-expressions) or [ALTER TABLE...ADD CONSTRAINT](#add-constraint) statement, you can either set a `constraint_name` yourself, or allow MariaDB to auto-generate one for you. To view constraints on a table, query [information\_schema.TABLE\_CONSTRAINTS](../information-schema-table_constraints-table/index). For instance, ``` CREATE TABLE t ( a INT, b INT, c INT, CONSTRAINT CHECK(a > b), CONSTRAINT check_equals CHECK(a = c)); SELECT CONSTRAINT_NAME, TABLE_NAME, CONSTRAINT_TYPE FROM information_schema.TABLE_CONSTRAINTS WHERE TABLE_NAME = 't'; +-----------------+----------------+-----------------+ | CONSTRAINT_NAME | TABLE_NAME | CONSTRAINT_TYPE | +-----------------+----------------+-----------------+ | check_equals | t | CHECK | | CONSTRAINT_1 | t | CHECK | +-----------------+----------------+-----------------+ ``` To remove a constraint from the table, issue an `ALTER TABLE...DROP CONSTRAINT` statement. For example, ``` ALTER TABLE t DROP CONSTRAINT is_unique; ``` ### ADD SYSTEM VERSIONING **MariaDB starting with [10.3.4](https://mariadb.com/kb/en/mariadb-1034-release-notes/)**[System-versioned tables](../system-versioned-tables/index) was added in [MariaDB 10.3.4](https://mariadb.com/kb/en/mariadb-1034-release-notes/). Add system versioning. ### DROP SYSTEM VERSIONING **MariaDB starting with [10.3.4](https://mariadb.com/kb/en/mariadb-1034-release-notes/)**[System-versioned tables](../system-versioned-tables/index) was added in [MariaDB 10.3.4](https://mariadb.com/kb/en/mariadb-1034-release-notes/). Drop system versioning. ### ADD PERIOD FOR SYSTEM\_TIME **MariaDB starting with [10.3.4](https://mariadb.com/kb/en/mariadb-1034-release-notes/)**[System-versioned tables](../system-versioned-tables/index) was added in [MariaDB 10.3.4](https://mariadb.com/kb/en/mariadb-1034-release-notes/). ### FORCE `ALTER TABLE ... FORCE` can force MariaDB to re-build the table. In [MariaDB 5.5](../what-is-mariadb-55/index) and before, this could only be done by setting the [ENGINE](../create-table/index#storage-engine) table option to its old value. For example, for an InnoDB table, one could execute the following: ``` ALTER TABLE tab_name ENGINE = InnoDB; ``` The `FORCE` option can be used instead. For example, : ``` ALTER TABLE tab_name FORCE; ``` With InnoDB, the table rebuild will only reclaim unused space (i.e. the space previously used for deleted rows) if the [innodb\_file\_per\_table](../innodb-system-variables/index#innodb_file_per_table) system variable is set to `ON`. If the system variable is `OFF`, then the space will not be reclaimed, but it will be-re-used for new data that's later added. ### EXCHANGE PARTITION This is used to exchange the tablespace files between a partition and another table. See [copying InnoDB's transportable tablespaces](../innodb-file-per-table-tablespaces/index#copying-transportable-tablespaces) for more information. ### DISCARD TABLESPACE This is used to discard an InnoDB table's tablespace. See [copying InnoDB's transportable tablespaces](../innodb-file-per-table-tablespaces/index#copying-transportable-tablespaces) for more information. ### IMPORT TABLESPACE This is used to import an InnoDB table's tablespace. The tablespace should have been copied from its original server after executing [FLUSH TABLES FOR EXPORT](../flush-tables-for-export/index). See [copying InnoDB's transportable tablespaces](../innodb-file-per-table-tablespaces/index#copying-transportable-tablespaces) for more information. `ALTER TABLE ... IMPORT` only applies to InnoDB tables. Most other popular storage engines, such as Aria and MyISAM, will recognize their data files as soon as they've been placed in the proper directory under the datadir, and no special DDL is required to import them. ### ALGORITHM The `ALTER TABLE` statement supports the `ALGORITHM` clause. This clause is one of the clauses that is used to implement online DDL. `ALTER TABLE` supports several different algorithms. An algorithm can be explicitly chosen for an `ALTER TABLE` operation by setting the `ALGORITHM` clause. The supported values are: * `ALGORITHM=DEFAULT` - This implies the default behavior for the specific statement, such as if no `ALGORITHM` clause is specified. * `ALGORITHM=COPY` * `ALGORITHM=INPLACE` * `ALGORITHM=NOCOPY` - This was added in [MariaDB 10.3.7](https://mariadb.com/kb/en/mariadb-1037-release-notes/). * `ALGORITHM=INSTANT` - This was added in [MariaDB 10.3.7](https://mariadb.com/kb/en/mariadb-1037-release-notes/). See [InnoDB Online DDL Overview: ALGORITHM](../innodb-online-ddl-overview/index#algorithm) for information on how the `ALGORITHM` clause affects InnoDB. #### ALGORITHM=DEFAULT The default behavior, which occurs if `ALGORITHM=DEFAULT` is specified, or if `ALGORITHM` is not specified at all, usually only makes a copy if the operation doesn't support being done in-place at all. In this case, the most efficient available algorithm will usually be used. However, in [MariaDB 10.3.6](https://mariadb.com/kb/en/mariadb-1036-release-notes/) and before, if the value of the [old\_alter\_table](../server-system-variables/index#old_alter_table) system variable is set to `ON`, then the default behavior is to perform `ALTER TABLE` operations by making a copy of the table using the old algorithm. In [MariaDB 10.3.7](https://mariadb.com/kb/en/mariadb-1037-release-notes/) and later, the [old\_alter\_table](../server-system-variables/index#old_alter_table) system variable is deprecated. Instead, the [alter\_algorithm](../server-system-variables/index#alter_algorithm) system variable defines the default algorithm for `ALTER TABLE` operations. #### ALGORITHM=COPY `ALGORITHM=COPY` is the name for the original [ALTER TABLE](index) algorithm from early MariaDB versions. When `ALGORITHM=COPY` is set, MariaDB essentially does the following operations: ``` -- Create a temporary table with the new definition CREATE TEMPORARY TABLE tmp_tab ( ... ); -- Copy the data from the original table INSERT INTO tmp_tab SELECT * FROM original_tab; -- Drop the original table DROP TABLE original_tab; -- Rename the temporary table, so that it replaces the original one RENAME TABLE tmp_tab TO original_tab; ``` This algorithm is very inefficient, but it is generic, so it works for all storage engines. If `ALGORITHM=COPY` is specified, then the copy algorithm will be used even if it is not necessary. This can result in a lengthy table copy. If multiple [ALTER TABLE](index) operations are required that each require the table to be rebuilt, then it is best to specify all operations in a single [ALTER TABLE](index) statement, so that the table is only rebuilt once. #### ALGORITHM=INPLACE `ALGORITHM=COPY` can be incredibly slow, because the whole table has to be copied and rebuilt. `ALGORITHM=INPLACE` was introduced as a way to avoid this by performing operations in-place and avoiding the table copy and rebuild, when possible. When `ALGORITHM=INPLACE` is set, the underlying storage engine uses optimizations to perform the operation while avoiding the table copy and rebuild. However, `INPLACE` is a bit of a misnomer, since some operations may still require the table to be rebuilt for some storage engines. Regardless, several operations can be performed without a full copy of the table for some storage engines. A more accurate name would have been `ALGORITHM=ENGINE`, where `ENGINE` refers to an "engine-specific" algorithm. If an [ALTER TABLE](index) operation supports `ALGORITHM=INPLACE`, then it can be performed using optimizations by the underlying storage engine, but it may rebuilt. See [InnoDB Online DDL Operations with ALGORITHM=INPLACE](../innodb-online-ddl-operations-with-the-inplace-alter-algorithm/index) for more. #### ALGORITHM=NOCOPY `ALGORITHM=NOCOPY` was introduced in [MariaDB 10.3.7](https://mariadb.com/kb/en/mariadb-1037-release-notes/). `ALGORITHM=INPLACE` can sometimes be surprisingly slow in instances where it has to rebuild the clustered index, because when the clustered index has to be rebuilt, the whole table has to be rebuilt. `ALGORITHM=NOCOPY` was introduced as a way to avoid this. If an `ALTER TABLE` operation supports `ALGORITHM=NOCOPY`, then it can be performed without rebuilding the clustered index. If `ALGORITHM=NOCOPY` is specified for an `ALTER TABLE` operation that does not support `ALGORITHM=NOCOPY`, then an error will be raised. In this case, raising an error is preferable, if the alternative is for the operation to rebuild the clustered index, and perform unexpectedly slowly. See [InnoDB Online DDL Operations with ALGORITHM=NOCOPY](../innodb-online-ddl-operations-with-algorithmnocopy/index) for more. #### ALGORITHM=INSTANT `ALGORITHM=INSTANT` was introduced in [MariaDB 10.3.7](https://mariadb.com/kb/en/mariadb-1037-release-notes/). `ALGORITHM=INPLACE` can sometimes be surprisingly slow in instances where it has to modify data files. `ALGORITHM=INSTANT` was introduced as a way to avoid this. If an `ALTER TABLE` operation supports `ALGORITHM=INSTANT`, then it can be performed without modifying any data files. If `ALGORITHM=INSTANT` is specified for an `ALTER TABLE` operation that does not support `ALGORITHM=INSTANT`, then an error will be raised. In this case, raising an error is preferable, if the alternative is for the operation to modify data files, and perform unexpectedly slowly. See [InnoDB Online DDL Operations with ALGORITHM=INSTANT](../innodb-online-ddl-operations-with-algorithminstant/index) for more. ### LOCK The `ALTER TABLE` statement supports the `LOCK` clause. This clause is one of the clauses that is used to implement online DDL. `ALTER TABLE` supports several different locking strategies. A locking strategy can be explicitly chosen for an `ALTER TABLE` operation by setting the `LOCK` clause. The supported values are: * `DEFAULT`: Acquire the least restrictive lock on the table that is supported for the specific operation. Permit the maximum amount of concurrency that is supported for the specific operation. * `NONE`: Acquire no lock on the table. Permit **all** concurrent DML. If this locking strategy is not permitted for an operation, then an error is raised. * `SHARED`: Acquire a read lock on the table. Permit **read-only** concurrent DML. If this locking strategy is not permitted for an operation, then an error is raised. * `EXCLUSIVE`: Acquire a write lock on the table. Do **not** permit concurrent DML. Different storage engines support different locking strategies for different operations. If a specific locking strategy is chosen for an `ALTER TABLE` operation, and that table's storage engine does not support that locking strategy for that specific operation, then an error will be raised. If the `LOCK` clause is not explicitly set, then the operation uses `LOCK=DEFAULT`. [ALTER ONLINE TABLE](alter-online-table) is equivalent to `LOCK=NONE`. Therefore, the [ALTER ONLINE TABLE](alter-online-table) statement can be used to ensure that your `ALTER TABLE` operation allows all concurrent DML. See [InnoDB Online DDL Overview: LOCK](../innodb-online-ddl-overview/index#lock) for information on how the `LOCK` clause affects InnoDB. Progress Reporting ------------------ MariaDB provides progress reporting for `ALTER TABLE` statement for clients that support the new progress reporting protocol. For example, if you were using the [mysql](../mysql-command-line-client/index) client, then the progress report might look like this:: ``` ALTER TABLE test ENGINE=Aria; Stage: 1 of 2 'copy to tmp table' 46% of stage ``` The progress report is also shown in the output of the [SHOW PROCESSLIST](../show-processlist/index) statement and in the contents of the [information\_schema.PROCESSLIST](../information-schema-processlist-table/index) table. See [Progress Reporting](../progress-reporting/index) for more information. Aborting ALTER TABLE Operations ------------------------------- If an `ALTER TABLE` operation is being performed and the connection is killed, the changes will be rolled back in a controlled manner. The rollback can be a slow operation as the time it takes is relative to how far the operation has progressed. **MariaDB starting with [10.2.13](https://mariadb.com/kb/en/mariadb-10213-release-notes/)**Aborting `ALTER TABLE ... ALGORITHM=COPY` was made faster by removing excessive undo logging ([MDEV-11415](https://jira.mariadb.org/browse/MDEV-11415)). This significantly shortens the time it takes to abort a running ALTER TABLE operation. Atomic ALTER TABLE ------------------ **MariaDB starting with [10.6.1](https://mariadb.com/kb/en/mariadb-1061-release-notes/)**From [MariaDB 10.6](../what-is-mariadb-106/index), `ALTER TABLE` is atomic for most engines, including InnoDB, MyRocks, MyISAM and Aria ([MDEV-25180](https://jira.mariadb.org/browse/MDEV-25180)). This means that if there is a crash (server down or power outage) during an `ALTER TABLE` operation, after recovery, either the old table and associated triggers and status will be intact, or the new table will be active. In older MariaDB versions one could get leftover #sql-alter..', '#sql-backup..' or 'table\_name.frm˝' files if the system crashed during the `ALTER TABLE` operation. See [Atomic DDL](../atomic-ddl/index) for more information. Replication ----------- **MariaDB starting with [10.8.0](https://mariadb.com/kb/en/mariadb-1080-release-notes/)**Before [MariaDB 10.8.0](https://mariadb.com/kb/en/mariadb-1080-release-notes/), ALTER TABLE got fully executed on the primary first, and only then was it replicated and started executing on replicas. From [MariaDB 10.8.0](https://mariadb.com/kb/en/mariadb-1080-release-notes/), ALTER TABLE gets replicated and starts executing on replicas when it *starts* executing on the primary, not when it *finishes*. This way the replication lag caused by a heavy ALTER TABLE can be completely eliminated ([MDEV-11675](https://jira.mariadb.org/browse/MDEV-11675)). Examples -------- Adding a new column: ``` ALTER TABLE t1 ADD x INT; ``` Dropping a column: ``` ALTER TABLE t1 DROP x; ``` Modifying the type of a column: ``` ALTER TABLE t1 MODIFY x bigint unsigned; ``` Changing the name and type of a column: ``` ALTER TABLE t1 CHANGE a b bigint unsigned auto_increment; ``` Combining multiple clauses in a single ALTER TABLE statement, separated by commas: ``` ALTER TABLE t1 DROP x, ADD x2 INT, CHANGE y y2 INT; ``` Changing the storage engine and adding a comment: ``` ALTER TABLE t1 ENGINE = InnoDB COMMENT = 'First of three tables containing usage info'; ``` Rebuilding the table (the previous example will also rebuild the table if it was already InnoDB): ``` ALTER TABLE t1 FORCE; ``` Dropping an index: ``` ALTER TABLE rooms DROP INDEX u; ``` Adding a unique index: ``` ALTER TABLE rooms ADD UNIQUE INDEX u(room_number); ``` From [MariaDB 10.5.3](https://mariadb.com/kb/en/mariadb-1053-release-notes/), adding a primary key for an [application-time period table](../application-time-periods/index) with a [WITHOUT OVERLAPS](../application-time-periods/index#without-overlaps) constraint: ``` ALTER TABLE rooms ADD PRIMARY KEY(room_number, p WITHOUT OVERLAPS); ``` See Also -------- * [CREATE TABLE](../create-table/index) * [DROP TABLE](../drop-table/index) * [Character Sets and Collations](../character-sets-and-collations/index) * [SHOW CREATE TABLE](../show-create-table/index) * [Instant ADD COLUMN for InnoDB](../instant-add-column-for-innodb/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb Sequence Storage Engine Sequence Storage Engine ======================= This article is about the Sequence storage engine. For details about sequence objects, see [Sequences](../sequences/index). A **Sequence** engine allows the creation of ascending or descending sequences of numbers (positive integers) with a given starting value, ending value and increment. It creates completely virtual, ephemeral tables automatically when you need them. There is no way to create a Sequence table explicitly. Nor are they ever written to disk or create `.frm` files. They are read-only, [transactional](../transactions/index), and [support XA](../xa-transactions/index). Installing ---------- The Sequence engine is installed by default, and [SHOW ENGINES](../show-engines/index) will list the Sequence storage engine as supported: ``` SHOW ENGINES\G ... *************************** 5. row *************************** Engine: MyISAM Support: YES Comment: MyISAM storage engine Transactions: NO XA: NO Savepoints: NO *************************** 6. row *************************** Engine: SEQUENCE Support: YES Comment: Generated tables filled with sequential values Transactions: YES XA: YES Savepoints: YES *************************** 7. row *************************** Engine: MRG_MyISAM Support: YES Comment: Collection of identical MyISAM tables Transactions: NO XA: NO Savepoints: NO ... ``` Usage and Examples ------------------ To use a Sequence table, you simply select from it, as in ``` SELECT * FROM seq_1_to_5; +-----+ | seq | +-----+ | 1 | | 2 | | 3 | | 4 | | 5 | +-----+ ``` To use a sequence in a statement, you select from the table named by a pattern **seq\_**`FROM`**\_to\_**`TO` or **seq\_**`FROM`**\_to\_**`TO`**\_step\_**`STEP`. In the case of an odd step, the sequence will commence with the `FROM`, and end at the final result before `TO`. ``` SELECT * FROM seq_1_to_15_step_3; +-----+ | seq | +-----+ | 1 | | 4 | | 7 | | 10 | | 13 | +-----+ ``` A sequence can go backwards too. In this case the final value will always be the `TO` value, so that a descending sequence has the same values as an ascending sequence: ``` SELECT * FROM seq_5_to_1_step_2; +-----+ | seq | +-----+ | 5 | | 3 | | 1 | +-----+ ``` ``` SELECT * FROM seq_15_to_1_step_3; +-----+ | seq | +-----+ | 13 | | 10 | | 7 | | 4 | | 1 | +-----+ ``` ``` SELECT * FROM seq_15_to_2_step_3; +-----+ | seq | +-----+ | 14 | | 11 | | 8 | | 5 | | 2 | +-----+ ``` This engine is particularly useful with joins and subqueries. For example, this query finds all prime numbers below 50: ``` SELECT seq FROM seq_2_to_50 s1 WHERE 0 NOT IN (SELECT s1.seq % s2.seq FROM seq_2_to_50 s2 WHERE s2.seq <= sqrt(s1.seq)); +-----+ | seq | +-----+ | 2 | | 3 | | 5 | | 7 | | 11 | | 13 | | 17 | | 19 | | 23 | | 29 | | 31 | | 37 | | 41 | | 43 | | 47 | +-----+ ``` And almost (without 2, the only even prime number) the same result with joins: ``` SELECT s1.seq FROM seq_2_to_50 s1 JOIN seq_2_to_50 s2 WHERE s1.seq > s2.seq AND s1.seq % s2.seq <> 0 GROUP BY s1.seq HAVING s1.seq - COUNT(*) = 2; +-----+ | seq | +-----+ | 3 | | 5 | | 7 | | 11 | | 13 | | 17 | | 19 | | 23 | | 29 | | 31 | | 37 | | 41 | | 43 | | 47 | +-----+ ``` Sequence tables can also be useful in date calculations. For example, to find the day of the week that a particular date has fallen on over a 40 year period (perhaps for birthday planning ahead!): ``` SELECT DAYNAME('1980-12-05' + INTERVAL (seq) YEAR) day, '1980-12-05' + INTERVAL (seq) YEAR date FROM seq_0_to_40; +-----------+------------+ | day | date | +-----------+------------+ | Friday | 1980-12-05 | | Saturday | 1981-12-05 | | Sunday | 1982-12-05 | ... | Friday | 2014-12-05 | | Saturday | 2015-12-05 | | Monday | 2016-12-05 | | Tuesday | 2017-12-05 | | Wednesday | 2018-12-05 | | Thursday | 2019-12-05 | | Saturday | 2020-12-05 | +-----------+------------+ ``` Although Sequence tables can only directly make use of positive integers, they can indirectly be used to return negative results by making use of the [CAST](../cast/index) statement. For example: ``` SELECT CAST(seq AS INT) - 5 x FROM seq_5_to_1; +----+ | x | +----+ | 0 | | -1 | | -2 | | -3 | | -4 | +----+ ``` [CAST](../cast/index) is required to avoid a `BIGINT UNSIGNED value is out of range` error. Sequence tables, while virtual, are still tables, so they must be in a database. This means that a default database must be selected (for example, via the [USE](../use/index) command) to be able to query a Sequence table. The [information\_schema](../information-schema/index) database cannot be used as the default for a Sequence table. Table Name Conflicts -------------------- If the SEQUENCE storage engine is installed, it is not possible to create a table with a name which follows the SEQUENCE pattern: ``` CREATE TABLE seq_1_to_100 (col INT) ENGINE = InnoDB; ERROR 1050 (42S01): Table 'seq_1_to_100' already exists ``` However, a SEQUENCE table can be converted to another engine and the new table can be referred in any statement: ``` ALTER TABLE seq_1_to_100 ENGINE = BLACKHOLE; SELECT * FROM seq_1_to_100; Empty set (0.00 sec) ``` While a SEQUENCE table cannot be dropped, it is possible to drop the converted table. The SEQUENCE table with the same name will still exist: ``` DROP TABLE seq_1_to_100; SELECT COUNT(*) FROM seq_1_to_100; +----------+ | COUNT(*) | +----------+ | 100 | +----------+ 1 row in set (0.00 sec) ``` A temporary table with a SEQUENCE-like name can always be created and used: ``` CREATE TEMPORARY TABLE seq_1_to_100 (col INT) ENGINE = InnoDB; SELECT * FROM seq_1_to_100; Empty set (0.00 sec) ``` Resources --------- * [Sometimes its the little things](https://mariadb.com/blog/sometimes-its-little-things) - Dean Ellis tries out the Sequence engine. * [MariaDB’s Sequence Storage Engine](http://falseisnotnull.wordpress.com/2013/06/23/mariadbs-sequence-storage-engine/) - Federico Razzoli writes more in-depth on the engine. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb MEMORY Storage Engine MEMORY Storage Engine ===================== Contents of the MEMORY storage engine (previously known as HEAP) are stored in memory rather than on disk. It is best-used for read-only caches of data from other tables, or for temporary work areas. Since the data is stored in memory, it is highly vulnerable to power outages or hardware failure, and is unsuitable for permanent data storage. In fact, after a server restart, `MEMORY` tables will be recreated (because the definition file is stored on disk), but they will be empty. It is possible to re-populate them with a query using the `--init-file` server startup option. Variable-length types like `[VARCHAR](../varchar/index)` can be used in MEMORY tables. `[BLOB](../blob/index)` or `[TEXT](../text/index)` columns are not supported for MEMORY tables. The maximum total size of MEMORY tables cannot exceed the `[max\_heap\_table\_size](../server-system-variables/index#max_heap_table_size)` system server variable. When a table is created this value applies to that table, and when the server is restarted this value applies to existing tables. Changing this value has no effect on existing tables. However, executing a `ALTER TABLE ... ENGINE=MEMORY` statement applies the current value of `max_heap_table_size` to the table. Also, it is possible to change the session value of `max_heap_table_size` before creating a table, to make sure that tables created by other sessions are not affected. The `MAX_ROWS` table option provides a hint about the number of rows you plan to store in them. This is not a hard limit that cannot be exceeded, and does not allow to exceed `max_heap_table_size`. The storage engine uses max\_heap\_table\_size and MAX\_ROWS to calculate the maximum memory that could be allocated for the table. When rows are deleted, space is not automatically freed. The only way to free space without dropping the table is using `ALTER TABLE tbl_name ENGINE = MEMORY`. `[TRUNCATE TABLE](../truncate-table/index)` frees the memory too. Index Type ---------- The MEMORY storage engine permits indexes to be either B-tree or Hash. Hash is the default type for MEMORY. See [Storage Engine index types](../storage-engine-index-types/index) for more on their characteristics. A MEMORY table can have up to 64 indexes, 16 columns for each index and a maximum key length of 3072 bytes. See Also -------- * [Performance of MEMORY tables](../performance-of-memory-tables/index) Example ------- The following example shows how to create a `MEMORY` table with a given maximum size, as described above. ``` SET max_heap_table_size = 1024*516; CREATE TABLE t (a VARCHAR(10), b INT) ENGINE = MEMORY; SET max_heap_table_size = @@max_heap_table_size; ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb InnoDB Tablespaces InnoDB Tablespaces =================== Tables that use the InnoDB storage engine are written to disk in data files called tablespaces. An individual tablespace can contain data from one or more InnoDB tables as well as the associated indexes. | Title | Description | | --- | --- | | [InnoDB System Tablespaces](../innodb-system-tablespaces/index) | The system tablespace, how to change its size, and the use of raw disk partitions. | | [InnoDB File-Per-Table Tablespaces](../innodb-file-per-table-tablespaces/index) | InnoDB file-per-table tablespaces: what they are, where they're located, ho... | | [InnoDB Temporary Tablespaces](../innodb-temporary-tablespaces/index) | Information on tablespaces for user-created temporary tables. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Information Schema INNODB_LOCK_WAITS Table Information Schema INNODB\_LOCK\_WAITS Table ============================================ The [Information Schema](../information_schema/index) `INNODB_LOCK_WAITS` table contains information about blocked InnoDB transactions. The `PROCESS` [privilege](../grant/index) is required to view the table. It contains the following columns: | Column | Description | | --- | --- | | `REQUESTING_TRX_ID` | Requesting transaction ID from the [INNODB\_TRX](../information-schema-innodb_trx-table/index) table. | | `REQUESTED_LOCK_ID` | Lock ID from the [INNODB.LOCKS](../information-schema-innodb_locks-table/index) table for the waiting transaction. | | `BLOCKING_TRX_ID` | Blocking transaction ID from the [INNODB\_TRX](../information-schema-innodb_trx-table/index) table. | | `BLOCKING_LOCK_ID` | Lock ID from the [INNODB.LOCKS](../information-schema-innodb_locks-table/index) table of a lock held by a transaction that is blocking another transaction. | The table is often used in conjunction with the [INNODB\_LOCKS](../information-schema-innodb_locks-table/index) and [INNODB\_TRX](../information-schema-innodb_trx-table/index) tables to diagnose problematic locks and transactions. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Handling Too Many Connections Handling Too Many Connections ============================= Systems that get too busy can return the `too_many_connections` error. When the number of [threads\_connected](../server-status-variables/index#threads_connected) exceeds the `[max\_connections](../server-system-variables/index#max_connections)` server variable, it's time to make a change. Viewing the [threads\_connected](../server-status-variables/index#threads_connected) status variable shows only the current number of connections, but it's more useful to see what the value has peaked at, and this is shown by the [max\_used\_connections](../server-status-variables/index#max_used_connections) status variable. This error may be a symptom of slow queries and other bottlenecks, but if the system is running smoothly this can be addressed by increasing the value of max\_connections. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb WSREP_LAST_SEEN_GTID WSREP\_LAST\_SEEN\_GTID ======================= **MariaDB starting with [10.4.2](https://mariadb.com/kb/en/mariadb-1042-release-notes/)**WSREP\_LAST\_SEEN\_GTID was added as part of Galera 4 in [MariaDB 10.4.2](https://mariadb.com/kb/en/mariadb-1042-release-notes/). Syntax ------ ``` WSREP_LAST_SEEN_GTID() ``` Description ----------- Returns the [Global Transaction ID](../gtid/index) of the most recent write transaction observed by the client. The result can be useful to determine the transaction to provide to [WSREP\_SYNC\_WAIT\_UPTO\_GTID](../wsrep_sync_wait_upto_gtid/index) for waiting and unblocking purposes. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb SHOW BINARY LOGS SHOW BINARY LOGS ================ Syntax ------ ``` SHOW BINARY LOGS SHOW MASTER LOGS ``` Description ----------- Lists the [binary log](../binary-log/index) files on the server. This statement is used as part of the procedure described in `[PURGE BINARY LOGS](../purge-logs/index)`, that shows how to determine which logs can be purged. This statement requires the [SUPER](../grant/index#super) privilege, the [REPLICATION\_CLIENT](../grant/index#replication-client) privilege, or, from [MariaDB 10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/), the [BINLOG MONITOR](../grant/index#binlog-monitor) privilege. Examples -------- ``` SHOW BINARY LOGS; +--------------------+-----------+ | Log_name | File_size | +--------------------+-----------+ | mariadb-bin.000001 | 19039 | | mariadb-bin.000002 | 717389 | | mariadb-bin.000003 | 300 | | mariadb-bin.000004 | 333 | | mariadb-bin.000005 | 899 | | mariadb-bin.000006 | 125 | | mariadb-bin.000007 | 18907 | | mariadb-bin.000008 | 19530 | | mariadb-bin.000009 | 151 | | mariadb-bin.000010 | 151 | | mariadb-bin.000011 | 125 | | mariadb-bin.000012 | 151 | | mariadb-bin.000013 | 151 | | mariadb-bin.000014 | 125 | | mariadb-bin.000015 | 151 | | mariadb-bin.000016 | 314 | +--------------------+-----------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb SUM SUM === Syntax ------ ``` SUM([DISTINCT] expr) ``` Description ----------- Returns the sum of *`expr`*. If the return set has no rows, `SUM()` returns `NULL`. The `DISTINCT` keyword can be used to sum only the distinct values of `expr`. From [MariaDB 10.2.0](https://mariadb.com/kb/en/mariadb-1020-release-notes/), SUM() can be used as a [window function](../window-functions/index), although not with the DISTINCT specifier. Examples -------- ``` CREATE TABLE sales (sales_value INT); INSERT INTO sales VALUES(10),(20),(20),(40); SELECT SUM(sales_value) FROM sales; +------------------+ | SUM(sales_value) | +------------------+ | 90 | +------------------+ SELECT SUM(DISTINCT(sales_value)) FROM sales; +----------------------------+ | SUM(DISTINCT(sales_value)) | +----------------------------+ | 70 | +----------------------------+ ``` Commonly, SUM is used with a [GROUP BY](../select/index#group-by) clause: ``` CREATE TABLE sales (name CHAR(10), month CHAR(10), units INT); INSERT INTO sales VALUES ('Chun', 'Jan', 75), ('Chun', 'Feb', 73), ('Esben', 'Jan', 43), ('Esben', 'Feb', 31), ('Kaolin', 'Jan', 56), ('Kaolin', 'Feb', 88), ('Tatiana', 'Jan', 87), ('Tatiana', 'Feb', 83); SELECT name, SUM(units) FROM sales GROUP BY name; +---------+------------+ | name | SUM(units) | +---------+------------+ | Chun | 148 | | Esben | 74 | | Kaolin | 144 | | Tatiana | 170 | +---------+------------+ ``` The [GROUP BY](../select/index#group-by) clause is required when using an aggregate function along with regular column data, otherwise the result will be a mismatch, as in the following common type of mistake: ``` SELECT name,SUM(units) FROM sales ;+------+------------+ | name | SUM(units) | +------+------------+ | Chun | 536 | +------+------------+ ``` As a [window function](../window-functions/index): ``` CREATE OR REPLACE TABLE student_test (name CHAR(10), test CHAR(10), score TINYINT); INSERT INTO student_test VALUES ('Chun', 'SQL', 75), ('Chun', 'Tuning', 73), ('Esben', 'SQL', 43), ('Esben', 'Tuning', 31), ('Kaolin', 'SQL', 56), ('Kaolin', 'Tuning', 88), ('Tatiana', 'SQL', 87); SELECT name, test, score, SUM(score) OVER (PARTITION BY name) AS total_score FROM student_test; +---------+--------+-------+-------------+ | name | test | score | total_score | +---------+--------+-------+-------------+ | Chun | SQL | 75 | 148 | | Chun | Tuning | 73 | 148 | | Esben | SQL | 43 | 74 | | Esben | Tuning | 31 | 74 | | Kaolin | SQL | 56 | 144 | | Kaolin | Tuning | 88 | 144 | | Tatiana | SQL | 87 | 87 | +---------+--------+-------+-------------+ ``` See Also -------- * [AVG](../avg/index) (average) * [MAX](../max/index) (maximum) * [MIN](../min/index) (minimum) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb DECODE_ORACLE DECODE\_ORACLE ============== **MariaDB starting with [10.3.2](https://mariadb.com/kb/en/mariadb-1032-release-notes/)**`DECODE_ORACLE` is a synonym for the [Oracle mode](../sql_modeoracle/index) version of the [DECODE function](../decode/index), and is available in all modes. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb CONNECT VEC Table Type CONNECT VEC Table Type ====================== Warning: Avoid using this table type in production applications. This file format is specific to CONNECT and may not be supported in future versions. Tables of type `VEC` are binary files that in some cases can provide good performance on read-intensive query workloads. CONNECT organizes their data on disk as columns of values from the same attribute, as opposed to storing it as rows of tabular records. This organization means that when a query needs to access only a few columns of a particular table, only those columns need to be read from disk. Conversely, in a row-oriented table, all values in a table are typically read from disk, wasting I/O bandwidth. CONNECT provides two integral VEC formats, in which each column's data is adjacent. Integral vector formats ----------------------- In these true vertical formats, the VEC files are made of all the data of the first column, followed by all the data of the second column etc. All this can be in one physical file or each column data can be in a separate file. In the first case, the option max\_rows=m, where m is the estimate of the maximum size (number of rows) of the table, must be specified to be able to insert some new records. This leaves an empty space after each column area in which new data can be inserted. In the second case, the “Split” option can be specified[[2](#_note-1)] at table creation and each column will be stored in a file named sequentially from the table file name followed by the rank of the column. Inserting new lines can freely augment such a table. Differences between vector formats ---------------------------------- These formats correspond to different needs. The integral vector format provides the best performance gain. It will be chosen when the speed of decisional queries must be optimized. In the case of a unique file, inserting new data will be limited but there will be only one open and close to do. However, the size of the table cannot be calculated from the file size because of the eventual unused space in the file. It must be kept in a header containing the maximum number of rows and the current number of valid rows in the table. To achieve this, specify the option Header=*n* when creating the table. If `n=1` the header will be placed at the beginning of the file, if `n=2` it will be a separate file with the type ‘.blk’, and if `n=3` the header will be place at the end of the file. This last value is provided because batch inserting is sometimes slower when the header is at the beginning of the file. If not specified, the header option will default to 2 for this table type. On the other hand, the "Split" format with separate files have none of these issues, and is a much safer solution when the table must frequently inserted or shared among several users. For instance: ``` create table vtab ( a int not null, b char(10) not null) engine=CONNECT table_type=VEC file_name='vt.vec'; ``` This table, split by default, will have the column values in files vt1.vec and vt2.vec. For vector tables, the option *block\_size=n* is used for block reading and writing; however, to have a file made of blocks of equal size, the internal value of the *max\_rows=m* option is eventually increased to become a multiple of n. Like for BIN tables, numeric values are stored using platform internal layout, the correspondence between column types and internal format being the same than the default ones given above for BIN. However, field formats are not available for VEC tables. Header option ------------- This applies to VEC tables that are not split. Because the file size depends on the MAX\_ROWS value, CONNECT cannot know how many valid records exist in the file. Depending on the value of the HEADER option, this information is stored in a header that can be placed at the beginning of the file, at the end of the file or in a separate file called fn.blk. The valid values for the HEADER option are: | | | | --- | --- | | 0 | Defaults to 2 for standard tables and to 3 for inward tables. | | 1 | The header is at the beginning of the file. | | 2 | The header is in a separate file. | | 3 | The header is at the end of the file. | The value 2 can be used when dealing with files created by another application with no header. The value 3 makes sometimes inserting in the file faster than when the header is at the beginning of the file. Note: VEC being a file format specific to CONNECT, no big endian / little endian conversion is provided. These files are not portable between machines using a different byte order setting. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb CHARACTER_LENGTH CHARACTER\_LENGTH ================= Syntax ------ ``` CHARACTER_LENGTH(str) ``` Description ----------- `CHARACTER_LENGTH()` is a synonym for `[CHAR\_LENGTH()](../char_length/index)`. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb COERCIBILITY COERCIBILITY ============ Syntax ------ ``` COERCIBILITY(str) ``` Description ----------- Returns the collation coercibility value of the string argument. Coercibility defines what will be converted to what in case of collation conflict, with an expression with higher coercibility being converted to the collation of an expression with lower coercibility. | Coercibility | Description | Example | | --- | --- | --- | | 0 | Explicit | Value using a COLLATE clause | | 1 | No collation | Concatenated strings using different collations | | 2 | Implicit | Column value | | 3 | Constant | USER() return value | | 4 | Coercible | Literal string | | 5 | Ignorable | NULL or derived from NULL | Examples -------- ``` SELECT COERCIBILITY('abc' COLLATE latin1_swedish_ci); +-----------------------------------------------+ | COERCIBILITY('abc' COLLATE latin1_swedish_ci) | +-----------------------------------------------+ | 0 | +-----------------------------------------------+ SELECT COERCIBILITY(USER()); +----------------------+ | COERCIBILITY(USER()) | +----------------------+ | 3 | +----------------------+ SELECT COERCIBILITY('abc'); +---------------------+ | COERCIBILITY('abc') | +---------------------+ | 4 | +---------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Performance Schema replication_connection_configuration Table Performance Schema replication\_connection\_configuration Table =============================================================== **MariaDB starting with [10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/)**The `replication_connection_configuration` table was added in [MariaDB 10.6.0](https://mariadb.com/kb/en/mariadb-1060-release-notes/). The [Performance Schema](../performance-schema/index) replication\_connection\_configuration table displays replica's configuration settings used for connecting to the primary. It contains the following fields. | Column | Type | Null | Description | | --- | --- | --- | --- | | CHANNEL\_NAME | varchar(256) | NO | The replication channel used. | | HOST | char(60) | NO | The host name of the source that the replica is connected to. | | PORT | int(11) | NO | The port used to connect to the source. | | USER | char(32) | NO | The user name of the replication user account used to connect to the source. | | USING\_GTID | enum('NO', 'CURRENT\_POS', 'SLAVE\_POS') | NO | Whether replication is using GTIDs or not. | | SSL\_ALLOWED | enum('YES', 'NO', 'IGNORED') | NO | Whether SSL is allowed for the replica connection. | | SSL\_CA\_FILE | varchar(512) | NO | Path to the file that contains one or more certificates for trusted Certificate Authorities (CA) to use for TLS. | | SSL\_CA\_PATH | varchar(512) | NO | Path to a directory that contains one or more PEM files that contain X509 certificates for a trusted Certificate Authority (CA) to use for TLS. | | SSL\_CERTIFICATE | varchar(512) | NO | Path to the certificate used to authenticate the master. | | SSL\_CIPHER | varchar(512) | NO | Which cipher is used for encription. | | SSL\_KEY | varchar(512) | NO | Path to the private key used for TLS. | | SSL\_VERIFY\_SERVER\_CERTIFICATE | enum('YES','NO') | NO | Whether the server certificate is verified as part of the SSL connection. | | SSL\_CRL\_FILE | varchar(255) | NO | Path to the PEM file containing one or more revoked X.509 certificates. | | SSL\_CRL\_PATH | varchar(255) | NO | PATH to a folder containing PEM files containing one or more revoked X.509 certificates. | | CONNECTION\_RETRY\_INTERVAL | int(11) | NO | The number of seconds between connect retries. | | CONNECTION\_RETRY\_COUNT | bigint(20) unsigned | NO | The number of times the replica can attempt to reconnect to the source in the event of a lost connection. | | HEARTBEAT\_INTERVAL | double(10,3) unsigned | NO | Number of seconds after which a heartbeat will be sent. | | IGNORE\_SERVER\_IDS | longtext | NO | Binary log events from servers (ids) to ignore. | | REPL\_DO\_DOMAIN\_IDS | longtext | NO | Only apply binary logs from these domain ids. | | REPL\_IGNORE\_DOMAIN\_IDS | longtext | NO | Binary log events from domains to ignore. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb CONNECT MYSQL Table Type: Accessing MySQL/MariaDB Tables CONNECT MYSQL Table Type: Accessing MySQL/MariaDB Tables ======================================================== This table type uses libmysql API to access a MySQL or MariaDB table or view. This table must be created on the current server or on another local or remote server. This is similar to what the [FederatedX](../federatedx/index) storage engine provides with some differences. Currently the Federated-like syntax can be used to create such a table, for instance: ``` create table essai ( num integer(4) not null, line char(15) not null) engine=CONNECT table_type=MYSQL connection='mysql://root@localhost/test/people'; ``` The connection string can have the same syntax as that used by FEDERATED ``` scheme://username:password@hostname:port/database/tablename scheme://username@hostname/database/tablename scheme://username:password@hostname/database/tablename scheme://username:password@hostname/database/tablename ``` However, it can also be mixed with connect standard options. For instance: ``` create table essai ( num integer(4) not null, line char(15) not null) engine=CONNECT table_type=MYSQL dbname=test tabname=people connection='mysql://root@localhost'; ``` It can also be specified as a reference to a federated server: ``` connection="connection_one" connection="connection_one/table_foo" ``` The pure (deprecated) CONNECT syntax is also accepted: ``` create table essai ( num integer(4) not null, line char(15) not null) engine=CONNECT table_type=MYSQL dbname=test tabname=people option_list='user=root,host=localhost'; ``` The specific connection items are: | Option | Default value | Description | | --- | --- | --- | | Table | The table name | The name of the table to access. | | Database | The current DB name | The database where the table is located. | | Host | localhost\* | The host of the server, a name or an IP address. | | User | The current user | The connection user name. | | Password | No password | An optional user password. | | Port | The currently used port | The port of the server. | | Quoted | 0 | 1 if remote Tabname must be quoted. | * - When the host is specified as “localhost”, the connection is established on Linux using Linux sockets. On Windows, the connection is established by default using shared memory if it is enabled. If not, the TCP protocol is used. An alternative is to specify the host as “.” to use a named pipe connection (if it is enabled). This makes possible to use these table types with server skipping networking. **Caution:** Take care not to refer to the MYSQL table itself to avoid an infinite loop! MYSQL table can refer to the current server as well as to another server. Views can be referred by name or directly giving a source definition, for instance: ``` create table grp engine=connect table_type=mysql CONNECTION='mysql://root@localhost/test/people' SRCDEF='select title, count(*) as cnt from employees group by title'; ``` When specified, the columns of the mysql table must exist in the accessed table with the same name, but can be only a subset of them and specified in a different order. Their type must be a type supported by CONNECT and, if it is not identical to the type of the accessed table matching column, a conversion can be done according to the rules given in [Data type conversion](../connect-data-types/index#data-type-conversion). Note: For columns prone to be targeted by a where clause, keep the column type compatible with the source table column type (numeric or character) to have a correct rephrasing of the where clause. If you do not want to restrict or change the column definition, do not provide it and leave CONNECT get the column definition from the remote server. For instance: ``` create table essai engine=CONNECT table_type=MYSQL connection='mysql://root@localhost/test/people'; ``` This will create the *essai* table with the same columns than the people table. If the target table contains CONNECT incompatible type columns, see [Data type conversion](../connect-data-types/index#data-type-conversion) to know how these columns can be converted or skipped. Charset Specification --------------------- When accessing the remote table, CONNECT sets the connection charset set to the default local table charset as the FEDERATED engine does. Do not specify a column character set if it is different from the table default character set even when it is the case on the remote table. This is because the remote column is translated to the local table character set when reading it. This is the default but it can be modified by the setting the [character\_set\_results](../server-system-variables/index#character_set_results) variable of the target server. If it must keep its setting, for instance to UTF8 when containing Unicode characters, specify the local default charset to its character set. This means that it is not possible to correctly retrieve a remote table if it contains columns having different character sets. A solution is to retrieve it by several local tables, each accessing only columns with the same character set. Indexing of MYSQL tables ------------------------ Indexes are rarely useful with MYSQL tables. This is because CONNECT tries to access only the requested rows. For instance if you ask: ``` select * from essai where num = 23; ``` CONNECT will construct and send to the server the query: ``` SELECT num, line FROM people WHERE num = 23 ``` If the *people* table is indexed on *num*, indexing will be used on the remote server. This, in all cases, will limit the amount of data to retrieve on the network. However, an index can be specified for columns that are prone to be used to join another table to the MYSQL table. For instance: ``` select d.id, d.name, f.dept, f.salary from loc_tab d straight_join cnc_tab f on d.id = f.id where f.salary > 10000; ``` If the *id* column of the remote table addressed by the *cnc\_tab* MYSQL table is indexed (which is likely if it is a key) you should also index the *id* column of the MYSQL *cnc\_tab* table. If so, using “remote” indexing as does FEDERATED, only the useful rows of the remote table will be retrieved during the join process. However, because these rows are retrieved by separate [SELECT](../select/index) statements, this will be useful only when retrieving a few rows of a big table. In particular, you should not specify an index for columns not used for joining and above all DO NOT index a joined column if it is not indexed in the remote table. This would cause multiple scans of the remote table to retrieve the joined rows one by one. Data Modifying Operations ------------------------- The CONNECT MYSQL type supports [SELECT](../select/index) and [INSERT](../insert/index) and a somewhat limited form of [UPDATE](../update/index) and [DELETE](../delete/index). These are described below. The MYSQL type uses similar methods than the ODBC type to implement the [INSERT](../insert/index), [UPDATE](../update/index) and [DELETE](../delete/index) commands. Refer to the ODBC chapter for the restrictions concerning them. For the [UPDATE](../update/index) and [DELETE](../delete/index) commands, there are fewer restrictions because the remote server being a MySQL server, the syntax of the command will be always acceptable by the remote server. For instance, you can freely use keywords like IGNORE or LOW\_PRIORITY as well as scalar functions in the SET and WHERE clauses. However, there is still an issue on multi-table statements. Let us suppose you have a *t1* table on the remote server and want to execute a query such as: ``` update essai as x set line = (select msg from t1 where id = x.num) where num = 2; ``` When parsed locally, you will have errors if no *t1* table exists or if it does not have the referenced columns. When *t1* does not exist, you can overcome this issue by creating a local dummy *t1* table: ``` create table t1 (id int, msg char(1)) engine=BLACKHOLE; ``` This will make the local parser happy and permit to execute the command on the remote server. Note however that having a local MySQL table defined on the remote *t1* table does not solve the problem unless it is also names *t1* locally. This is why, to permit to have all types of commands executed by the data source without any restriction, CONNECT provides a specific MySQL table subtype described now. Sending commands to a MariaDB Server ------------------------------------ This can be done like for ODBC or JDBC tables by defining a specific table that will be used to send commands and get the result of their execution.. ``` create table send ( command varchar(128) not null, warnings int(4) not null flag=3, number int(5) not null flag=1, message varchar(255) flag=2) engine=connect table_type=mysql connection='mysql://user@host/database' option_list='Execsrc=1,Maxerr=2'; ``` The key points in this create statement are the EXECSRC option and the column definition. The EXECSRC option tells that this table will be used to send commands to the MariaDB server. Most of the sent commands do not return result set. Therefore, the table columns are used to specify the command to be executed and to get the result of the execution. The name of these columns can be chosen arbitrarily, their function coming from the FLAG value: | | | | --- | --- | | **Flag=0:** | The command to execute (the default) | | **Flag=1:** | The number of affected rows, or the result number of columns if the command would return a result set. | | **Flag=2:** | The returned (eventually error) message. | | **Flag=3:** | The number of warnings. | How to use this table and specify the command to send? By executing a command such as: ``` select * from send where command = 'a command'; ``` This will send the command specified in the WHERE clause to the data source and return the result of its execution. The syntax of the WHERE clause must be exactly as shown above. For instance: ``` select * from send where command = 'CREATE TABLE people ( num integer(4) primary key autoincrement, line char(15) not null'; ``` This command returns: | command | warnings | number | message | | --- | --- | --- | --- | | `CREATE TABLE people (num integer(4) primary key aut...` | 0 | 0 | Affected rows | ### Sending several commands in one call It can be faster to execute because there will be only one connection for all of them. To send several commands in one call, use the following syntax: ``` select * from send where command in ( "update people set line = 'Two' where id = 2", "update people set line = 'Three' where id = 3"); ``` When several commands are sent, the execution stops at the end of them or after a command that is in error. To continue after n errors, set the option maxerr=*n* (0 by default) in the option list. **Note 1:** It is possible to specify the SRCDEF option when creating an EXECSRC table. It will be the command sent by default when a WHERE clause is not specified. **Note 2:** Backslashes inside commands must be escaped. Simple quotes must be escaped if the command is specified between simple quotes, and double quotes if it is specified between double quotes. **Note 3:** Sent commands apply in the specified database. However, they can address any table within this database. **Note 4:** Currently, all commands are executed in mode AUTOCOMMIT. ### Retrieving Warnings and Notes If a sent command causes warnings to be issued, it is useless to resend a “show warnings” command because the MariaDB server is opened and closed when sending commands. Therefore, getting warnings requires a specific (and tricky) way. To indicate that warning text must be added to the returned result, you must send a multi-command query containing “pseudo” commands that are not sent to the server but directly interpreted by the EXECSRC table. These “pseudo” commands are: | | | | --- | --- | | **Warning** | To get warnings | | **Note** | To get notes | | **Error** | To get errors returned as warnings (?) | Note that they must be spelled (case insensitive) exactly as above, no final “s”. For instance: ``` select * from send where command in ('Warning','Note', 'drop table if exists try', 'create table try (id int key auto_increment, msg varchar(32) not null) engine=aria', "insert into try(msg) values('One'),(NULL),('Three') ", "insert into try values(2,'Deux') on duplicate key update msg = 'Two'", "insert into try(message) values('Four'),('Five'),('Six')", 'insert into try(id) values(NULL)', "update try set msg = 'Four' where id = 4", 'select * from try'); ``` This can return something like this: | command | warnings | number | message | | --- | --- | --- | --- | | `drop table if exists try` | 1 | 0 | Affected rows | | Note | 0 | 1051 | Unknown table 'try' | | `create table try (id int key auto_increment, msg...` | 0 | 0 | Affected rows | | `insert into try(msg) values('One'),(NULL),('Three')` | 1 | 3 | Affected rows | | Warning | 0 | 1048 | Column 'msg' cannot be null | | `insert into try values(2,'Deux') on duplicate key...` | 0 | 2 | Affected rows | | `insert into try(msge) values('Four'),('Five'),('Six')` | 0 | 1054 | Unknown column 'msge' in 'field list' | | `insert into try(id) values(NULL)` | 1 | 1 | Affected rows | | Warning | 0 | 1364 | Field 'msg' doesn't have a default value | | `update try set msg = 'Four' where id = 4` | 0 | 1 | Affected rows | | `select * from try` | 0 | 2 | Result set columns | The execution continued after the command in error because of the MAXERR option. Normally this would have stopped the execution. Of course, the last “select” command is useless here because it cannot return the table contain. Another MYSQL table without the EXECSRC option and with proper column definition should be used instead. Connection Engine Limitations ----------------------------- ### Data types There is a maximum key.index length of 255 bytes. You may be able to declare the table without an index and rely on the engine condition pushdown and remote schema. The following types can't be used: * [BIT](../bit/index) * [BINARY](../binary/index) * [TINYBLOB](../tinyblob/index), [BLOB](../blob/index), [MEDIUMBLOB](../mediumblob/index), [LONGBLOB](../longblob/index) * [TINYTEXT](../tinytext/index), [MEDIUMTEXT](../mediumtext/index), [LONGTEXT](../longtext/index) * [ENUM](../enum/index) * [SET](../set/index) * [Geometry types](../geometry-types/index) Note: [TEXT](../text/index) is allowed. However, the handling depends on the values given to the [connect\_type\_conv](../connect-system-variables/index#connect_type_conv) and [connect\_conv\_size](../connect-system-variables/index#connect_conv_size) system variables, and by default no conversion of TEXT columns is permitted. ### SQL Limitations The following SQL queries are not supported * [REPLACE INTO](../replace/index) * [INSERT ... ON DUPLICATE KEY UPDATE](../insert-on-duplicate-key-update/index) CONNECT MYSQL versus FEDERATED ------------------------------ The CONNECT MYSQL table type should not be regarded as a replacement for the [FEDERATED(X)](../federatedx-storage-engine/index) engine. The main use of the MYSQL type is to access other engine tables as if they were CONNECT tables. This was necessary when accessing tables from some CONNECT table types such as [TBL](../connect-table-types-tbl-table-type-table-list/index), [XCOL](../connect-table-types-xcol-table-type/index), [OCCUR](../connect-table-types-occur-table-type/index), or [PIVOT](../connect-table-types-pivot-table-type/index) that are designed to access CONNECT tables only. When their target table is not a CONNECT table, these types are silently using internally an intermediate MYSQL table. However, there are cases where you can use MYSQL CONNECT tables yourself, for instance: 1. When the table will be used by a [TBL](../connect-table-types-tbl-table-type-table-list/index) table. This enables you to specify the connection parameters for each sub-table and is more efficient than using a local FEDERATED sub-table. 2. When the desired returned data is directly specified by the SRCDEF option. This is great to let the remote server do most of the job, such as grouping and/or joining tables. This cannot be done with the FEDERATED engine. 3. To take advantage of the *push\_cond* facility that adds a where clause to the command sent to the remote table. This restricts the size of the result set and can be crucial for big tables. 4. For tables with the EXECSRC option on. 5. When doing tests. For instance to check a connection string. If you need multi-table updating, deleting, or bulk inserting on a remote table, you can alternatively use the FEDERATED engine or a “send” table specifying the EXECSRC option on. See also -------- * [Using the TBL and MYSQL types together](../connect-table-types-using-the-tbl-and-mysql-types-together/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb System Variables Added in MariaDB 10.0 System Variables Added in MariaDB 10.0 ====================================== This is a list of [system variables](../server-system-variables/index) that were added in the [MariaDB 10.0](../what-is-mariadb-100/index) series. The list excludes the following variables, related to storage engines and plugins included in [MariaDB 10.0](../what-is-mariadb-100/index): * [Connect System Variables](../connect-system-variables/index) * [Galera System Variables](../galera-cluster-system-variables/index) * [Mroonga System Variables](../mroonga-system-variables/index) * [Query Response Time Plugin Variables](../query_response_time-plugin/index) * [Spider System Variables](../spider-server-system-variables/index) | Variable | Added | | --- | --- | | [aria\_pagecache\_file\_hash\_size](../aria-system-variables/index#aria_pagecache_file_hash_size) | [MariaDB 10.0.13](https://mariadb.com/kb/en/mariadb-10013-release-notes/) | | [binlog\_commit\_wait\_count](../replication-and-binary-log-server-system-variables/index#binlog_commit_wait_count) | [MariaDB 10.0.5](https://mariadb.com/kb/en/mariadb-1005-release-notes/) | | [binlog\_commit\_wait\_usec](../replication-and-binary-log-server-system-variables/index#binlog_commit_wait_usec) | [MariaDB 10.0.5](https://mariadb.com/kb/en/mariadb-1005-release-notes/) | | [default\_master\_connection](../replication-and-binary-log-server-system-variables/index#default_master_connection) | [MariaDB 10.0.1](https://mariadb.com/kb/en/mariadb-1001-release-notes/) | | [default\_regex\_flags](../server-system-variables/index#default_regex_flags) | [MariaDB 10.0.11](https://mariadb.com/kb/en/mariadb-10011-release-notes/) | | [gtid\_binlog\_pos](../global-transaction-id/index#gtid_binlog_pos) | [MariaDB 10.0.3](https://mariadb.com/kb/en/mariadb-1003-release-notes/) | | [gtid\_binlog\_state](../global-transaction-id/index#gtid_binlog_state) | [MariaDB 10.0.5](https://mariadb.com/kb/en/mariadb-1005-release-notes/) | | [gtid\_current\_pos](../global-transaction-id/index#gtid_current_pos) | [MariaDB 10.0.3](https://mariadb.com/kb/en/mariadb-1003-release-notes/) | | [gtid\_domain\_id](../global-transaction-id/index#gtid_domain_id) | [MariaDB 10.0.2](https://mariadb.com/kb/en/mariadb-1002-release-notes/) | | [gtid\_ignore\_duplicates](../global-transaction-id/index#gtid_ignore_duplicates) | [MariaDB 10.0.10](https://mariadb.com/kb/en/mariadb-10010-release-notes/) | | [gtid\_seq\_no](../global-transaction-id/index#gtid_seq_no) | [MariaDB 10.0.2](https://mariadb.com/kb/en/mariadb-1002-release-notes/) | | [gtid\_slave\_pos](../global-transaction-id/index#gtid_slave_pos) | [MariaDB 10.0.3](https://mariadb.com/kb/en/mariadb-1003-release-notes/) | | [gtid\_strict\_mode](../global-transaction-id/index#gtid_strict_mode) | [MariaDB 10.0.3](https://mariadb.com/kb/en/mariadb-1003-release-notes/) | | [histogram\_size](../server-system-variables/index#histogram_size) | [MariaDB 10.0.2](https://mariadb.com/kb/en/mariadb-1002-release-notes/) | | [histogram\_type](../server-system-variables/index#histogram_type) | [MariaDB 10.0.2](https://mariadb.com/kb/en/mariadb-1002-release-notes/) | | [innodb\_adaptive\_flushing\_lwm](../xtradbinnodb-server-system-variables/index#innodb_adaptive_flushing_lwm) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_adaptive\_max\_sleep\_delay](../xtradbinnodb-server-system-variables/index#innodb_adaptive_max_sleep_delay) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_api\_bk\_commit\_interval](../xtradbinnodb-server-system-variables/index#innodb_api_bk_commit_interval) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_api\_disable\_rowlock](../xtradbinnodb-server-system-variables/index#innodb_api_disable_rowlock) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_api\_enable\_binlog](../xtradbinnodb-server-system-variables/index#innodb_api_enable_binlog) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_api\_enable\_mdl](../xtradbinnodb-server-system-variables/index#innodb_api_enable_mdl) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_api\_trx\_level](../xtradbinnodb-server-system-variables/index#innodb_api_trx_level) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_buffer\_pool\_dump\_at\_shutdown](../xtradbinnodb-server-system-variables/index#innodb_buffer_pool_dump_at_shutdown) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_buffer\_pool\_dump\_now](../xtradbinnodb-server-system-variables/index#innodb_buffer_pool_dump_now) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_buffer\_pool\_filename](../xtradbinnodb-server-system-variables/index#innodb_buffer_pool_filename) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_buffer\_pool\_load\_abort](../xtradbinnodb-server-system-variables/index#innodb_buffer_pool_load_abort) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_buffer\_pool\_load\_at\_startup](../xtradbinnodb-server-system-variables/index#innodb_buffer_pool_load_at_startup) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_buffer\_pool\_load\_now](../xtradbinnodb-server-system-variables/index#innodb_buffer_pool_load_now) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_change\_buffer\_max\_size](../xtradbinnodb-server-system-variables/index#innodb_change_buffer_max_size) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_checksum\_algorithm](../xtradbinnodb-server-system-variables/index#innodb_checksum_algorithm) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_cleaner\_lsn\_age\_factor](../xtradbinnodb-server-system-variables/index#innodb_cleaner_lsn_age_factor) | [MariaDB 10.0.9](https://mariadb.com/kb/en/mariadb-1009-release-notes/) | | [innodb\_cmp\_per\_index\_enabled](../xtradbinnodb-server-system-variables/index#innodb_cmp_per_index_enabled) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_compression\_failure\_threshold\_pct](../xtradbinnodb-server-system-variables/index#innodb_compression_failure_threshold_pct) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_compression\_level](../xtradbinnodb-server-system-variables/index#innodb_compression_level) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_compression\_pad\_pct\_max](../xtradbinnodb-server-system-variables/index#innodb_compression_pad_pct_max) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_disable\_sort\_file\_cache](../xtradbinnodb-server-system-variables/index#innodb_disable_sort_file_cachex) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_empty\_free\_list\_algorithm](../xtradbinnodb-server-system-variables/index#innodb_empty_free_list_algorithm) | [MariaDB 10.0.9](https://mariadb.com/kb/en/mariadb-1009-release-notes/) | | [innodb\_flush\_neighbors](../xtradbinnodb-server-system-variables/index#innodb_flush_neighbors) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_foreground\_preflush](../xtradbinnodb-server-system-variables/index#innodb_foreground_preflush) | [MariaDB 10.0.9](https://mariadb.com/kb/en/mariadb-1009-release-notes/) | | [innodb\_ft\_aux\_table](../xtradbinnodb-server-system-variables/index#innodb_ft_aux_table) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_ft\_cache\_size](../xtradbinnodb-server-system-variables/index#innodb_ft_cache_size) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_ft\_enable\_diag\_print](../xtradbinnodb-server-system-variables/index#innodb_ft_enable_diag_print) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_ft\_enable\_stopword](../xtradbinnodb-server-system-variables/index#innodb_ft_enable_stopword) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_ft\_max\_token\_size](../xtradbinnodb-server-system-variables/index#innodb_ft_max_token_size) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_ft\_min\_token\_size](../xtradbinnodb-server-system-variables/index#innodb_ft_min_token_size) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_ft\_num\_word\_optimize](../xtradbinnodb-server-system-variables/index#innodb_ft_num_word_optimize) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_ft\_result\_cache\_limit](../xtradbinnodb-server-system-variables/index#innodb_ft_result_cache_limit) | [MariaDB 10.0.9](https://mariadb.com/kb/en/mariadb-1009-release-notes/) | | [innodb\_ft\_server\_stopword\_table](../xtradbinnodb-server-system-variables/index#innodb_ft_server_stopword_table) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_ft\_sort\_pll\_degree](../xtradbinnodb-server-system-variables/index#innodb_ft_sort_pll_degree) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_ft\_total\_cache\_size](../xtradbinnodb-server-system-variables/index#innodb_ft_total_cache_size) | [MariaDB 10.0.9](https://mariadb.com/kb/en/mariadb-1009-release-notes/) | | [innodb\_ft\_user\_stopword\_table](../xtradbinnodb-server-system-variables/index#innodb_ft_user_stopword_table) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_io\_capacity\_max](../xtradbinnodb-server-system-variables/index#innodb_io_capacity_max) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_log\_arch\_dir](../xtradbinnodb-server-system-variables/index#innodb_log_arch_dir) | [MariaDB 10.0.9](https://mariadb.com/kb/en/mariadb-1009-release-notes/) | | [innodb\_log\_arch\_expire\_sec](../xtradbinnodb-server-system-variables/index#innodb_log_arch_expire_sec) | [MariaDB 10.0.9](https://mariadb.com/kb/en/mariadb-1009-release-notes/) | | [innodb\_log\_archive](../xtradbinnodb-server-system-variables/index#innodb_log_archive) | [MariaDB 10.0.9](https://mariadb.com/kb/en/mariadb-1009-release-notes/) | | [innodb\_log\_compressed\_pages](../xtradbinnodb-server-system-variables/index#innodb_log_compressed_pages) | [MariaDB 10.0.9](https://mariadb.com/kb/en/mariadb-1009-release-notes/) | | [innodb\_max\_dirty\_pages\_pct\_lwm](../xtradbinnodb-server-system-variables/index#innodb_max_dirty_pages_pct_lwm) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_max\_purge\_lag\_delay](../xtradbinnodb-server-system-variables/index#innodb_max_purge_lag_delay) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_monitor\_disable](../xtradbinnodb-server-system-variables/index#innodb_monitor_disable) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_monitor\_enable](../xtradbinnodb-server-system-variables/index#innodb_monitor_enable) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_monitor\_reset](../xtradbinnodb-server-system-variables/index#innodb_monitor_reset) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_monitor\_reset\_all](../xtradbinnodb-server-system-variables/index#innodb_monitor_reset_all) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_online\_alter\_log\_max\_size](../xtradbinnodb-server-system-variables/index#innodb_online_alter_log_max_size) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_optimize\_fulltext\_only](../xtradbinnodb-server-system-variables/index#innodb_optimize_fulltext_only) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_random\_read\_ahead](../xtradbinnodb-server-system-variables/index#innodb_random_read_ahead) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_read\_only](../xtradbinnodb-server-system-variables/index#innodb_read_only) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_recovery\_stats](../xtradbinnodb-server-system-variables/index#innodb_recovery_stats) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_sched\_priority\_cleaner](../xtradbinnodb-server-system-variables/index#innodb_sched_priority_cleaner) | [MariaDB 10.0.9](https://mariadb.com/kb/en/mariadb-1009-release-notes/) | | [innodb\_simulate\_comp\_failures](../xtradbinnodb-server-system-variables/index#innodb_simulate_comp_failures) | [MariaDB 10.0.14](https://mariadb.com/kb/en/mariadb-10014-release-notes/) | | [innodb\_sort\_buffer\_size](../xtradbinnodb-server-system-variables/index#innodb_sort_buffer_size) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_stats\_auto\_recalc](../xtradbinnodb-server-system-variables/index#innodb_stats_auto_recalc) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_stats\_modified\_counter](../xtradbinnodb-server-system-variables/index#innodb_stats_modified_counter) | [MariaDB 10.0.15](https://mariadb.com/kb/en/mariadb-10015-release-notes/) | | [innodb\_stats\_persistent](../xtradbinnodb-server-system-variables/index#innodb_stats_persistent) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_stats\_persistent\_sample\_pages](../xtradbinnodb-server-system-variables/index#innodb_stats_persistent_sample_pages) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_stats\_traditional](../xtradbinnodb-server-system-variables/index#innodb_stats_traditional) | [MariaDB 10.0.16](https://mariadb.com/kb/en/mariadb-10016-release-notes/) | | [innodb\_stats\_transient\_sample\_pages](../xtradbinnodb-server-system-variables/index#innodb_stats_transient_sample_pages) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_status\_output](../xtradbinnodb-server-system-variables/index#innodb_status_output) | [MariaDB 10.0.14](https://mariadb.com/kb/en/mariadb-10014-release-notes/) | | [innodb\_status\_output\_locks](../xtradbinnodb-server-system-variables/index#innodb_status_output_locks) | [MariaDB 10.0.14](https://mariadb.com/kb/en/mariadb-10014-release-notes/) | | [innodb\_sync\_array\_size](../xtradbinnodb-server-system-variables/index#innodb_sync_array_size) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_undo\_directory](../xtradbinnodb-server-system-variables/index#innodb_undo_directory) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_undo\_logs](../xtradbinnodb-server-system-variables/index#innodb_undo_logs) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [innodb\_undo\_tablespaces](../xtradbinnodb-server-system-variables/index#innodb_undo_tablespaces) | [MariaDB 10.0](../what-is-mariadb-100/index) | | [key\_cache\_file\_hash\_size](../myisam-system-variables/index#key_cache_file_hash_size) | [MariaDB 10.0.13](https://mariadb.com/kb/en/mariadb-10013-release-notes/) | | [last\_gtid](../global-transaction-id/index#last_gtid) | [MariaDB 10.0.9](https://mariadb.com/kb/en/mariadb-1009-release-notes/) | | [oqgraph\_allow\_create\_integer\_latch](../server-system-variables/index#oqgraph_allow_create_integer_latch) | [MariaDB 10.0.7](https://mariadb.com/kb/en/mariadb-1007-release-notes/) | | [performance\_schema\_accounts\_size](../performance-schema-system-variables/index#performance_schema_accounts_size) | [MariaDB 10.0.0](https://mariadb.com/kb/en/mariadb-1000-release-notes/) | | [performance\_schema\_digests\_size](../performance-schema-system-variables/index#performance_schema_digests_size) | [MariaDB 10.0.0](https://mariadb.com/kb/en/mariadb-1000-release-notes/) | | [performance\_schema\_events\_stages\_history\_long\_size](../performance-schema-system-variables/index#performance_schema_events_stages_history_long_size) | [MariaDB 10.0.0](https://mariadb.com/kb/en/mariadb-1000-release-notes/) | | [performance\_schema\_events\_stages\_history\_size](../performance-schema-system-variables/index#performance_schema_events_stages_history_size) | [MariaDB 10.0.0](https://mariadb.com/kb/en/mariadb-1000-release-notes/) | | [performance\_schema\_events\_statements\_history\_long\_size](../performance-schema-system-variables/index#performance_schema_events_statements_history_long_size) | [MariaDB 10.0.0](https://mariadb.com/kb/en/mariadb-1000-release-notes/) | | [performance\_schema\_events\_statements\_history\_size](../performance-schema-system-variables/index#performance_schema_events_statements_history_size) | [MariaDB 10.0.0](https://mariadb.com/kb/en/mariadb-1000-release-notes/) | | [performance\_schema\_hosts\_size](../performance-schema-system-variables/index#performance_schema_hosts_size) | [MariaDB 10.0.0](https://mariadb.com/kb/en/mariadb-1000-release-notes/) | | [performance\_schema\_max\_digest\_length](../performance-schema-system-variables/index#performance_schema_max_digest_length) | [MariaDB 10.0.21](https://mariadb.com/kb/en/mariadb-10021-release-notes/) | | [performance\_schema\_max\_socket\_classes](../performance-schema-system-variables/index#performance_schema_max_socket_classes) | [MariaDB 10.0.0](https://mariadb.com/kb/en/mariadb-1000-release-notes/) | | [performance\_schema\_max\_socket\_instances](../performance-schema-system-variables/index#performance_schema_max_socket_instances) | [MariaDB 10.0.0](https://mariadb.com/kb/en/mariadb-1000-release-notes/) | | [performance\_schema\_max\_stage\_classes](../performance-schema-system-variables/index#performance_schema_max_stage_classes) | [MariaDB 10.0.0](https://mariadb.com/kb/en/mariadb-1000-release-notes/) | | [performance\_schema\_max\_statement\_classes](../performance-schema-system-variables/index#performance_schema_max_statement_classes) | [MariaDB 10.0.0](https://mariadb.com/kb/en/mariadb-1000-release-notes/) | | [performance\_schema\_session\_connect\_attrs\_size](../performance-schema-system-variables/index#performance_schema_session_connect_attrs_size) | [MariaDB 10.0.4](https://mariadb.com/kb/en/mariadb-1004-release-notes/) | | [performance\_schema\_setup\_actors\_size](../performance-schema-system-variables/index#performance_schema_setup_actors_size) | [MariaDB 10.0.0](https://mariadb.com/kb/en/mariadb-1000-release-notes/) | | [performance\_schema\_setup\_objects\_size](../performance-schema-system-variables/index#performance_schema_setup_objects_size) | [MariaDB 10.0.0](https://mariadb.com/kb/en/mariadb-1000-release-notes/) | | [performance\_schema\_users\_size](../performance-schema-system-variables/index#performance_schema_users_size) | [MariaDB 10.0.0](https://mariadb.com/kb/en/mariadb-1000-release-notes/) | | [slave\_ddl\_exec\_mode](../replication-and-binary-log-server-system-variables/index#slave_ddl_exec_mode) | [MariaDB 10.0.8](https://mariadb.com/kb/en/mariadb-1008-release-notes/) | | [slave\_domain\_parallel\_threads](../replication-and-binary-log-server-system-variables/index#slave_domain_parallel_threads) | [MariaDB 10.0.9](https://mariadb.com/kb/en/mariadb-1009-release-notes/) | | [slave\_parallel\_max\_queued](../replication-and-binary-log-server-system-variables/index#slave_parallel_max_queued) | [MariaDB 10.0.5](https://mariadb.com/kb/en/mariadb-1005-release-notes/) | | [slave\_parallel\_threads](../replication-and-binary-log-server-system-variables/index#slave_parallel_threads) | [MariaDB 10.0.5](https://mariadb.com/kb/en/mariadb-1005-release-notes/) | | [ssl\_crl](../ssl-system-variables/index#ssl_crl) | [MariaDB 10.0.0](https://mariadb.com/kb/en/mariadb-1000-release-notes/) | | [ssl\_crlpath](../ssl-system-variables/index#ssl_crlpath) | [MariaDB 10.0.0](https://mariadb.com/kb/en/mariadb-1000-release-notes/) | | [use\_stat\_tables](../server-system-variables/index#use_stat_tables) | [MariaDB 10.0.1](https://mariadb.com/kb/en/mariadb-1001-release-notes/) | | [version\_malloc\_library](../server-system-variables/index#version_malloc_library) | [MariaDB 10.0.1](https://mariadb.com/kb/en/mariadb-1001-release-notes/) | See Also -------- * [Status Variables Added in MariaDB 10.0](../status-variables-added-in-mariadb-100/index) * [System Variables Added in MariaDB 10.1](../system-variables-added-in-mariadb-101/index) * [Upgrading from MariaDB 5.5 to MariaDB 10.0](../upgrading-from-mariadb-55-to-mariadb-100/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Migrating to MariaDB from PostgreSQL Migrating to MariaDB from PostgreSQL ==================================== There are many different ways to migrate from [PostgreSQL](https://www.postgresql.org/) to MariaDB. This article will discuss some of those options. MariaDB's CONNECT Storage Engine -------------------------------- MariaDB's [CONNECT](../connect/index) storage engine can be used to migrate from PostgreSQL to MariaDB. There are two primary ways that this can be done. See [Loading the CONNECT Storage Engine](../loading-the-connect-storage-engine/index) for information on how to install the CONNECT storage engine. ### Tables with ODBC table\_type The CONNECT storage engine allows you to create tables that refer to tables on an external server, and it can fetch the data using a compatible [ODBC](https://en.wikipedia.org/wiki/Open_Database_Connectivity) driver. PostgreSQL does have a freely available ODBC driver called `[psqlODBC](https://odbc.postgresql.org/)`. Therefore, if you install `psqlODBC` on the MariaDB Server, and then configure the system's ODBC framework (such as [unixODBC](http://www.unixodbc.org/)), then the MariaDB server will be able to connect to the remote PostgreSQL server. At that point, you can create tables with the `[ENGINE=CONNECT](../create-table/index#storage-engine)` and `[table\_type=ODBC](../connect-odbc-table-type-accessing-tables-from-another-dbms/index)` table options set, so that you can access the PostgreSQL tables from MariaDB. See [CONNECT ODBC Table Type: Accessing Tables From Another DBMS](../connect-odbc-table-type-accessing-tables-from-another-dbms/index) for more information on how to do that. Once the remote table is setup, you can migrate the data to local tables very simply. For example: ``` CREATE TABLE psql_tab ( id int, str varchar(50) ) ENGINE = CONNECT table_type=ODBC tabname='tab' connection='DSN=psql_server'; CREATE TABLE tab ( id int, str varchar(50) ) ENGINE = InnoDB; INSERT INTO tab SELECT * FROM psql_tab; ``` ### Tables with JDBC table\_type The CONNECT storage engine allows you to create tables that refer to tables on an external server, and it can fetch the data using a compatible [JDBC](https://en.wikipedia.org/wiki/Java_Database_Connectivity) driver. PostgreSQL does have a freely available [JDBC driver](https://jdbc.postgresql.org/). If you install this JDBC driver on the MariaDB server, then the MariaDB server will be able to connect to the remote PostgreSQL server via JDBC. At that point, you can create tables with the `[ENGINE=CONNECT](../create-table/index#storage-engine)` and `[table\_type=JDBC](../connect-odbc-table-type-accessing-tables-from-another-dbms/index)` table options set, so that you can access the PostgreSQL tables from MariaDB. See [CONNECT JDBC Table Type: Accessing Tables from Another DBMS](../connect-jdbc-table-type-accessing-tables-from-another-dbms/index) for more information on how to do that. Once the remote table is setup, you can migrate the data to local tables very simply. For example: ``` CREATE TABLE psql_tab ( id int, str varchar(50) ) ENGINE = CONNECT table_type=JDBC tabname='tab' connection='jdbc:postgresql://psql_server/db1'; CREATE TABLE tab ( id int, str varchar(50) ) ENGINE = InnoDB; INSERT INTO tab SELECT * FROM psql_tab; ``` PostgreSQL's Foreign Data Wrappers ---------------------------------- PostgreSQL's [foreign data wrappers](https://wiki.postgresql.org/wiki/Foreign_data_wrappers) can also be used to migrate from PostgreSQL to MariaDB. ### mysql\_fdw [mysql\_fdw](https://github.com/EnterpriseDB/mysql_fdw) allows you to create a table in PostgreSQL that actual refers to a remote MySQL or MariaDB server. Since MySQL and MariaDB are compatible at the protocol level, this should also support MariaDB. The foreign data wrapper also supports writes, so you should be able to write to the remote MariaDB table to migrate your PostgreSQL data. For example: ``` CREATE TABLE tab ( id int, str text ); INSERT INTO tab VALUES (1, 'str1'); CREATE SERVER mariadb_server FOREIGN DATA WRAPPER mysql_fdw OPTIONS (host '10.1.1.101', port '3306'); CREATE USER MAPPING FOR postgres SERVER mariadb_server OPTIONS (username 'foo', password 'bar'); CREATE FOREIGN TABLE mariadb_tab ( id int, str text ) SERVER mariadb_server OPTIONS (dbname 'db1', table_name 'tab'); INSERT INTO mariadb_tab SELECT * FROM tab; ``` PostgreSQL's COPY TO -------------------- PostgreSQL's `[COPY TO](https://www.postgresql.org/docs/current/sql-copy.html)` allows you to copy the data from a PostgreSQL table to a text file. This data can then be loaded into MariaDB with `[LOAD DATA INFILE](../load-data-infile/index)`. MySQL Workbench --------------- MySQL Workbench has a [migration feature](https://www.mysql.com/products/workbench/migrate/) that requires an [ODBC](https://en.wikipedia.org/wiki/Open_Database_Connectivity) driver. PostgreSQL does have a freely available ODBC driver called `[psqlODBC](https://odbc.postgresql.org/)`. See [Set up and configure PostgreSQL ODBC drivers for the MySQL Workbench Migration Wizard](http://mysqlworkbench.org/2012/11/set-up-and-configure-postgresql-odbc-drivers-for-the-mysql-workbench-migration-wizard/) for more information. Known Issues ------------ ### Migrating Functions and Procedures PostgreSQL's [functions](https://www.postgresql.org/docs/current/sql-createfunction.html) and [procedures](https://www.postgresql.org/docs/11/sql-createprocedure.html) use a language called `[PL/pgSQL](https://www.postgresql.org/docs/current/plpgsql.html)`. This language is quite different than the default `SQL/PSM` language used for MariaDB's [stored procedures](../stored-procedures/index). `PL/pgSQL` is more similar to `PL/PSQL` from Oracle, so you may find it beneficial to try migrate with `[SQL\_MODE=ORACLE](../sql_modeoracle-from-mariadb-103/index)` set. See also -------- * [Set up and configure PostgreSQL ODBC drivers for the MySQL Workbench Migration Wizard](http://mysqlworkbench.org/2012/11/set-up-and-configure-postgresql-odbc-drivers-for-the-mysql-workbench-migration-wizard/) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb Information Schema VIEWS Table Information Schema VIEWS Table ============================== The [Information Schema](../information_schema/index) `VIEWS` table contains information about [views](../views/index). The `SHOW VIEW` [privilege](../grant/index) is required to view the table. It has the following columns: | Column | Description | | --- | --- | | `TABLE_CATALOG` | Aways `def`. | | `TABLE_SCHEMA` | Database name containing the view. | | `TABLE_NAME` | View table name. | | `VIEW_DEFINITION` | Definition of the view. | | `CHECK_OPTION` | `YES` if the `WITH CHECK_OPTION` clause has been specified, `NO` otherwise. | | `IS_UPDATABLE` | Whether the view is updatable or not. | | `DEFINER` | Account specified in the DEFINER clause (or the default when created). | | `SECURITY_TYPE` | `SQL SECURITY` characteristic, either `DEFINER` or `INVOKER`. | | `CHARACTER_SET_CLIENT` | The client [character set](../data-types-character-sets-and-collations/index) when the view was created, from the session value of the [character\_set\_client](../server-system-variables/index#character_set_client) system variable. | | `COLLATION_CONNECTION` | The client [collation](../data-types-character-sets-and-collations/index) when the view was created, from the session value of the [collation\_connection](../server-system-variables/index#collation_connection) system variable. | | `ALGORITHM` | The algorithm used in the view. See [View Algorithms](../view-algorithms/index). | Example ------- ``` SELECT * FROM information_schema.VIEWS\G *************************** 1. row *************************** TABLE_CATALOG: def TABLE_SCHEMA: test TABLE_NAME: v VIEW_DEFINITION: select `test`.`t`.`qty` AS `qty`,`test`.`t`.`price` AS `price`,(`test`.`t`.`qty` * `test`.`t`.`price`) AS `value` from `test`.`t` CHECK_OPTION: NONE IS_UPDATABLE: YES DEFINER: root@localhost SECURITY_TYPE: DEFINER CHARACTER_SET_CLIENT: utf8 COLLATION_CONNECTION: utf8_general_ci ALGORITHM: UNDEFINED ``` See Also -------- * [CREATE VIEW](../create-view/index) * [ALTER VIEW](../alter-view/index) * [DROP VIEW](../drop-view/index) * [SHOW CREATE VIEWS](show-create-views) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Aria Aria ===== Information about the Aria storage engine. From [MariaDB 10.4](../what-is-mariadb-104/index), [system tables](../system-tables/index) use the Aria storage engine. | Title | Description | | --- | --- | | [Aria Storage Engine](../aria-storage-engine/index) | The Aria storage engine is compiled-in by default and is considered as an upgrade to MyISAM. | | [Aria Clients and Utilities](../aria-clients-and-utilities/index) | Clients and utilities for working with Aria tables | | [Aria FAQ](../aria-faq/index) | Frequently-asked questions about the Aria storage engine. | | [Aria Storage Formats](../aria-storage-formats/index) | Table storage formats in Aria - PAGE, FIXED and DYNAMIC | | [Aria Status Variables](../aria-status-variables/index) | Aria-related server status variables. | | [Aria System Variables](../aria-system-variables/index) | Aria-related system variables. | | [Aria Group Commit](../aria-group-commit/index) | Aria group commits for speeding up multi-user inserts | | [Benchmarking Aria](../benchmarking-aria/index) | Aria benchmarks | | [Aria Two-step Deadlock Detection](../aria-two-step-deadlock-detection/index) | How Aria detects and deals with deadlocks | | [Aria Encryption Overview](../aria-encryption-overview/index) | Data-at-rest encryption for user-created tables and internal on-disk tempor... | | [The Aria Name](../the-aria-name/index) | How Aria got its name. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb User Statistics User Statistics =============== The User Statistics feature was first released in [MariaDB 5.2.0](https://mariadb.com/kb/en/mariadb-520-release-notes/), and moved to the `userstat` plugin in [MariaDB 10.1.1](https://mariadb.com/kb/en/mariadb-1011-release-notes/). The `userstat` plugin creates the [USER\_STATISTICS](../information-schema-user_statistics-table/index), [CLIENT\_STATISTICS](../information-schema-client_statistics-table/index), the [INDEX\_STATISTICS](../information-schema-index_statistics-table/index), and the [TABLE\_STATISTICS](../information-schema-table_statistics-table/index) tables in the [INFORMATION\_SCHEMA](../information-schema/index) database. As an alternative to these tables, the plugin also adds the [SHOW USER\_STATISTICS](../show-user-statistics/index), the [SHOW CLIENT\_STATISTICS](../show-client-statistics/index), the [SHOW INDEX\_STATISTICS](../show-index-statistics/index), and the [SHOW TABLE\_STATISTICS](../show-table-statistics/index) statements. These tables and commands can be used to understand the server activity better and to identify the sources of your database's load. The plugin also adds the [FLUSH USER\_STATISTICS](../flush/index), [FLUSH CLIENT\_STATISTICS](../flush/index), [FLUSH INDEX\_STATISTICS](../flush/index), and [FLUSH TABLE\_STATISTICS](../flush/index) statements. The MariaDB implementation of this plugin is based on the [userstatv2 patch](http://www.percona.com/docs/wiki/patches:userstatv2) from Percona and Ourdelta. The original code comes from Google (Mark Callaghan's team) with additional work from Percona, Ourdelta, and Weldon Whipple. The MariaDB implementation provides the same functionality as the userstatv2 patch but a lot of changes have been made to make it faster and to better fit the MariaDB infrastructure. How it Works ------------ The `userstat` plugin works by keeping several hash tables in memory. All variables are incremented while the query is running. At the end of each statement the global values are updated. Enabling the Plugin ------------------- By default statistics are not collected. This is to ensure that statistics collection does not cause any extra load on the server unless desired. Set the [userstat=ON](#userstat) system variable in a relevant server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index) to enable the plugin. For example: ``` [mariadb] ... userstat = 1 ``` The value can also be changed dynamically. For example: ``` SET GLOBAL userstat=1; ``` Using the Plugin ---------------- ### Using the Information Schema Table The `userstat` plugin creates the [USER\_STATISTICS](../information-schema-user_statistics-table/index), [CLIENT\_STATISTICS](../information-schema-client_statistics-table/index), the [INDEX\_STATISTICS](../information-schema-index_statistics-table/index), and the [TABLE\_STATISTICS](../information-schema-table_statistics-table/index) tables in the [INFORMATION\_SCHEMA](../information-schema/index) database. ``` SELECT * FROM INFORMATION_SCHEMA.USER_STATISTICS\G *************************** 1. row *************************** USER: root TOTAL_CONNECTIONS: 1 CONCURRENT_CONNECTIONS: 0 CONNECTED_TIME: 297 BUSY_TIME: 0.001725 CPU_TIME: 0.001982 BYTES_RECEIVED: 388 BYTES_SENT: 2327 BINLOG_BYTES_WRITTEN: 0 ROWS_READ: 0 ROWS_SENT: 12 ROWS_DELETED: 0 ROWS_INSERTED: 13 ROWS_UPDATED: 0 SELECT_COMMANDS: 4 UPDATE_COMMANDS: 0 OTHER_COMMANDS: 3 COMMIT_TRANSACTIONS: 0 ROLLBACK_TRANSACTIONS: 0 DENIED_CONNECTIONS: 0 LOST_CONNECTIONS: 0 ACCESS_DENIED: 0 EMPTY_QUERIES: 1 ``` ``` SELECT * FROM INFORMATION_SCHEMA.CLIENT_STATISTICS\G *************************** 1. row *************************** CLIENT: localhost TOTAL_CONNECTIONS: 3 CONCURRENT_CONNECTIONS: 0 CONNECTED_TIME: 4883 BUSY_TIME: 0.009722 CPU_TIME: 0.0102131 BYTES_RECEIVED: 841 BYTES_SENT: 13897 BINLOG_BYTES_WRITTEN: 0 ROWS_READ: 0 ROWS_SENT: 214 ROWS_DELETED: 0 ROWS_INSERTED: 207 ROWS_UPDATED: 0 SELECT_COMMANDS: 10 UPDATE_COMMANDS: 0 OTHER_COMMANDS: 13 COMMIT_TRANSACTIONS: 0 ROLLBACK_TRANSACTIONS: 0 DENIED_CONNECTIONS: 0 LOST_CONNECTIONS: 0 ACCESS_DENIED: 0 EMPTY_QUERIES: 1 1 row in set (0.00 sec) ``` ``` SELECT * FROM INFORMATION_SCHEMA.INDEX_STATISTICS WHERE TABLE_NAME = "author"; +--------------+------------+------------+-----------+ | TABLE_SCHEMA | TABLE_NAME | INDEX_NAME | ROWS_READ | +--------------+------------+------------+-----------+ | books | author | by_name | 15 | +--------------+------------+------------+-----------+ ``` ``` SELECT * FROM INFORMATION_SCHEMA.TABLE_STATISTICS WHERE TABLE_NAME='user'; +--------------+------------+-----------+--------------+------------------------+ | TABLE_SCHEMA | TABLE_NAME | ROWS_READ | ROWS_CHANGED | ROWS_CHANGED_X_INDEXES | +--------------+------------+-----------+--------------+------------------------+ | mysql | user | 5 | 2 | 2 | +--------------+------------+-----------+--------------+------------------------+ ``` ### Using the SHOW Statements As an alternative to the [INFORMATION\_SCHEMA](../information_schema/index) tables, the `userstat` plugin also adds the [SHOW USER\_STATISTICS](../show-user-statistics/index), the [SHOW CLIENT\_STATISTICS](../show-client-statistics/index), the [SHOW INDEX\_STATISTICS](../show-index-statistics/index), and the [SHOW TABLE\_STATISTICS](../show-table-statistics/index) statements. These commands are another way to display the information stored in the information schema tables. WHERE clauses are accepted. LIKE clauses are accepted but ignored. ``` SHOW USER_STATISTICS SHOW CLIENT_STATISTICS SHOW INDEX_STATISTICS SHOW TABLE_STATISTICS ``` ### Flushing Plugin Data The `userstat` plugin also adds the [FLUSH USER\_STATISTICS](../flush/index), [FLUSH CLIENT\_STATISTICS](../flush/index), [FLUSH INDEX\_STATISTICS](../flush/index), and [FLUSH TABLE\_STATISTICS](../flush/index) statements, which discard the information stored in the specified information schema table. ``` FLUSH USER_STATISTICS FLUSH CLIENT_STATISTICS FLUSH INDEX_STATISTICS FLUSH TABLE_STATISTICS ``` Versions -------- ### USER\_STATISTICS | Version | Status | Introduced | | --- | --- | --- | | 2.0 | Stable | [MariaDB 10.1.18](https://mariadb.com/kb/en/mariadb-10118-release-notes/) | | 2.0 | Gamma | [MariaDB 10.1.1](https://mariadb.com/kb/en/mariadb-1011-release-notes/) | ### CLIENT\_STATISTICS | Version | Status | Introduced | | --- | --- | --- | | 2.0 | Stable | [MariaDB 10.1.13](https://mariadb.com/kb/en/mariadb-10113-release-notes/) | | 2.0 | Gamma | [MariaDB 10.1.1](https://mariadb.com/kb/en/mariadb-1011-release-notes/) | ### INDEX\_STATISTICS | Version | Status | Introduced | | --- | --- | --- | | 2.0 | Stable | [MariaDB 10.1.13](https://mariadb.com/kb/en/mariadb-10113-release-notes/) | | 2.0 | Gamma | [MariaDB 10.1.1](https://mariadb.com/kb/en/mariadb-1011-release-notes/) | ### TABLE\_STATISTICS | Version | Status | Introduced | | --- | --- | --- | | 2.0 | Stable | [MariaDB 10.1.18](https://mariadb.com/kb/en/mariadb-10118-release-notes/) | | 2.0 | Gamma | [MariaDB 10.1.1](https://mariadb.com/kb/en/mariadb-1011-release-notes/) | System Variables ---------------- ### `userstat` * **Description:** If set to `1`, [user statistics](index) will be activated. * **Commandline:** `--userstat=1` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `OFF` --- Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Stored Function Limitations Stored Function Limitations =========================== The following restrictions apply to [stored functions](../stored-functions/index). * All of the restrictions listed in [Stored Routine Limitations](../stored-routine-limitations/index). * Any statements that return a result set are not permitted. For example, a regular [SELECTs](../select/index) is not permitted, but a [SELECT INTO](../select-into/index) is. A cursor and [FETCH](../fetch/index) statement is permitted. * [FLUSH](../flush/index) statements are not permitted. * Statements that perform explicit or implicit commits or rollbacks are not permitted * Cannot be used recursively. * Cannot make changes to a table that is already in use (reading or writing) by the statement invoking the stored function. * Cannot refer to a temporary table multiple times under different aliases, even in different statements. * ROLLBACK TO SAVEPOINT and RELEASE SAVEPOINT statement which are in a stored function cannot refer to a savepoint which has been defined out of the current function. * Prepared statements ([PREPARE](../prepare-statement/index), [EXECUTE](../execute-statement/index), [DEALLOCATE PREPARE](../deallocate-drop-prepared-statement/index)) cannot be used, and therefore nor can statements be constructed as strings and then executed. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Fusion-io Fusion-io ========== This category contains information about Fusion-io support in MariaDB | Title | Description | | --- | --- | | [Fusion-io Introduction](../fusion-io-introduction/index) | Fusion-io PCIe SSD cards to speed up MariaDB. | | [Atomic Write Support](../atomic-write-support/index) | Enabling atomic writes to speed up InnoDB on selected SSD cards. | | [MariaDB 10.0.15 Fusion-io Release Notes](https://mariadb.com/kb/en/mariadb-10015-fusion-io-release-notes/) | Status: | Release Date: 12 Dec 2014 | | [MariaDB 10.0.15 Fusion-io Changelog](https://mariadb.com/kb/en/mariadb-10015-fusion-io-changelog/) | Status: | Release Date: 12 Dec 2014 | | [InnoDB Page Flushing](../innodb-page-flushing/index) | Configuring when and how InnoDB flushes dirty pages to disk. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb EXPLAIN FORMAT=JSON in MySQL EXPLAIN FORMAT=JSON in MySQL ============================ There are some things that we in MariaDB are not happy with in MySQL/Oracle's implementation of EXPLAIN FORMAT=JSON. The most important issues are already fixed in MariaDB's [EXPLAIN FORMAT=JSON](../explain-format-json/index) implementation. See [EXPLAIN FORMAT=JSON Differences From MySQL](../explain-format-json-differences/index) for details. This page lists things are are not fixed yet. Higher priority --------------- * Better display for ORDER/GROUP BY ([MDEV-6995](https://jira.mariadb.org/browse/MDEV-6995)) * Better display for Batched Key Access plans (Plain join buffering is fixed already) Nice to have ------------ ### Show ranges being scanned Currently, one can only find the ranges produced by the range optimizer by looking into optimizer\_trace. It would be nice if EXPLAIN showed them, too ``` MySQL [dbt3sf1]> explain format=json select * from customer where c_acctbal < -1000 \G *************************** 1. row *************************** EXPLAIN: { "query_block": { "select_id": 1, "table": { "table_name": "customer", "access_type": "range", "possible_keys": [ "c_acctbal", "i_c_acctbal_nationkey" ], "key": "c_acctbal", "used_key_parts": [ "c_acctbal" ], "key_length": "9", "rows": 1, "filtered": 100, "index_condition": "(`dbt3sf1`.`customer`.`c_acctbal` < -(1000))" } } } ``` Low priority ------------ ### Filesort/priority queue Neither version of EXPLAIN in 5.6 shows the "filesort with small limit" optimization. See [MDEV-6430](https://jira.mariadb.org/browse/MDEV-6430). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb BETWEEN AND BETWEEN AND =========== Syntax ------ ``` expr BETWEEN min AND max ``` Description ----------- If expr is greater than or equal to min and expr is less than or equal to max, BETWEEN returns 1, otherwise it returns 0. This is equivalent to the expression (min <= expr AND expr <= max) if all the arguments are of the same type. Otherwise type conversion takes place according to the rules described at [Type Conversion](../type-conversion/index), but applied to all the three arguments. Examples -------- ``` SELECT 1 BETWEEN 2 AND 3; +-------------------+ | 1 BETWEEN 2 AND 3 | +-------------------+ | 0 | +-------------------+ ``` ``` SELECT 'b' BETWEEN 'a' AND 'c'; +-------------------------+ | 'b' BETWEEN 'a' AND 'c' | +-------------------------+ | 1 | +-------------------------+ ``` ``` SELECT 2 BETWEEN 2 AND '3'; +---------------------+ | 2 BETWEEN 2 AND '3' | +---------------------+ | 1 | +---------------------+ ``` ``` SELECT 2 BETWEEN 2 AND 'x-3'; +-----------------------+ | 2 BETWEEN 2 AND 'x-3' | +-----------------------+ | 0 | +-----------------------+ 1 row in set, 1 warning (0.00 sec) Warning (Code 1292): Truncated incorrect DOUBLE value: 'x-3' ``` NULL: ``` SELECT 1 BETWEEN 1 AND NULL; +----------------------+ | 1 BETWEEN 1 AND NULL | +----------------------+ | NULL | +----------------------+ ``` DATE, DATETIME and TIMESTAMP examples. Omitting the time component compares against `00:00`, so later times on the same date are not returned: ``` CREATE TABLE `x` ( a date , b datetime, c timestamp ) INSERT INTO x VALUES ('2018-11-11', '2018-11-11 05:15', '2018-11-11 05:15'), ('2018-11-12', '2018-11-12 05:15', '2018-11-12 05:15'); SELECT * FROM x WHERE a BETWEEN '2018-11-11' AND '2018-11-12'; +------------+---------------------+---------------------+ | a | b | c | +------------+---------------------+---------------------+ | 2018-11-11 | 2018-11-11 05:15:00 | 2018-11-11 05:15:00 | | 2018-11-12 | 2018-11-12 05:15:00 | 2018-11-12 05:15:00 | +------------+---------------------+---------------------+ SELECT * FROM x WHERE b BETWEEN '2018-11-11' AND '2018-11-12'; +------------+---------------------+---------------------+ | a | b | c | +------------+---------------------+---------------------+ | 2018-11-11 | 2018-11-11 05:15:00 | 2018-11-11 05:15:00 | +------------+---------------------+---------------------+ SELECT * FROM x WHERE c BETWEEN '2018-11-11' AND '2018-11-12'; +------------+---------------------+---------------------+ | a | b | c | +------------+---------------------+---------------------+ | 2018-11-11 | 2018-11-11 05:15:00 | 2018-11-11 05:15:00 | +------------+---------------------+---------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb Database Workbench Database Workbench ================== [Database Workbench](http://www.upscene.com/database_workbench/) is a Windows application (*which works fine under Wine on Linux*) for database design, development, maintenance and testing for several database systems: MySQL, MariaDB, Oracle, Firebird, InterBase, Microsoft SQL Server, SQL Anywhere and NexusDB. With Database Workbench you can: * design a database * connect to multiple databases * view and modify meta data * view and modify data * import and export data * connect to any ODBC/ADO data source * transfer data between database systems * migrate meta data * compare meta data * manage privileges * debug stored procedure * print meta data or data It includes numerous other tools, [more screen shots are available](http://www.upscene.com/database_workbench/learnmore). Database Workbench comes in multiple editions and is licensed on a per module basis, so there's always a version that suits you. ![dbwoverview](https://mariadb.com/kb/en/database-workbench/+image/dbwoverview "dbwoverview") Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb MariaDB ColumnStore software upgrade 1.0.4 to 1.0.6 MariaDB ColumnStore software upgrade 1.0.4 to 1.0.6 =================================================== MariaDB ColumnStore software upgrade 1.0.4 to 1.0.6 --------------------------------------------------- Note: Columnstore.xml modifications you manually made are not automatically carried forward on an upgrade. These modifications will need to be incorporated back into .XML once the upgrade has occurred. The previous configuration file will be saved as /usr/local/mariadb/columnstore/etc/Columnstore.xml.rpmsave. If you have specified a root database password (which is good practice), then you must configure a .my.cnf file with user credentials for the upgrade process to use. Create a .my.cnf file in the user home directory with 600 file permissions with the following content (updating PASSWORD as appropriate): ``` [mysqladmin] user = root password = PASSWORD ``` ### Choosing the type of upgrade #### Root User Installs #### Upgrading MariaDB ColumnStore using RPMs Upgrade MariaDB ColumnStore as user root on the server designated as PM1: **Download the package mariadb-columnstore-1.0.6-1-centos#.x86\_64.rpm.tar.gz to the PM1 server where you are installing MariaDB ColumnStore.** Shutdown the MariaDB ColumnStore system: ``` # mcsadmin shutdownsystem y ``` * Unpack the tarball, which will generate a set of RPMs that will reside in the /root/ directory. `tar -zxf mariadb-columnstore-1.0.6-1-centos#.x86_64.rpm.tar.gz` * Upgrade the RPMs. The MariaDB ColumnStore software will be installed in /usr/local/. ``` rpm -e --nodeps $(rpm -qa | grep '^mariadb-columnstore') rpm -ivh mariadb-columnstore-*1.0.6*rpm ``` * Run postConfigure using the upgrade option, which will utilize the configuration from the Columnstore.xml.rpmsave ``` # /usr/local/mariadb/columnstore/bin/postConfigure -u ``` For RPM Upgrade, the previous configuration file will be saved as: /usr/local/mariadb/columnstore/etc/Columnstore.xml.rpmsave ### Initial download/install of MariaDB ColumnStore binary package Upgrade MariaDB ColumnStore as user root on the server designated as PM1: * Download the package into the /usr/local directory -mariadb-columnstore-1.0.6-1.x86\_64.bin.tar.gz (Binary 64-BIT)to the server where you are installing MariaDB ColumnStore. * Shutdown the MariaDB ColumnStore system: `mcsadmin shutdownsystem y` * Run pre-uninstall script `/usr/local/mariadb/columnstore/bin/pre-uninstall` * Unpack the tarball, in the /usr/local/ directory. `tar -zxvf -mariadb-columnstore-1.0.6-1.x86_64.bin.tar.gz` * Run post-install scripts `/usr/local/mariadb/columnstore/bin/post-install` * Run postConfigure using the upgrade option, which will utilize the configuration from the Columnstore.xml,rpmsave `/usr/local/mariadb/columnstore/bin/postConfigure -u` ### Upgrading MariaDB ColumnStore using the DEB package A DEB upgrade would be done on a system that supports DEBs like Debian or Ubuntu systems. Upgrade MariaDB ColumnStore as user root on the server designated as PM1: * Download the package into the /root directory ``` mariadb-columnstore-1.0.6-1.amd64.deb.tar.gz ``` (DEB 64-BIT) to the server where you are installing MariaDB ColumnStore. * Shutdown the MariaDB ColumnStore system: ``` mcsadmin shutdownsystem y ``` * Unpack the tarball, which will generate DEBs. ``` tar -zxf mariadb-columnstore-1.0.6-1.amd64.deb.tar.gz ``` * Remove, purge and install all MariaDB ColumnStore debs ``` cd /root/ dpkg -r mariadb-columnstore*deb dpkg -P mariadb-columnstore*deb ``` * Run postConfigure using the upgrade option, which will utilize the configuration from the Columnstore.xml,rpmsave ``` /usr/local/mariadb/columnstore/bin/postConfigure -u ``` #### Non-Root User Installs ### Initial download/install of MariaDB ColumnStore binary package Upgrade MariaDB ColumnStore as user root on the server designated as PM1: * Download the package into the /home/'non-root-user" directory mariadb-columnstore-1.0.6-1.x86\_64.bin.tar.gz (Binary 64-BIT)to the server where you are installing MariaDB ColumnStore. * Shutdown the MariaDB ColumnStore system: `mcsadmin shutdownsystem y` * Run pre-uninstall script `$HOME/mariadb/columnstore/bin/pre-uninstall -i /home/guest/mariadb/columnstore` * Unpack the tarball, which will generate the $HOME/ directory. `tar -zxvf -mariadb-columnstore-1.0.6-1.x86_64.bin.tar.gz` * Run post-install scripts 1. $HOME/mariadb/columnstore/bin/post-install -i /home/guest/mariadb/columnstore * Run postConfigure using the upgrade option, which will utilize the configuration from the Columnstore.xml,rpmsave `$HOME/mariadb/columnstore/bin/postConfigure -u -i /home/guest/mariadb/columnstore` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Using CONNECT - General Information Using CONNECT - General Information =================================== The main characteristic of [CONNECT](../connect/index) is to enable accessing data scattered on a machine as if it was a centralized database. This, and the fact that locking is not used by connect (data files are open and closed for each query) makes CONNECT very useful for importing or exporting data into or from a MariaDB database and also for all types of Business Intelligence applications. However, it is not suited for transactional applications. For instance, the index type used by CONNECT is closer to bitmap indexing than to B-trees. It is very fast for retrieving result but not when updating is done. In fact, even if only one indexed value is modified in a big table, the index is entirely remade (yet this being four to five times faster than for a b-tree index). But normally in Business Intelligence applications, files are not modified so often. If you are using CONNECT to analyze files that can be modified by an external process, the indexes are of course not modified by it and become outdated. Use the OPTIMIZE TABLE command to update them before using the tables based on them. This means also that CONNECT is not designed to be used by centralized servers, which are mostly used for transactions and often must run a long time without human intervening. ### Performance Performances vary a great deal depending on the table type. For instance, ODBC tables are only retrieved as fast as the other DBMS can do. If you have a lot of queries to execute, the best way to optimize your work can be sometime to translate the data from one type to another. Fortunately this is very simple with CONNECT. Fixed formats like FIX, BIN or VEC tables can be created from slower ones by commands such as: ``` Create table fastable table_specs select * from slowtable; ``` `FIX` and `BIN` are often the better choice because the I/O functions are done on blocks of `BLOCK_SIZE` rows. `VEC` tables can be very efficient for tables having many columns only a few being used in each query. Furthermore, for tables of reasonable size, the `MAPPED` option can very often speed up many queries. ### Create Table statement Be aware of the two broad kinds of CONNECT tables: | | | | --- | --- | | **Inward** | They are table whose file name is not specified at create. An empty file will be given a default name (*tabname.tabtype*) and will be populated like for other engines. They do not require the FILE privilege and can be used for testing purpose. | | **Outward** | They are all other `CONNECT` tables and access external data sources or files. They are the true useful tables but require the `FILE` privilege. | ### Drop Table statement For outward tables, the [DROP TABLE](../drop-table/index) statement just removes the table definition but does not erase the table data. However, dropping an inward tables also erase the table data as well. ### Alter Table statement Be careful using the [ALTER TABLE](../alter-table/index) statement. Currently the data compatibility is not tested and the modified definition can become incompatible with the data. In particular, Alter modifies the table definition only but does not modify the table data. Consequently, the table type should not be modified this way, except to correct an incorrect definition. Also adding, dropping or modifying columns may be wrong because the default offset values (when not explicitly given by the FLAG option) may be wrong when recompiled with missing columns. Safe use of ALTER is for indexing, as we have seen earlier, and to change options such as MAPPED or HUGE those do not impact the data format but just the way the data file is accessed. Modifying the BLOCK\_SIZE option is all right with FIX, BIN, DBF, split VEC tables; however it is unsafe for VEC tables that are not split (only one data file) because at their creation the estimate size has been made a multiple of the block size. This can cause errors if this estimate is not a multiple of the new value of the block size. In all cases, it is safer to drop and re-create the table (outward tables) or to make another one from the table that must be modified. ### Update and Delete for File Tables CONNECT can execute these commands using two different algorithms: * It can do it in place, directly modifying rows (update) or moving rows (delete) within the table file. This is a fast way to do it in particular when indexing is used. * It can do it using a temporary file to make the changes. This is required when updating variable record length tables and is more secure in all cases. The choice between these algorithms depends on the session variable [connect\_use\_tempfile](../connect-system-variables/index#connect_use_tempfile). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb RESTORE TABLE (removed) RESTORE TABLE (removed) ======================= **MariaDB until [5.3](../what-is-mariadb-53/index)**RESTORE TABLE was removed in [MariaDB 5.5](../what-is-mariadb-55/index). Syntax ------ ``` RESTORE TABLE tbl_name [, tbl_name] ... FROM '/path/to/backup/directory' ``` Description ----------- **Note:** Like [BACKUP TABLE](../backup-table/index), this command was not reliable and has been removed in current versions of MariaDB. For doing a backup of MariaDB use [mysqldump](../mysqldump/index), [mysqlhotcopy](../mysqlhotcopy/index) or [XtraBackup](../backup-restore-and-import-xtrabackup/index). See [Backing Up and Restoring](../backing-up-and-restoring/index). `RESTORE TABLE` restores the table or tables from a backup that was made with `[BACKUP TABLE](../backup-table/index)`. The directory should be specified as a full path name. Existing tables are not overwritten; if you try to restore over an existing table, an error occurs. Just as for `BACKUP TABLE`, `RESTORE TABLE` works only for [MyISAM](../myisam/index) tables. Restored tables are not replicated from master to slave. The backup for each table consists of its .frm format file and .MYD data file. The restore operation restores those files, and then uses them to rebuild the .MYI index file. Restoring takes longer than backing up due to the need to rebuild the indexes. The more indexes the table has, the longer it takes. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb ColumnStore Architectural Overview ColumnStore Architectural Overview ================================== MariaDB ColumnStore is a columnar storage engine designed for distributed massively parallel processing (MPP), such as for big data analysis. Deployments are composed of several MariaDB servers, operating as modules, working together to provide linear scalability and exceptional performance with real-time response to analytical queries. These modules include [User](#user-module), [Performance](#performance-module) and [Storage](#storage). ### User Module [User Modules](../columnstore-user-module/index) are MariaDB Server instances configured to operate as a front-ends to ColumnStore. The server runs a number of additional processes to handle concurrency scaling. When a client queries the server, the storage engine passes the query to one of these processes, which then break down the SQL request and distributed the various parts to one or more [Performance Modules](#performance-module) to process the query and read from storage. The User module then collects the query results and assembles them into the result-set to return to the client. For more information, see the [ColumnStore User Module](../columnstore-user-module/index). ### Performance Module [Performance Modules](../columnstore-performance-module/index) are responsible for storing, retrieving and managing data, processing block requests for query operations, and for passing it back to the User module or modules to finalize the query requests. The module selects data from disk and caches it in a shared-nothing buffer that is part of the server on which it runs. You can configure as many Performance modules as you want. Each additional module increases the size of the cache of the overall database as well as the amount of processing power available to you. For more information, see [ColumnStore Performance Module](../columnstore-performance-module/index). ### Storage MariaDB ColumnStore is extremely flexible with the storage system. When running on premise, you can use either local storage (that is, the [Performance Modules](#performance-module)), or shared storage, (for instance, SAN), to store data. With Amazon EC2 environments, you can use ephemeral or Elastic Block Store (EBS) volumes. In situations where data redundancy is required for shared-nothing deployments, you can integrate it with GlusterFS. For more information, see [Storage Architecture](../columnstore-storage-architecture/index). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb mysql_secure_installation mysql\_secure\_installation =========================== Note that many of the reasons for the existence of this script no longer apply. In particular, from [MariaDB 10.4](../what-is-mariadb-104/index), [Unix socket authentication](../authentication-plugin-unix-socket/index) is applied by default, and there is usually no need to create a root password. See [Authentication from MariaDB 10.4](../authentication-from-mariadb-104/index). **MariaDB starting with [10.4.6](https://mariadb.com/kb/en/mariadb-1046-release-notes/)**From [MariaDB 10.4.6](https://mariadb.com/kb/en/mariadb-1046-release-notes/), `mariadb-secure-installation` is a symlink to `mysql_secure_installation`. **MariaDB starting with [10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/)**From [MariaDB 10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/), `mysql_secure_installation` is the symlink, and `mariadb-secure-installation` the binary name. Description ----------- `mysql_secure_installation` is a shell script available on Unix systems, and enables you to improve the security of your MariaDB installation in the following ways: * You can set a password for root accounts. * You can remove root accounts that are accessible from outside the local host. * You can remove anonymous-user accounts. * You can remove the test database, which by default can be accessed by anonymous users. `mysql_secure_installation` can be invoked without arguments: ``` shell> mysql_secure_installation ``` The script will prompt you to determine which actions to perform. ``` Example: localhost:# mysql_secure_installation NOTE: RUNNING ALL PARTS OF THIS SCRIPT IS RECOMMENDED FOR ALL MariaDB SERVERS IN PRODUCTION USE! PLEASE READ EACH STEP CAREFULLY! In order to log into MariaDB to secure it, we'll need the current password for the root user. If you've just installed MariaDB, and you haven't set the root password yet, the password will be blank, so you should just press enter here. Enter current password for root (enter for none): OK, successfully used password, moving on... Setting the root password ensures that nobody can log into the MariaDB root user without the proper authorisation. You already have a root password set, so you can safely answer 'n'. Change the root password? [Y/n] n ... skipping. By default, a MariaDB installation has an anonymous user, allowing anyone to log into MariaDB without having to have a user account created for them. This is intended only for testing, and to make the installation go a bit smoother. You should remove them before moving into a production environment. Remove anonymous users? [Y/n] y ... Success! Normally, root should only be allowed to connect from 'localhost'. This ensures that someone cannot guess at the root password from the network. Disallow root login remotely? [Y/n] y ... Success! By default, MariaDB comes with a database named 'test' that anyone can access. This is also intended only for testing, and should be removed before moving into a production environment. Remove test database and access to it? [Y/n] y - Dropping test database... ... Success! - Removing privileges on test database... ... Success! Reloading the privilege tables will ensure that all changes made so far will take effect immediately. Reload privilege tables now? [Y/n] y ... Success! Cleaning up... All done! If you've completed all of the above steps, your MariaDB installation should now be secure. Thanks for using MariaDB! ``` ### Options `mysql_secure_installation` accepts some options: | Option | Description | | --- | --- | | `--basedir=dir` | Base directory. | | `--no-defaults` | Don't read default options from any option file. | | `--defaults-file=#` | Only read default options from the given file #. | | `--defaults-extra-file=#` | Read this file after the global files are read. | Other unrecognized options will be passed on to the server. ### Option Files In addition to reading options from the command-line, `mysql_secure_installation` can also read options from [option files](../configuring-mariadb-with-option-files/index). If an unknown option is provided to `mysql_secure_installation` in an option file, then it is ignored. The following options relate to how MariaDB command-line tools handles option files. They must be given as the first argument on the command-line: | Option | Description | | --- | --- | | `--no-defaults` | Don't read default options from any option file. | | `--defaults-file=#` | Only read default options from the given file #. | | `--defaults-extra-file=#` | Read this file after the global files are read. | | `--defaults-group-suffix=#` | In addition to the default option groups, also read option groups with this suffix. | #### Option Groups `mysql_secure_installation` reads options from the following [option groups](../configuring-mariadb-with-option-files/index#option-groups) from [option files](../configuring-mariadb-with-option-files/index): | Group | Description | | --- | --- | | `[client]` | Options read by all MariaDB and MySQL [client programs](../clients-utilities/index), which includes both MariaDB and MySQL clients. For example, `mysqldump`. | | `[client-server]` | Options read by all MariaDB [client programs](../clients-utilities/index) and the MariaDB Server. This is useful for options like socket and port, which is common between the server and the clients. | | `[client-mariadb]` | Options read by all MariaDB [client programs](../clients-utilities/index). | ### Use With Galera Cluster This script is not 100% safe for use with [Galera Cluster](../galera/index) as it directly manipulates the [mysql.user](../mysqluser-table/index)/[mysql.global\_priv](../mysqlglobal_priv-table/index) table, which is not transported by Galera to the other nodes. You should run this script on the first node in the cluster before adding more nodes. If you want to run this after the cluster is up and running you should find alternative ways. Anyone can vote for this to be fixed at <https://jira.mariadb.org/browse/MDEV-10112>. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb NOW NOW === Syntax ------ ``` NOW([precision]) CURRENT_TIMESTAMP CURRENT_TIMESTAMP([precision]) LOCALTIME, LOCALTIME([precision]) LOCALTIMESTAMP LOCALTIMESTAMP([precision]) ``` Description ----------- Returns the current date and time as a value in `'YYYY-MM-DD HH:MM:SS'` or `YYYYMMDDHHMMSS.uuuuuu` format, depending on whether the function is used in a string or numeric context. The value is expressed in the current [time zone](../time-zones/index). The optional *precision* determines the microsecond precision. See [Microseconds in MariaDB](../microseconds-in-mariadb/index). `NOW()` (or its synonyms) can be used as the default value for [TIMESTAMP](../timestamp/index) columns as well as, since [MariaDB 10.0.1](https://mariadb.com/kb/en/mariadb-1001-release-notes/), [DATETIME](../datetime/index) columns. Before [MariaDB 10.0.1](https://mariadb.com/kb/en/mariadb-1001-release-notes/), it was only possible for a single TIMESTAMP column per table to contain the CURRENT\_TIMESTAMP as its default. When displayed in the [INFORMATION\_SCHEMA.COLUMNS](../information-schema-columns-table/index) table, a default [CURRENT TIMESTAMP](../current_timestamp/index) is displayed as `CURRENT_TIMESTAMP` up until [MariaDB 10.2.2](https://mariadb.com/kb/en/mariadb-1022-release-notes/), and as `current_timestamp()` from [MariaDB 10.2.3](https://mariadb.com/kb/en/mariadb-1023-release-notes/), due to to [MariaDB 10.2](../what-is-mariadb-102/index) accepting expressions in the DEFAULT clause. Examples -------- ``` SELECT NOW(); +---------------------+ | NOW() | +---------------------+ | 2010-03-27 13:13:25 | +---------------------+ SELECT NOW() + 0; +-----------------------+ | NOW() + 0 | +-----------------------+ | 20100327131329.000000 | +-----------------------+ ``` With precision: ``` SELECT CURRENT_TIMESTAMP(2); +------------------------+ | CURRENT_TIMESTAMP(2) | +------------------------+ | 2018-07-10 09:47:26.24 | +------------------------+ ``` Used as a default TIMESTAMP: ``` CREATE TABLE t (createdTS TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP); ``` From [MariaDB 10.2.2](https://mariadb.com/kb/en/mariadb-1022-release-notes/): ``` SELECT * FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_SCHEMA='test' AND COLUMN_NAME LIKE '%ts%'\G *************************** 1. row *************************** TABLE_CATALOG: def TABLE_SCHEMA: test TABLE_NAME: t COLUMN_NAME: ts ORDINAL_POSITION: 1 COLUMN_DEFAULT: current_timestamp() ... ``` <= [MariaDB 10.2.1](https://mariadb.com/kb/en/mariadb-1021-release-notes/) ``` SELECT * FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_SCHEMA='test' AND COLUMN_NAME LIKE '%ts%'\G *************************** 1. row *************************** TABLE_CATALOG: def TABLE_SCHEMA: test TABLE_NAME: t COLUMN_NAME: createdTS ORDINAL_POSITION: 1 COLUMN_DEFAULT: CURRENT_TIMESTAMP ... ``` See Also -------- * [Microseconds in MariaDB](../microseconds-in-mariadb/index) * [timestamp server system variable](../server-system-variables/index#timestamp) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb File Organization in PBXT File Organization in PBXT ========================= A short description of the files used by PBXT. If you do the following create: ``` create table test.t9 (a int) engine=pbxt'. ``` You will find the following files in your database directory. ``` (/my/data) ls -Rl pbxt pbxt: total 32 -rw-rw---- 1 monty my 7 Nov 4 16:41 location -rw-rw---- 1 monty my 8672 Nov 4 16:41 location.frm -rw-rw---- 1 monty my 8687 Nov 4 16:41 statistics.frm drwxrwxr-x 2 monty my 4096 Nov 4 16:41 system pbxt/system: total 32776 -rw-rw---- 1 monty my 9 Nov 4 16:41 ilog-1.xt -rw-rw---- 1 monty my 44 Nov 4 16:41 restart-1.xt -rw-rw---- 1 monty my 33554432 Nov 4 16:41 xlog-1.xt (/my/data) ls -l test/t9* -rw-rw---- 1 monty my 4 Nov 4 16:41 test/t9-1.xtr -rw-rw---- 1 monty my 8554 Nov 4 16:41 test/t9.frm -rw-rw---- 1 monty my 155 Nov 4 16:41 test/t9.xtd -rw-rw---- 1 monty my 4096 Nov 4 16:41 test/t9.xti ``` TODO: Fill in a description of what the above files are used for. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb version_minor version\_minor ============== Syntax ------ ``` sys.version_minor() ``` Description ----------- `version_minor` is a [stored function](../stored-functions/index) available with the [Sys Schema](../sys-schema/index). It returns the MariaDB Server minor release version. Examples -------- ``` SELECT VERSION(), sys.version_major() AS major, sys.version_minor() AS minor, sys.version_patch() AS patch; +----------------+-------+-------+-------+ | VERSION() | major | minor | patch | +----------------+-------+-------+-------+ | 10.8.2-MariaDB | 10 | 8 | 2 | +----------------+-------+-------+-------+ ``` See Also -------- * [version\_major](../version_major/index) * [version\_patch](../version_patch/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb ColumnStore Delete ColumnStore Delete ================== The DELETE statement is used to remove rows from tables. Syntax ------ ``` DELETE [FROM] tbl_name [WHERE where_condition] [ORDER BY ...] [LIMIT row_count] ``` No disk space is recovered after a DELETE. TRUNCATE and DROP PARTITION can be used to recover space, or alternatively CREATE TABLE, loading only the remaining rows, then using DROP TABLE on the original table and RENAME TABLE). LIMIT will limit the number of rows deleted, which will perform the DELETE more quickly. The DELETE ... LIMIT statement can then be performed multiple times to achieve the same effect as DELETE with no LIMIT. The following statement deletes customer records with a customer key identification between 1001 and 1999: ``` DELETE FROM customer WHERE custkey > 1000 and custkey <2000 ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb ColumnStore Query Processing ColumnStore Query Processing ============================ MariaDB ColumnStore processes an end user query from the user to User and Performance modules. 1. Clients issue a query to the MariaDB Server running on the User Module. The server performs a table operation for all tables needed to fulfill the request and obtains the initial query execution plan. 2. Using the MariaDB storage engine interface, ColumnStore converts the server table object into ColumnStore objects. These objects are then sent to the User Module processes. 3. The User Module converts the MariaDB execution plan and optimizes the given objects into a ColumnStore execution plan. It then determines the steps needed to run the query and the order in which they need to be run. 4. The User Module then consults the Extent Map to determine which Performance Modules to consult for the data it needs, it then performs Extent Elimination, eliminating any Performance Modules from the list that only contain data outside the range of what the query requires. 5. The User Module then sends commands to one or more Performance Modules to perform block I/O operations. 6. The Performance Module or Modules carry out predicate filtering, join processing, initial aggregation of data from local or external storage, then send the data back to the User Module. 7. The User Module performs the final result-set aggregation and composes the result-set for the query. 8. The User Module / ExeMgr implements any window function calculations, as well as any necessary sorting on the result-set. It then returns the result-set to the server. 9. The MariaDB Server performs any select list functions, `ORDER BY` and `LIMIT` operations on the result-set. 10. The MariaDB Server returns the result-set to the client. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Using mysqlbinlog Using mysqlbinlog ================= **MariaDB starting with [10.4.6](https://mariadb.com/kb/en/mariadb-1046-release-notes/)**From [MariaDB 10.4.6](https://mariadb.com/kb/en/mariadb-1046-release-notes/), `mariadb-binlog` is a symlink to `mysqlbinlog`. **MariaDB starting with [10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/)**From [MariaDB 10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/), `mariadb-binlog` is the name of the tool, with `mysqlbinlog` a symlink . The MariaDB server's [binary log](../binary-log/index) is a set of files containing "events" which represent modifications to the contents of a MariaDB database. These events are written in a binary (i.e. non-human-readable) format. The *mysqlbinlog* utility is used to view these events in plain text. Run [mysqlbinlog](../mysqlbinlog/index) from a command-line like this: ``` shell> mysqlbinlog [options] log_file ... ``` See [mysqlbinlog Options](../mysqlbinlog-options/index) for details on the available options. As an example, here is how you could display the contents of a [binary log](../binary-log/index) file named "mariadb-bin.000152": ``` shell> mysqlbinlog mariadb-bin.000152 ``` If you are using statement-based logging (the default) the output includes the SQL statement, the ID of the server the statement was executed on, a timestamp, and how much time the statement took to execute. If you are using row-based logging the output of an event will not include an SQL statement but will instead output how individual rows were changed. The output from mysqlbinlog can be used as input to the mysql client to redo the statements contained in a [binary log](../binary-log/index). This is useful for recovering after a server crash. Here is an example: ``` shell> mysqlbinlog binlog-filenames | mysql -u root -p ``` If you would like to view and possibly edit the file before applying it to your database, use the '-r' flag to redirect the output to a file: ``` shell> mysqlbinlog -r filename binlog-filenames ``` You can then open the file and view it and delete any statements you don't want executed (such as an accidental DROP DATABASE). Once you are satisfied with the contents you can execute it with: ``` shell> mysql -u root -p < filename ``` Be careful to process multiple log files in a single connection, especially if one or more of them have any `CREATE TEMPORARY TABLE ...` statements. Temporary tables are dropped when the mysql client terminates, so if you are processing multiple log files one at a time (i.e. multiple connections) and one log file creates a temporary table and then a subsequent log file refers to the table you will get an 'unknown table' error. To execute multiple logfiles using a single connection, list them all on the mysqlbinlog command line: ``` shell> mysqlbinlog mariadb-bin.000001 mariadb-bin.000002 | mysql -u root -p ``` If you need to manually edit the binlogs before executing them, combine them all into a single file before processing. Here is an example: ``` shell> mysqlbinlog mariadb-bin.000001 > /tmp/mariadb-bin.sql shell> mysqlbinlog mariadb-bin.000002 >> /tmp/mariadb-bin.sql shell> # make any edits shell> mysql -u root -p -e "source /tmp/mariadb-bin.sql" ``` See Also -------- * [mysqlbinlog](../mysqlbinlog/index) * [mysqlbinlog Options](../mysqlbinlog-options/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb mariadb-setpermission mariadb-setpermission ===================== **MariaDB starting with [10.4.6](https://mariadb.com/kb/en/mariadb-1046-release-notes/)**From [MariaDB 10.4.6](https://mariadb.com/kb/en/mariadb-1046-release-notes/), `mariadb-setpermission` is a symlink to `mysql_setpermission`, the script for assisting with adding users or databases or changing passwords in MariaDB. **MariaDB starting with [10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/)**From [MariaDB 10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/), `mysql_setpermission` is the symlink, and `mariadb-setpermission` the binary name. See [mysql\_setpermission](../mysql_setpermission/index) for details. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Recursive Common Table Expressions Overview Recursive Common Table Expressions Overview =========================================== **MariaDB starting with [10.2.2](https://mariadb.com/kb/en/mariadb-1022-release-notes/)**Recursive Common Table Expressions have been supported since [MariaDB 10.2.2](https://mariadb.com/kb/en/mariadb-1022-release-notes/). Common Table Expressions (CTEs) are a standard SQL feature, and are essentially temporary named result sets. CTEs first appeared in the SQL standard in 1999, and the first implementations began appearing in 2007. There are two kinds of CTEs: * [Non-recursive](../common-table-expressions-overview/index) * Recursive, which this article covers. SQL is generally poor at recursive structures. CTEs permit a query to reference itself. A recursive CTE will repeatedly execute subsets of the data until it obtains the complete result set. This makes it particularly useful for handing hierarchical or tree-structured data. [max\_recursive\_iterations](../server-system-variables/index#max_recursive_iterations) avoids infinite loops. ### Syntax example [WITH RECURSIVE](../with/index) signifies a recursive CTE. It is given a name, followed by a body (the main query) as follows: ### Computation Given the following structure: First execute the anchor part of the query: Next, execute the recursive part of the query: ### Summary so far ``` with recursive R as ( select anchor_data union [all] select recursive_part from R, ... ) select ... ``` 1. Compute anchor\_data 2. Compute recursive\_part to get the new data 3. if (new data is non-empty) goto 2; ### CAST to avoid truncating data As currently implemented by MariaDB and by the SQL Standard, data may be truncated if not correctly cast. It is necessary to [CAST](../cast/index) the column to the correct width if the CTE's recursive part produces wider values for a column than the CTE's nonrecursive part. Some other DBMS give an error in this situation, and MariaDB's behavior may change in future - see [MDEV-12325](https://jira.mariadb.org/browse/MDEV-12325). See the [examples below](#cast-to-avoid-data-truncation). ### Examples #### Transitive closure - determining bus destinations Sample data: ``` CREATE TABLE bus_routes (origin varchar(50), dst varchar(50)); INSERT INTO bus_routes VALUES ('New York', 'Boston'), ('Boston', 'New York'), ('New York', 'Washington'), ('Washington', 'Boston'), ('Washington', 'Raleigh'); ``` Now, we want to return the bus destinations with New York as the origin: ``` WITH RECURSIVE bus_dst as ( SELECT origin as dst FROM bus_routes WHERE origin='New York' UNION SELECT bus_routes.dst FROM bus_routes JOIN bus_dst ON bus_dst.dst= bus_routes.origin ) SELECT * FROM bus_dst; +------------+ | dst | +------------+ | New York | | Boston | | Washington | | Raleigh | +------------+ ``` The above example is computed as follows: First, the anchor data is calculated: * Starting from New York * Boston and Washington are added Next, the recursive part: * Starting from Boston and then Washington * Raleigh is added * UNION excludes nodes that are already present. #### Computing paths - determining bus routes This time, we are trying to get bus routes such as “New York -> Washington -> Raleigh”. Using the same sample data as the previous example: ``` WITH RECURSIVE paths (cur_path, cur_dest) AS ( SELECT origin, origin FROM bus_routes WHERE origin='New York' UNION SELECT CONCAT(paths.cur_path, ',', bus_routes.dst), bus_routes.dst FROM paths JOIN bus_routes ON paths.cur_dest = bus_routes.origin AND NOT FIND_IN_SET(bus_routes.dst, paths.cur_path) ) SELECT * FROM paths; +-----------------------------+------------+ | cur_path | cur_dest | +-----------------------------+------------+ | New York | New York | | New York,Boston | Boston | | New York,Washington | Washington | | New York,Washington,Boston | Boston | | New York,Washington,Raleigh | Raleigh | +-----------------------------+------------+ ``` #### CAST to avoid data truncation In the following example, data is truncated because the results are not specifically cast to a wide enough type: ``` WITH RECURSIVE tbl AS ( SELECT NULL AS col UNION SELECT "THIS NEVER SHOWS UP" AS col FROM tbl ) SELECT col FROM tbl +------+ | col | +------+ | NULL | | | +------+ ``` Explicitly use [CAST](../cast/index) to overcome this: ``` WITH RECURSIVE tbl AS ( SELECT CAST(NULL AS CHAR(50)) AS col UNION SELECT "THIS NEVER SHOWS UP" AS col FROM tbl ) SELECT * FROM tbl; +---------------------+ | col | +---------------------+ | NULL | | THIS NEVER SHOWS UP | +---------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb | | = Syntax ------ ``` | ``` Description ----------- Bitwise OR. Converts the values to binary and compares bits. If either of the corresponding bits has a value of 1, the resulting bit is also 1. See also [bitwise AND](../bitwise_and/index). Examples -------- ``` SELECT 2|1; +-----+ | 2|1 | +-----+ | 3 | +-----+ SELECT 29 | 15; +---------+ | 29 | 15 | +---------+ | 31 | +---------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb External Tutorials External Tutorials ================== Here are some links to external MariaDB, MySQL and SQL tutorials that may be of interest MariaDB-Focused Tutorials ------------------------- * [Tutorialspoint MariaDB tutorial for beginners](https://www.tutorialspoint.com/mariadb/index.htm) * [MariaDB Tutorial by "Tech on the net"](https://www.techonthenet.com/mariadb/index.php) * [Learn MySQL / MariaDB for Beginners](https://www.tecmint.com/learn-mysql-mariadb-for-beginners) * [MariaDB Tutorial from javatpoint](https://www.javatpoint.com/mariadb-tutorial) MySQL-Focused Tutorials (But Should Work For MariaDB Too) --------------------------------------------------------- * [mysqltutorial](http://www.mysqltutorial.org). Site with a lot of MySQL usage information and also how to connect to MySQL from different programming languages. * [MySQL Tutorial for Beginners Learn in 7 Days](https://www.guru99.com/mysql-tutorial.htm) * [MySQL Tutorial from javatpoint](https://www.javatpoint.com/mysql-tutorial) * [MySQL Tutorial from w3resource](https://www.w3resource.com/mysql/mysql-tutorials.php) * [MySQL by Examples for Beginners](http://www.ntu.edu.sg/home/ehchua/programming/sql/mysql_beginner.html) * [MySQL Tutorial – A Beginner’s Guide To Learn MySQL](https://www.edureka.co/blog/mysql-tutorial/) * [Php/MySQL Tutorial from tizag](http://www.tizag.com/mysqlTutorial/) * [PHP & MySQL Tutorial from siteground](https://www.siteground.com/tutorials/php-mysql/) General SQL Tutorials --------------------- * [w3schools general SQL tutorial](https://www.w3schools.com/sql) * [sqltutorial](http://www.sqltutorial.org/). Helps you get started with SQL quickly and effectively through many practical examples. See Also -------- * [MariaDB Knowledge Base Training and Tutorials](../training-tutorials/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb Big DELETEs Big DELETEs =========== The problem ----------- How to [DELETE](../delete/index) lots of rows from a large table? Here is an example of purging items older than 30 days: ``` DELETE FROM tbl WHERE ts < CURRENT_DATE() - INTERVAL 30 DAY ``` If there are millions of rows in the table, this statement may take minutes, maybe hours. Any suggestions on how to speed this up? Why it is a problem ------------------- * [MyISAM](../myisam/index) will lock the table during the entire operation, thereby nothing else can be done with the table. * [InnoDB](../innodb/index) won't lock the table, but it will chew up a lot of resources, leading to sluggishness. * InnoDB has to write the undo information to its transaction logs; this significantly increases the I/O required. * [Replication](../replication/index), being asynchronous, will effectively be delayed (on Slaves) while the DELETE is running. InnoDB and undo --------------- To be ready for a crash, a transactional engine such as InnoDB will record what it is doing to a log file. To make that somewhat less costly, the log file is sequentially written. If the log files you have (there are usually 2) fill up because the delete is really big, then the undo information spills into the actual data blocks, leading to even more I/O. Deleting in chunks avoids some of this excess overhead. Limited benchmarking of total delete elapsed time show two observations: * Total delete time approximately doubles above some 'chunk' size (as opposed to below that threshold). I do not have a formula relating the log file size with the threshold cutoff. * Chunk size below several hundred rows is slower. This is probably because the overhead of starting/ending each chunk dominates the timing. Solutions * PARTITION -- Requires some careful setup, but is excellent for purging a time-base series. * DELETE in chunks -- Carefully walk through the table N rows at a time. PARTITION --------- The idea here is to have a sliding window of [partitions](../managing-mariadb-partitioning/index). Let's say you need to purge news articles after 30 days. The "partition key" would be the [datetime](../datetime/index) (or [timestamp](../timestamp/index)) that is to be used for purging, and the PARTITIONs would be "range". Every night, a cron job would come along and build a new partition for the next day, and drop the oldest partition. Dropping a partition is essentially instantaneous, much faster than deleting that many rows. However, you must design the table so that the entire partition can be dropped. That is, you cannot have some items living longer than others. PARTITION tables have a lot of restrictions, some are rather weird. You can either have no UNIQUE (or PRIMARY) key on the table, or every UNIQUE key must include the partition key. In this use case, the partition key is the datetime. It should not be the first part of the PRIMARY KEY (if you have a PRIMARY KEY). You can PARTITION InnoDB or MyISAM tables. Since two news articles could have the same timestamp, you cannot assume the partition key is sufficient for uniqueness of the PRIMARY KEY, so you need to find something else to help with that. Reference implementation for Partition maintenance [MariaDB docs on PARTITION](../managing-mariadb-partitioning/index) Deleting in chunks ------------------ Although the discussion in this section talks about DELETE, it can be used for any other "chunking", such as, say, UPDATE, or SELECT plus some complex processing. (This discussion applies to both MyISAM and InnoDB.) When deleting in chunks, be sure to avoid doing a table scan. The code below is good at that; it scans no more than 1001 rows in any one query. (The 1000 is tunable.) Assuming you have news articles that need to be purged, and you have a schema something like ``` CREATE TABLE tbl id INT UNSIGNED NOT NULL AUTO_INCREMENT, ts TIMESTAMP, ... PRIMARY KEY(id) ``` Then, this pseudo-code is a good way to delete the rows older than 30 days: ``` @a = 0 LOOP DELETE FROM tbl WHERE id BETWEEN @a AND @a+999 AND ts < DATE_SUB(CURRENT_DATE(), INTERVAL 30 DAY) SET @a = @a + 1000 sleep 1 -- be a nice guy UNTIL end of table ``` Notes (Most of these caveats will be covered later): * It uses the PK instead of the secondary key. This gives much better locality of disk hits, especially for InnoDB. * You could (should?) do something to avoid walking through recent days but doing nothing. Caution -- the code for this could be costly. * The 1000 should be tweaked so that the DELETE usually takes under, say, one second. * No INDEX on ts is needed. (This helps INSERTs a little.) * If your PRIMARY KEY is compound, the code gets messier. * This code will not work without a numeric PRIMARY or UNIQUE key. * Read on, we'll develop messier code to deal with most of these caveats. If there are big gaps in `id` values (and there will after the first purge), then ``` @a = SELECT MIN(id) FROM tbl LOOP SELECT @z := id FROM tbl WHERE id >= @a ORDER BY id LIMIT 1000,1 If @z is null exit LOOP -- last chunk DELETE FROM tbl WHERE id >= @a AND id < @z AND ts < DATE_SUB(CURRENT_DATE(), INTERVAL 30 DAY) SET @a = @z sleep 1 -- be a nice guy, especially in replication ENDLOOP # Last chunk: DELETE FROM tbl WHERE id >= @a AND ts < DATE_SUB(CURRENT_DATE(), INTERVAL 30 DAY) ``` That code works whether id is numeric or character, and it mostly works even if id is not UNIQUE. With a non-unique key, the risk is that you could be caught in a loop whenever @z==@a. That can be detected and fixed thus: ``` ... SELECT @z := id FROM tbl WHERE id >= @a ORDER BY id LIMIT 1000,1 If @z == @a SELECT @z := id FROM tbl WHERE id > @a ORDER BY id LIMIT 1 ... ``` The drawback is that there could be more than 1000 items with a single id. In most practical cases, that is unlikely. If you do not have a primary (or unique) key defined on the table, and you have an INDEX on ts, then consider ``` LOOP DELETE FROM tbl WHERE ts < DATE_SUB(CURRENT_DATE(), INTERVAL 30 DAY) ORDER BY ts -- to use the index, and to make it deterministic LIMIT 1000 UNTIL no rows deleted ``` This technique is NOT recommended because the LIMIT leads to a warning on replication about it being non-deterministic (discussed below). InnoDB chunking recommendation ------------------------------ * Have a 'reasonable' size for [innodb\_log\_file\_size](../xtradbinnodb-server-system-variables/index#innodb_log_file_size). * Use AUTOCOMMIT=1 for the session doing the deletions. * Pick about 1000 rows for the chunk size. * Adjust the row count down if asynchronous replication (Statement Based) causes too much delay on the Slaves or hogs the table too much. Iterating through a compound key -------------------------------- To perform the chunked deletes recommended above, you need a way to walk through the PRIMARY KEY. This can be difficult if the PK has more than one column in it. To efficiently to do compound 'greater than': Assume that you left off at ($g, $s) (and have handled that row): ``` INDEX(Genus, species) SELECT/DELETE ... WHERE Genus >= '$g' AND ( species > '$s' OR Genus > '$g' ) ORDER BY Genus, species LIMIT ... ``` Addenda: The above AND/OR works well in older versions of MySQL; this works better in MariaDB and newer versions of MySQL: ``` WHERE ( Genus = '$g' AND species > '$s' ) OR Genus > '$g' ) ``` A caution about using @variables for strings. If, instead of '$g', you use @g, you need to be careful to make sure that @g has the same CHARACTER SET and COLLATION as `Genus`, else there could be a charset/collation conversion on the fly that prevents the use of the INDEX. Using the INDEX is vital for performance. It may require a COLLATE clause on SET NAMES and/or the @g in the SELECT. Reclaiming the disk space ------------------------- This is costly. (Switch to the PARTITION solution if practical.) MyISAM leaves gaps in the table (.MYD file); [OPTIMIZE TABLE](../optimize-table/index) will reclaim the freed space after a big delete. But it may take a long time and lock the table. InnoDB is block-structured, organized in a BTree on the PRIMARY KEY. An isolated deleted row leaves a block less full. A lot of deleted rows can lead to coalescing of adjacent blocks. (Blocks are normally 16KB - see [innodb\_page\_size](../xtradbinnodb-server-system-variables/index#innodb_page_size).) In InnoDB, there is no practical way to reclaim the freed space from ibdata1, other than to reuse the freed blocks eventually. The only option with [innodb\_file\_per\_table = 0](../xtradbinnodb-server-system-variables/index#innodb_file_per_table) is to dump ALL tables, remove ibdata\*, restart, and reload. That is rarely worth the effort and time. InnoDB, even with innodb\_file\_per\_table = 1, won't give space back to the OS, but at least it is only one table to rebuild with. In this case, something like this should work: ``` CREATE TABLE new LIKE main; INSERT INTO new SELECT * FROM main; -- This could take a long time RENAME TABLE main TO old, new TO main; -- Atomic swap DROP TABLE old; -- Space freed up here ``` You do need enough disk space for both copies. You must not write to the table during the process. Deleting more than half a table ------------------------------- The following technique can be used for any combination of * Deleting a large portion of the table more efficiently * Add PARTITIONing * Converting to [innodb\_file\_per\_table = ON](../xtradbinnodb-server-system-variables/index#innodb_file_per_table) * Defragmenting This can be done by chunking, or (if practical) all at once: ``` -- Optional: SET GLOBAL innodb_file_per_table = ON; CREATE TABLE New LIKE Main; -- Optional: ALTER TABLE New ADD PARTITION BY RANGE ...; -- Do this INSERT..SELECT all at once, or with chunking: INSERT INTO New SELECT * FROM Main WHERE ...; -- just the rows you want to keep RENAME TABLE main TO Old, New TO Main; DROP TABLE Old; -- Space freed up here ``` Notes: * You do need enough disk space for both copies. * You must not write to the table during the process. (Changes to Main may not be reflected in New.) Non-deterministic replication ----------------------------- Any UPDATE, DELETE, etc with LIMIT that is replicated to slaves (via [Statement Based Replication](../binary-log-formats/index)) *may* cause inconsistencies between the Master and Slaves. This is because the actual order of the records discovered for updating/deleting may be different on the slave, thereby leading to a different subset being modified. To be safe, add ORDER BY to such statements. Moreover, be sure the ORDER BY is deterministic -- that is, the fields/expressions in the ORDER BY are unique. An example of an ORDER BY that does not quite work: Assume there are multiple rows for each 'date': ``` DELETE * FROM tbl ORDER BY date LIMIT 111 ``` Given that id is the PRIMARY KEY (or UNIQUE), this will be safe: ``` DELETE * FROM tbl ORDER BY date, id LIMIT 111 ``` Unfortunately, even with the ORDER BY, MySQL has a deficiency that leads to a bogus warning in mysqld.err. See Spurious "Statement is not safe to log in statement format." warnings Some of the above code avoids this spurious warning by doing ``` SELECT @z := ... LIMIT 1000,1; -- not replicated DELETE ... BETWEEN @a AND @z; -- deterministic ``` That pair of statements guarantees no more than 1000 rows are touched, not the whole table. Replication and KILL -------------------- If you KILL a DELETE (or any? query) on the master in the middle of its execution, what will be replicated? If it is InnoDB, the query should be rolled back. (Exceptions??) In MyISAM, rows are DELETEd as the statement is executed, and there is no provision for ROLLBACK. Some of the rows will be deleted, some won't. You probably have no clue of how much was deleted. In a single server, simply run the delete again. The delete is put into the binlog, but with error 1317. Since replication is supposed to keep the master and slave in sync, and since it has no clue of how to do that, replication stops and waits for manual intervention. In a HA (High Available) system using replication, this is a minor disaster. Meanwhile, you need to go to each slave(s) and verify that it is stuck for this reason, then do ``` SET GLOBAL SQL_SLAVE_SKIP_COUNTER = 1; START SLAVE; ``` Then (presumably) re-executing the DELETE will finish the aborted task. (That is yet another reason to move all your tables [from MyISAM to InnoDB](../converting-tables-from-myisam-to-innodb/index).) SBR vs RBR; Galera ------------------ TBD -- "Row Based Replication" may impact this discussion. Postlog ------- The tips in this document apply to MySQL, MariaDB, and Percona. See also -------- Rick James graciously allowed us to use this article in the Knowledge Base. [Rick James' site](http://mysql.rjweb.org/) has other useful tips, how-tos, optimizations, and debugging tips. Original source: <http://mysql.rjweb.org/doc.php/deletebig> Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Installing and Testing SphinxSE with MariaDB Installing and Testing SphinxSE with MariaDB ============================================ To use [SphinxSE](../sphinx-storage-engine/index) with MariaDB you need to first [download and install Sphinx](../installing-sphinx/index). Complete Sphinx documentation is available on the [Sphinx website](http://sphinxsearch.com/docs/). Tips for Installing Sphinx -------------------------- ### libexpat One library we know you will need on Linux before you can install Sphinx is `libexpat`. If it is not installed, you will get the warning `checking for libexpat... not found`. On Suse the package is called `libexpat-devel`, on Ubuntu the package is called `libexpat1-dev`. ### MariaDB detection If you run into problems with MariaDB not being detected, use the following options: ``` --with-mysql compile with MySQL support (default is enabled) --with-mysql-includes path to MySQL header files --with-mysql-libs path to MySQL libraries ``` The above will tell the `configure` script where your MySQL/MariaDB installation is. Testing Sphinx -------------- After installing Sphinx, you can check that things are working in MariaDB by doing the following: ``` cd installation-dir/mysql-test ./mysql-test-run --suite=sphinx ``` If the above test doesn't pass, check the logs in the `'var'` directory. If there is a problem with the sphinx installation, the reason can probably be found in the log file at: `var/log/sphinx.sphinx/searchd/sphinx.log`. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Galera Use Cases Galera Use Cases ================ Here are some common use cases for Galera replication: | | | | --- | --- | | Read Master | Traditional MariaDB master-slave topology, but with Galera all "slave" nodes are capable masters at all times - it is just the application that treats them as slaves. Galera replication can guarantee zero slave lag for such installations and, due to parallel slave applying, much better throughput for the cluster. | | WAN Clustering | Synchronous replication works fine over the WAN network. There will be a delay, which is proportional to the network round trip time (RTT), but it only affects the commit operation. | | Disaster Recover | Disaster recovery is a sub-class of WAN replication. Here one data center is passive and only receives replication events, but does not process any client transactions. Such a remote data center will be up to date at all times and no data loss can happen. During recovery, the spare site is just nominated as primary and application can continue as normal with a minimal fail over delay. | | Latency Eraser | With WAN replication topology, cluster nodes can be located close to clients. Therefore all read & write operations will be super fast with the local node connection. The RTT related delay will be experienced only at commit time, and even then it can be generally accepted by end user, usually the kill-joy for end user experiences is the slow browsing response time, and read operations are as fast as they possibly can be. | See Also -------- * [What is MariaDB Galera Cluster?](../what-is-mariadb-galera-cluster/index) * [About Galera Replication](../about-galera-replication/index) * [Codership: Using Galera Cluster](http://codership.com/content/using-galera-cluster) * [Getting Started with MariaDB/Galera Cluster](../getting-started-with-mariadb-galera-cluster/index) * [MariaDB Galera Cluster and M/S replication](https://www.youtube.com/watch?v=Nd0nvltLPdQ) (video) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Information Schema CHECK_CONSTRAINTS Table Information Schema CHECK\_CONSTRAINTS Table =========================================== **MariaDB starting with [10.2.22](https://mariadb.com/kb/en/mariadb-10222-release-notes/)**The Information Schema CHECK\_CONSTRAINTS Table was introduced in [MariaDB 10.3.10](https://mariadb.com/kb/en/mariadb-10310-release-notes/) and [MariaDB 10.2.22](https://mariadb.com/kb/en/mariadb-10222-release-notes/). The [Information Schema](../information_schema/index) `CHECK_CONSTRAINTS` table stores metadata about the [constraints](../constraint/index) defined for tables in all databases. It contains the following columns: | Column | Description | | --- | --- | | `CONSTRAINT_CATALOG` | Always contains the string 'def'. | | `CONSTRAINT_SCHEMA` | Database name. | | `CONSTRAINT_NAME` | Constraint name. | | `TABLE_NAME` | Table name. | | `LEVEL` | Type of the constraint ('Column' or 'Table'). From [MariaDB 10.5.10](https://mariadb.com/kb/en/mariadb-10510-release-notes/) | | `CHECK_CLAUSE` | Constraint clause. | Example ------- A table with a numeric table check constraint and with a default check constraint name: ``` CREATE TABLE t ( a int, CHECK (a>10)); ``` To see check constraint call `check_constraints` table from [information schema](../information_schema/index). ``` SELECT * from INFORMATION_SCHEMA.CHECK_CONSTRAINTS\G ``` ``` *************************** 1. row *************************** CONSTRAINT_CATALOG: def CONSTRAINT_SCHEMA: test CONSTRAINT_NAME: CONSTRAINT_1 TABLE_NAME: t CHECK_CLAUSE: `a` > 10 ``` A new table check constraint called `a_upper`: ``` ALTER TABLE t ADD CONSTRAINT a_upper CHECK (a<100); ``` ``` SELECT * from INFORMATION_SCHEMA.CHECK_CONSTRAINTS\G ``` ``` *************************** 1. row *************************** CONSTRAINT_CATALOG: def CONSTRAINT_SCHEMA: test CONSTRAINT_NAME: CONSTRAINT_1 TABLE_NAME: t CHECK_CLAUSE: `a` > 10 *************************** 2. row *************************** CONSTRAINT_CATALOG: def CONSTRAINT_SCHEMA: test CONSTRAINT_NAME: a_upper TABLE_NAME: t CHECK_CLAUSE: `a` < 100 ``` A new table `tt` with a field check constraint called `b` , as well as a table check constraint called `b_upper`: ``` CREATE TABLE tt(b int CHECK(b>0),CONSTRAINT b_upper CHECK(b<50)); SELECT * from INFORMATION_SCHEMA.CHECK_CONSTRAINTS; +--------------------+-------------------+-----------------+------------+--------------+ | CONSTRAINT_CATALOG | CONSTRAINT_SCHEMA | CONSTRAINT_NAME | TABLE_NAME | CHECK_CLAUSE | +--------------------+-------------------+-----------------+------------+--------------+ | def | test | b | tt | `b` > 0 | | def | test | b_upper | tt | `b` < 50 | | def | test | CONSTRAINT_1 | t | `a` > 10 | | def | test | a_upper | t | `a` < 100 | +--------------------+-------------------+-----------------+------------+--------------+ ``` *Note:* The name of the field constraint is the same as the field name. After dropping the default table constraint called `CONSTRAINT_1`: ``` ALTER TABLE t DROP CONSTRAINT CONSTRAINT_1; SELECT * from INFORMATION_SCHEMA.CHECK_CONSTRAINTS; +--------------------+-------------------+-----------------+------------+--------------+ | CONSTRAINT_CATALOG | CONSTRAINT_SCHEMA | CONSTRAINT_NAME | TABLE_NAME | CHECK_CLAUSE | +--------------------+-------------------+-----------------+------------+--------------+ | def | test | b | tt | `b` > 0 | | def | test | b_upper | tt | `b` < 50 | | def | test | a_upper | t | `a` < 100 | +--------------------+-------------------+-----------------+------------+--------------+ ``` Trying to insert invalid arguments into table `t` and `tt` generates an error. ``` INSERT INTO t VALUES (10),(20),(100); ERROR 4025 (23000): CONSTRAINT `a_upper` failed for `test`.`t` INSERT INTO tt VALUES (10),(-10),(100); ERROR 4025 (23000): CONSTRAINT `b` failed for `test`.`tt` INSERT INTO tt VALUES (10),(20),(100); ERROR 4025 (23000): CONSTRAINT `b_upper` failed for `test`.`tt` ``` From [MariaDB 10.5.10](https://mariadb.com/kb/en/mariadb-10510-release-notes/): ``` create table majra(check(x>0), x int, y int check(y < 0), z int, constraint z check(z>0), constraint xyz check(x<10 and y<10 and z<10)); Query OK, 0 rows affected (0.036 sec) show create table majra; +-------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ | Table | Create Table | +-------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ | majra | CREATE TABLE `majra` ( `x` int(11) DEFAULT NULL, `y` int(11) DEFAULT NULL CHECK (`y` < 0), `z` int(11) DEFAULT NULL, CONSTRAINT `CONSTRAINT_1` CHECK (`x` > 0), CONSTRAINT `z` CHECK (`z` > 0), CONSTRAINT `xyz` CHECK (`x` < 10 and `y` < 10 and `z` < 10) ) ENGINE=InnoDB DEFAULT CHARSET=latin1 | +-------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ 1 row in set (0.000 sec) select * from information_schema.check_constraints where table_name='majra'; +--------------------+-------------------+------------+-----------------+--------+------------------------------------+ | CONSTRAINT_CATALOG | CONSTRAINT_SCHEMA | TABLE_NAME | CONSTRAINT_NAME | LEVEL | CHECK_CLAUSE | +--------------------+-------------------+------------+-----------------+--------+------------------------------------+ | def | test | majra | y | Column | `y` < 0 | | def | test | majra | CONSTRAINT_1 | Table | `x` > 0 | | def | test | majra | z | Table | `z` > 0 | | def | test | majra | xyz | Table | `x` < 10 and `y` < 10 and `z` < 10 | +--------------------+-------------------+------------+-----------------+--------+------------------------------------+ 4 rows in set (0.001 sec) ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb mysql.time_zone_transition Table mysql.time\_zone\_transition Table ================================== The `mysql.time_zone_transition` table is one of the `mysql` system tables that can contain [time zone](../time-zones/index) information. It is usually preferable for the system to handle the time zone, in which case the table will be empty (the default), but you can populate the `mysql` time zone tables using the [mysql\_tzinfo\_to\_sql](../mysql_tzinfo_to_sql/index) utility. See [Time Zones](../time-zones/index) for details. **MariaDB starting with [10.4](../what-is-mariadb-104/index)**In [MariaDB 10.4](../what-is-mariadb-104/index) and later, this table uses the [Aria](../aria/index) storage engine. **MariaDB until [10.3](../what-is-mariadb-103/index)**In [MariaDB 10.3](../what-is-mariadb-103/index) and before, this table uses the [MyISAM](../myisam-storage-engine/index) storage engine. The `mysql.time_zone_transition` table contains the following fields: | Field | Type | Null | Key | Default | Description | | --- | --- | --- | --- | --- | --- | | `Time_zone_id` | `int(10) unsigned` | NO | PRI | `NULL` | | | `Transition_time` | `bigint(20)` | NO | PRI | `NULL` | | | `Transition_type_id` | `int(10) unsigned` | NO | | `NULL` | | Example ------- ``` SELECT * FROM mysql.time_zone_transition; +--------------+-----------------+--------------------+ | Time_zone_id | Transition_time | Transition_type_id | +--------------+-----------------+--------------------+ | 1 | -1830383032 | 1 | | 2 | -1640995148 | 2 | | 2 | -1556841600 | 1 | | 2 | -1546388400 | 2 | | 2 | -1525305600 | 1 | | 2 | -1514852400 | 2 | | 2 | -1493769600 | 1 | | 2 | -1483316400 | 2 | | 2 | -1462233600 | 1 | | 2 | -1451780400 | 2 | ... +--------------+-----------------+--------------------+ ``` See Also -------- * [mysql.time\_zone table](../mysqltime_zone-table/index) * [mysql.time\_zone\_leap\_second table](../mysqltime_zone_leap_second-table/index) * [mysql.time\_zone\_name table](../mysqltime_zone_name-table/index) * [mysql.time\_zone\_transition\_type table](../mysqltime_zone_transition_type-table/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb SHOW PLUGINS SHOW PLUGINS ============ Syntax ------ ``` SHOW PLUGINS; ``` Description ----------- `SHOW PLUGINS` displays information about installed [plugins](../mariadb-plugins/index). The `Library` column indicates the plugin library - if it is `NULL`, the plugin is built-in and cannot be uninstalled. The `[PLUGINS](../information_schemaplugins-table/index)` table in the `information_schema` database contains more detailed information. For specific information about storage engines (a particular type of plugin), see the `[information\_schema.ENGINES](../information-schema-engines-table/index)` table and the `[SHOW ENGINES](../show-engines/index)` statement. Examples -------- ``` SHOW PLUGINS; +----------------------------+----------+--------------------+-------------+---------+ | Name | Status | Type | Library | License | +----------------------------+----------+--------------------+-------------+---------+ | binlog | ACTIVE | STORAGE ENGINE | NULL | GPL | | mysql_native_password | ACTIVE | AUTHENTICATION | NULL | GPL | | mysql_old_password | ACTIVE | AUTHENTICATION | NULL | GPL | | MRG_MyISAM | ACTIVE | STORAGE ENGINE | NULL | GPL | | MyISAM | ACTIVE | STORAGE ENGINE | NULL | GPL | | CSV | ACTIVE | STORAGE ENGINE | NULL | GPL | | MEMORY | ACTIVE | STORAGE ENGINE | NULL | GPL | | FEDERATED | ACTIVE | STORAGE ENGINE | NULL | GPL | | PERFORMANCE_SCHEMA | ACTIVE | STORAGE ENGINE | NULL | GPL | | Aria | ACTIVE | STORAGE ENGINE | NULL | GPL | | InnoDB | ACTIVE | STORAGE ENGINE | NULL | GPL | | INNODB_TRX | ACTIVE | INFORMATION SCHEMA | NULL | GPL | ... | INNODB_SYS_FOREIGN | ACTIVE | INFORMATION SCHEMA | NULL | GPL | | INNODB_SYS_FOREIGN_COLS | ACTIVE | INFORMATION SCHEMA | NULL | GPL | | SPHINX | ACTIVE | STORAGE ENGINE | NULL | GPL | | ARCHIVE | ACTIVE | STORAGE ENGINE | NULL | GPL | | BLACKHOLE | ACTIVE | STORAGE ENGINE | NULL | GPL | | FEEDBACK | DISABLED | INFORMATION SCHEMA | NULL | GPL | | partition | ACTIVE | STORAGE ENGINE | NULL | GPL | | pam | ACTIVE | AUTHENTICATION | auth_pam.so | GPL | +----------------------------+----------+--------------------+-------------+---------+ ``` See Also -------- * [List of Plugins](../list-of-plugins/index) * [Plugin Overview](../plugin-overview/index) * [INFORMATION\_SCHEMA.PLUGINS Table](../plugins-table-information-schema/index) * [INSTALL PLUGIN](../install-plugin/index) * [INFORMATION\_SCHEMA.ALL\_PLUGINS Table](../information-schema-all_plugins-table/index) (all plugins, installed or not) * [INSTALL SONAME](../install-soname/index) * [UNINSTALL PLUGIN](../uninstall-plugin/index) * [UNINSTALL SONAME](../uninstall-soname/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Cassandra Storage Engine Cassandra Storage Engine ========================= CassandraSE is no longer actively being developed and has been removed in [MariaDB 10.6](../what-is-mariadb-106/index). See [MDEV-23024](https://jira.mariadb.org/browse/MDEV-23024). A storage engine interface to [Cassandra](http://cassandra.apache.org/). Read the original [announcement information about CassandraSE](https://mariadb.org/announcing-the-cassandra-storage-engine/). | Title | Description | | --- | --- | | [Cassandra Storage Engine Overview](../cassandra-storage-engine-overview/index) | Introduction to the Cassandra storage engine | | [Cassandra Storage Engine Use Example](../cassandra-storage-engine-use-example/index) | Short demo of what using Cassandra Storage Engine looks like. | | [Cassandra Storage Engine Issues](../cassandra-storage-engine-issues/index) | Difficulties and peculiarities of the Cassandra Storage Engine. | | [Cassandra Storage Engine Future Plans](../cassandra-storage-engine-future-plans/index) | Brainstorming possible future directions for the Cassandra Storage Engine. | | [Handling Joins With Cassandra](../handling-joins-with-cassandra/index) | Joins with data stored in a Cassandra database are only possible on the MariaDB side | | [Virtual Machine to Test the Cassandra Storage Engine](../virtual-machine-to-test-the-cassandra-storage-engine/index) | Julien Duponchelle has made a virtual machine available for testing the Cassandra storage engine. | | [Building Cassandra Storage Engine](../building-cassandra-storage-engine/index) | THIS PAGE IS OBSOLETE, it describes how to build a branch of MariaDB-5.5 w... | | [Building Cassandra Storage Engine for Packaging](../building-cassandra-storage-engine-for-packaging/index) | OBSOLETE. How to build a branch of MariaDB-5.5 with Cassandra SE | | [Cassandra Status Variables](../cassandra-status-variables/index) | Cassandra-related status variables | | [Cassandra System Variables](../cassandra-system-variables/index) | Cassandra system variables | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Partitions Metadata Partitions Metadata =================== The [PARTITIONS](../information-schema-partitions-table/index) table in the [INFORMATION\_SCHEMA](../information-schema/index) database contains information about partitions. The [SHOW TABLE STATUS](../show-table-status/index) statement contains a `Create_options` column, that contains the string 'partitioned' for partitioned tables. The [SHOW CREATE TABLE](../show-create-table/index) statement returns the [CREATE TABLE](../create-table/index) statement that can be used to re-create a table, including the partitions definition. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb SQL Statements & Structure SQL Statements & Structure =========================== The letters *SQL* stand for Structured Query Language. As with all languages—even computer languages—there are grammar rules. This includes a certain structure to statements, acceptable punctuation (i.e., operators and delimiters), and a vocabulary (i.e., reserve words). | Title | Description | | --- | --- | | [SQL Statements](../sql-statements/index) | Explanations of all of the MariaDB SQL statements. | | [SQL Language Structure](../sql-language-structure/index) | Explanation of SQL grammar rules, including reserved words and literals. | | [Geographic & Geometric Features](../geographic-geometric-features/index) | Spatial extensions for geographic and geometric features. | | [NoSQL](../nosql/index) | NoSQL-related commands and interfaces | | [Operators](../operators/index) | Operators for comparing and assigning values. | | [Sequences](../sequences/index) | Sequence objects, an alternative to AUTO\_INCREMENT. | | [Temporal Tables](../temporal-tables/index) | MariaDB supports system-versioning, application-time periods and bitemporal tables. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb TOUCHES TOUCHES ======= Syntax ------ ``` Touches(g1,g2) ``` Description ----------- Returns `1` or `0` to indicate whether `g1` spatially touches `g2`. Two geometries spatially touch if the interiors of the geometries do not intersect, but the boundary of one of the geometries intersects either the boundary or the interior of the other. TOUCHES() is based on the original MySQL implementation and uses object bounding rectangles, while [ST\_TOUCHES()](../st_touches/index) uses object shapes. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Athens - Xentio Presentation - notes Athens - Xentio Presentation - notes ==================================== **Note:** This page is obsolete. The information is old, outdated, or otherwise currently incorrect. We are keeping the page for historical reasons only. **Do not** rely on the information in this article. Xentio works in the field of Business Intelligence. Their product is Swarm Cluster (SC) A Data Warehouse in the TB range costs a lot. SC can do it for a lot less. SC is a Shared-nothing distributed OLAP (Online Analytical Processing) server. It is optimized for running analytical workloads. It runs on clusters of commodity hardware. Apache Hadoop distributes the workload and MariaDB/MySQL powers node-local processing. It seamlessly integrates with your favorite reporting tool (anything which can process SQL or XML/A). Xentio's website: <http://xentio.com> Photos from the presentation: * <https://plus.google.com/b/102059736934609902389/102059736934609902389/posts/ddmfNy8KSjF> * <https://plus.google.com/b/102059736934609902389/102059736934609902389/posts/4FdXbFyu2DF> * <https://plus.google.com/b/102059736934609902389/102059736934609902389/posts/8mm6BNT8rfB> Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb CONNECT - Files Retrieved Using Rest Queries CONNECT - Files Retrieved Using Rest Queries ============================================ Starting with [CONNECT version 1.07.0001](../connect/index), JSON, XML and possibly CSV data files can be retrieved as results from REST queries when creating or querying such tables. This is done internally by CONNECT using the CURL program generally available on all systems (if not just install it). This can also be done using the Microsoft Casablanca (cpprestsdk) package. To enable it, first, install the package as explained in <https://github.com/microsoft/cpprestsdk>. Then make the GetRest library (dll or so) as explained in [Making the GetRest Library](../connect-making-the-getrest-library/index). Note: If both are available, cpprestsdk is used preferably because it is faster. This can be changed by specifying ‘curl=1’ in the option list. Note: If you want to use this feature with an older distributed version of MariaDB not featuring REST, it is possible to add it as an OEM module as explained in [Adding the REST Feature as a Library Called by an OEM Table](../connect-making-the-getrest-library/index). ### Creating Tables using REST To do so, specify the HTTP of the web client and eventually the URI of the request in the [CREATE TABLE](../create-table/index) statement. For example, for a query returning JSON data: ``` CREATE TABLE webusers ( id bigint(2) NOT NULL, name char(24) NOT NULL, username char(16) NOT NULL, email char(25) NOT NULL, address varchar(256) DEFAULT NULL, phone char(21) NOT NULL, website char(13) NOT NULL, company varchar(256) DEFAULT NULL ) ENGINE=CONNECT DEFAULT CHARSET=utf8 TABLE_TYPE=JSON FILE_NAME='users.json' HTTP='http://jsonplaceholder.typicode.com' URI='/users'; ``` As with standard JSON tables, discovery is possible, meaning that you can leave CONNECT to define the columns by analyzing the JSON file. Here you could just do: ``` CREATE TABLE webusers ENGINE=CONNECT DEFAULT CHARSET=utf8 TABLE_TYPE=JSON FILE_NAME='users.json' HTTP='http://jsonplaceholder.typicode.com' URI='/users'; ``` For example, executing: ``` SELECT name, address FROM webusers2 LIMIT 1; ``` returns: | name | address | | --- | --- | | Leanne Graham | Kulas Light Apt. 556 Gwenborough 92998-3874 -37.3159 81.1496 | Here we see that for some complex elements such as *address*, which is a Json object containing values and objects, CONNECT by default has just listed their texts separated by blanks. But it is possible to ask it to analyze in more depth the json result by adding the DEPTH option. For instance: ``` CREATE OR REPLACE TABLE webusers ENGINE=CONNECT DEFAULT CHARSET=utf8 TABLE_TYPE=JSON FILE_NAME='users.json' HTTP='http://jsonplaceholder.typicode.com' URI='/users' OPTION_LIST='Depth=2'; ``` Then the table will be created as: ``` CREATE TABLE `webusers3` ( `id` bigint(2) NOT NULL, `name` char(24) NOT NULL, `username` char(16) NOT NULL, `email` char(25) NOT NULL, `address_street` char(17) NOT NULL `JPATH`='$.address.street', `address_suite` char(9) NOT NULL `JPATH`='$.address.suite', `address_city` char(14) NOT NULL `JPATH`='$.address.city', `address_zipcode` char(10) NOT NULL `JPATH`='$.address.zipcode', `address_geo_lat` char(8) NOT NULL `JPATH`='$.address.geo.lat', `address_geo_lng` char(9) NOT NULL `JPATH`='$.address.geo.lng', `phone` char(21) NOT NULL, `website` char(13) NOT NULL, `company_name` char(18) NOT NULL `JPATH`='$.company.name', `company_catchPhrase` char(40) NOT NULL `JPATH`='$.company.catchPhrase', `company_bs` varchar(36) NOT NULL `JPATH`='$.company.bs' ) ENGINE=CONNECT DEFAULT CHARSET=utf8 `TABLE_TYPE`='JSON' `FILE_NAME`='users.json' `OPTION_LIST`='Depth=2' `HTTP`='http://jsonplaceholder.typicode.com' `URI`='/users'; ``` Allowing one to get all the values of the Json result, for example: ``` SELECT name, address_city city, company_name company FROM webusers3; ``` That results in: | name | city | company | | --- | --- | --- | | Leanne Graham | Gwenborough | Romaguera-Crona | | Ervin Howell | Wisokyburgh | Deckow-Crist | | Clementine Bauch McKenziehaven | Romaguera-Jacobson | | Patricia Lebsack | South Elvis | Robel-Corkery | | Chelsey Dietrich | Roscoeview | Keebler LLC | | Mrs. Dennis Schulist | South Christy | Considine-Lockman | | Kurtis Weissnat | Howemouth | Johns Group | | Nicholas Runolfsdottir V | Aliyaview | Abernathy Group | | Glenna Reichert | Bartholomebury | Yost and Sons | | Clementina DuBuque | Lebsackbury | Hoeger LLC | Of course, the complete create table (obtained by SHOW CREATE TABLE) can later be edited to make your table return exactly what you want to get. See the [JSON table type](../connect-json-table-type/index) for details about what and how to specify these. Note that such tables are read only. In addition, the data will be retrieved from the web each time you query the table with a [SELECT](../select/index) statement. This is fine if the result varies each time, such as when you query a weather forecasting site. But if you want to use the retrieved file many times without reloading it, just create another table on the same file without specifying the HTTP option. Note: For JSON tables, specifying the file name is optional and defaults to tabname.type. However, you should specify it if you want to use the file later for other tables. See the [JSON table type](../connect-json-table-type/index) for changes that will occur in the new CONNECT versions (distributed in early 2021). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Information Schema INNODB_SYS_FIELDS Table Information Schema INNODB\_SYS\_FIELDS Table ============================================ The [Information Schema](../information_schema/index) `INNODB_SYS_FIELDS` table contains information about fields that are part of an InnoDB index. The `PROCESS` [privilege](../grant/index) is required to view the table. It has the following columns: | Column | Description | | --- | --- | | `INDEX_ID` | Index identifier, matching the value from [INNODB\_SYS\_INDEXES.INDEX\_ID](../information-schema-innodb_sys_indexes-table/index). | | `NAME` | Field name, matching the value from [INNODB\_SYS\_COLUMNS.NAME](../information-schema-innodb_sys_columns-table/index). | | `POS` | Ordinal position of the field within the index, starting from `0`. This is adjusted as columns are removed. | Example ------- ``` SELECT * FROM information_schema.INNODB_SYS_FIELDS LIMIT 3\G *************************** 1. row *************************** INDEX_ID: 11 NAME: ID POS: 0 *************************** 2. row *************************** INDEX_ID: 12 NAME: FOR_NAME POS: 0 *************************** 3. row *************************** INDEX_ID: 13 NAME: REF_NAME POS: 0 3 rows in set (0.00 sec) ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb Buildbot Setup for Virtual Machines - Debian 6 i386 Buildbot Setup for Virtual Machines - Debian 6 i386 =================================================== Base Install ------------ ``` cd /kvm/vms qemu-img create -f qcow2 vm-debian6-i386-serial.qcow2 8G kvm -m 2047 -hda /kvm/vms/vm-debian6-i386-serial.qcow2 -cdrom /kvm/debian-6a1-i386-netinst.iso -redir 'tcp:2245::22' -boot d -smp 2 -cpu qemu64 -net nic,model=virtio -net user ``` Serial console and account setup -------------------------------- From base install, setup for serial port, and setup accounts for passwordless ssh login and sudo: ``` kvm -m 2047 -hda /kvm/vms/vm-debian6-i386-serial.qcow2 -redir 'tcp:2245::22' -boot c -smp 2 -cpu qemu64 -net nic,model=virtio -net user su apt-get install sudo openssh-server visudo # Add: %sudo ALL=NOPASSWD: ALL # add user account to group sudo `addgroup <USER> sudo`. # Copy in public ssh key. # Add in /etc/inittab: S0:2345:respawn:/sbin/getty -L ttyS0 19200 vt100 ``` Editing /etc/default/grub: ``` sudo vi /etc/default/grub # Add/edit these entries: GRUB_CMDLINE_LINUX_DEFAULT="console=tty0 console=ttyS0,115200n8" GRUB_TERMINAL="serial" GRUB_SERIAL_COMMAND="serial --unit=0 --speed=115200 --word=8 --parity=no --stop=1" sudo update-grub ``` Add user buildbot, with disabled password. Add as sudo, and add ssh key. ``` sudo adduser --disabled-password buildbot sudo adduser buildbot sudo sudo su - buildbot mkdir .ssh # Add all necessary keys. cat >.ssh/authorized_keys chmod -R go-rwx .ssh ``` VM for building .deb -------------------- ``` qemu-img create -b vm-debian6-i386-serial.qcow2 -f qcow2 vm-debian6-i386-build.qcow2 kvm -m 2047 -hda /kvm/vms/vm-debian6-i386-build.qcow2 -redir 'tcp:2245::22' -boot c -smp 2 -cpu qemu64 -net nic,model=virtio -net user -nographic sudo apt-get build-dep mysql-server-5.1 sudo apt-get install devscripts hardening-wrapper doxygen texlive-latex-base ghostscript libevent-dev libssl-dev zlib1g-dev libreadline-dev ``` VM for install testing ---------------------- ``` qemu-img create -b vm-debian6-i386-serial.qcow2 -f qcow2 vm-debian6-i386-install.qcow2 kvm -m 2047 -hda /kvm/vms/vm-debian6-i386-install.qcow2 -redir 'tcp:2245::22' -boot c -smp 2 -cpu qemu64 -net nic,model=virtio -net user -nographic ``` See above for how to obtain my.seed ``` # No packages mostly! sudo apt-get install debconf-utils cat >>/etc/apt/sources.list <<END deb file:///home/buildbot/buildbot/debs binary/ deb-src file:///home/buildbot/buildbot/debs source/ END sudo debconf-set-selections /tmp/my.seed ``` VM for upgrade testing ---------------------- ``` qemu-img create -b vm-debian6-i386-install.qcow2 -f qcow2 vm-debian6-i386-upgrade.qcow2 kvm -m 2047 -hda /kvm/vms/vm-debian6-i386-upgrade.qcow2 -redir 'tcp:2245::22' -boot c -smp 2 -cpu qemu64 -net nic,model=virtio -net user -nographic sudo apt-get install mysql-server-5.1 mysql -uroot -prootpass -e "create database mytest; use mytest; create table t(a int primary key); insert into t values (1); select * from t" ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb ST_X ST\_X ===== Syntax ------ ``` ST_X(p) X(p) ``` Description ----------- Returns the X-coordinate value for the point `p` as a double-precision number. `ST_X()` and `X()` are synonyms. Examples -------- ``` SET @pt = 'Point(56.7 53.34)'; SELECT X(GeomFromText(@pt)); +----------------------+ | X(GeomFromText(@pt)) | +----------------------+ | 56.7 | +----------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Installing and Configuring a Single Server ColumnStore System - 1.2.x Installing and Configuring a Single Server ColumnStore System - 1.2.x ===================================================================== Preparing to Install -------------------- Review the [Preparing for Installations Document](../preparing-for-columnstore-installation-12x/index) and ensure that any necessary pre-requisites have been completed on the target servers including installing the ColumnStore software packages. If installing a single combined functionality server with no plans to add additional servers, Single Node should be chosen. Going from single server to multi-server configuration to another will require a re-installation of the MariaDB ColumnStore software. MariaDB ColumnStore Quick Installer for a single server system -------------------------------------------------------------- The script quick\_installer\_single\_server.sh provides a simple 1 step install of MariaDB ColumnStore bypassing the interactive wizard style interface and works for both root and non-root installs. It will perform an install with these defaults: * System-Name = columnstore-1 * Single-Server Install with 1 Performance Module * Storage - Internal * DBRoot - DBroot #1 assigned to Performance Module #1 ### Running quick\_installer\_single\_server.sh ``` # /usr/local/mariadb/columnstore/bin/quick_installer_single_server.sh ``` Now you are ready to use the system. Custom Installation of Single-Server ColumnStore System ------------------------------------------------------- If you choose not to do the quick install and chose to customize the various options of installations using a wizard, you may use MariaDB ColumnStore postConfigure script. ### Custom Install Wizard: postConfigure The postConfigure script is a custom wizard to do the system(server and storage) configuration and setup. Before running the postConfigure script, you must have done [Preparing for ColumnStore Installation 1.2.x](../preparing-for-columnstore-installation-12x/index) steps. Once you have done these steps, then run the postConfigure script from the single server where you are installing ColumnStore. Run the script 'postConfigure' to complete the configuration and installation. #### Running postConfigure as root user: ``` /usr/local/mariadb/columnstore/bin/postConfigure ``` #### Running postConfigure as non-root user: ``` export COLUMNSTORE_INSTALL_DIR=/home/guest/mariadb/columnstore export LD_LIBRARY_PATH=/home/guest/mariadb/columnstore/lib:/home/guest/mariadb/columnstore/mysql/lib /home/guest/mariadb/columnstore/bin/postConfigure -i /home/guest/mariadb/columnstore ``` ### Common Installation Examples Once you start postConfigure, it will give general instruction, then for each configuration would give you options to select from. Next we look at these options #### Setup System Server Type Configuration ``` There are 2 options when configuring the System Server Type: single and multi 'single' - Single-Server install is used when there will only be 1 server configured on the system. It can also be used for production systems, if the plan is to stay single-server. 'multi' - Multi-Server install is used when you want to configure multiple servers now or in the future. With Multi-Server install, you can still configure just 1 server now and add on addition servers/modules in the future. Select the type of System Server install [1=single, 2=multi] (2) > 1 Performing a Single Server Install. Enter System Name (columnstore-1) > mymcs1 ``` **Notes**: You should give this system a name that will appear in various Admin utilities, SNMP messages, etc. The name can be composed of any number of printable characters and spaces. #### Setup High Availability Data Storage Mount Configuration ``` There are 2 options when configuring the storage: internal and external 'internal' - This is specified when a local disk is used for the DBRoot storage. High Availability Server Failover is not Supported in this mode 'external' - This is specified when the DBRoot directories are mounted. High Availability Server Failover is Supported in this mode. <<code>> Select the type of Data Storage [1=internal, 2=external] (1) > **<Enter>** ``` Notes: Choosing internal and using softlinks to point to an externally mounted storage will allow you to use any format (i.e., ext2, ext3, etc.). ``` Enter the list (Nx,Ny,Nz) or range (Nx-Nz) of dbroot IDs assigned to module 'pm1' (1) > 1 ``` **Notes**: The installer will set up the number of dbroot directories based on this answer. #### Performing Configuration Setup and MariaDB Columnstore Startup ``` NOTE: Setting 'NumBlocksPct' to 50% Setting 'TotalUmMemory' to 25% of total memory (Combined Server Install maximum value is 16G). Value set to 4G ``` **Notes**: The default maximum for a single server is 16Gb. ``` Running the MariaDB Columnstore MySQL setup scripts post-mysqld-install Successfully Completed post-mysql-install Successfully Completed Starting MariaDB ColumnStore Database Platform Starting MariaDB ColumnStore Database Platform, please wait......... DONE System Catalog Successfully Created MariaDB ColumnStore Install Successfully Completed, System is Active Enter the following command to define MariaDB ColumnStore Alias Commands . /usr/local/mariadb/columnstore/bin/columnstoreAlias Enter 'mcsmysql' to access the MariaDB Columnstore MySQL console Enter 'mcsadmin' to access the MariaDB Columnstore Admin console ``` #### MariaDB Columnstore Memory Configuration During the installation process, postConfigure will set the 2 main Memory configuration settings based on the size of memory detected on the local node. The 2 settings are in the MariaDB Columnstore Configuration file, /usr/local/mariadb/columnstore/etc Columnstore.xml. These 2 settings are: ``` 'NumBlocksPct' - Performance Module Data cache memory setting TotalUmMemory - User Module memory setting, used as temporary memory for joins ``` On a Single Server Install, this is the default settings: ``` NumBlocksPct - 50% of total memory TotalUmMemory - 25% of total memory, default maximum the percentage equal to 16G ``` The user can choose to change these settings after the install is completed, if for instance they want to setup more memory for Joins to utilize. On a single server or combined UM/PM server, it is recommended to not have the combination of these 2 settings over 75% of total memory. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Division Operator (/) Division Operator (/) ===================== Syntax ------ ``` / ``` Description ----------- Division operator. Dividing by zero will return NULL. By default, returns four digits after the decimal. This is determined by the server system variable [div\_precision\_increment](../server-system-variables/index#div_precision_increment) which by default is four. It can be set from 0 to 30. Dividing by zero returns `NULL`. If the `ERROR_ON_DIVISION_BY_ZERO` [SQL\_MODE](../sql-mode/index) is used (the default since [MariaDB 10.2.4](https://mariadb.com/kb/en/mariadb-1024-release-notes/)), a division by zero also produces a warning. Examples -------- ``` SELECT 4/5; +--------+ | 4/5 | +--------+ | 0.8000 | +--------+ SELECT 300/(2-2); +-----------+ | 300/(2-2) | +-----------+ | NULL | +-----------+ SELECT 300/7; +---------+ | 300/7 | +---------+ | 42.8571 | +---------+ ``` Changing [div\_precision\_increment](../server-system-variables/index#div_precision_increment) for the session from the default of four to six: ``` SET div_precision_increment = 6; SELECT 300/7; +-----------+ | 300/7 | +-----------+ | 42.857143 | +-----------+ SELECT 300/7; +-----------+ | 300/7 | +-----------+ | 42.857143 | +-----------+ ``` See Also -------- * [Type Conversion](../type-conversion/index) * [Addition Operator (+)](../addition-operator/index) * [Subtraction Operator (-)](../subtraction-operator-/index) * [Multiplication Operator (\*)](../multiplication-operator/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Using the Non-blocking Library Using the Non-blocking Library ============================== The MariaDB non-blocking client API is modelled after the normal blocking library calls. This makes it easy to learn and remember. It makes it easier to translate code from using the blocking API to using the non-blocking API (or vice versa). And it also makes it simple to mix blocking and non-blocking calls in the same code path. For every library call that may block on socket I/O, such as '`int mysql_real_query(MYSQL, query, query_length)`', two additional non-blocking calls are introduced: ``` int mysql_real_query_start(&status, MYSQL, query, query_length) int mysql_real_query_cont(&status, MYSQL, wait_status) ``` To do non-blocking operation, an application first calls `mysql_real_query_start()` instead of `mysql_real_query()`, passing the same parameters. If `mysql_real_query_start()` returns zero, then the operation completed without blocking, and 'status' is set to the value that would normally be returned from `mysql_real_query()`. Else, the return value from `mysql_real_query_start()` is a bitmask of events that the library is waiting on. This can be `MYSQL_WAIT_READ`, `MYSQL_WAIT_WRITE`, or `MYSQL_WAIT_EXCEPT`, corresponding to the similar flags for `select()` or `poll()`; and it can include `MYSQL_WAIT_TIMEOUT` when waiting for a timeout to occur (e.g. a connection timeout). In this case, the application continues other processing and eventually checks for the appropriate condition(s) to occur on the socket (or for timeout). When this occurs, the application can resume the operation by calling `mysql_real_query_cont()`, passing in 'wait\_status' a bitmask of the events which actually occurred. Just like `mysql_real_query_start()`, `mysql_real_query_cont()` returns zero when done, or a bitmask of events it needs to wait on. Thus the application continues to repeatedly call `mysql_real_query_cont()`, intermixed with other processing of its choice; until zero is returned, after which the result of the operation is stored in 'status'. Some calls, like `mysql_option()`, do not do any socket I/O, and so can never block. For these, there are no separate `_start()` or `_cont()` calls. See the "[Non-blocking API reference](../non-blocking-api-reference/index)" page for a full list of what functions can and can not block. The checking for events on the socket / timeout can be done with `select()` or `poll()` or a similar mechanism. Though often it will be done using a higher-level framework (such as libevent), which supplies facilities for registering and acting on such conditions. The descriptor of the socket on which to check for events can be obtained by calling `mysql_get_socket()`. The duration of any timeout can be obtained from `mysql_get_timeout_value()`. Here is a trivial (but full) example of running a query with the non-blocking API. The example is found in the MariaDB source tree as `client/async_example.c`. (A larger, more realistic example using libevent is found as `tests/async_queries.c` in the source): ``` static void run_query(const char *host, const char *user, const char *password) { int err, status; MYSQL mysql, *ret; MYSQL_RES *res; MYSQL_ROW row; mysql_init(&mysql); mysql_options(&mysql, MYSQL_OPT_NONBLOCK, 0); status = mysql_real_connect_start(&ret, &mysql, host, user, password, NULL, 0, NULL, 0); while (status) { status = wait_for_mysql(&mysql, status); status = mysql_real_connect_cont(&ret, &mysql, status); } if (!ret) fatal(&mysql, "Failed to mysql_real_connect()"); status = mysql_real_query_start(&err, &mysql, SL("SHOW STATUS")); while (status) { status = wait_for_mysql(&mysql, status); status = mysql_real_query_cont(&err, &mysql, status); } if (err) fatal(&mysql, "mysql_real_query() returns error"); /* This method cannot block. */ res= mysql_use_result(&mysql); if (!res) fatal(&mysql, "mysql_use_result() returns error"); for (;;) { status= mysql_fetch_row_start(&row, res); while (status) { status= wait_for_mysql(&mysql, status); status= mysql_fetch_row_cont(&row, res, status); } if (!row) break; printf("%s: %s\n", row[0], row[1]); } if (mysql_errno(&mysql)) fatal(&mysql, "Got error while retrieving rows"); mysql_free_result(res); mysql_close(&mysql); } /* Helper function to do the waiting for events on the socket. */ static int wait_for_mysql(MYSQL *mysql, int status) { struct pollfd pfd; int timeout, res; pfd.fd = mysql_get_socket(mysql); pfd.events = (status & MYSQL_WAIT_READ ? POLLIN : 0) | (status & MYSQL_WAIT_WRITE ? POLLOUT : 0) | (status & MYSQL_WAIT_EXCEPT ? POLLPRI : 0); if (status & MYSQL_WAIT_TIMEOUT) timeout = 1000*mysql_get_timeout_value(mysql); else timeout = -1; res = poll(&pfd, 1, timeout); if (res == 0) return MYSQL_WAIT_TIMEOUT; else if (res < 0) return MYSQL_WAIT_TIMEOUT; else { int status = 0; if (pfd.revents & POLLIN) status |= MYSQL_WAIT_READ; if (pfd.revents & POLLOUT) status |= MYSQL_WAIT_WRITE; if (pfd.revents & POLLPRI) status |= MYSQL_WAIT_EXCEPT; return status; } } ``` Setting MYSQL\_OPT\_NONBLOCK ---------------------------- Before using any non-blocking operation, it is necessary to enable it first by setting the `MYSQL_OPT_NONBLOCK` option: ``` mysql_options(&mysql, MYSQL_OPT_NONBLOCK, 0); ``` This call can be made at any time — typically it will be done at the start, before `mysql_real_connect()`, but it can be done at any time to start using non-blocking operations. If a non-blocking operation is attempted without setting the `MYSQL_OPT_NONBLOCK` option, the program will typically crash with a `NULL` pointer exception. The argument for `MYSQL_OPT_NONBLOCK` is the size of the stack used to save the state of a non-blocking operation while it is waiting for I/O and the application is doing other processing. Normally, applications will not have to change this, and it can be passed as zero to use the default value. Mixing blocking and non-blocking operation ------------------------------------------ It is possible to freely mix blocking and non-blocking calls on the same `MYSQL` connection. Thus, an application can do a normal blocking `mysql_real_connect()` and subsequently do a non-blocking `mysql_real_query_start()`. Or vice versa, do a non-blocking `mysql_real_connect_start()`, and later do a blocking `mysql_real_query()` on the resulting connection. Mixing can be useful to allow code to use the simpler blocking API in parts of the program where waiting is not a problem. For example establishing the connection(s) at program startup, or doing small quick queries between large, long-running ones. The only restriction is that any previous non-blocking operation must have finished before starting a new blocking (or non-blocking) operation, see the next section: "Terminating a non-blocking operation early" below. Terminating a non-blocking operation early ------------------------------------------ When a non-blocking operation is started with `mysql_real_query_start()` or another `_start()` function, it must be allowed to finish before starting a new operation. Thus, the application must continue calling `mysql_real_query_cont()` until zero is returned, indicating that the operation is completed. It is not allowed to leave one operation "hanging" in the middle of processing and then start a new one on top of it. It is, however, permissible to terminate the connection completely with `mysql_close()` in the middle of processing a non-blocking call. A new connection must then be initiated with `mysql_real_connect` before new queries can be run, either with a new `MYSQL` object or re-using the old one. In the future, we may implement an abort facility to force an on-going operation to terminate as quickly as possible (but it will still be necessary to call `mysql_real_query_cont()` one last time after abort, allowing it to clean up the operation and return immediately with an appropriate error code). Restrictions ------------ ### DNS When `mysql_real_connect_start()` is passed a hostname (as opposed to a local unix socket or an IP address, it may need to look up the hostname in DNS, depending on local host configuration (e.g. if the name is not in `/etc/hosts` or cached). Such DNS lookups do **not** happen in a non-blocking way. This means that `mysql_real_connect_start()` will not return control to the application while waiting for the DNS response. Thus the application may "hang" for some time if DNS is slow or non-functional. If this is a problem, the application can pass an IP address to `mysql_real_connect_start()` instead of a hostname, which avoids the problem. The IP address can be obtained by the application with whatever non-blocking DNS loopup operation is available to it from the operating system or event framework used. Alternatively, a simple solution may be to just add the hostname to the local host lookup file (`/etc/hosts` on Posix/Unix/Linux machines). ### Windows Named Pipes and Shared Memory connections There is no support in the non-blocking API for connections using Windows named pipes or shared memory Named pipes and shared memory can still be used, using either the blocking or the non-blocking API. However, operations that need to wait on I/O on the named pipe will not return control to the application; instead they will "hang" waiting for the operation to complete, just like the normal blocking API calls. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb Database Design Example Phase 1: Analysis Database Design Example Phase 1: Analysis ========================================= This article follows on from [Database Design Phase 6: Maintenance](../database-design-phase-6-maintenance/index). Real-world example: creating a publishing tracking system --------------------------------------------------------- Now let's walk through the database design process with a step-by-step example. The Poet's Circle is a publisher that publishes poetry and poetry anthologies. It is keen to develop a new system that tracks poets, poems, anthologies and sales. The following sections show the steps taken from the initial analysis to the final, working database. ### Poet's circle database phase 1: analysis The following information is gleaned from speaking to the various stakeholders at Poet's Circle. They want to develop a database system to track the poets they have recorded, the poems they write, the publications they appear in, as well as the sales to customers that these publications make. The designer asks various questions to get more detailed information, such as "What is a poet, as far as the system goes? Does Poet's Circle keep track of poets even if they haven't written or published poems? Are publications recorded even before there are any associated poems? Does a publication consist of one poem, or many? Are potential customer's details recorded?" The following summarizes the responses in our example: * Poet's Circle is a publisher that bases its choices of publications on an active poetry community on its website. If enough of the community wants a poem published, Poet's Circle will do so. * A poet can be anybody who wants to be a poet, not necessarily someone who has a poem captured in the system or someone who has even written a poem. * Poems can be submitted through a web interface, by email or on paper. * All captured poems are written by an associated poet, whose details are already in the system. There can be no poems submitted and stored without a full set of details of the poet. * A publication can be a single poem, a poetry anthology, or a work of literary criticism. * Customers can sign up through a web interface and may order publications at that point in time, or express interest in receiving updates for possible later purchases. * Sales of publications are made to customers whose details are stored in the system. There are no anonymous sales. * A single sale can be for one publication, but many publications can also be purchased at the same time. If more than one customer is involved in this sale, Poet's Circle treats it as more than one sale. Each customer has their own sale. * Not all publications make sales — some may be special editions, and others simply never sell any copies. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb METADATA_LOCK_INFO Plugin METADATA\_LOCK\_INFO Plugin =========================== The `METADATA_LOCK_INFO` plugin creates the [METADATA\_LOCK\_INFO](../information-schema-metadata_lock_info-table/index) table in the [INFORMATION\_SCHEMA](../information-schema/index) database. This table shows active [metadata locks](../metadata-locking/index). The table will be empty if there are no active metadata locks. Installing the Plugin --------------------- Although the plugin's shared library is distributed with MariaDB by default, the plugin is not actually installed by MariaDB by default. There are two methods that can be used to install the plugin with MariaDB. The first method can be used to install the plugin without restarting the server. You can install the plugin dynamically by executing [INSTALL SONAME](../install-soname/index) or [INSTALL PLUGIN](../install-plugin/index). For example: ``` INSTALL SONAME 'metadata_lock_info'; ``` The second method can be used to tell the server to load the plugin when it starts up. The plugin can be installed this way by providing the [--plugin-load](../mysqld-options/index#-plugin-load) or the [--plugin-load-add](../mysqld-options/index#-plugin-load-add) options. This can be specified as a command-line argument to [mysqld](../mysqld-options/index) or it can be specified in a relevant server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index). For example: ``` [mariadb] ... plugin_load_add = metadata_lock_info ``` Uninstalling the Plugin ----------------------- You can uninstall the plugin dynamically by executing [UNINSTALL SONAME](../uninstall-soname/index) or [UNINSTALL PLUGIN](../uninstall-plugin/index). For example: ``` UNINSTALL SONAME 'metadata_lock_info'; ``` If you installed the plugin by providing the [--plugin-load](../mysqld-options/index#-plugin-load) or the [--plugin-load-add](../mysqld-options/index#-plugin-load-add) options in a relevant server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index), then those options should be removed to prevent the plugin from being loaded the next time the server is restarted. Examples -------- ### Viewing all Metadata Locks ``` SELECT * FROM information_schema.metadata_lock_info; +-----------+--------------------------+---------------+----------------------+-----------------+-------------+ | THREAD_ID | LOCK_MODE | LOCK_DURATION | LOCK_TYPE | TABLE_SCHEMA | TABLE_NAME | +-----------+--------------------------+---------------+----------------------+-----------------+-------------+ | 31 | MDL_INTENTION_EXCLUSIVE | MDL_EXPLICIT | Global read lock | | | | 31 | MDL_INTENTION_EXCLUSIVE | MDL_EXPLICIT | Commit lock | | | | 31 | MDL_INTENTION_EXCLUSIVE | MDL_EXPLICIT | Schema metadata lock | dbname | | | 31 | MDL_SHARED_NO_READ_WRITE | MDL_EXPLICIT | Table metadata lock | dbname | exotics | +-----------+--------------------------+---------------+----------------------+-----------------+-------------+ 4 rows in set (0.00 sec) ``` ### Matching Metadata Locks with Threads and Queries ``` SELECT CONCAT('Thread ',P.ID,' executing "',P.INFO,'" IS LOCKED BY Thread ', M.THREAD_ID) WhoLocksWho FROM INFORMATION_SCHEMA.PROCESSLIST P, INFORMATION_SCHEMA.METADATA_LOCK_INFO M WHERE LOCATE(lcase(LOCK_TYPE), lcase(STATE))>0; +-----------------------------------------------------------------------------------+ | WhoLocksWho | +-----------------------------------------------------------------------------------+ | Thread 3 executing "INSERT INTO foo ( b ) VALUES ( 'FOO' )" IS LOCKED BY Thread 2 | +-----------------------------------------------------------------------------------+ 1 row in set (0.00 sec) SHOW PROCESSLIST; +----+------+-----------+------+---------+------+------------------------------+----------------------------------------+----------+ | Id | User | Host | db | Command | Time | State | Info | Progress | +----+------+-----------+------+---------+------+------------------------------+----------------------------------------+----------+ | 2 | root | localhost | test | Sleep | 123 | | NULL | 0.000 | | 3 | root | localhost | test | Query | 103 | Waiting for global read lock | INSERT INTO foo ( b ) VALUES ( 'FOO' ) | 0.000 | | 4 | root | localhost | test | Query | 0 | init | SHOW PROCESSLIST | 0.000 | +----+------+-----------+------+---------+------+------------------------------+----------------------------------------+----------+ 3 rows in set (0.00 sec) ``` Versions -------- | Version | Status | Introduced | | --- | --- | --- | | 0.1 | Stable | [MariaDB 10.1.13](https://mariadb.com/kb/en/mariadb-10113-release-notes/) | | 0.1 | Beta | [MariaDB 10.0.10](https://mariadb.com/kb/en/mariadb-10010-release-notes/) | | 0.1 | Alpha | [MariaDB 10.0.7](https://mariadb.com/kb/en/mariadb-1007-release-notes/) | Options ------- ### `metadata_lock_info` * **Description:** Controls how the server should treat the plugin when the server starts up. + Valid values are: - `OFF` - Disables the plugin without removing it from the [mysql.plugins](../mysqlplugin-table/index) table. - `ON` - Enables the plugin. If the plugin cannot be initialized, then the server will still continue starting up, but the plugin will be disabled. - `FORCE` - Enables the plugin. If the plugin cannot be initialized, then the server will fail to start with an error. - `FORCE_PLUS_PERMANENT` - Enables the plugin. If the plugin cannot be initialized, then the server will fail to start with an error. In addition, the plugin cannot be uninstalled with [UNINSTALL SONAME](../uninstall-soname/index) or [UNINSTALL PLUGIN](../uninstall-plugin/index) while the server is running. + See [Plugin Overview: Configuring Plugin Activation at Server Startup](../plugin-overview/index#configuring-plugin-activation-at-server-startup) for more information. * **Commandline:** `--metadata-lock-info=value` * **Data Type:** `enumerated` * **Default Value:** `ON` * **Valid Values:** `OFF`, `ON`, `FORCE`, `FORCE_PLUS_PERMANENT` --- Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Performance Schema socket_summary_by_event_name Table Performance Schema socket\_summary\_by\_event\_name Table ========================================================= It aggregates timer and byte count statistics for all socket I/O operations by socket instrument. | Column | Description | | --- | --- | | `EVENT_NAME` | Socket instrument. | | `COUNT_STAR` | Number of summarized events | | `SUM_TIMER_WAIT` | Total wait time of the summarized events that are timed. | | `MIN_TIMER_WAIT` | Minimum wait time of the summarized events that are timed. | | `AVG_TIMER_WAIT` | Average wait time of the summarized events that are timed. | | `MAX_TIMER_WAIT` | Maximum wait time of the summarized events that are timed. | | `COUNT_READ` | Number of all read operations, including `RECV`, `RECVFROM`, and `RECVMSG`. | | `SUM_TIMER_READ` | Total wait time of all read operations that are timed. | | `MIN_TIMER_READ` | Minimum wait time of all read operations that are timed. | | `AVG_TIMER_READ` | Average wait time of all read operations that are timed. | | `MAX_TIMER_READ` | Maximum wait time of all read operations that are timed. | | `SUM_NUMBER_OF_BYTES_READ` | Bytes read by read operations. | | `COUNT_WRITE` | Number of all write operations, including `SEND`, `SENDTO`, and `SENDMSG`. | | `SUM_TIMER_WRITE` | Total wait time of all write operations that are timed. | | `MIN_TIMER_WRITE` | Minimum wait time of all write operations that are timed. | | `AVG_TIMER_WRITE` | Average wait time of all write operations that are timed. | | `MAX_TIMER_WRITE` | Maximum wait time of all write operations that are timed. | | `SUM_NUMBER_OF_BYTES_WRITE` | Bytes written by write operations. | | `COUNT_MISC` | Number of all miscellaneous operations not counted above, including `CONNECT`, `LISTEN`, `ACCEPT`, `CLOSE`, and `SHUTDOWN`. | | `SUM_TIMER_MISC` | Total wait time of all miscellaneous operations that are timed. | | `MIN_TIMER_MISC` | Minimum wait time of all miscellaneous operations that are timed. | | `AVG_TIMER_MISC` | Average wait time of all miscellaneous operations that are timed. | | `MAX_TIMER_MISC` | Maximum wait time of all miscellaneous operations that are timed. | You can [TRUNCATE](../truncate-table/index) the table, which will reset all counters to zero. Example ------- ``` SELECT * FROM socket_summary_by_event_name\G *************************** 1. row *************************** EVENT_NAME: wait/io/socket/sql/server_tcpip_socket COUNT_STAR: 0 SUM_TIMER_WAIT: 0 MIN_TIMER_WAIT: 0 AVG_TIMER_WAIT: 0 MAX_TIMER_WAIT: 0 COUNT_READ: 0 SUM_TIMER_READ: 0 MIN_TIMER_READ: 0 AVG_TIMER_READ: 0 MAX_TIMER_READ: 0 SUM_NUMBER_OF_BYTES_READ: 0 COUNT_WRITE: 0 SUM_TIMER_WRITE: 0 MIN_TIMER_WRITE: 0 AVG_TIMER_WRITE: 0 MAX_TIMER_WRITE: 0 SUM_NUMBER_OF_BYTES_WRITE: 0 COUNT_MISC: 0 SUM_TIMER_MISC: 0 MIN_TIMER_MISC: 0 AVG_TIMER_MISC: 0 MAX_TIMER_MISC: 0 *************************** 2. row *************************** EVENT_NAME: wait/io/socket/sql/server_unix_socket COUNT_STAR: 0 SUM_TIMER_WAIT: 0 MIN_TIMER_WAIT: 0 AVG_TIMER_WAIT: 0 MAX_TIMER_WAIT: 0 COUNT_READ: 0 SUM_TIMER_READ: 0 MIN_TIMER_READ: 0 AVG_TIMER_READ: 0 MAX_TIMER_READ: 0 SUM_NUMBER_OF_BYTES_READ: 0 COUNT_WRITE: 0 SUM_TIMER_WRITE: 0 MIN_TIMER_WRITE: 0 AVG_TIMER_WRITE: 0 MAX_TIMER_WRITE: 0 SUM_NUMBER_OF_BYTES_WRITE: 0 COUNT_MISC: 0 SUM_TIMER_MISC: 0 MIN_TIMER_MISC: 0 AVG_TIMER_MISC: 0 MAX_TIMER_MISC: 0 ... ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb ColumnStore Update ColumnStore Update ================== The UPDATE statement changes data stored in rows. Syntax ------ Single-table syntax: ``` UPDATE table_reference SET col1={expr1|DEFAULT} [,col2={expr2|DEFAULT}] ... [WHERE where_condition] [ORDER BY ...] [LIMIT row_count] ``` Multiple-table syntax: ``` UPDATE table_references SET col1={expr1|DEFAULT} [, col2={expr2|DEFAULT}] ... [WHERE where_condition] ``` Note: It can only 1 table (but multiple columns) be updated from the table list in table\_references. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Aria Encryption Overview Aria Encryption Overview ======================== MariaDB can encrypt data in tables that use the [Aria storage engine](../aria/index). This includes both user-created tables and internal on-disk temporary tables that use the Aria storage engine. This ensures that your Aria data is only accessible through MariaDB. For encryption with the InnoDB and XtraDB storage engines, see [Encrypting Data for InnoDB/XtraDB](../encrypting-data-for-innodb-xtradb/index). Basic Configuration ------------------- In order to enable encryption for tables using the [Aria storage engine](../aria/index), there are a couple server system variables that you need to set and configure. Most users will want to set `[aria\_encrypt\_tables](../aria-system-variables/index#aria_encrypt_tables)` and `[encrypt\_tmp\_disk\_tables](../server-system-variables/index#encrypt_tmp_disk_tables)`. Users of data-at-rest encryption will also need to have a [key management and encryption plugin](../encryption-key-management/index) configured. Some examples are [File Key Management Plugin](../file-key-management-encryption-plugin/index) and [AWS Key Management Plugin](../aws-key-management-encryption-plugin/index). ``` [mariadb] ... # File Key Management plugin_load_add = file_key_management file_key_management_filename = /etc/mysql/encryption/keyfile.enc file_key_management_filekey = FILE:/etc/mysql/encryption/keyfile.key file_key_management_encryption_algorithm = AES_CTR # Aria Encryption aria_encrypt_tables=ON encrypt_tmp_disk_tables=ON ``` Determining Whether a Table is Encrypted ---------------------------------------- The [InnoDB storage engine](../xtradb-and-innodb/index) has the [information\_schema.INNODB\_TABLESPACES\_ENCRYPTION table](../information-schema-innodb_tablespaces_encryption-table/index) that can be used to get information about which tables are encrypted. Aria does not currently have anything like that (see [MDEV-17324](https://jira.mariadb.org/browse/MDEV-17324) about that). To determine whether an Aria table is encrypted, you currently have to search the data file for some plain text that you know is in the data. For example, let's say that we have the following table: ``` SELECT * FROM db1.aria_tab LIMIT 1; +----+------+ | id | str | +----+------+ | 1 | str1 | +----+------+ 1 row in set (0.00 sec ``` Then, we could search the data file that belongs to `db1.aria_tab` for `str1` using a command-line tool, such as [strings](https://linux.die.net/man/1/strings): ``` $ sudo strings /var/lib/mysql/db1/aria_tab.MAD | grep "str1" str1 ``` If you can find the plain text of the string, then you know that the table is not encrypted. Encryption and the Aria Log --------------------------- Only Aria tables are currently encrypted. The [Aria log](../aria-faq/index#differences-between-aria-and-myisam) is not yet encrypted. See [MDEV-8587](https://jira.mariadb.org/browse/MDEV-8587) about that. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb ST_LineFromWKB ST\_LineFromWKB =============== Syntax ------ ``` ST_LineFromWKB(wkb[,srid]) LineFromWKB(wkb[,srid]) ST_LineStringFromWKB(wkb[,srid]) LineStringFromWKB(wkb[,srid]) ``` Description ----------- Constructs a LINESTRING value using its [WKB](../well-known-binary-wkb-format/index) representation and SRID. `ST_LineFromWKB()`, `LineFromWKB()`, `ST_LineStringFromWKB()`, and `LineStringFromWKB()` are synonyms. Examples -------- ``` SET @g = ST_AsBinary(ST_LineFromText('LineString(0 4,4 6)')); SELECT ST_AsText(ST_LineFromWKB(@g)) AS l; +---------------------+ | l | +---------------------+ | LINESTRING(0 4,4 6) | +---------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb DEGREES DEGREES ======= Syntax ------ ``` DEGREES(X) ``` Description ----------- Returns the argument *`X`*, converted from radians to degrees. This is the converse of the [RADIANS()](../radians/index) function. Examples -------- ``` SELECT DEGREES(PI()); +---------------+ | DEGREES(PI()) | +---------------+ | 180 | +---------------+ SELECT DEGREES(PI() / 2); +-------------------+ | DEGREES(PI() / 2) | +-------------------+ | 90 | +-------------------+ SELECT DEGREES(45); +-----------------+ | DEGREES(45) | +-----------------+ | 2578.3100780887 | +-----------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb Building MariaDB on Debian Building MariaDB on Debian ========================== In the event that you are using the Linux-based operating system Debian or any of its direct derivatives and would like to compile MariaDB from source code, you can do so using the MariaDB source repository for the release that interests you. For Ubuntu and its derivatives, see [Building on Ubuntu](../building-mariadb-on-ubuntu/index). Before you begin, install the `software-properties-common` and `devscripts` packages: ``` $ sudo apt-get install -y software-properties-common \ devscripts ``` Installing Build Dependencies ----------------------------- MariaDB requires a number of packages to compile from source. Fortunately, you can use the MariaDB repositories to retrieve the necessary code for the version you want. Use the [Repository Configuration](https://downloads.mariadb.org/mariadb/repositories/) tool to determine how to set up the MariaDB repository for your release of Debian, the version of MariaDB that you want to install, and the mirror that you want to use. First add the authentication key for the repository, then add the repository. ``` $ sudo apt-key adv --recv-keys \ --keyserver hkp://keyserver.ubuntu.com:80 \ 0xF1656F24C74CD1D8 $ sudo add-apt-repository 'deb [arch=amd64] http://nyc2.mirrors.digitalocean.com/mariadb/repo/10.3/debian stretch main' ``` The second command added text to the `/etc/apt/sources.list` file. One of these lines is the repository containing binary packages for MariaDB, the other contains the source packages. The line for the source packages is commented out by default. This can be scripted: ``` sed -e '/^# deb-src.*mariadb/s/^# //' -i /etc/apt/sources.list ``` Alternately, open the file using your preferred text editor and uncomment the source repository. ``` $ sudo vim /etc/apt/sources.list ... deb [arch=amd64] http://nyc2.mirrors.digitalocean.com/mariadb/repo/10.3/debian stretch main deb-src [arch=amd64] http://nyc2.mirrors.digitalocean.com/mariadb/repo/10.3/debian stretch main ``` Once the repository is set up, you can use `apt-get` to retrieve the build dependencies. MariaDB packages supplied by Ubuntu and packages supplied by the MariaDB repository have the same base name of `mariadb-server`. You need to specify the specific version you want to retrieve. ``` $ sudo apt-get update $ sudo apt-get build-dep -y mariadb-server-10.3 ``` Building MariaDB ---------------- Once you have the base dependencies installed, you can retrieve the source code and start building MariaDB. The source code is available on GitHub. Use the `--branch` option to specify the particular version of MariaDB you want to build. ``` $ git clone --branch 10.3 https://github.com/MariaDB/server.git ``` The source code includes scripts to install the remaining build dependencies. For Ubuntu, they're located in the `debian/` directory. Navigate into the repository and run the `autobake-deb.sh` script. Then use ``` $ export DEB_BUILD_OPTIONS=parallel=$(nproc) $ cd server/ $ ./debian/autobake-deb.sh ``` ### After Building After building the packages, it is a good idea to put them in a repository. See the [Creating a Debian Repository](../creating_a_debian_repository/index) page for instructions. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Atomic DDL Atomic DDL ========== From [MariaDB 10.6.1](https://mariadb.com/kb/en/mariadb-1061-release-notes/), we have improved readability for DDL (Data Definition Language) operations to make most of them atomic, and the rest crash-safe, even if the server crashes in the middle of an operation. The design of Atomic/Crash-safe DDL ([MDEV-17567](https://jira.mariadb.org/browse/MDEV-17567)) allows it to work with all storage engines. Definitions ----------- * Atomic means that either the operation succeeds (and is logged to the [binary log](../binary-log/index) or is completely reversed. * Crash-safe means that in case of a crash, after the server has restarted, all tables are consistent, there are no temporary files or tables on disk and the binary log matches the status of the server. * DDL Data definition language. * DML Data manipulation language. * 'DDL recovery log' or 'DDL log' for short, is the new log file, `ddl_recovery.log` by default, that stores all DDL operations in progress. This is used to recover the state of the server in case of sudden crash. Background ---------- Before 10.6, in case of a crash, there was a small possibility that one of the following things could happen: * There could be temporary tables starting with `#sql-alter` or `#sql-shadow` or temporary files ending with '' left. * The table in the storage engine and the table's .frm file could be out of sync. * During a multi-table rename, only some of the tables were renamed. Which DDL Operations are Now Atomic ----------------------------------- * [CREATE TABLE](../create-table/index), except when used with [CREATE OR REPLACE](../create-table/index), which is only crash safe. * [RENAME TABLE](../rename-table/index) and [RENAME TABLES](../rename-table/index). * [CREATE VIEW](../create-view/index) * [CREATE SEQUENCE](../create-sequence/index) * [CREATE TRIGGER](../create-trigger/index) * [DROP TRIGGER](../drop-trigger/index) * [DROP TABLE](../drop-table/index) and [DROP VIEW](../drop-view/index). Dropping multiple tables is only crash safe. * [ALTER TABLE](../alter-table/index) * [ALTER SEQUENCE](../alter-sequence/index) is not listed above as it is internally implemented as a DML. Which DDL Operations are Now Crash Safe --------------------------------------- ### DROP TABLE of Multiple Tables. [DROP TABLE](../drop-table/index) over multiple tables is treated as if every DROP is a separate, atomic operation. This means that after a crash, all fully, or partly, dropped tables will be dropped and logged to the binary log. The undropped tables will be left untouched. ### CREATE OR REPLACE TABLE [CREATE OR REPLACE TABLE foo](../create-table/index) is implemented as: ``` DROP TABLE IF EXISTS foo; CREATE TABLE foo ... ``` This means that if there is a crash during `CREATE TABLE` then the original table 'foo' will be dropped even if the new table was not created. If the table was not re-created, the binary log will contain the `DROP TABLE`. #### DROP DATABASE [DROP DATABASE](../drop-database/index) is implemented as: ``` loop over all tables DROP TABLE table ``` Each [DROP TABLE](../drop-table/index) is atomic, but in case of a crash, things will work the same way as [DROP TABLE](../drop-table/index) with multiple tables. ### Atomic with Different Storage Engines Atomic/Crash-safe DDL works with all storage engines that either have atomic DDLs internally or are able to re-execute `DROP` or `RENAME` in case of failure. This should be true for most storage engines. The ones that still need some work are: * The [S3 storage engine](../s3-storage-engine/index). * The [partitioning engine](../partitioning-tables/index). Partitioning should be atomic for most cases, but there are still some known issues that need to be tested and fixed. ### The DDL Log Recovery File The new startup option [--log-ddl-recovery=path](../mysqld-options/index#-log-ddl-recovery) (`ddl_recovery.log` by default) can be used to specify the place for the DDL log file. This is mainly useful in the case when one has a filesystem on persistent memory, as there is a lot of sync on this file during DDL operations. This file contains all DDL operations that are in progress. At MariaDB server startup, the DDL log file is copied to a file with the same base name but with a `-backup.log` suffix. This is mainly done to be able to find out what went wrong if recovery fails. If the server crashes during recovery (unlikely but possible), the recovery will continue where it was before. The recovery will retry each entry up to 3 times before giving up and proceeding with the next entry. ### Conclusions * We believe that a clean separation of layers leads to an easier-to-maintain solution. The Atomic DDL implementation in [MariaDB 10.6](../what-is-mariadb-106/index) introduced minimal changes to the storage engine API, mainly for native ALTER TABLE. * In our InnoDB implementation, no file format changes were needed on top of the RENAME undo log that was introduced in [MariaDB 10.2.19](https://mariadb.com/kb/en/mariadb-10219-release-notes/) for a backup-safe TRUNCATE re-implementation. Correct use of sound design principles (write-ahead logging and transactions; also file creation now follows the ARIES protocol) is sufficient. We removed the hacks (at most one CREATE or DROP per transaction) and correctly implemented `rollback` and `purge` triggers for the InnoDB SYS\_INDEXES table. * Numerous DDL recovery bugs in InnoDB were found and fixed quickly thanks to <https://rr-project.org>. We are still working on one: data files must not be deleted before the DDL transaction is committed. Thanks to Atomic/Crash-safe DDL, the MariaDB server is now much more stable and reliable in unstable environments. There is still ongoing work to fix the few remaining issues mentioned above to make all DDL operations Atomic. The target for these is [MariaDB 10.7](../what-is-mariadb-107/index). ### See Also * [MDEV-17567](https://jira.mariadb.org/browse/MDEV-17567) Atomic DDL. This MDEV entry links to all other entries related to Atomic operations that contains a lot of information how things are implemented. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Rotating Logs on Unix and Linux Rotating Logs on Unix and Linux =============================== Unix and Linux distributions offer the `[logrotate](https://linux.die.net/man/8/logrotate)` utility, which makes it very easy to rotate log files. This page will describe how to configure log rotation for the [error log](../error-log/index), [general query log](../general-query-log/index), and the [slow query log](../slow-query-log/index). Configuring Locations and File Names of Logs -------------------------------------------- The first step is to configure the locations and file names of logs. To make the log rotation configuration easier, it can be best to put these logs in a dedicated log directory. We will need to configure the following: * The [error log](../error-log/index) location and file name is configured with the `[log\_error](../server-system-variables/index#log_error)` system variable. * The [general query log](../general-query-log/index) location and file name is configured with the `[general\_log\_file](../server-system-variables/index#general_log_file)` system variable. * The [slow query log](../slow-query-log/index) location and file name is configured with the `[slow\_query\_log\_file](../server-system-variables/index#slow_query_log_file)` system variable. If you want to enable the [general query log](../general-query-log/index) and [slow query log](../slow-query-log/index) immediately, then you will also have to configure the following: * The [general query log](../general-query-log/index) is enabled with the `[general\_log](../server-system-variables/index#general_log)` system variable. * The [slow query log](../slow-query-log/index) is enabled with the `[slow\_query\_log](../server-system-variables/index#slow_query_log)` system variable. These options can be set in a server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index) prior to starting up the server. For example, if we wanted to put our log files in `/var/log/mysql/`, then we could configure the following: ``` [mariadb] ... log_error=/var/log/mysql/mariadb.err general_log general_log_file=/var/log/mysql/mariadb.log slow_query_log slow_query_log_file=/var/log/mysql/mariadb-slow.log long_query_time=5 ``` We will also need to create the relevant directory: ``` sudo mkdir /var/log/mysql/ sudo chown mysql:mysql /var/log/mysql/ sudo chmod 0770 /var/log/mysql/ ``` If you are using [SELinux](../selinux/index), then you may also need to set the SELinux context for the directory. See [SELinux: Setting the File Context for Log Files](../selinux/index#setting-the-file-context-for-log-files) for more information. For example: ``` sudo semanage fcontext -a -t mysqld_log_t "/var/log/mysql(/.*)?" sudo restorecon -Rv /var/log/mysql ``` After MariaDB is [restarted](../starting-and-stopping-mariadb-starting-and-stopping-mariadb/index), it will use the new log locations and file names. Configuring Authentication for Logrotate ---------------------------------------- The `[logrotate](https://linux.die.net/man/8/logrotate)` utility needs to be able to authenticate with MariaDB in order to flush the log files. The easiest way to allow the `[logrotate](https://linux.die.net/man/8/logrotate)` utility to authenticate with MariaDB is to configure the `root@localhost` user account to use `[unix\_socket](../authentication-plugin-unix-socket/index)` authentication. **MariaDB starting with [10.4](../what-is-mariadb-104/index)**In [MariaDB 10.4](../what-is-mariadb-104/index) and later, the `root@localhost` user account is configured to use `[unix\_socket](../authentication-plugin-unix-socket/index)` authentication by default, so this part can be skipped in those versions. **MariaDB until [10.3](../what-is-mariadb-103/index)**In [MariaDB 10.3](../what-is-mariadb-103/index) and before, a user account is only able to have one authentication method at a time. In these versions, this means that once you enable `[unix\_socket](../authentication-plugin-unix-socket/index)` authentication for the `root@localhost` user account, you will no longer be able to use a password to log in with that user account. The user account will only be able to use `[unix\_socket](../authentication-plugin-unix-socket/index)` authentication. In [MariaDB 10.3](../what-is-mariadb-103/index) and before, you need to [install the unix\_socket plugin](../authentication-plugin-unix-socket/index#installing-the-plugin) before you can configure the `root@localhost` user account to use it. For example: ``` INSTALL SONAME 'auth_socket'; ``` After the plugin is installed, the `root@localhost` user account can be configured to use `[unix\_socket](../authentication-plugin-unix-socket/index)` authentication. How this is done depends on the version of MariaDB. **MariaDB starting with [10.2](../what-is-mariadb-102/index)**In [MariaDB 10.2](../what-is-mariadb-102/index) and later, the `root@localhost` user account can be altered to use `[unix\_socket](../authentication-plugin-unix-socket/index)` authentication with the `[ALTER USER](../alter-user/index)` statement. For example: ``` ALTER USER 'root'@'localhost' IDENTIFIED VIA unix_socket; ``` **MariaDB until [10.1](../what-is-mariadb-101/index)**In [MariaDB 10.1](../what-is-mariadb-101/index) and before, the `root@localhost` user account can be altered to use `[unix\_socket](../authentication-plugin-unix-socket/index)` authentication with the `[GRANT](../grant/index)` statement. For example: ``` GRANT ALL PRIVILEGES ON *.* TO 'root'@'localhost' IDENTIFIED VIA unix_socket WITH GRANT OPTION; ``` Configuring Logrotate --------------------- At this point, we can configure the `[logrotate](https://linux.die.net/man/8/logrotate)` utility to rotate the log files. On many systems, the primary `[logrotate](https://linux.die.net/man/8/logrotate)` configuration file is located at the following path: * `/etc/logrotate.conf` And the `[logrotate](https://linux.die.net/man/8/logrotate)` configuration files for individual services are located in the following directory: * `/etc/logrotate.d/` We can create a `[logrotate](https://linux.die.net/man/8/logrotate)` configuration file for MariaDB by executing the following command in a shell: ``` $ sudo tee /etc/logrotate.d/mariadb <<EOF /var/log/mysql/* { su mysql mysql missingok create 660 mysql mysql notifempty daily minsize 1M # only use with logrotate >= 3.7.4 maxsize 100M # only use with logrotate >= 3.8.1 rotate 30 # dateext # only use if your logrotate version is compatible with below dateformat # dateformat .%Y-%m-%d-%H-%M-%S # only use with logrotate >= 3.9.2 compress delaycompress sharedscripts olddir archive/ createolddir 770 mysql mysql # only use with logrotate >= 3.8.9 postrotate # just if mysqld is really running if test -x /usr/bin/mysqladmin && \ /usr/bin/mysqladmin ping &>/dev/null then /usr/bin/mysqladmin --local flush-error-log \ flush-engine-log flush-general-log flush-slow-log fi endscript } EOF ``` You may have to modify this configuration file to use it on your system, depending on the specific version of the `[logrotate](https://linux.die.net/man/8/logrotate)` utility that is installed. See the description of each configuration directive below to determine which `[logrotate](https://linux.die.net/man/8/logrotate)` versions support that configuration directive. Each specific configuration directive does the following: * **`missingok`**: This directive configures it to ignore missing files, rather than failing with an error. * **`create 660 mysql mysql`**: This directive configures it to recreate the log files after log rotation with the specified permissions and owner. * **`notifempty`**: This directive configures it to skip a log file during log rotation if it is empty. * **`daily`**: This directive configures it to rotate each log file once per day. * **`minsize 1M`**: This directive configures it to skip a log file during log rotation if it is smaller than 1 MB. This directive is only available with `[logrotate](https://linux.die.net/man/8/logrotate)` 3.7.4 and later. * **`maxsize 100M`**: This directive configures it to rotate a log file more frequently than daily if it grows larger than 100 MB. This directive is only available with `[logrotate](https://linux.die.net/man/8/logrotate)` 3.8.1 and later. * **`rotate 30`**: This directive configures it to keep 30 old copies of each log file. * **`dateext`**: This directive configures it to use the date as an extension, rather than just a number. This directive is only available with `[logrotate](https://linux.die.net/man/8/logrotate)` 3.7.6 and later. * **`dateformat .%Y-%m-%d-%H-%M-%S`**: This directive configures it to use this date format string (as defined by the format specification for `[strftime](https://linux.die.net/man/3/strftime)`) for the date extension configured by the `dateext` directive. This directive is only available with `[logrotate](https://linux.die.net/man/8/logrotate)` 3.7.7 and later. Support for `%H` is only available with `[logrotate](https://linux.die.net/man/8/logrotate)` 3.9.0 and later. Support for `%M` and `%S` is only available with `[logrotate](https://linux.die.net/man/8/logrotate)` 3.9.2 and later. * **`compress`**: This directive configures it to compress the log files with `[gzip](https://linux.die.net/man/1/gzip)`. * **`delaycompress`**: This directive configures it to delay compression of each log file until the next log rotation. If the log file is compressed at the same time that it is rotated, then there may be cases where a log file is being compressed while the MariaDB server is still writing to the log file. Delaying compression of a log file until the next log rotation can prevent race conditions such as these that can happen between the compression operation and the MariaDB server's log flush operation. * **`olddir archive/`**: This directive configures it to archive the rotated log files in `/var/log/mysql/archive/`. * **`createolddir 770 mysql mysql`**: This directive configures it to create the directory specified by the `olddir` directive with the specified permissions and owner, if the directory does not already exist. This directive is only available with `[logrotate](https://linux.die.net/man/8/logrotate)` 3.8.9 and later. * **`sharedscripts`**: This directive configures it to run the `postrotate` script just once, rather than once for each rotated log file. * **`postrotate`**: This directive configures it to execute a script after log rotation. This particular script executes the `[mysqladmin](../mysqladmin/index)` utility, which executes the `[FLUSH](../flush/index)` statement, which tells the MariaDB server to flush its various log files. When MariaDB server flushes a log file, it closes its existing file handle and reopens a new one. This ensure that MariaDB server does not continue writing to a log file after it has been rotated. This is an important component of the log rotation process. If our system does not have `[logrotate](https://linux.die.net/man/8/logrotate)` 3.8.9 or later, which is needed to support the `createolddir` directive, then we will also need to create the relevant directory specified by the `olddir` directive: ``` sudo mkdir /var/log/mysql/archive/ sudo chown mysql:mysql /var/log/mysql/archive/ sudo chmod 0770 /var/log/mysql/archive/ ``` Testing Log Rotation -------------------- We can test log rotation by executing the `[logrotate](https://linux.die.net/man/8/logrotate)` utility with the `--force` option. For example: ``` sudo logrotate --force /etc/logrotate.d/mariadb ``` Keep in mind that under normal operation, the `[logrotate](https://linux.die.net/man/8/logrotate)` utility may skip a log file during log rotation if the utility does not believe that the log file needs to be rotated yet. For example: * If you set the `notifempty` directive mentioned above, then it will be configured to skip a log file during log rotation if the log file is empty. * If you set the `daily` directive mentioned above, then it will be configured to only rotate each log file once per day. * If you set the `minsize 1M` directive mentioned above, then it will be configured to skip a log file during log rotation if the log file size is smaller than 1 MB. However, when running tests with the `--force` option, the `[logrotate](https://linux.die.net/man/8/logrotate)` utility does not take these options into consideration. After a few tests, we can see that the log rotation is indeed working: ``` $ sudo ls -l /var/log/mysql/archive/ total 48 -rw-rw---- 1 mysql mysql 440 Mar 31 15:31 mariadb.err.1 -rw-rw---- 1 mysql mysql 138 Mar 31 15:30 mariadb.err.2.gz -rw-rw---- 1 mysql mysql 145 Mar 31 15:28 mariadb.err.3.gz -rw-rw---- 1 mysql mysql 1007 Mar 31 15:27 mariadb.err.4.gz -rw-rw---- 1 mysql mysql 1437 Mar 31 15:32 mariadb.log.1 -rw-rw---- 1 mysql mysql 429 Mar 31 15:31 mariadb.log.2.gz -rw-rw---- 1 mysql mysql 439 Mar 31 15:28 mariadb.log.3.gz -rw-rw---- 1 mysql mysql 370 Mar 31 15:27 mariadb.log.4.gz -rw-rw---- 1 mysql mysql 3915 Mar 31 15:32 mariadb-slow.log.1 -rw-rw---- 1 mysql mysql 554 Mar 31 15:31 mariadb-slow.log.2.gz -rw-rw---- 1 mysql mysql 569 Mar 31 15:28 mariadb-slow.log.3.gz -rw-rw---- 1 mysql mysql 487 Mar 31 15:27 mariadb-slow.log.4.gz ``` Logrotate in Ansible -------------------- Let's see an example of how to configure logrotate in Ansible. First, we'll create a couple of tasks in our playbook: ``` - name: Create mariadb_logrotate_old_dir file: path: "{{ mariadb_logrotate_old_dir }}" owner: mysql group: mysql mode: '770' state: directory - name: Configure logrotate template: src: "../templates/logrotate.j2" dest: "/etc/logrotate.d/mysql" ``` The first task creates a directory to store the old, compressed logs, and set proper permissions. The second task uploads logrotate configuration file into the proper directory, and calls it `mysql`. As you can see the original name is different, and it ends with the `.j2` extension, because it is a Jinja 2 template. The file will look like the following: ``` {{ mariadb_log_dir }}/* { su mysql mysql missingok create 660 mysql mysql notifempty daily minsize 1M {{ mariadb_logrotate_min_size }} maxsize 100M {{ mariadb_logrotate_max_size }} rotate {{ mariadb_logrotate_old_dir }} dateformat .%Y-%m-%d-%H-%M-%S # only use with logrotate >= 3.9.2 compress delaycompress sharedscripts olddir archive/ createolddir 770 mysql mysql # only use with logrotate >= 3.8.9 postrotate # just if mysqld is really running if test -x /usr/bin/mysqladmin && \ /usr/bin/mysqladmin ping &>/dev/null then /usr/bin/mysqladmin --local flush-error-log \ flush-engine-log flush-general-log flush-slow-log fi endscript } ``` The file is very similar to the file shown above, which is obvious because we're still uploading a logrotate configuration file. Ansible is just a tool we've chosen to do this. However, both in the tasks and in the template, we used some variables. This allows to use different paths and rotation parameters for different hosts, or host groups. If we have a group host called `mariadb` that contains the default configuration for all our MariaDB servers, we can define these variables in a file called `group_vars/mariadb.yml`: ``` # MariaDB writes its logs here mariadb_log_dir: /var/lib/mysql/logs # logrotate configuration mariadb_logrotate_min_size: 500M mariadb_logrotate_max_size: 1G mariadb_logrotate_old_files: 7 mariadb_logrotate_old_dir: /var/mysql/old-logs ``` After setting up logrotate in Ansible, you may want to deploy it to a non-production server and test it manually as explained above. Once you're sure that it works fine on one server, you can be confident in the new Ansible tasks and deploy them on all servers. For more information on how to use Ansible to automate MariaDB configuration, see [Ansible and MariaDB](../ansible-and-mariadb/index). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb Using MariaDB GTIDs with MariaDB Galera Cluster Using MariaDB GTIDs with MariaDB Galera Cluster =============================================== MariaDB's [global transaction IDs (GTIDs)](../gtid/index) are very useful when used with [MariaDB replication](../high-availability-performance-tuning-mariadb-replication/index), which is primarily what that feature was developed for. [Galera Cluster](http://galeracluster.com/), on the other hand, was developed by Codership for all MySQL and MariaDB variants, and the initial development of the technology pre-dated MariaDB's [GTID](../gtid/index) implementation. As a side effect, [MariaDB Galera Cluster](../galera-cluster/index) (at least until [MariaDB 10.5.1](https://mariadb.com/kb/en/mariadb-1051-release-notes/)) only partially supports MariaDB's [GTID](../gtid/index) implementation. GTID Support for Write Sets Replicated by Galera Cluster -------------------------------------------------------- Galera Cluster has its own [certification-based replication method](../about-galera-replication/index) that is substantially different from [MariaDB replication](../high-availability-performance-tuning-mariadb-replication/index). However, it would still be beneficial if [MariaDB Galera Cluster](../galera-cluster/index) was able to associate a Galera Cluster write set with a [GTID](../gtid/index) that is globally unique, but that is also consistent for that write set on each cluster node. Before [MariaDB 10.5.1](https://mariadb.com/kb/en/mariadb-1051-release-notes/), [MariaDB Galera Cluster](../galera-cluster/index) did not replicate the original [GTID](../gtid/index) with the write set except in cases where the transaction was originally applied by a [slave SQL thread](../replication-threads/index#slave-sql-thread). Each node independently generated its own [GTID](../gtid/index) for each write set in most cases. See [MDEV-20720](https://jira.mariadb.org/browse/MDEV-20720). ### Wsrep GTID Mode **MariaDB starting with [10.1.4](https://mariadb.com/kb/en/mariadb-1014-release-notes/)**MariaDB has supported `[wsrep\_gtid\_mode](../galera-cluster-system-variables/index#wsrep_gtid_mode)` since version 10.1.4. [MariaDB 10.1](../what-is-mariadb-101/index) and above has a feature called wsrep GTID mode. When this mode is enabled, MariaDB uses some tricks to try to associate each Galera Cluster write set with a [GTID](../gtid/index) that is globally unique, but that is also consistent for that write set on each cluster node. These tricks work in some cases, but [GTIDs](../gtid/index) can still become inconsistent among cluster nodes. #### Enabling Wsrep GTID Mode Several things need to be configured for wsrep GTID mode to work, such as: * `[wsrep\_gtid\_mode=ON](../galera-cluster-system-variables/index#wsrep_gtid_mode)` needs to be set on all nodes in the cluster. * `[wsrep\_gtid\_domain\_id](../galera-cluster-system-variables/index#wsrep_gtid_domain_id)` needs to be set to the same value on all nodes in a given cluster, so that each cluster node uses the same domain when assigning [GTIDs](../gtid/index) for Galera Cluster's write sets. When replicating between two clusters, each cluster should have this set to a different value, so that each cluster uses different domains when assigning [GTIDs](../gtid/index) for their write sets. * `[log\_slave\_updates](../replication-and-binary-log-system-variables/index#log_slave_updates)` needs to be enabled on all nodes in the cluster. See [MDEV-9855](https://jira.mariadb.org/browse/MDEV-9855). * `[log\_bin](../replication-and-binary-log-server-system-variables/index#log_bin)` needs to be set to the same path on all nodes in the cluster. See [MDEV-9856](https://jira.mariadb.org/browse/MDEV-9856). And as an extra safety measure: * `[gtid\_domain\_id](../gtid/index#gtid_domain_id)` should be set to a different value on all nodes in a given cluster, and each of these values should be different than the configured `[wsrep\_gtid\_domain\_id](../galera-cluster-system-variables/index#wsrep_gtid_domain_id)` value. This is to prevent a node from using the same domain used for Galera Cluster's write sets when assigning [GTIDs](../gtid/index) for non-Galera transactions, such as DDL executed with `[wsrep\_sst\_method=RSU](../galera-cluster-system-variables/index#wsrep_sst_method)` set or DML executed with `[wsrep\_on=OFF](../galera-cluster-system-variables/index#wsrep_on)` set. For information on setting `[server\_id](../replication-and-binary-log-system-variables/index#server_id)`, see [Using MariaDB Replication with MariaDB Galera Cluster: Setting server\_id on Cluster Nodes](../using-mariadb-replication-with-mariadb-galera-cluster-using-mariadb-replica/index#setting-server_id-on-cluster-nodes). #### Known Problems with Wsrep GTID Mode Until [MariaDB 10.5.1](https://mariadb.com/kb/en/mariadb-1051-release-notes/), there were known cases where [GTIDs](../gtid/index) could become inconsistent across the cluster nodes. A known issue (fixed in [MariaDB 10.5.1](https://mariadb.com/kb/en/mariadb-1051-release-notes/)) is: * Implicitly dropped temporary tables can make GTIDs inconsistent. See [MDEV-14153](https://jira.mariadb.org/browse/MDEV-14153) and [MDEV-20720](https://jira.mariadb.org/browse/MDEV-20720). This does not necessarily imply that wsrep GTID mode works perfectly in all other situations. If you discover any other issues with it, please [report a bug](../mariadb-community-bug-reporting/index#reporting-a-bug). ### GTIDs for Transactions Applied by Slave Thread If a Galera Cluster node is also a [replication slave](../replication-overview/index), then that node's [slave SQL thread](../replication-threads/index#slave-sql-thread) will be applying transactions that it replicates from its replication master. If the node has `[log\_slave\_updates=ON](../replication-and-binary-log-system-variables/index#log_slave_updates)` set, then each transaction that the [slave SQL thread](../replication-threads/index#slave-sql-thread) applies will also generate a Galera Cluster write set that is replicated to the rest of the nodes in the cluster. In [MariaDB 10.1.30](https://mariadb.com/kb/en/mariadb-10130-release-notes/) and earlier, the node acting as slave would apply the transaction with the original GTID that it received from the master, and the other Galera Cluster nodes would generate their own GTIDs for the transaction when they replicated the write set. In [MariaDB 10.1.31](https://mariadb.com/kb/en/mariadb-10131-release-notes/) and later, the node acting as slave will include the transaction's original `Gtid_Log_Event` in the replicated write set, so all nodes should associate the write set with its original GTID. See [MDEV-13431](https://jira.mariadb.org/browse/MDEV-13431) about that. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb CSV CSV ==== The CSV storage engine | Title | Description | | --- | --- | | [CSV Overview](../csv-overview/index) | Used to read and append to files stored in CSV (comma-separated-values) format. | | [Checking and Repairing CSV Tables](../checking-and-repairing-csv-tables/index) | CSV tables support the CHECK TABLE and REPAIR TABLE statements. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Encryption, Hashing and Compression Functions Encryption, Hashing and Compression Functions ============================================== Encryption, hashing and compression functions, such as ENCRYPT, DECRYPT, COMPRESS, PASSWORD etc. | Title | Description | | --- | --- | | [AES\_DECRYPT](../aes_decrypt/index) | Decryption data encrypted with AES\_ENCRYPT | | [AES\_ENCRYPT](../aes_encrypt/index) | Encrypts a string with the AES algorithm. | | [COMPRESS](../compress/index) | Returns a binary, compressed string. | | [DECODE](../decode/index) | Decrypts a string encoded with ENCODE(), or, in Oracle mode, matches expressions. | | [DES\_DECRYPT](../des_decrypt/index) | Decrypts a string encrypted with DES\_ENCRYPT(). | | [DES\_ENCRYPT](../des_encrypt/index) | Encrypts a string using the Triple-DES algorithm. | | [ENCODE](../encode/index) | Encrypts a string. | | [ENCRYPT](../encrypt/index) | Encrypts a string with Unix crypt(). | | [MD5](../md5/index) | MD5 checksum. | | [OLD\_PASSWORD](../old_password/index) | Pre MySQL 4.1 password implementation. | | [PASSWORD](../password/index) | Calculates a password string. | | [RANDOM\_BYTES](../random_bytes/index) | Generates a binary string of random bytes. | | [SHA1](../sha1/index) | Calculates an SHA-1 checksum. | | [SHA2](../sha2/index) | Calculates an SHA-2 checksum. | | [UNCOMPRESS](../uncompress/index) | Uncompresses string compressed with COMPRESS(). | | [UNCOMPRESSED\_LENGTH](../uncompressed_length/index) | Returns length of a string before being compressed with COMPRESS(). | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb PURGE BINARY LOGS PURGE BINARY LOGS ================= Syntax ------ ``` PURGE { BINARY | MASTER } LOGS { TO 'log_name' | BEFORE datetime_expr } ``` Description ----------- The `PURGE BINARY LOGS` statement deletes all the [binary log](../binary-log/index) files listed in the log index file prior to the specified log file name or date. `BINARY` and `MASTER` are synonyms. Deleted log files also are removed from the list recorded in the index file, so that the given log file becomes the first in the list. The datetime expression is in the format 'YYYY-MM-DD hh:mm:ss'. If a replica is active but has yet to read from a binary log file you attempt to delete, the statement will fail with an error. However, if the replica is not connected and has yet to read from a log file you delete, the file will be deleted, but the replica will be unable to continue replicating once it connects again. This statement has no effect if the server was not started with the [--log-bin](../replication-and-binary-log-system-variables/index#log_bin) option to enable binary logging. To list the binary log files on the server, use [SHOW BINARY LOGS](../show-binary-logs/index). To see which files they are reading, use [SHOW SLAVE STATUS](../show-slave-status/index) (or [SHOW REPLICA STATUS](../show-replica-status/index) from [MariaDB 10.5.1](https://mariadb.com/kb/en/mariadb-1051-release-notes/)). You can only delete the files that are older than the oldest file that is used by the slaves. To delete all binary log files, use [RESET MASTER](../reset-master/index). To move to a new log file (for example if you want to remove the current log file), use [FLUSH LOGS](../flush/index) before you execute `PURGE LOGS`. If the [expire\_logs\_days](../server-system-variables/index#expire_logs_days) server system variable is not set to 0, the server automatically deletes binary log files after the given number of days. From [MariaDB 10.6](../what-is-mariadb-106/index), the [binlog\_expire\_logs\_seconds](../replication-and-binary-log-system-variables/index#binlog_expire_logs_seconds) variable allows more precise control over binlog deletion, and takes precedence if both are non-zero. Requires the [SUPER](super) privilege or, from [MariaDB 10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/), the [BINLOG ADMIN](../grant/index#binlog-admin) privilege, to run. Examples -------- ``` PURGE BINARY LOGS TO 'mariadb-bin.000063'; ``` ``` PURGE BINARY LOGS BEFORE '2013-04-21'; ``` ``` PURGE BINARY LOGS BEFORE '2013-04-22 09:55:22'; ``` See Also -------- * [Using and Maintaining the Binary Log](../using-and-maintaining-the-binary-log/index) * [FLUSH LOGS](../flush/index). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb LOAD DATA INFILE LOAD DATA INFILE ================ Syntax ------ ``` LOAD DATA [LOW_PRIORITY | CONCURRENT] [LOCAL] INFILE 'file_name' [REPLACE | IGNORE] INTO TABLE tbl_name [CHARACTER SET charset_name] [{FIELDS | COLUMNS} [TERMINATED BY 'string'] [[OPTIONALLY] ENCLOSED BY 'char'] [ESCAPED BY 'char'] ] [LINES [STARTING BY 'string'] [TERMINATED BY 'string'] ] [IGNORE number LINES] [(col_name_or_user_var,...)] [SET col_name = expr,...] ``` Description ----------- `LOAD DATA INFILE` is [unsafe](../unsafe-statements-for-replication/index) for statement-based replication. Reads rows from a text file into the designated table on the database at a very high speed. The file name must be given as a literal string. Files are written to disk using the [SELECT INTO OUTFILE](../select-into-outfile/index) statement. You can then read the files back into a table using the `LOAD DATA INFILE` statement. The `FIELDS` and `LINES` clauses are the same in both statements. These clauses are optional, but if both are specified then the `FIELDS` clause must precede `LINES`. Executing this statement activates `INSERT` [triggers](../triggers/index). One must have the [FILE](../grant/index#file) privilege to be able to execute LOAD DATA. This is the ensure the normal users will not attempt to read system files. Note that MariaDB's [systemd](../systemd/index) unit file restricts access to `/home`, `/root`, and `/run/user` by default. See [Configuring access to home directories](../systemd/index#configuring-access-to-home-directories). ### `LOAD DATA LOCAL INFILE` When you execute the `LOAD DATA INFILE` statement, MariaDB Server attempts to read the input file from its own file system. In contrast, when you execute the `LOAD DATA LOCAL INFILE` statement, the client attempts to read the input file from its file system, and it sends the contents of the input file to the MariaDB Server. This allows you to load files from the client's local file system into the database. In the event that you don't want to permit this operation (such as for security reasons), you can disable the `LOAD DATA LOCAL INFILE` statement on either the server or the client. * The `LOAD DATA LOCAL INFILE` statement can be disabled on the server by setting the [local\_infile](../server-system-variables/index#local_infile) system variable to `0`. * The `LOAD DATA LOCAL INFILE` statement can be disabled on the client. If you are using [MariaDB Connector/C](../about-mariadb-connector-c/index), this can be done by unsetting the `CLIENT_LOCAL_FILES` capability flag with the [mysql\_real\_connect](../mysql_real_connect/index) function or by unsetting the `MYSQL_OPT_LOCAL_INFILE` option with [mysql\_optionsv](../mysql_optionsv/index) function. If you are using a different client or client library, then see the documentation for your specific client or client library to determine how it handles the `LOAD DATA LOCAL INFILE` statement. If the `LOAD DATA LOCAL INFILE` statement is disabled by either the server or the client and if the user attempts to execute it, then the server will cause the statement to fail with the following error message: ``` The used command is not allowed with this MariaDB version ``` Note that it is not entirely accurate to say that the MariaDB version does not support the command. It would be more accurate to say that the MariaDB configuration does not support the command. See [MDEV-20500](https://jira.mariadb.org/browse/MDEV-20500) for more information. From [MariaDB 10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/), the error message is more accurate: ``` The used command is not allowed because the MariaDB server or client has disabled the local infile capability ``` ### `REPLACE` and `IGNORE` In cases where you load data from a file into a table that already contains data and has a [primary key](../getting-started-with-indexes/index#primary-key), you may encounter issues where the statement attempts to insert a row with a primary key that already exists. When this happens, the statement fails with Error 1064, protecting the data already on the table. In cases where you want MariaDB to overwrite duplicates, use the `REPLACE` keyword. The `REPLACE` keyword works like the [REPLACE](../replace/index) statement. Here, the statement attempts to load the data from the file. If the row does not exist, it adds it to the table. If the row contains an existing Primary Key, it replaces the table data. That is, in the event of a conflict, it assumes the file contains the desired row. This operation can cause a degradation in load speed by a factor of 20 or more if the part that has already been loaded is larger than the capacity of the [InnoDB Buffer Pool](../innodb-buffer-pool/index). This happens because it causes a lot of turnaround in the buffer pool. Use the `IGNORE` keyword when you want to skip any rows that contain a conflicting primary key. Here, the statement attempts to load the data from the file. If the row does not exist, it adds it to the table. If the row contains an existing primary key, it ignores the addition request and moves on to the next. That is, in the event of a conflict, it assumes the table contains the desired row. ### Character-sets When the statement opens the file, it attempts to read the contents using the default character-set, as defined by the [character\_set\_database](../server-system-variables/index#character_set_database) system variable. In the cases where the file was written using a character-set other than the default, you can specify the character-set to use with the `CHARACTER SET` clause in the statement. It ignores character-sets specified by the [SET NAMES](../set-names/index) statement and by the [character\_set\_client](../server-system-variables/index#character_set_client) system variable. Setting the `CHARACTER SET` clause to a value of `binary` indicates "no conversion." The statement interprets all fields in the file as having the same character-set, regardless of the column data type. To properly interpret file contents, you must ensure that it was written with the correct character-set. If you write a data file with [mysqldump -T](../mysqldump/index) or with the [SELECT INTO OUTFILE](../select-into-outfile/index) statement with the [mysql](../mysql-command-line-client/index) client, be sure to use the `--default-character-set` option, so that the output is written with the desired character-set. When using mixed character sets, use the `CHARACTER SET` clause in both [SELECT INTO OUTFILE](../select-into-outfile/index) and `LOAD DATA INFILE` to ensure that MariaDB correctly interprets the escape sequences. The [character\_set\_filesystem](../server-system-variables/index#character_set_filesystem) system variable controls the interpretation of the filename. It is currently not possible to load data files that use the `ucs2` character set. ### Preprocessing Inputs *col\_name\_or\_user\_var* can be a column name, or a user variable. In the case of a variable, the [SET](../set/index) statement can be used to preprocess the value before loading into the table. ### Priority and Concurrency In storage engines that perform table-level locking ([MyISAM](../myisam/index), [MEMORY](../memory/index) and [MERGE](../merge/index)), using the [LOW\_PRIORITY](../high_priority-and-low_priority-clauses/index) keyword, MariaDB delays insertions until no other clients are reading from the table. Alternatively, when using the [MyISAM](../myisam/index) storage engine, you can use the [CONCURRENT](../concurrent-inserts/index) keyword to perform concurrent insertion. The `LOW_PRIORITY` and `CONCURRENT` keywords are mutually exclusive. They cannot be used in the same statement. ### Progress Reporting The `LOAD DATA INFILE` statement supports [progress reporting](../progress-reporting/index). You may find this useful when dealing with long-running operations. Using another client you can issue a [SHOW PROCESSLIST](../show-processlist/index) query to check the progress of the data load. ### Using mariadb-import/mysqlimport MariaDB ships with a separate utility for loading data from files: [mariadb-import](../mysqlimport/index) (or `mysqlimport` before [MariaDB 10.5](../what-is-mariadb-105/index)). It operates by sending `LOAD DATA INFILE` statements to the server. Using [mariadb-import/mysqlimport](../mysqlimport/index) you can compress the file using the `--compress` option, to get better performance over slow networks, providing both the client and server support the compressed protocol. Use the `--local` option to load from the local file system. ### Indexing In cases where the storage engine supports [ALTER TABLE... DISABLE KEYS](../alter-table/index#enable-disable-keys) statements ([MyISAM](../myisam/index) and [Aria](../aria/index)), the `LOAD DATA INFILE` statement automatically disables indexes during the execution. Examples -------- You have a file with this content (note the the separator is ',', not tab, which is the default): ``` 2,2 3,3 4,4 5,5 6,8 ``` ``` CREATE TABLE t1 (a int, b int, c int, d int); LOAD DATA LOCAL INFILE '/tmp/loaddata7.dat' into table t1 fields terminated by ',' (a,b) set c=a+b; SELECT * FROM t1; +------+------+------+ | a | b | c | +------+------+------+ | 2 | 2 | 4 | | 3 | 3 | 6 | | 4 | 4 | 8 | | 5 | 5 | 10 | | 6 | 8 | 14 | +------+------+------+ ``` Another example, given the following data (the separator is a tab): ``` 1 a 2 b ``` The value of the first column is doubled before loading: ``` LOAD DATA INFILE 'ld.txt' INTO TABLE ld (@i,v) SET i=@i*2; SELECT * FROM ld; +------+------+ | i | v | +------+------+ | 2 | a | | 4 | b | +------+------+ ``` See Also -------- * [How to quickly insert data into MariaDB](../how-to-quickly-insert-data-into-mariadb/index) * [Character Sets and Collations](../character-sets-and-collations/index) * [SELECT ... INTO OUTFILE](../select-into-outfile/index) * [mariadb-import/mysqlimport](../mysqlimport/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb Files Created by Mariabackup Files Created by Mariabackup ============================ Mariabackup creates the following files: `backup-my.cnf` --------------- During the backup, any server options relevant to Mariabackup are written to the `backup-my.cnf` [option file](../configuring-mariadb-with-option-files/index), so that they can be re-read later during the `--prepare` stage. `ib_logfile0` ------------- In [MariaDB 10.2.10](https://mariadb.com/kb/en/mariadb-10210-release-notes/) and later, Mariabackup creates an empty [InnoDB redo log](../xtradbinnodb-redo-log/index) file called `ib_logfile0` as part of the `[--prepare](../mariabackup-options/index#-prepare)` stage. This file has 3 roles: 1. In the source server, `ib_logfile0` is the first (and possibly the only) [InnoDB redo log](../xtradbinnodb-redo-log/index) file. 2. In the non-prepared backup, `ib_logfile0` contains all of the [InnoDB redo log](../xtradbinnodb-redo-log/index) copied during the backup. Previous versions of Mariabackup would use a file called `[xtrabackup\_logfile](#xtrabackup_logfile)` for this. 3. During the `[--prepare](../mariabackup-options/index#-prepare)` stage, `ib_logfile0` would previously be deleted. Now during the `--prepare` stage, `ib_logfile0` is initialized as an empty [InnoDB redo log](../xtradbinnodb-redo-log/index) file. That way, if the backup is manually restored, any pre-existing [InnoDB redo log](../xtradbinnodb-redo-log/index) files would get overwritten by the empty one. This helps to prevent certain kinds of known issues. For example, see [Mariabackup Overview: Manual Restore with Pre-existing InnoDB Redo Log files](../mariabackup-overview/index#manual-restore-with-pre-existing-innodb-redo-log-files). `xtrabackup_logfile` -------------------- In [MariaDB 10.2.9](https://mariadb.com/kb/en/mariadb-1029-release-notes/) and before, Mariabackup creates `xtrabackup_logfile` to store the [InnoDB redo log](../xtradbinnodb-redo-log/index), In later versions, `[ib\_logfile0](#ib_logfile0)` is created instead. `xtrabackup_binlog_info` ------------------------ This file stores the [binary log](../binary-log/index) file name and position that corresponds to the backup. This file also stores the value of the `[gtid\_current\_pos](../gtid/index#gtid_current_pos)` system variable that correspond to the backup. For example: ``` mariadb-bin.000096 568 0-1-2 ``` The values in this file are only guaranteed to be consistent with the backup if the `[--no-lock](../mariabackup-options/index#-no-lock)` option was **not** provided when the backup was taken. `xtrabackup_binlog_pos_innodb` ------------------------------ Mariabackup inherited this file from Percona XtraBackup 2.3. However, this file is only safe to use with Percona Server versions that have a special lockless binary log feature. This feature is described by the [Percona Server documentation](https://www.percona.com/doc/percona-server/5.6/management/backup_locks.html#backup-safe-binlog-information): Starting with Percona Server for MySQL 5.6.26-74.0 LOCK TABLES FOR BACKUP flushes the current binary log coordinates to InnoDB. Thus, under active LOCK TABLES FOR BACKUP, the binary log coordinates in InnoDB are consistent with its redo log and any non-transactional updates (as the latter are blocked by LOCK TABLES FOR BACKUP). It is planned that this change will enable Percona XtraBackup to avoid issuing the more invasive LOCK BINLOG FOR BACKUP command under some circumstances. And the way it's used by Percona XtraBackup 2.3 is described by the [Percona XtraBackup 2.3 documentation](https://www.percona.com/doc/percona-xtrabackup/2.3/advanced/lockless_bin-log.html): Percona XtraBackup implemented support for lock-less binary log information in 2.3.2. When the Lockless binary log information feature is available [1] on the server, Percona XtraBackup can trust binary log information stored in the InnoDB system header and avoid executing LOCK BINLOG FOR BACKUP (and thus, blocking commits for the duration of finalizing the REDO log copy) under a number of circumstances: * when the server is not a GTID-enabled Galera cluster node * when the replication I/O thread information should not be stored as a part of the backup (i.e. when the xtrabackup --slave-info option is not specified) Mariabackup no longer creates this file starting with [MariaDB 10.1.39](https://mariadb.com/kb/en/mariadb-10139-release-notes/), [MariaDB 10.2.23](https://mariadb.com/kb/en/mariadb-10223-release-notes/), [MariaDB 10.3.14](https://mariadb.com/kb/en/mariadb-10314-release-notes/), and [MariaDB 10.4.4](https://mariadb.com/kb/en/mariadb-1044-release-notes/). See [MDEV-18917](https://jira.mariadb.org/browse/MDEV-18917) for more information. `xtrabackup_checkpoints` ------------------------ The `xtrabackup_checkpoints` file contains metadata about the backup. For example: ``` backup_type = full-backuped from_lsn = 0 to_lsn = 1635102 last_lsn = 1635102 recover_binlog_info = 0 ``` See below for a description of the fields. If the `[--extra-lsndir](../mariabackup-options/index#-extra-lsndir)` option is provided, then an extra copy of this file will be saved in that directory. ### `backup_type` If the backup is a non-prepared [full backup](../full-backup-and-restore-with-mariabackup/index) or a non-prepared [partial backup](../partial-backup-and-restore-with-mariabackup/index), then `backup_type` is set to `full-backuped`. If the backup is a non-prepared [incremental backup](../incremental-backup-and-restore-with-mariabackup/index), then `backup_type` is set to `incremental`. If the backup has already been prepared, then `backup_type` is set to `log-applied`. ### `from_lsn` If `backup_type` is `full-backuped`, then `from_lsn` has the value of `0`. If `backup_type` is `incremental`, then `from_lsn` has the value of the [log sequence number (LSN)](../innodb-redo-log/index#log-sequence-number-lsn) at which the backup started reading from the [InnoDB redo log](../innodb-redo-log/index). This is internally used by Mariabackup when preparing incremental backups. This value can be manually set during an [incremental backup](../incremental-backup-and-restore-with-mariabackup/index) with the `[--incremental-lsn](../mariabackup-options/index#-incremental-lsn)` option. However, it is generally better to let Mariabackup figure out the `from_lsn` automatically by specifying a parent backup with the `[--incremental-basedir](../mariabackup-options/index#-incremental-basedir)` option. ### `to_lsn` `to_lsn` has the value of the [log sequence number (LSN)](../innodb-redo-log/index#log-sequence-number-lsn) of the last checkpoint in the [InnoDB redo log](../innodb-redo-log/index). This is internally used by Mariabackup when preparing incremental backups. ### `last_lsn` `last_lsn` has the value of the last [log sequence number (LSN)](../innodb-redo-log/index#log-sequence-number-lsn) read from the [InnoDB redo log](../innodb-redo-log/index). This is internally used by Mariabackup when preparing incremental backups. `xtrabackup_info` ----------------- The `xtrabackup_info` file contains information about the backup. The fields in this file are listed below. If the `[--extra-lsndir](../mariabackup-options/index#-extra-lsndir)` option is provided, then an extra copy of this file will be saved in that directory. ### `uuid` If a UUID was provided by the `[--incremental-history-uuid](../mariabackup-options/index#-incremental-history-uuid)` option, then it will be saved here. Otherwise, this will be the empty string. ### `name` If a name was provided by the `[--history](../mariabackup-options/index#-history)` or the `[---incremental-history-name](../mariabackup-options/index#-incremental-history-name)` options, then it will be saved here. Otherwise, this will be the empty string. ### `tool_name` The name of the Mariabackup executable that performed the backup. This is generally `mariabackup`. ### `tool_command` The arguments that were provided to Mariabackup when it performed the backup. ### `tool_version` The version of Mariabackup that performed the backup. ### `ibbackup_version` The version of Mariabackup that performed the backup. ### `server_version` The version of MariaDB Server that was backed up. ### `start_time` The time that the backup started. ### `end_time` The time that the backup ended. ### `lock_time` The amount of time that Mariabackup held its locks. ### `binlog_pos` This field stores the [binary log](../binary-log/index) file name and position that corresponds to the backup. This field also stores the value of the `[gtid\_current\_pos](../gtid/index#gtid_current_pos)` system variable that correspond to the backup. The values in this field are only guaranteed to be consistent with the backup if the `[--no-lock](../mariabackup-options/index#-no-lock)` option was **not** provided when the backup was taken. ### `innodb_from_lsn` This is identical to `from_lsn` in `[xtrabackup\_checkpoints](#xtrabackup_checkpoints)`. If the backup is a [full backup](../full-backup-and-restore-with-mariabackup/index), then `innodb_from_lsn` has the value of `0`. If the backup is an [incremental backup](../incremental-backup-and-restore-with-mariabackup/index), then `innodb_from_lsn` has the value of the [log sequence number (LSN)](../innodb-redo-log/index#log-sequence-number-lsn) at which the backup started reading from the [InnoDB redo log](../innodb-redo-log/index). ### `innodb_to_lsn` This is identical to `to_lsn` in `[xtrabackup\_checkpoints](#xtrabackup_checkpoints)`. `innodb_to_lsn` has the value of the [log sequence number (LSN)](../innodb-redo-log/index#log-sequence-number-lsn) of the last checkpoint in the [InnoDB redo log](../innodb-redo-log/index). ### `partial` If the backup is a [partial backup](../partial-backup-and-restore-with-mariabackup/index), then this value will be `Y`. Otherwise, this value will be `N`. ### `incremental` If the backup is an [incremental backup](../incremental-backup-and-restore-with-mariabackup/index), then this value will be `Y`. Otherwise, this value will be `N`. ### `format` This field's value is the format of the backup. If the `[--stream](../mariabackup-options/index#-stream)` option was set to `xbstream`, then this value will be `xbstream`. If the `[--stream](../mariabackup-options/index#-stream)` option was **not** provided, then this value will be `file`. ### `compressed` If the `[--compress](../mariabackup-options/index#-compress)` option was provided, then this value will be `compressed`. Otherwise, this value will be `N`. `xtrabackup_slave_info` ----------------------- If the `[--slave-info](../mariabackup-options/index#-slave-info)` option is provided, then this file contains the `[CHANGE MASTER](../change-master-to/index)` command that can be used to set up a new server as a slave of the original server's master after the backup has been restored. Mariabackup does **not** check if [GTIDs](../gtid/index) are being used in replication. It takes a shortcut and assumes that if the `[gtid\_slave\_pos](../gtid/index#gtid_slave_pos)` system variable is non-empty, then it writes the `[CHANGE MASTER](../change-master-to/index)` command with the `[MASTER\_USE\_GTID](../change-master-to/index#master_use_gtid)` option set to `slave_pos`. Otherwise, it writes the `[CHANGE MASTER](../change-master-to/index)` command with the `[MASTER\_LOG\_FILE](../change-master-to/index#master_log_file)` and `[MASTER\_LOG\_POS](../change-master-to/index#master_log_pos)` options using the master's [binary log](../binary-log/index) file and position. See [MDEV-19264](https://jira.mariadb.org/browse/MDEV-19264) for more information. `xtrabackup_galera_info` ------------------------ If the `[--galera-info](../mariabackup-options/index#-galera-info)` option is provided, then this file contains information about a [Galera Cluster](../galera/index) node's state. The file contains the values of the `[wsrep\_local\_state\_uuid](../galera-cluster-status-variables/index#wsrep_local_state_uuid)` and `[wsrep\_last\_committed](../galera-cluster-status-variables/index#wsrep_last_committed)` status variables. The values are written in the following format: ``` wsrep_local_state_uuid:wsrep_last_committed ``` For example: ``` d38587ce-246c-11e5-bcce-6bbd0831cc0f:1352215 ``` `<table>.delta` --------------- If the backup is an [incremental backup](../incremental-backup-and-restore-with-mariabackup/index), then this file contains changed pages for the table. `<table>.delta.meta` -------------------- If the backup is an [incremental backup](../incremental-backup-and-restore-with-mariabackup/index), then this file contains metadata about `<table>.delta` files. The fields in this file are listed below. ### `page_size` This field contains either the value of `[innodb\_page\_size](../innodb-system-variables/index#innodb_page_size)` or the value of the `[KEY\_BLOCK\_SIZE](../create-table/index#key_block_size)` table option for the table if the `[ROW\_FORMAT](../create-table/index#row_format)` table option for the table is set to `[COMPRESSED](../innodb-storage-formats/index#compressed)`. ### `zip_size` If the `[ROW\_FORMAT](../create-table/index#row_format)` table option for this table is set to `[COMPRESSED](../innodb-storage-formats/index#compressed)`, then this field contains the value of the compressed page size. ### `space_id` This field contains the value of the table's `space_id`. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Development Articles Development Articles ===================== Articles of interest to MariaDB Developers | Title | Description | | --- | --- | | [General Development Information](../general-development-information/index) | | | [MariaDB Server Releases](../mariadb-server-release-dates/index) | Information about MariaDB releases and release policies and procedures. | | [MariaDB Internals Documentation](../mariadb-internals-documentation/index) | Documentation on the internal workings of MariaDB. | | [MariaDB Development Tools](../tools/index) | Tools for developing MariaDB. | | [Debugging MariaDB](../debugging-mariadb/index) | This section is for articles on debugging MariaDB. | | [Quality](../quality/index) | This section collects articles related to MariaDB quality assurance efforts. | | [Security Vulnerabilities Fixed in MariaDB](../security/index) | Security vulnerabilities (CVEs) fixed in MariaDB | | [Security Vulnerabilities Fixed in Oracle MySQL That Did Not Exist in MariaDB](../security-vulnerabilities-in-oracle-mysql-that-did-not-exist-in-mariadb/index) | Lists of CVEs fixed in MySQL but that were never present in MariaDB. | | [Using Git](../using-git/index) | Working with the git repository for the source code of MariaDB on GitHub. | | [DBT3 Benchmark Queries](../dbt3-benchmark-queries/index) | Known things about DBT-3 benchmark and its queries Q1 A simple, one-table query. select | | [EXPLAIN FORMAT=JSON in MySQL](../explain-formatjson-in-mysql/index) | Listing of things to improve in MySQL's implementation of EXPLAIN FORMAT=JSON | | [HBase Storage Engine](../hbase-storage-engine/index) | Data mapping from HBase to SQL. | | [LevelDB Storage Engine](../leveldb/index) | Implementation details on the LevelDB storage engine | | [LevelDB Storage Engine Development](../leveldb-storage-engine-development/index) | Items under consideration for development of the LevelDB Storage Engine | | [LevelDB Storage Engine MS1](../leveldb-storage-engine-ms1/index) | MIlestone 1 LevelDB storage engine development | | [LevelDB Storage Engine MS2](../leveldb-storage-engine-ms2/index) | Milestone 2 LevelDB storage engine development | | [Stuff in MySQL 5.6](../stuff-in-mysql-56/index) | This is SergeyP's list of patches in MySQL 5.6 that he has found interesti... | | [EXPLAIN FORMAT=JSON Differences From MySQL](../explain-format-json-differences/index) | Differences between MariaDB's and MySQL's EXPLAIN JSON output. | | [Profiling with Linux perf tool](../profiling-with-linux-perf-tool/index) | Linux perf tool can be used to do non-intrusive profiling. Frequency Based ... | | [Uploading Package to PPA](../uploading-package-to-ppa/index) | After creating a Launchpad account: Docker build, cloning the MariaDB repo... | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Account Locking Account Locking =============== **MariaDB starting with [10.4.2](https://mariadb.com/kb/en/mariadb-1042-release-notes/)**Account locking was introduced in [MariaDB 10.4.2](https://mariadb.com/kb/en/mariadb-1042-release-notes/). ### Description Account locking permits privileged administrators to lock/unlock user accounts. No new client connections will be permitted if an account is locked (existing connections are not affected). User accounts can be locked at creation, with the [CREATE USER](../create-user/index) statement, or modified after creation with the [ALTER USER](../alter-user/index) statement. For example: ``` CREATE USER 'lorin'@'localhost' ACCOUNT LOCK; ``` or ``` ALTER USER 'marijn'@'localhost' ACCOUNT LOCK; ``` The server will return an `ER_ACCOUNT_HAS_BEEN_LOCKED` error when locked users attempt to connect: ``` mysql -ulorin ERROR 4151 (HY000): Access denied, this account is locked ``` The [ALTER USER](../alter-user/index) statement is also used to unlock a user: ``` ALTER USER 'lorin'@'localhost' ACCOUNT UNLOCK; ``` The [SHOW CREATE USER](../show-create-user/index) statement will show whether the account is locked: ``` SHOW CREATE USER 'marijn'@'localhost'; +-----------------------------------------------+ | CREATE USER for marijn@localhost | +-----------------------------------------------+ | CREATE USER 'marijn'@'localhost' ACCOUNT LOCK | +-----------------------------------------------+ ``` as well as querying the [mysql.global\_priv table](../mysqlglobal_priv-table/index): ``` SELECT CONCAT(user, '@', host, ' => ', JSON_DETAILED(priv)) FROM mysql.global_priv WHERE user='marijn'; +--------------------------------------------------------------------------------------+ | CONCAT(user, '@', host, ' => ', JSON_DETAILED(priv)) | +--------------------------------------------------------------------------------------+ | marijn@localhost => { "access": 0, "plugin": "mysql_native_password", "authentication_string": "", "account_locked": true, "password_last_changed": 1558017158 } | +--------------------------------------------------------------------------------------+ ``` See Also -------- * [Account Locking and Password Expiry](https://www.youtube.com/watch?v=AWM_fWZ3XIw) video tutorial Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Storage Engine Summit 2010 Storage Engine Summit 2010 ========================== **Note:** This page is obsolete. The information is old, outdated, or otherwise currently incorrect. We are keeping the page for historical reasons only. **Do not** rely on the information in this article. Storage Engine Summit is a traditional yearly one-day meeting of Storage Engine vendors, typically held right after the MySQL User Conference. In 2010 it was organized by [Monty Program Ab](http://montyprogram.com). Location -------- The [Network Meeting Center](http://www.networkmeetingcenter.com/) - across the street from the Convention Center. ([map](http://goo.gl/D0ru)) Date and Time ------------- Friday April 16, 2010 - 9:00 a.m. to 6:30 p.m. Audience -------- Invited were all MySQL/MariaDB Storage Engine vendors and anyone interested in the MySQL/MariaDB Storage Engine API. There were about 25 participants from MariaDB, Oracle, and eight storage engine vendors. Meeting Minutes --------------- ### Presenting Monty Program Ab 1 Unlike Drizzle, MariaDB will stay fully compatible with MySQL (for a while) MariaDB is GPL only **Monty:** But we want to evolve the interface. **Mikael:** It is a bad idea for MariaDB to compete on new APIs as there is a need for a single standard rather than competing APIs. **Sergei:** Totally agree, we want to improve the API, but stay compatible MariaDB 5.2 released, good progress with MariaDB 5.3 We do NRE ### Upcoming changes in the Storage Engine API 2 CREATE TABLE extensions in MariaDB 5.2.0 3 **Question:** Are there per-partition attributes? **Sergei:** No, it's a bug, we will add them in 5.2.1 Performance Schema in MySQL 5.5 4,5 **Mikael:** InnoDB has added probes for this in MySQL 5.5.4 Transactional LOCK TABLES **Question:** What if the engine does not support it? **Sergei:** No problem, it's an optional feature, if not supported MySQL will use old style table locks Multi Read Range (MRR) and how it is used in Batch Key Access (BKA) 6 **Question:** Isn't it in MySQL 5.1? **Igor Babaev:** No, the interface in MariaDB 5.3 is different, more generic Server Services for Plugins 7 **Paul McCullah:** Plugins need some "magic autoconf code" to detect whether libservices should be used (to support both MariaDB 5.1 and 5.2) Query Fragment Pushdown 8 **Mikael:** It is in MySQL in a working tree **Sergei:** Yes, but it's we are talking about a much more general approach here ### Discussion: What Storage Engine needs Query Fragment Pushdown: Sub-problems: * Abstract Query Tree (AQT) or query and database model ([MySQL Worklog #4533](https://dev.mysql.com/worklog/task/?id=4533)) * Storage Engine Pushdown API ([MySQL Worklog #4535](https://dev.mysql.com/worklog/task/?id=4535)) * Virtual Tables ([MySQL Worklog #4537](https://dev.mysql.com/worklog/task/?id=4537)) * Query decomposition and optimization for query fragments ([MySQL Worklog #4536](https://dev.mysql.com/worklog/task/?id=4536)) * Cost mode calibration ([MySQL Worklog #4553](https://dev.mysql.com/worklog/task/?id=4553)) **Question:** Some engines has extra knowledge, like for example some materialised views. Would it be possible to make these available as extra tables for the MySQL optimiser? **Kostja:** *You can already do this today, similar to how the merge tables work* **Jonas:** *We thought about it when designing for NDB. It is much easier to implement, but the "real" solution is much better.* **Timour:** *The basic framework is only 30% of the full problem. The main part is the query optimisation, and that can be developed incrementally once the rest of the framework is in place.* **Comment:** *Storage engines do not want to have to implement their own optimiser inside the engine.* **Sergei:** *But if there is one, it should be possible to use it.* **Timour:** *We are trying to implement a general solution that makes multiple engines happy. The optimiser should be cost based rather than rule based to cover a general set of cases well.* **Comment:** *It should be simple by engines such as Spider, Federated to re-construct an SQL query from the proposed representation.* Majority feels that Query re-write is not realistic to work on due to dependency on highly complex internal data structures. Range Pushdown for all columns **Sergei:** *These can be derived from a query pushdown* **Comment:** *As a separate feature it's much easier to implement and to use*9 Online Backup Engines want it Perhaps backport it from MySQL 6.0 ? Table discovery enhancements **Sergei:** *There was a patch from Google Summer of Code that included enhanced discovery. MySQL now works on that feature, using the patch as a starting point.* Parallel query execution across multiple cores **Sergei:** *Parallel query execution is a general feature, and although it would be nice to have it, it is not directly relevant to this storage engine summit discussion.* Support in the optimiser for clustering non-primary keys HA\_EXTRA\_WRITE\_CAN\_IGNORE hint Consolidate the range query apis Make sure the range boundaries are always sent to the engine (in order by desc, JT\_REF, rnd\_\*, etc) Transactional DDL **Comment:** *We do not really need full transactions, just crash recovery.* **Monty:** *For partial DDL, what we can do is log DDL changes, to be able to recover things after a crash.* **Mikael:** *There is this already in 5.1 for partitions. But it is only for partitions, not for the tables.* Monty is willing to write specs for crash-safe DDL Smarter "ALTER TABLE" **Comment:** *Need to fix ALTER TABLE to fully support online operations.* **Jonas:** *This is already implemented, but currently only in the -telco cluster trees.* Antony is willing to look into backporting new ALTER TABLE to MariaDB Fast, engine-specific LOAD DATA Certain engines are so fast for bulk inserts that server adds too much overhead Faster export (SELECT ... OUTFILE) Same as with LOAD DATA Can be done with a special Protocol class or select\_result class ? Engine-provided SQL commands. EXECUTE COMMAND maybe? **Comment:** *Want to be able to make/extend SHOW ENGINE xxx STATUS* **Sergei:** *No need, create an INFORMATION\_SCHEMA table instead.* InnoDB statistics in the slow log Perhaps, audit api can be used for that ? Engine independent test suite **Sergei:** *This was presented by Sun on the Storage Engine Summit last year, but no trace has been seen of it ever since* Paul described how it is done in Drizzle, an engine can override a .result file An author of the Spider engine started recently a new project [Engine Independent Test for MySQL](https://launchpad.net/engineindependenttestformysql) - we all can collaborate and extend it **Comment:** *What about unit tests for the storage engine API?* Need a unit test that loads a storage engine plugin and exercises every call in it. **Sergei:** *this is also something that Sun tried to do10* ### Conclusions Few simple feature requests we can do straight away: * many clustered keys (not only primary) - [MWL#113](http://askmonty.org/worklog/?tid=113) * insert ignore ha\_extra hint - [MWL#114](http://askmonty.org/worklog/?tid=114) * consolidating the range query apis * innodb statistics in the slow log - [MWL#115](http://askmonty.org/worklog/?tid=115) We will work together to create an engine independent test suite - all engines will benefit from it. More complex features are open. Monty Program will be happy to do them as NREs or discuss alternative ways of collaborating on having them implemented. ### References 1. **MariaDB, Monty Program, Collaboration** by Henrik Ingo ([slides, odp](http://askmonty.org/w/images/3/3a/MP_intro_SE_summit.odp)) 2. **Storage Engine API: Beyond 5.1** by Sergei Golubchik ([slides, zipped html](http://askmonty.org/w/images/b/b8/SE_API_Beyond_5.1.maff)) 3. CREATE TABLE extension [manual](../extending-create-table/index) 4. Performance Schema [manual](http://dev.mysql.com/doc/performance-schema/en/index.html) 5. Marc Alff's [MySQL University session](http://forge.mysql.com/wiki/Performance_Schema:_Instrumenting_Code) about the instrumentation. 6. See slides 10-18 from the Sergey Petrunya's [MySQL UC2010 talk](http://en.oreilly.com/mysql2010/public/schedule/detail/13509) 7. Server Services in the [MySQL manual](http://dev.mysql.com/doc/refman/5.5/en/plugin-services.html) 8. **Query Fragment Pushdown Design** by Timour Katchaounov ([slides, pdf](http://askmonty.org/w/images/4/47/Qfpd-query-model-design.pdf)) 9. post-conference, a quick patch was made for this functionality: <https://lists.launchpad.net/maria-developers/msg02961.html> 10. <http://forge.mysql.com/wiki/Storage_Engine_API_Testing_Framework> Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb MPolyFromWKB MPolyFromWKB ============ Syntax ------ ``` MPolyFromWKB(wkb[,srid]) MultiPolygonFromWKB(wkb[,srid]) ``` Description ----------- Constructs a [MULTIPOLYGON](../multipolygon/index) value using its [WKB](../well-known-binary-wkb-format/index) representation and [SRID](../srid/index). `MPolyFromWKB()` and `MultiPolygonFromWKB()` are synonyms. Examples -------- ``` SET @g = ST_AsBinary(MPointFromText('MULTIPOLYGON(((28 26,28 0,84 0,84 42,28 26),(52 18,66 23,73 9,48 6,52 18)),((59 18,67 18,67 13,59 13,59 18)))')); SELECT ST_AsText(MPolyFromWKB(@g))\G *************************** 1. row *************************** ST_AsText(MPolyFromWKB(@g)): MULTIPOLYGON(((28 26,28 0,84 0,84 42,28 26),(52 18,66 23,73 9,48 6,52 18)),((59 18,67 18,67 13,59 13,59 18))) ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Partitioning Overview Partitioning Overview ===================== In MariaDB, a table can be split in smaller subsets. Both data and indexes are partitioned. Uses for partitioning --------------------- There can be several reasons to use this feature: * Very big tables and indexes can be slow even with optimized queries. But if the target table is partitioned, queries that read a small number of partitions can be much faster. * Partitioning allows one to distribute files over multiple storage devices. For example, we can have historical data on slower, larger disks (historical data are not supposed to be frequently read); and current data can be on faster disks, or SSD devices. * In case we separate historical data from recent data, we will probably need to take regular backups of one partition, not the whole table. ### Partitioning for specific storage engines Some MariaDB [storage engines](../storage-engines/index) allow more interesting uses for partitioning. [SPIDER](../spider/index) allows one to: * Move partitions of the same table on different servers. In this way, the workload can be distributed on more physical or virtual machines (*data sharding*). * All partitions of a SPIDER table can also live on the same machine. In this case there will be a small overhead (SPIDER will use connections to localhost), but queries that read multiple partitions will use parallel threads. [CONNECT](../connect/index) allows one to: * Build a table whose partitions are tables using different storage engines (like InnoDB, MyISAM, or even engines that do not support partitioning). * Build an indexable, writeable table on several data files. These files can be in different formats. See also: [Using CONNECT - Partitioning and Sharding](../using-connect-partitioning-and-sharding/index) Partitioning types ------------------ When partitioning a table, the use should decide: * a *partitioning type*; * a *partitioning expression*. A partitioning type is the method used by MariaDB to decide how rows are distributed over existing partitions. Choosing the proper partitioning type is important to distribute rows over partitions in an efficient way. With some partitioning types, a partitioning expression is also required. A partitioning function is an SQL expression returning an integer or temporal value, used to determine which row will contain a given row. The partitioning expression is used for all reads and writes on involving the partitioned table, thus it should be fast. See [Partioning Types](../partitioning-types/index) for a detailed description. How to use partitioning ----------------------- By default, MariaDB permits partitioning. You can determine this by using the [SHOW PLUGINS](../show-plugins/index) statement, for example: ``` SHOW PLUGINS; ... | Aria | ACTIVE | STORAGE ENGINE | NULL | GPL | | FEEDBACK | DISABLED | INFORMATION SCHEMA | NULL | GPL | | partition | ACTIVE | STORAGE ENGINE | NULL | GPL | +-------------------------------+----------+--------------------+---------+---------+ ``` If partition is listed as DISABLED: ``` | partition | DISABLED | STORAGE ENGINE | NULL | GPL | +-------------------------------+----------+--------------------+---------+---------+ ``` MariaDB has either been built without partitioning support, or has been started with the the [--skip-partition](../mysqld-options/index#-skip-partition) option, or one of its variants: ``` --skip-partition --disable-partition --partition=OFF ``` and you will not be able to create partitions. It is possible to create a new partitioned table using [CREATE TABLE](../create-table/index). [ALTER TABLE](../alter-table/index) allows one to: * Partition an existing table; * Remove partitions from a partitioned table (**with all data in the partition**); * Add/remove partitions, or reorganize them, as long as the partitioning function allows these operations (see below); * Exchange a partition with a table; * Perform administrative operations on some or all partitions (analyze, optimize, check, repair). The [INFORMATION\_SCHEMA.PARTITIONS](../information-schema-partitions-table/index) table contains information about existing partitions. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb String Data Types String Data Types ================== | Title | Description | | --- | --- | | [String Literals](../string-literals/index) | Strings are sequences of characters and are enclosed with quotes. | | [BINARY](../binary/index) | Fixed-length binary byte string. | | [BLOB](../blob/index) | Binary large object up to 65,535 bytes. | | [BLOB and TEXT Data Types](../blob-and-text-data-types/index) | Binary large object data types and the corresponding TEXT types. | | [CHAR](../char/index) | Fixed-length string. | | [CHAR BYTE](../char-byte/index) | Alias for BINARY. | | [ENUM](../enum/index) | Enumeration, or string object that can have one value chosen from a list of values. | | [INET4](../inet4/index) | For storage of IPv4 addresses. | | [INET6](../inet6/index) | For storage of IPv6 addresses. | | [JSON Data Type](../json-data-type/index) | Compatibility data type that is an alias for LONGTEXT. | | [MEDIUMBLOB](../mediumblob/index) | Medium binary large object up to 16,777,215 bytes. | | [MEDIUMTEXT](../mediumtext/index) | A TEXT column with a maximum length of 16,777,215 characters. | | [LONGBLOB](../longblob/index) | Long BLOB holding up to 4GB. | | [LONG and LONG VARCHAR](../long-and-long-varchar/index) | LONG and LONG VARCHAR are synonyms for MEDIUMTEXT. | | [LONGTEXT](../longtext/index) | A TEXT column with a maximum length of 4,294,967,295 characters. | | [ROW](../row/index) | Data type for stored procedure variables. | | [TEXT](../text/index) | A TEXT column with a maximum length of 65,535 characters. | | [TINYBLOB](../tinyblob/index) | Tiny binary large object up to 255 bytes. | | [TINYTEXT](../tinytext/index) | A TEXT column with a maximum length of 255 characters. | | [VARBINARY](../varbinary/index) | Variable-length binary byte string. | | [VARCHAR](../varchar/index) | Variable-length string. | | [SET Data Type](../set-data-type/index) | Set, or string object that can have 0 or more values chosen from a list of values. | | [UUID Data Type](../uuid-data-type/index) | Data type intended for the storage of UUID data. | | [Data Type Storage Requirements](../data-type-storage-requirements/index) | Storage requirements for the various data types. | | [Supported Character Sets and Collations](../supported-character-sets-and-collations/index) | MariaDB supports the following character sets and collations. | | [Character Sets and Collations](../character-sets/index) | Setting character set and collation for a language. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb JSON_ARRAY_INSERT JSON\_ARRAY\_INSERT =================== **MariaDB starting with [10.2.3](https://mariadb.com/kb/en/mariadb-1023-release-notes/)**JSON functions were added in [MariaDB 10.2.3](https://mariadb.com/kb/en/mariadb-1023-release-notes/). Syntax ------ ``` JSON_ARRAY_INSERT(json_doc, path, value[, path, value] ...) ``` Description ----------- Inserts a value into a JSON document, returning the modified document, or NULL if any of the arguments are NULL. Evaluation is performed from left to right, with the resulting document from the previous pair becoming the new value against which the next pair is evaluated. If the `json_doc` is not a valid JSON document, or if any of the paths are not valid, or contain a `*` or `**` wildcard, an error is returned. Examples -------- ``` SET @json = '[1, 2, [3, 4]]'; SELECT JSON_ARRAY_INSERT(@json, '$[0]', 5); +-------------------------------------+ | JSON_ARRAY_INSERT(@json, '$[0]', 5) | +-------------------------------------+ | [5, 1, 2, [3, 4]] | +-------------------------------------+ SELECT JSON_ARRAY_INSERT(@json, '$[1]', 6); +-------------------------------------+ | JSON_ARRAY_INSERT(@json, '$[1]', 6) | +-------------------------------------+ | [1, 6, 2, [3, 4]] | +-------------------------------------+ SELECT JSON_ARRAY_INSERT(@json, '$[1]', 6, '$[2]', 7); +------------------------------------------------+ | JSON_ARRAY_INSERT(@json, '$[1]', 6, '$[2]', 7) | +------------------------------------------------+ | [1, 6, 7, 2, [3, 4]] | +------------------------------------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb <= <= == Syntax ------ ``` <= ``` Description ----------- Less than or equal operator. Evaluates both SQL expressions and returns 1 if the left value is less than or equal to the right value and 0 if it is not, or `NULL` if either expression is NULL. If the expressions return different data types, (for instance, a number and a string), performs type conversion. When used in row comparisons these two queries return the same results: ``` SELECT (t1.a, t1.b) <= (t2.x, t2.y) FROM t1 INNER JOIN t2; SELECT (t1.a < t2.x) OR ((t1.a = t2.x) AND (t1.b <= t2.y)) FROM t1 INNER JOIN t2; ``` Examples -------- ``` SELECT 0.1 <= 2; +----------+ | 0.1 <= 2 | +----------+ | 1 | +----------+ ``` ``` SELECT 'a'<='A'; +----------+ | 'a'<='A' | +----------+ | 1 | +----------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Numeric Data Types Numeric Data Types =================== | Title | Description | | --- | --- | | [Numeric Data Type Overview](../numeric-data-type-overview/index) | Overview and usage of the numeric data types. | | [TINYINT](../tinyint/index) | Tiny integer, -128 to 127 signed. | | [BOOLEAN](../boolean/index) | Synonym for TINYINT(1). | | [SMALLINT](../smallint/index) | Small integer from -32768 to 32767 signed. | | [MEDIUMINT](../mediumint/index) | Medium integer from -8388608 to 8388607 signed. | | [INT](../int/index) | Integer from -2147483648 to 2147483647 signed. | | [INTEGER](../integer/index) | Synonym for INT | | [BIGINT](../bigint/index) | Large integer. | | [DECIMAL](../decimal/index) | A packed "exact" fixed-point number. | | [DEC, NUMERIC, FIXED](../dec-numeric-fixed/index) | Synonyms for DECIMAL | | [NUMBER](../number/index) | Synonym for DECIMAL in Oracle mode. | | [FLOAT](../float/index) | Single-precision floating-point number | | [DOUBLE](../double/index) | Normal-size (double-precision) floating-point number | | [DOUBLE PRECISION](../double-precision/index) | REAL and DOUBLE PRECISION are synonyms for DOUBLE. | | [BIT](../bit/index) | Bit field type. | | [Floating-point Accuracy](../floating-point-accuracy/index) | Not all floating-point numbers can be stored with exact precision | | [INT1](../int1/index) | A synonym for TINYINT. | | [INT2](../int2/index) | Synonym for SMALLINT. | | [INT3](../int3/index) | Synonym for MEDIUMINT. | | [INT4](../int4/index) | Synonym for INT. | | [INT8](../int8/index) | Synonym for BIGINT. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Rowid Filtering Optimization Rowid Filtering Optimization ============================ **MariaDB starting with [10.4](../what-is-mariadb-104/index)**Rowid filtering is an optimization available from [MariaDB 10.4](../what-is-mariadb-104/index). The target use case for rowid filtering is as follows: * a table uses ref access on index IDX1 * but it also has a fairly restrictive range predicate on another index IDX2. In this case, it is advantageous to: * Do an index-only scan on index IDX2 and collect rowids of index records into a data structure that allows filtering (let's call it $FILTER). * When doing ref access on IDX1, check $FILTER before reading the full record. Example ------- Consider a query ``` SELECT ... FROM orders JOIN lineitem ON o_orderkey=l_orderkey WHERE l_shipdate BETWEEN '1997-01-01' AND '1997-01-31' AND o_totalprice between 200000 and 230000; ``` Suppose the condition on `l_shipdate` is very restrictive, which means lineitem table should go first in the join order. Then, the optimizer can use `o_orderkey=l_orderkey` equality to do an index lookup to get the order the line item is from. On the other hand `o_totalprice between ...` can also be rather selective. With filtering, the query plan would be: ``` *************************** 1. row *************************** id: 1 select_type: SIMPLE table: lineitem type: range possible_keys: PRIMARY,i_l_shipdate,i_l_orderkey,i_l_orderkey_quantity key: i_l_shipdate key_len: 4 ref: NULL rows: 98 Extra: Using index condition *************************** 2. row *************************** id: 1 select_type: SIMPLE table: orders type: eq_ref|filter possible_keys: PRIMARY,i_o_totalprice key: PRIMARY|i_o_totalprice key_len: 4|9 ref: dbt3_s001.lineitem.l_orderkey rows: 1 (5%) Extra: Using where; Using rowid filter ``` Note that table `orders` has "Using rowid filter". The `type` column has `"|filter"`, the `key` column shows the index that is used to construct the filter. `rows` column shows the expected filter selectivity, it is 5%. ANALYZE FORMAT=JSON output for table orders will show ``` "table": { "table_name": "orders", "access_type": "eq_ref", "possible_keys": ["PRIMARY", "i_o_totalprice"], "key": "PRIMARY", "key_length": "4", "used_key_parts": ["o_orderkey"], "ref": ["dbt3_s001.lineitem.l_orderkey"], "rowid_filter": { "range": { "key": "i_o_totalprice", "used_key_parts": ["o_totalprice"] }, "rows": 69, "selectivity_pct": 4.6, "r_rows": 71, "r_selectivity_pct": 10.417, "r_buffer_size": 53, "r_filling_time_ms": 0.0716 } ``` Note the `rowid_filter` element. It has a `range` element inside it. `selectivity_pct` is the expected selectivity, accompanied by the `r_selectivity_pct` showing the actual observed selectivity. Details ------- * The optimizer makes a cost-based decision about when the filter should be used. * The filter data structure is currently an ordered array of rowids. (a Bloom filter would be better here and will probably be introduced in the future versions). * The optimization needs to be supported by the storage engine. At the moment, it is supported by [InnoDB](../innodb/index) and [MyISAM](../myisam/index). It is not supported in [partitioned tables](../partitioning-tables/index). Control ------- Rowid filtering can be switched on/off using `rowid_filter` flag in the [optimizer\_switch](../server-system-variables/index#optimizer_switch) variable. By default, the optimization is enabled. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb User-Defined Variables User-Defined Variables ====================== User-defined variables are variables which can be created by the user and exist in the session. This means that no one can access user-defined variables that have been set by another user, and when the session is closed these variables expire. However, these variables can be shared between several queries and [stored programs](../stored-programs-and-views/index). User-defined variables names must be preceded by a single *at* character (`@`). While it is safe to use a reserved word as a user-variable name, the only allowed characters are ASCII letters, digits, dollar sign (`$`), underscore (`_`) and dot (`.`). If other characters are used, the name can be quoted in one of the following ways: * @`var\_name` * @'var\_name' * @"var\_name" These characters can be escaped as usual. User-variables names are case insensitive, though they were case sensitive in MySQL 4.1 and older versions. User-defined variables cannot be declared. They can be read even if no value has been set yet; in that case, they are NULL. To set a value for a user-defined variable you can use: * [SET](../set/index) statement; * [:=](../assignment-operator/index) operator within a SQL statement; * [SELECT ... INTO](../select-into/index). Since user-defined variables type cannot be declared, the only way to force their type is using [CAST()](../cast/index) or [CONVERT()](../convert/index): ``` SET @str = CAST(123 AS CHAR(5)); ``` If a variable has not been used yet, its value is NULL: ``` SELECT @x IS NULL; +------------+ | @x IS NULL | +------------+ | 1 | +------------+ ``` It is unsafe to read a user-defined variable and set its value in the same statement (unless the command is SET), because the order of these actions is undefined. User-defined variables can be used in most MariaDB's statements and clauses which accept an SQL expression. However there are some exceptions, like the [LIMIT](../select/index#limit) clause. They must be used to [PREPARE](../prepare-statement/index) a prepared statement: ``` @sql = 'DELETE FROM my_table WHERE c>1;'; PREPARE stmt FROM @sql; EXECUTE stmt; DEALLOCATE PREPARE stmt; ``` Another common use is to include a counter in a query: ``` SET @var = 0; SELECT a, b, c, (@var:=@var+1) AS counter FROM my_table; ``` Information Schema ------------------ User-defined variables can be viewed in the [Information Schema USER\_VARIABLES Table](../information-schema-user_variables-table/index) (as part of the [User Variables plugin](../user-variables-plugin/index)) from [MariaDB 10.2](../what-is-mariadb-102/index). Flushing User-Defined Variables ------------------------------- User-defined variables are reset and the [Information Schema table](../information-schema-user_variables-table/index) emptied with the [FLUSH USER\_VARIABLES](../flush/index) statement. ``` SET @str = CAST(123 AS CHAR(5)); SELECT * FROM information_schema.USER_VARIABLES ORDER BY VARIABLE_NAME; +---------------+----------------+---------------+--------------------+ | VARIABLE_NAME | VARIABLE_VALUE | VARIABLE_TYPE | CHARACTER_SET_NAME | +---------------+----------------+---------------+--------------------+ | str | 123 | VARCHAR | utf8mb3 | +---------------+----------------+---------------+--------------------+ FLUSH USER_VARIABLES; SELECT * FROM information_schema.USER_VARIABLES ORDER BY VARIABLE_NAME; Empty set (0.000 sec) ``` See Also -------- * [DECLARE VARIABLE](../declare-variable/index) * [Performance Schema user\_variables\_by\_thread Table](../performance-schema-user_variables_by_thread-table/index) * [Information Schema USER\_VARIABLES Table](../information-schema-user_variables-table/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb mysql.host Table mysql.host Table ================ ### Usage Until [MariaDB 5.5](../what-is-mariadb-55/index), the `mysql.host` table contained information about hosts and their related privileges. When determining permissions, if a matching record in the [mysql.db table](../mysqldb-table/index) had a blank host value, the mysql.host table would be examined. This table is not affected by any [GRANT](../grant/index) statements, and had to be updated manually. Since [MariaDB 10.0](../what-is-mariadb-100/index), this table is no longer used. See [privileges](../grant/index) for a more complete view of the MariaDB privilege system. **MariaDB until [10.3](../what-is-mariadb-103/index)**In [MariaDB 10.3](../what-is-mariadb-103/index) and before, this table was created the [MyISAM](../myisam-storage-engine/index) storage engine. **MariaDB starting with [10.4](../what-is-mariadb-104/index)**In [MariaDB 10.4](../what-is-mariadb-104/index) and later, this table is no longer created. However if the table is created it will be used. ### Table fields The `mysql.host` table contains the following fields: | Field | Type | Null | Key | Default | Description | | --- | --- | --- | --- | --- | --- | | `Host` | `char(60)` | NO | PRI | | Host (together with `Db` makes up the unique identifier for this record. | | `Db` | `char(64)` | NO | PRI | | Database (together with `Host` makes up the unique identifier for this record. | | `Select_priv` | `enum('N','Y')` | NO | | N | Can perform [SELECT](../select/index) statements. | | `Insert_priv` | `enum('N','Y')` | NO | | N | Can perform [INSERT](../insert/index) statements. | | `Update_priv` | `enum('N','Y')` | NO | | N | Can perform [UPDATE](../update/index) statements. | | `Delete_priv` | `enum('N','Y')` | NO | | N | Can perform [DELETE](../delete/index) statements. | | `Create_priv` | `enum('N','Y')` | NO | | N | Can [CREATE TABLEs](../create-table/index). | | `Drop_priv` | `enum('N','Y')` | NO | | N | Can [DROP DATABASEs](../drop-database/index) or [DROP TABLEs](../drop-table/index). | | `Grant_priv` | `enum('N','Y')` | NO | | N | User can [grant](../grant/index) privileges they possess. | | `References_priv` | `enum('N','Y')` | NO | | N | Unused | | `Index_priv` | `enum('N','Y')` | NO | | N | Can create an index on a table using the [CREATE INDEX](../create-index/index) statement. Without the `INDEX` privilege, user can still create indexes when creating a table using the [CREATE TABLE](../create-table/index) statement if the user has have the `CREATE` privilege, and user can create indexes using the [ALTER TABLE](../alter-table/index) statement if they have the `ALTER` privilege. | | `Alter_priv` | `enum('N','Y')` | NO | | N | Can perform [ALTER TABLE](../alter-table/index) statements. | | `Create_tmp_table_priv` | `enum('N','Y')` | NO | | N | Can create temporary tables with the [CREATE TEMPORARY TABLE](../create-table/index) statement. | | `Lock_tables_priv` | `enum('N','Y')` | NO | | N | Acquire explicit locks using the [LOCK TABLES](../transactions-lock/index) statement; user also needs to have the `SELECT` privilege on a table in order to lock it. | | `Create_view_priv` | `enum('N','Y')` | NO | | N | Can create a view using the [CREATE\_VIEW](../create-view/index) statement. | | `Show_view_priv` | `enum('N','Y')` | NO | | N | Can show the [CREATE VIEW](../create-view/index) statement to create a view using the [SHOW CREATE VIEW](../show-create-view/index) statement. | | `Create_routine_priv` | `enum('N','Y')` | NO | | N | Can create stored programs using the [CREATE PROCEDURE](../create-procedure/index) and [CREATE FUNCTION](../create-function/index) statements. | | `Alter_routine_priv` | `enum('N','Y')` | NO | | N | Can change the characteristics of a stored function using the [ALTER FUNCTION](../alter-function/index) statement. | | `Execute_priv` | `enum('N','Y')` | NO | | N | Can execute [stored procedure](../stored-procedures/index) or functions. | | `Trigger_priv` | `enum('N','Y')` | NO | | N | Can execute [triggers](../triggers/index) associated with tables the user updates, execute the [CREATE TRIGGER](../create-trigger/index) and [DROP TRIGGER](../drop-trigger/index) statements. | ### How to Create If you need the functionality to only allow access to your database from a given set of hosts, you can create the host table with the following command: ``` CREATE TABLE IF NOT EXISTS mysql.host (Host char(60) binary DEFAULT '' NOT NULL, Db char(64) binary DEFAULT '' NOT NULL, Select_priv enum('N','Y') COLLATE utf8_general_ci DEFAULT 'N' NOT NULL, Insert_priv enum('N','Y') COLLATE utf8_general_ci DEFAULT 'N' NOT NULL, Update_priv enum('N','Y') COLLATE utf8_general_ci DEFAULT 'N' NOT NULL, Delete_priv enum('N','Y') COLLATE utf8_general_ci DEFAULT 'N' NOT NULL, Create_priv enum('N','Y') COLLATE utf8_general_ci DEFAULT 'N' NOT NULL, Drop_priv enum('N','Y') COLLATE utf8_general_ci DEFAULT 'N' NOT NULL, Grant_priv enum('N','Y') COLLATE utf8_general_ci DEFAULT 'N' NOT NULL, References_priv enum('N','Y') COLLATE utf8_general_ci DEFAULT 'N' NOT NULL, Index_priv enum('N','Y') COLLATE utf8_general_ci DEFAULT 'N' NOT NULL, Alter_priv enum('N','Y') COLLATE utf8_general_ci DEFAULT 'N' NOT NULL, Create_tmp_table_priv enum('N','Y') COLLATE utf8_general_ci DEFAULT 'N' NOT NULL, Lock_tables_priv enum('N','Y') COLLATE utf8_general_ci DEFAULT 'N' NOT NULL, Create_view_priv enum('N','Y') COLLATE utf8_general_ci DEFAULT 'N' NOT NULL, Show_view_priv enum('N','Y') COLLATE utf8_general_ci DEFAULT 'N' NOT NULL, Create_routine_priv enum('N','Y') COLLATE utf8_general_ci DEFAULT 'N' NOT NULL, Alter_routine_priv enum('N','Y') COLLATE utf8_general_ci DEFAULT 'N' NOT NULL, Execute_priv enum('N','Y') COLLATE utf8_general_ci DEFAULT 'N' NOT NULL, Trigger_priv enum('N','Y') COLLATE utf8_general_ci DEFAULT 'N' NOT NULL, PRIMARY KEY /*Host*/ (Host,Db) ) engine=MyISAM CHARACTER SET utf8 COLLATE utf8_bin comment='Host privileges; Merged with database privileges'; ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Database Design Example Phase 2: Design Database Design Example Phase 2: Design ======================================= This article follows on from [Database Design Example Phase 1: Analysis](../database-design-example-phase-1-analysis/index). Based on the provided information, you can begin your logical design and should be able to identify the initial entities: * Poet * Poem * Publication * Sale * Customer The Poet's Circle is not an entity, or even of instance an a *publisher* entity. Only if the system were developed for many publishers would *publisher* be a valid entity. Neither *website* nor *poetry community* are entities. There is only one website, and anyway, a website is merely a means of producing data to populate the database. There is also only one poetry community as far as this system is concerned, and there is not much you'd want to store about it. Next, you need to determine the relationship between these entities. You can identify the following: * A poet can write many poems. The analysis identified the fact that a poet can be stored in the system even if there are no associated poems. Poems may be captured at a later point in time, or the poet may still be a potential poet. Conversely, many poets could conceivably write a poem, though the poem must have been written by at least one poet. * A publication may contain many poems (an anthology) or just one. It can also contain no poems (poetry criticism for example). A poem may or may not appear in a publication. * A sale must be for at least one publication, but it may be for many. A publication may or may not have made any sales. * A customer may be made for many sales, or none at all. A sale is only made for one and only one customer. You can identify the following attributes: * **Poet**: first name, surname, address, email address * **Poem**: poem title, poem contents * **Publication**: title, price * **Sales**: date, amount * **Customer**: first name, surname, address, email address Based on these entities and relationships, you can construct the entity-relationship diagram shown below: There are two many-to-many relationships in the figure above. These need to be converted into one-to-many relationships before you can implement them in a DBMS. After doing so, the intersection entities *poem-publication* and *sale-publication* are created. Now, to begin the logical and physical design, you need to add attributes that can create the relationship between the entities and specify primary keys. You do what's usually best, and create new, unique, primary keys. The following tables show the structures for the tables created from each of the entities: #### Poet table | Field | Definition | | --- | --- | | poet code | primary key, integer | | first name | character (30) | | surname | character (40) | | address | character (100) | | postcode | character (20) | | email address | character (254) | #### Poem table | Field | Definition | | --- | --- | | poem code | primary key, integer | | poem title | character(50) | | poem contents | text | | poet code | foreign key, integer | #### Poem-publication table | Field | Definition | | --- | --- | | poem code | joint primary key, foreign key, integer | | publication code | joint primary key, foreign key, integer | #### Publication table | Field | Definition | | --- | --- | | publication code | primary key, integer | | title | character(100) | | price | numeric(5.2) | #### Sale-publication table | Field | Definition | | --- | --- | | sale code | joint primary key, foreign key, integer | | publication code | joint primary key, foreign key, integer | #### Sale table | Field | Definition | | --- | --- | | sale code | primary key, integer | | date | date | | amount | numeric(10.2) | | customer code | foreign key, integer | #### Customer table | Field | Definition | | --- | --- | | customer code | primary key, integer | | first name | character (30) | | surname | character (40) | | address | character (100) | | postcode | character (20) | | email address | character (254) | MariaDB will have no problem with this, and is selected as the DBMS. Existing hardware and operating system platforms are also selected. The following section looks at the implementation and the SQL statements used to create the MariaDB tables. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb ST_ENDPOINT ST\_ENDPOINT ============ Syntax ------ ``` ST_EndPoint(ls) EndPoint(ls) ``` Description ----------- Returns the [Point](../point/index) that is the endpoint of the [LineString](../linestring/index) value `ls`. `ST_EndPoint()` and `EndPoint()` are synonyms. Examples -------- ``` SET @ls = 'LineString(1 1,2 2,3 3)'; SELECT AsText(EndPoint(GeomFromText(@ls))); +-------------------------------------+ | AsText(EndPoint(GeomFromText(@ls))) | +-------------------------------------+ | POINT(3 3) | +-------------------------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Information Schema INNODB_SYS_FOREIGN Table Information Schema INNODB\_SYS\_FOREIGN Table ============================================= The [Information Schema](../information_schema/index) `INNODB_SYS_FOREIGN` table contains information about InnoDB [foreign keys](../foreign-keys/index). The `PROCESS` [privilege](../grant/index) is required to view the table. It has the following columns: | Column | Description | | --- | --- | | `ID` | Database name and foreign key name. | | `FOR_NAME` | Database and table name of the foreign key child. | | `REF_NAME` | Database and table name of the foreign key parent. | | `N_COLS` | Number of foreign key index columns. | | `TYPE` | Bit flag providing information about the foreign key. | The `TYPE` column provides a bit flag with information about the foreign key. This information is `OR`'ed together to read: | Bit Flag | Description | | --- | --- | | `1` | `ON DELETE CASCADE` | | `2` | `ON UPDATE SET NULL` | | `4` | `ON UPDATE CASCADE` | | `8` | `ON UPDATE SET NULL` | | `16` | `ON DELETE NO ACTION` | | `32` | `ON UPDATE NO ACTION` | Example ------- ``` SELECT * FROM INNODB_SYS_FOREIGN\G *************************** 1. row *************************** ID: mysql/innodb_index_stats_ibfk_1 FOR_NAME: mysql/innodb_index_stats REF_NAME: mysql/innodb_table_stats N_COLS: 2 TYPE: 0 ... ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Non-Recursive Common Table Expressions Overview Non-Recursive Common Table Expressions Overview =============================================== Common Table Expressions (CTEs) are a standard SQL feature, and are essentially temporary named result sets. There are two kinds of CTEs: Non-Recursive, which this article covers; and [Recursive](../recursive-common-table-expressions-overview/index). **MariaDB starting with [10.2.1](https://mariadb.com/kb/en/mariadb-1021-release-notes/)**Common table expressions were introduced in [MariaDB 10.2.1](https://mariadb.com/kb/en/mariadb-1021-release-notes/). Non-Recursive CTEs ------------------ The [WITH](../with/index) keyword signifies a CTE. It is given a name, followed by a body (the main query) as follows: CTEs are similar to derived tables. For example ``` WITH engineers AS ( SELECT * FROM employees WHERE dept = 'Engineering' ) SELECT * FROM engineers WHERE ... ``` ``` SELECT * FROM ( SELECT * FROM employees WHERE dept = 'Engineering' ) AS engineers WHERE ... ``` A non-recursive CTE is basically a query-local [VIEW](../views/index). There are several advantages and caveats to them. The syntax is more readable than nested `FROM (SELECT ...)`. A CTE can refer to another and it can be referenced from multiple places. ### A CTE referencing Another CTE Using this format makes for a more readable SQL than a nested `FROM(SELECT ...)` clause. Below is an example of this: ``` WITH engineers AS ( SELECT * FROM employees WHERE dept IN('Development','Support') ), eu_engineers AS ( SELECT * FROM engineers WHERE country IN('NL',...) ) SELECT ... FROM eu_engineers; ``` ### Multiple Uses of a CTE This can be an 'anti-self join', for example: ``` WITH engineers AS ( SELECT * FROM employees WHERE dept IN('Development','Support') ) SELECT * FROM engineers E1 WHERE NOT EXISTS (SELECT 1 FROM engineers E2 WHERE E2.country=E1.country AND E2.name <> E1.name ); ``` Or, for year-over-year comparisons, for example: ``` WITH sales_product_year AS ( SELECT product, YEAR(ship_date) AS year, SUM(price) AS total_amt FROM item_sales GROUP BY product, year ) SELECT * FROM sales_product_year CUR, sales_product_year PREV, WHERE CUR.product=PREV.product AND CUR.year=PREV.year + 1 AND CUR.total_amt > PREV.total_amt ``` Another use is to compare individuals against their group. Below is an example of how this might be executed: ``` WITH sales_product_year AS ( SELECT product, YEAR(ship_date) AS year, SUM(price) AS total_amt FROM item_sales GROUP BY product, year ) SELECT * FROM sales_product_year S1 WHERE total_amt > (SELECT 0.1 * SUM(total_amt) FROM sales_product_year S2 WHERE S2.year = S1.year) ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb FLUSH Commands FLUSH Commands =============== Commands to reset (flush) various caches in MariaDB. | Title | Description | | --- | --- | | [FLUSH](../flush/index) | Clear or reload various internal caches. | | [FLUSH QUERY CACHE](../flush-query-cache/index) | Defragmenting the query cache | | [FLUSH TABLES FOR EXPORT](../flush-tables-for-export/index) | Flushes changes to disk for specific tables. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Building MyRocks in MariaDB Building MyRocks in MariaDB =========================== This page describes how to get [MyRocks in MariaDB](../myrocks/index) when compiling MariaDB from source. (See <https://github.com/facebook/mysql-5.6/wiki/Build-Steps> for instructions how to build the upstream) Build Process and Requirements ------------------------------ MariaDB compile process will compile [MyRocks](../myrocks/index) into `ha_rocksdb.so` by default if the platform supports it (That is, no WITH\_ROCKSDB switch is necessary). Platform requirements: * A 64-bit platform (due to some 32 bit compilers having difficulties with RocksDB) * git installed (or git submodules fetched somehow) * A sufficiently recent compiler: + gcc >= 4.8, or + clang >= 3.3, or + MS Visual Studio 2015 or newer Building on Ubuntu 16.04 ------------------------ The steps were checked on a fresh install of Ubuntu 16.04.2 LTS Xenial. ``` sudo apt-get update sudo apt-get -y install g++ cmake libbz2-dev libaio-dev bison zlib1g-dev libsnappy-dev sudo apt-get -y install libgflags-dev libreadline6-dev libncurses5-dev libssl-dev liblz4-dev gdb git ; ``` ``` git clone https://github.com/MariaDB/server.git mariadb-10.2 cd mariadb-10.2 git checkout 10.2 git submodule init git submodule update cmake . make -j10 ``` This should produce `storage/rocksdb/ha_rocksdb.so` which is MyRocks storage engine in the loadable form. Starting MyRocks ---------------- MyRocks does not require any special way to initialize the data directory. Minimal my.cnf flle: ``` cat > ~/my1.cnf <<EOF [mysqld] datadir=../mysql-test/var/install.db plugin-dir=../storage/rocksdb language=./share/english socket=/tmp/mysql.sock port=3307 plugin-load=ha_rocksdb default-storage-engine=rocksdb EOF ``` Run the server like this ``` (cd mysql-test; ./mtr alias) cp -r mysql-test/var/install.db ~/data1 cd ../sql ./mysqld --defaults-file=~/my1.cnf ``` Compression libraries. Supported compression libraries are listed in [rocksdb\_supported\_compression\_types](../myrocks-system-variables/index#rocksdb_supported_compression_types). Compiling like the above, I get: ``` Snappy,Zlib,LZ4,LZ4HC ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Branch Protection Using Buildbot Branch Protection Using Buildbot ================================ MariaDB uses branch protection to ensure that pushes to the MariaDB Server git repository cannot be made without first passing a series of tests. This page aims to describe what a developer should do in order to ensure that their changes get pushed to the main repository. The current protected branches are: **10.2, 10.3, 10.4, 10.5, 10.6, 10.7, 10.8** ### Protected Branches Flow 1. Rebase your work on top of the latest main branch. `git rebase 10.2` 2. Push to bb-\* branch 3. Wait for all the checks to run 4. If all checks are successful you can push to the main branch to be the same as bb-\* branch 5. If not (failed checks), check the build status, make changes accordingly and repeat this flow ### Protected Branches Builders The following are the **only** required builders at this point: 1. amd64-centos-7 2. amd64-debian-10 3. amd64-fedora-35 4. amd64-ubuntu-2004-clang11 5. amd64-windows 6. amd64-windows-packages The protected branches builders run a subset of tests in order to avoid sporadic failures. The list is defined by: ``` --suite=main --skip-test="^stack_crash$|^float$|^derived_split_innodb$|^mysql_client_test$|^kill$|^processlist_not_embedded$|^sp-big$" ``` All other checks are not required in order to make the push. However, please take a look at all the builders and look for failures. #### Disabled Protected Branches 1. ppc64le-rhel-8 (temporarily disabled, pending network bottleneck fix) 2. aarch64-debian-10 (temporarily disabled, till more compute power) ### Viewing Build Status The build status can be seen directly from GitHub near the commit message. Below, you can find an example (please note the **yellow dot** near the commit message): If you click on the **yellow dot**, you can find the list of checks performed and their status, as shown below: By clicking on **Details** you will be redirected to the buildbot page showing all the build details. Alternatively, you can look for the builds on the [buildbot Grid View](https://buildbot.mariadb.org/#/grid). This allows filtering by branch, so to only see changes for one particular branch you can use <https://buildbot.mariadb.org/#/grid?branch=10.5>. ### Status and Action Items * Yellow dot - specifies that one or more of checks are not yet completed. + Action item: Wait for all the checks to finish * Green tick - all checks were successful + Action item: No specific action is needed. The push can go through! * Red X - one or more checks have failed + Action item: Look at the status of failing builds and fix potential issues Note: Only buildbot and not external CI tests (Travis, AppVeyor, etc) are currently in the protected branches criteria. Please take note of other failures, and if they are acceptable and explainable, then merge. ### Re-trigger Checks In some cases it might be useful to re-trigger one or more checks. This can easily be done from the <https://buildbot.mariadb.org> interface. The steps are: 1. Login to <https://buildbot.mariadb.org> using the GitHub credentials: Hit the "Anonymous" button from the upper right corner and then "Login with GitHub" as shown below: * 2. Open the build details of the build you want to re-trigger 3. Hit the "Rebuild" button from the upper right corner **Note**: If you want to re-trigger all checks, the easiest approach is to make a new push. Alternatively, you can follow the above steps for all the checks Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb DROP DATABASE DROP DATABASE ============= Syntax ------ ``` DROP {DATABASE | SCHEMA} [IF EXISTS] db_name ``` Description ----------- `DROP DATABASE` drops all tables in the database and deletes the database. Be very careful with this statement! To use DROP DATABASE, you need the [DROP privilege](../grant/index#table-privileges) on the database. `DROP SCHEMA` is a synonym for `DROP DATABASE`. **Important:** When a database is dropped, user privileges on the database are not automatically dropped. See [GRANT](../grant/index). #### IF EXISTS Use `IF EXISTS` to prevent an error from occurring for databases that do not exist. A `NOTE` is generated for each non-existent database when using `IF EXISTS`. See [SHOW WARNINGS](../show-warnings/index). ### Atomic DDL **MariaDB starting with [10.6.1](https://mariadb.com/kb/en/mariadb-1061-release-notes/)**[MariaDB 10.6.1](https://mariadb.com/kb/en/mariadb-1061-release-notes/) supports [Atomic DDL](../atomic-ddl/index). `DROP DATABASE` is implemented as ``` loop over all tables DROP TABLE table ``` Each individual [DROP TABLE](../drop-table/index) is atomic while `DROP DATABASE` as a whole is crash-safe. Examples -------- ``` DROP DATABASE bufg; Query OK, 0 rows affected (0.39 sec) DROP DATABASE bufg; ERROR 1008 (HY000): Can't drop database 'bufg'; database doesn't exist \W Show warnings enabled. DROP DATABASE IF EXISTS bufg; Query OK, 0 rows affected, 1 warning (0.00 sec) Note (Code 1008): Can't drop database 'bufg'; database doesn't exist ``` See Also -------- * [CREATE DATABASE](../create-database/index) * [ALTER DATABASE](../alter-database/index) * [SHOW DATABASES](../show-databases/index) * [Information Schema SCHEMATA Table](../information-schema-schemata-table/index) * [SHOW CREATE DATABASE](../show-create-database/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Authentication Plugin - PAM Authentication Plugin - PAM =========================== The `pam` authentication plugin allows MariaDB to offload user authentication to the system's [Pluggable Authentication Module (PAM)](http://en.wikipedia.org/wiki/Pluggable_authentication_module) framework. PAM is an authentication framework used by Linux, FreeBSD, Solaris, and other Unix-like operating systems. **Note:** Windows does not support PAM, so the `pam` authentication plugin does not support Windows. However, one can use a MariaDB client on Windows to connect to MariaDB server that is installed on a Unix-like operating system and that is configured to use the `pam` authentication plugin. For an example of how to do this, see the blog post: [MariaDB: Improve Security with Two-Step Verification](https://mariadb.org/improve-security-with-two-step-verification/). Use Cases --------- PAM makes it possible to implement various authentication scenarios of different complexity. For example, * Authentication using passwords from `/etc/shadow` (indeed, this is what a default PAM configuration usually does). See the [pam\_unix](#pam_unix) PAM module. * Authentication using LDAP. See the [pam\_ldap](#pam_ldap) PAM module. * Authentication using Microsoft's Active Directory. See the [pam\_lsass](#pam_lsass), [pam\_winbind](#pam_winbind), and [pam\_centrifydc](#pam_centrifydc) PAM modules. * Authentication using one-time passwords (even with SMS confirmation!). See the [pam\_google\_authenticator](#pam_google_authenticator) and [pam\_securid](#pam_securid) PAM modules. * Authentication using SSH keys. See the [pam\_ssh](#pam_ssh) PAM module. * User and group mapping. See the [pam\_user\_map](#pam_user_map) PAM module. * Combining different authentication modules in interesting ways in a [PAM service](#configuring-the-pam-service). * Password expiration. * Limiting access by time, date, day of the week, etc. See the [pam\_time](#pam_time) PAM module. * Logging every login attempt. * and so on, the list is in no way exhaustive. Installing the Plugin --------------------- The `pam` authentication plugin's library is provided in [binary packages](../binary-packages/index) in all releases on Linux. Although the plugin's shared library is distributed with MariaDB by default, the plugin is not actually installed by MariaDB by default. There are two methods that can be used to install the plugin with MariaDB. The first method can be used to install the plugin without restarting the server. You can install the plugin dynamically by executing [INSTALL SONAME](../install-soname/index) or [INSTALL PLUGIN](../install-plugin/index). For example: ``` INSTALL SONAME 'auth_pam'; ``` The second method can be used to tell the server to load the plugin when it starts up. The plugin can be installed this way by providing the [--plugin-load](../mysqld-options/index#-plugin-load) or the [--plugin-load-add](../mysqld-options/index#-plugin-load-add) options. This can be specified as a command-line argument to [mysqld](../mysqld-options/index) or it can be specified in a relevant server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index). For example: ``` [mariadb] ... plugin_load_add = auth_pam ``` ### Installing the v1 Plugin **MariaDB starting with [10.4.0](https://mariadb.com/kb/en/mariadb-1040-release-notes/)**Starting in [MariaDB 10.4.0](https://mariadb.com/kb/en/mariadb-1040-release-notes/), the `auth_pam` shared library actually refers to version `2.0` of the `pam` authentication plugin. [MariaDB 10.4.0](https://mariadb.com/kb/en/mariadb-1040-release-notes/) and later also provides version `1.0` of the plugin as the `auth_pam_v1` shared library. In [MariaDB 10.4.0](https://mariadb.com/kb/en/mariadb-1040-release-notes/) and later, if you need to install version `1.0` of the authentication plugin instead of version `2.0`, then you can do so. For example, with [INSTALL SONAME](../install-soname/index) or [INSTALL PLUGIN](../install-plugin/index): ``` INSTALL SONAME 'auth_pam_v1'; ``` Or by specifying in a relevant server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index): ``` [mariadb] ... plugin_load_add = auth_pam_v1 ``` Uninstalling the Plugin ----------------------- You can uninstall the plugin dynamically by executing [UNINSTALL SONAME](../uninstall-soname/index) or [UNINSTALL PLUGIN](../uninstall-plugin/index). For example: ``` UNINSTALL SONAME 'auth_pam'; ``` If you installed the plugin by providing the [--plugin-load](../mysqld-options/index#-plugin-load) or the [--plugin-load-add](../mysqld-options/index#-plugin-load-add) options in a relevant server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index), then those options should be removed to prevent the plugin from being loaded the next time the server is restarted. ### Uninstalling the v1 Plugin If you installed version `1.0` of the authentication plugin, then you can uninstall that by executing a similar statement for `auth_pam_v1`. For example: ``` UNINSTALL SONAME 'auth_pam_v1'; ``` Configuring PAM --------------- The `pam` authentication plugin tells MariaDB to delegate the authentication to the PAM authentication framework. How exactly that authentication is performed depends on how PAM was configured. ### Configuring the PAM Service PAM is divided into `services`. PAM services are configured by [PAM configuration files](http://www.linux-pam.org/Linux-PAM-html/sag-configuration-file.html). Typically, the global PAM configuration file is located at `/etc/pam.conf` and [PAM directory-based configuration files](http://www.linux-pam.org/Linux-PAM-html/sag-configuration-directory.html) for individual services are located in `/etc/pam.d/`. If you want to use a PAM service called `mariadb` for your MariaDB PAM authentication, then the PAM configuration file for that service would also be called `mariadb`, and it would typically be located at `/etc/pam.d/mariadb`. For example, here is a minimal PAM service configuration file that performs simple password authentication with UNIX passwords: ``` auth required pam_unix.so audit account required pam_unix.so audit ``` Let's breakdown this relatively simple PAM service configuration file. Each line of a PAM service configuration file has the following general format: *type control module-path module-arguments* The above PAM service configuration file instructs the PAM authentication framework that for successful **authentication** (i.e. type=[auth](http://www.linux-pam.org/Linux-PAM-html/mwg-expected-of-module-auth.html)), it is **required** that the `pam_unix.so` PAM module returns a success. The above PAM service configuration file also instructs the PAM authentication framework that for an **account** (i.e. type=[account](http://www.linux-pam.org/Linux-PAM-html/mwg-expected-of-module-acct.html)) to be valid, it is **required** that the `pam_unix.so` PAM module returns a success. PAM also supports [session](http://www.linux-pam.org/Linux-PAM-html/mwg-expected-of-module-session.html) and [password](http://www.linux-pam.org/Linux-PAM-html/mwg-expected-of-module-chauthtok.html) types, but MariaDB's `pam` authentication plugin does not support those. The above PAM service configuration file also provides the `audit` module argument to the `pam_unix` PAM module. The [pam\_unix manual](https://linux.die.net/man/8/pam_unix) says that this module argument enables extreme debug logging to the syslog. On most systems, you can find many other examples of PAM service configuration files in your `/etc/pam.d/` directory. #### Configuring the pam\_unix PAM Module If you configure PAM to use the [pam\_unix](https://linux.die.net/man/8/pam_unix) PAM module (as in the above example), then you might notice on some systems that this will fail by default with errors like the following: ``` Apr 14 12:56:23 localhost unix_chkpwd[3332]: check pass; user unknown Apr 14 12:56:23 localhost unix_chkpwd[3332]: password check failed for user (alice) Apr 14 12:56:23 localhost mysqld: pam_unix(mysql:auth): authentication failure; logname= uid=991 euid=991 tty= ruser= rhost= user=alice ``` The problem is that on some systems, the `pam_unix` PAM module needs access to `/etc/shadow` in order to function, and most systems only allow `root` to access that file by default. Newer versions of PAM do not have this limitation, so you may want to try upgrading your version of PAM to see if that fixes the issue. If that does not work, then you can work around this problem by giving the user that runs [mysqld](../mysqld-options/index) access to `/etc/shadow`. For example, if the `mysql` user runs [mysqld](../mysqld-options/index), then you could do the following: ``` sudo groupadd shadow sudo usermod -a -G shadow mysql sudo chown root:shadow /etc/shadow sudo chmod g+r /etc/shadow ``` And then you would have to [restart the server](../starting-and-stopping-mariadb-starting-and-stopping-mariadb/index). At that point, the server should be able to read `/etc/shadow`. **MariaDB starting with [10.4.0](https://mariadb.com/kb/en/mariadb-1040-release-notes/)**Starting in [MariaDB 10.4.0](https://mariadb.com/kb/en/mariadb-1040-release-notes/), the `pam` authentication plugin uses a [setuid](https://linux.die.net/man/2/setuid) wrapper to perform its PAM checks, so it should not need any special workarounds to perform privileged operations, such as reading `/etc/shadow` when using the `pam_unix` PAM module. See [MDEV-7032](https://jira.mariadb.org/browse/MDEV-7032) for more information. Creating Users -------------- Similar to all other [authentication plugins](../authentication-plugins/index), to create a user in MariaDB which uses the `pam` authentication plugin, you would execute [CREATE USER](../create-user/index) while specifying the name of the plugin in the [IDENTIFIED VIA](../create-user/index#identified-viawith-authentication_plugin) clause. For example: ``` CREATE USER username@hostname IDENTIFIED VIA pam; ``` If [SQL\_MODE](../sql-mode/index) does not have `NO_AUTO_CREATE_USER` set, then you can also create the user this way with [GRANT](../grant/index). For example: ``` GRANT SELECT ON db.* TO username@hostname IDENTIFIED VIA pam; ``` You can also specify a [PAM service name](#configuring-the-pam-service) for MariaDB to use by providing it with the `USING` clause. For example: ``` CREATE USER username@hostname IDENTIFIED VIA pam USING 'mariadb'; ``` This line creates a user that needs to be authenticated via the `pam` authentication plugin using the [PAM service name](#configuring-the-pam-service) `mariadb`. As mentioned in a previous section, this service's configuration file will typically be present in `/etc/pam.d/mariadb`. If no service name is specified, then the plugin will use `mysql` as the default [PAM service name](#configuring-the-pam-service). Client Authentication Plugins ----------------------------- For clients that use the `libmysqlclient` or [MariaDB Connector/C](../mariadb-connector-c/index) libraries, MariaDB provides two client authentication plugins that are compatible with the `pam` authentication plugin: * `dialog` * `mysql_clear_password` When connecting with a [client or utility](../clients-utilities/index) to a server as a user account that authenticates with the `pam` authentication plugin, you may need to tell the client where to find the relevant client authentication plugin by specifying the `--plugin-dir` option. For example: ``` mysql --plugin-dir=/usr/local/mysql/lib64/mysql/plugin --user=alice ``` Both the `dialog` and the `mysql_clear_password` client authentication plugins transmit the password to the server in clear text. Therefore, when you use the `pam` authentication plugin, it is incredibly important to [encrypt client connections using TLS](../data-in-transit-encryption/index) to prevent the clear-text passwords from being seen by unauthorized users. ### `dialog` Usually the `pam` authentication plugin uses the `dialog` client authentication plugin to communicate with the user. This client authentication plugin allows MariaDB to support arbitrarily complex PAM configurations with regular or one-time passwords, challenge-response, multiple questions, or just about anything else. When using a MariaDB client library, there is no need to install or enable anything — the `dialog` client authentication plugin is loaded by the client library completely automatically and transparently for the application. The `dialog` client authentication plugin was developed by MariaDB, so MySQL's clients and client libraries as well as third party applications that bundle MySQL's client libraries do not support the `dialog` client authentication plugin out of the box. If the server tells an unsupported client to use the `dialog` client authentication plugin, then the client is likely to throw an error like the following: ``` ERROR 2059 (HY000): Authentication plugin 'dialog' cannot be loaded: /usr/lib/mysql/plugin/dialog.so: cannot open shared object file: No such file or directory ``` For some libraries or applications, this problem can be fixed by copying `dialog.so` or `dialog.dll` from a MariaDB client installation that is compatible with the system into the system's MySQL client authentication plugin directory. However, not all clients are compatible with the `dialog` client authentication plugin, so this may not work for every client. If your client does not support the `dialog` client authentication plugin, then you may need to use the [mysql\_clear\_password](#mysql_clear_password) client authentication plugin instead. The `dialog` client authentication plugin transmits the password to the server in clear text. Therefore, when you use the `pam` authentication plugin, it is incredibly important to [encrypt client connections using TLS](../data-in-transit-encryption/index) to prevent the clear-text passwords from being seen by unauthorized users. ### `mysql_clear_password` Users can instruct the `pam` authentication plugin to use the `mysql_clear_password` client authentication plugin instead of the [dialog](#dialog) client authentication plugin by configuring the [pam\_use\_cleartext\_plugin](#pam_use_cleartext_plugin) system variable on the server. It can be set in a relevant server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index). For example: ``` [mariadb] ... pam_use_cleartext_plugin ``` It is important to note that the `mysql_clear_password` plugin has very limited functionality. * The `mysql_clear_password` client authentication plugin only supports PAM services that require password-based authentication. * The `mysql_clear_password` client authentication plugin also only supports PAM services that ask the user a single question. * If the PAM service requires challenge-responses, multiple questions, or other similar complicated authentication schemes, then the PAM service is not compatible with `mysql_clear_password` client authentication plugin. In that case, the [dialog](#dialog) client authentication plugin will have to be used instead. The `mysql_clear_password` client authentication plugin transmits the password to the server in clear text. Therefore, when you use the `pam` authentication plugin, it is incredibly important to [encrypt client connections using TLS](../data-in-transit-encryption/index) to prevent the clear-text passwords from being seen by unauthorized users. #### Compatiblity with MySQL Clients and Client Libraries The `mysql_clear_password` client authentication plugin is similar to MySQL's [mysql\_clear\_password](https://dev.mysql.com/doc/refman/5.7/en/cleartext-pluggable-authentication.html) client authentication plugin. The `mysql_clear_password` client authentication plugin is compatible with MySQL clients and most MySQL client libraries, while the [dialog](#dialog) client authentication plugin is not always compatible with them. Therefore, the `mysql_clear_password` client authentication plugin is most useful if you need some kind of MySQL compatibility in your environment, but you still want to use the `pam` authentication plugin. Even though the `mysql_clear_password` client authentication plugin is compatible with MySQL clients and most MySQL client libraries, the `mysql_clear_password` client authentication plugin may be disabled by default by these clients and client libraries. For example, MySQL's version of the [mysql](https://dev.mysql.com/doc/refman/5.7/en/mysql.html) command-line client has the [--enable-cleartext-plugin](https://dev.mysql.com/doc/refman/5.7/en/mysql-command-options.html#option_mysql_enable-cleartext-plugin) option that must be set in order to use the `mysql_clear_password` client authentication plugin. For example: ``` mysql --enable-cleartext-plugin --user=alice -p ``` Other clients may require other methods to enable the authentication plugin. For example, [MySQL Workbench](https://www.mysql.com/products/workbench/) has a checkbox titled **Enable Cleartext Authentication Plugin** under the **Advanced** tab on the connection configuration screen. For applications that use MySQL's `libmysqlclient`, the authentication plugin can be enabled by setting the `MYSQL_ENABLE_CLEARTEXT_PLUGIN` option with the `mysql_options()` function. For example: ``` mysql_options(mysql, MYSQL_ENABLE_CLEARTEXT_PLUGIN, 1); ``` For MySQL compatibility, [MariaDB Connector/C](../mariadb-connector-c/index) also allows applications to set the `MYSQL_ENABLE_CLEARTEXT_PLUGIN` option with the [mysql\_optionsv](../mysql_optionsv/index) function. However, this option does not actually do anything in [MariaDB Connector/C](../mariadb-connector-c/index), because the `mysql_clear_password` client authentication plugin is always enabled for MariaDB clients and client libraries. Support in Client Libraries --------------------------- ### Using the Plugin with MariaDB Connector/C [MariaDB Connector/C](../mariadb-connector-c/index) supports `pam` authentication using the [client authentication plugins](client-authentication-plugins) mentioned in the previous section since MariaDB Connector/C 2.1.0, regardless of the value of the [pam\_use\_cleartext\_plugin](#pam_use_cleartext_plugin) system variable. ### Using the Plugin with MariaDB Connector/ODBC [MariaDB Connector/ODBC](../mariadb-connector-odbc/index) supports `pam` authentication using the [client authentication plugins](client-authentication-plugins) mentioned in the previous section since MariaDB Connector/ODBC 1.0.0, regardless of the value of the [pam\_use\_cleartext\_plugin](#pam_use_cleartext_plugin) system variable. ### Using the Plugin with MariaDB Connector/J [MariaDB Connector/J](../mariadb-connector-j/index) supports `pam v1` authentication since MariaDB Connector/J 1.4.0, regardless of the value of the [pam\_use\_cleartext\_plugin](#pam_use_cleartext_plugin) system variable. [MariaDB Connector/J](../mariadb-connector-j/index) supports `pam v2` authentication since MariaDB Connector/J 2.4.4, regardless of the value of the [pam\_use\_cleartext\_plugin](#pam_use_cleartext_plugin) system variable. ### Using the Plugin with MariaDB Connector/Node.js [MariaDB Connector/Node.js](../nodejs-connector/index) supports `pam` authentication since MariaDB Connector/Node.js 0.7.0, regardless of the value of the [pam\_use\_cleartext\_plugin](#pam_use_cleartext_plugin) system variable. ### Using the Plugin with MySqlConnector for .NET [MySqlConnector for ADO.NET](../mysqlconnector-for-adonet/index) supports `pam` authentication since MySqlConnector 0.20.0, but only if the [pam\_use\_cleartext\_plugin](#pam_use_cleartext_plugin) system variable is enabled on the server. Logging ------- ### PAM Module Logging Errors and messages from PAM modules are usually logged using the [syslog](https://linux.die.net/man/8/rsyslogd) daemon with the `authpriv` facility. To determine the specific log file where the `authpriv` facility is logged, you can check [rsyslog.conf](https://linux.die.net/man/5/rsyslog.conf). On RHEL, CentOS, Fedora, and other similar Linux distributions, the default location for these messages is usually `/var/log/secure`. On Debian, Ubuntu, and other similar Linux distributions, the default location for these messages is usually `/var/log/auth.log`. For example, the syslog can contain messages like the following when MariaDB's `pam` authentication plugin is configured to use the [pam\_unix](#pam_unix) PAM module, and the user enters an incorrect password: ``` Jan 9 05:35:41 ip-172-30-0-198 unix_chkpwd[1205]: password check failed for user (foo) Jan 9 05:35:41 ip-172-30-0-198 mysqld: pam_unix(mariadb:auth): authentication failure; logname= uid=997 euid=997 tty= ruser= rhost= user=foo ``` ### PAM Authentication Plugin's Debug Logging MariaDB's `pam` authentication plugin can also log additional verbose debug logging to the [error log](../error-log/index). This is only done if the plugin is a [debug build](../compiling-mariadb-for-debugging/index) and if [pam\_debug](#pam_debug) is set. The output looks like this: ``` PAM: pam_start(mariadb, alice) PAM: pam_authenticate(0) PAM: conv: send(Enter PASSCODE:) PAM: conv: recv(123456789) PAM: pam_acct_mgmt(0) PAM: pam_get_item(PAM_USER) PAM: status = 0 user = ��\> ``` ### Custom Logging with pam\_exec The [pam\_exec](https://linux.die.net/man/8/pam_exec) PAM module can be used to implement some custom logging. This can be very useful when debugging certain kinds of issues. For example, first, create a script that writes the log output: ``` tee /tmp/pam_log_script.sh <<EOF #!/bin/bash echo "\${PAM_SERVICE}:\${PAM_TYPE} - \${PAM_RUSER}@\${PAM_RHOST} is authenticating as \${PAM_USER}" EOF chmod 0775 /tmp/pam_log_script.sh ``` And then change the [PAM service configuration](#configuring-the-pam-service) to execute the script using the [pam\_exec](https://linux.die.net/man/8/pam_exec) PAM module. For example: ``` auth optional pam_exec.so log=/tmp/pam_output.txt /tmp/pam_log_script.sh auth required pam_unix.so audit account optional pam_exec.so log=/tmp/pam_output.txt /tmp/pam_log_script.sh account required pam_unix.so audit ``` Whenever the above PAM service is used, the output of the script will be written to `/tmp/pam_output.txt`. It may look similar to this: ``` *** Tue May 14 14:53:23 2019 mariadb:auth - @ is authenticating as alice *** Tue May 14 14:53:25 2019 mariadb:account - @ is authenticating as alice *** Tue May 14 14:53:28 2019 mariadb:auth - @ is authenticating as alice *** Tue May 14 14:53:31 2019 mariadb:account - @ is authenticating as alice ``` User and Group Mapping ---------------------- Even when using the `pam` authentication plugin, the authenticating PAM user account still needs to exist in MariaDB, and the account needs to have privileges in the database. Creating these MariaDB accounts and making sure the privileges are correct can be a lot of work. To decrease the amount of work involved, some users would like to be able to map a PAM user to a different MariaDB user. For example, let’s say that `alice` and `bob` are both DBAs. It would be nice if each of them could log into MariaDB with their own PAM username and password, while MariaDB sees both of them as the same `dba` user. That way, there is only one MariaDB account to keep track of. See [User and Group Mapping with PAM](../user-and-group-mapping-with-pam/index) for more information on how to do this. PAM Modules ----------- There are many PAM modules. The ones described below are the ones that have been seen most often by MariaDB. ### pam\_unix The [pam\_unix](https://linux.die.net/man/8/pam_unix) PAM module provides support for Unix password authentication. It is the default PAM module on most systems. For a tutorial on setting up PAM authentication and user or group mapping with Unix authentication, see [Configuring PAM Authentication and User Mapping with Unix Authentication](../configuring-pam-authentication-and-user-mapping-with-unix-authentication/index). ### pam\_user\_map The [pam\_user\_map](../user-and-group-mapping-with-pam/index) PAM module was developed by MariaDB to support user and group mapping. ### pam\_ldap The [pam\_ldap](https://linux.die.net/man/5/pam_ldap) PAM module provides support for LDAP authentication. For a tutorial on setting up PAM authentication and user or group mapping with LDAP authentication, see [Configuring PAM Authentication and User Mapping with LDAP Authentication](../configuring-pam-authentication-and-user-mapping-with-ldap-authentication/index). This can also be configured for [Active Directory](https://en.wikipedia.org/wiki/Active_Directory) authentication. ### pam\_sss The [pam\_sss](https://linux.die.net/man/8/pam_sss) PAM module provides support for authentication with [System Security Services Daemon (SSSD)](https://en.wikipedia.org/wiki/System_Security_Services_Daemon). This can be configured for [Active Directory](https://en.wikipedia.org/wiki/Active_Directory) authentication. ### pam\_lsass The `pam_lsass` PAM module provides support for [Active Directory](https://en.wikipedia.org/wiki/Active_Directory) authentication. It is provided by [PowerBroker Identity Services – Open Edition](https://github.com/BeyondTrust/pbis-open/wiki). ### pam\_winbind The [pam\_winbind](https://www.samba.org/samba/docs/current/man-html/pam_winbind.8.html) PAM module provides support for [Active Directory](https://en.wikipedia.org/wiki/Active_Directory) authentication. It is provided by [winbindd](https://www.samba.org/samba/docs/current/man-html/winbindd.8.html) from the [samba](https://www.samba.org/samba/docs/current/man-html/samba.7.html) suite. This PAM module converts all provided user names to lowercase. There is no way to disable this functionality. If you do not want to be forced to use all lowercase user names, then you may need to configure the [pam\_winbind\_workaround](#pam_winbind_workaround) system variable. See [MDEV-18686](https://jira.mariadb.org/browse/MDEV-18686) for more information. ### pam\_centrifydc The [pam\_centrifydc](https://docs.centrify.com/en/css/2018-html/index.html#page/Planning,_preparation,_and_deployment/unix_pam_services.html) PAM module provides support for [Active Directory](https://en.wikipedia.org/wiki/Active_Directory) authentication. It integrates with the commercial [Active Directory Bridge from Centrify](https://www.centrify.com/products/infrastructure-services/authentication/active-directory-bridge/integration/). ### pam\_krb5 The [pam\_krb5](https://linux.die.net/man/8/pam_krb5) PAM module provides support for [Kerberos](https://en.wikipedia.org/wiki/Kerberos_(protocol)) authentication. This can be configured for [Active Directory](https://en.wikipedia.org/wiki/Active_Directory) authentication. ### pam\_google\_authenticator The `pam_google_authenticator` PAM module provides two-factor identification with Google Authenticator. It is from Google's [google-authenticator-libpam](https://github.com/google/google-authenticator-libpam) open-source project. The PAM module should work with the open-source mobile apps built by Google's [google-authenticator](https://github.com/google/google-authenticator) and [google-authenticator-android](https://github.com/google/google-authenticator-android) projects as well as the the closed source Google Authenticator mobile apps that are present in each mobile app store. For an example of how to use this PAM module, see the blog post: [MariaDB: Improve Security with Two-Step Verification](https://mariadb.org/improve-security-with-two-step-verification/). ### pam\_securid The `pam_securid` PAM module provides support for multi-factor authentication. It is part of the commercial [RSA SecurID Suite](https://www.rsa.com/en-us/products/rsa-securid-suite). Note that current versions of this module are not [safe for multi-threaded environments](#multi-threaded-issues), and the vendor does not officially support the product on MariaDB. See [MDEV-10361](https://jira.mariadb.org/browse/MDEV-10361) about that. However, the module may work with [MariaDB 10.4.0](https://mariadb.com/kb/en/mariadb-1040-release-notes/) and above. ### pam\_ssh The [pam\_ssh](https://linux.die.net/man/8/pam_ssh) PAM module provides authentication using SSH keys. ### pam\_time The [pam\_time](https://linux.die.net/man/8/pam_time) PAM module provides time-controlled access. Known Issues ------------ ### Multi-Threaded Issues MariaDB is a multi-threaded program, which means that different connections concurrently run in different threads. Current versions of MariaDB's `pam` authentication plugin execute PAM module code in the server address space. This means that any PAM modules used with MariaDB must be safe for multi-threaded environments. Otherwise, if multiple clients try to authenticate with the same PAM module in parallel, undefined behavior can occur. For example, the `pam_fprintd` PAM module is not safe for multi-threaded environments, and if you use it with MariaDB, you may experience server crashes. **MariaDB starting with [10.4.0](https://mariadb.com/kb/en/mariadb-1040-release-notes/)**Starting in [MariaDB 10.4.0](https://mariadb.com/kb/en/mariadb-1040-release-notes/), the `pam` authentication plugin isolates PAM module code from the server address space, so even PAM modules that are known to be unsafe for multi-threaded environments should not cause issues with MariaDB. See [MDEV-15473](https://jira.mariadb.org/browse/MDEV-15473) for more information. ### Conflicts with Password Validation When a [password validation plugin](../password-validation-plugins/index) is enabled, MariaDB won't allow an account to be created if the password validation plugin says that the account's password is too weak. This creates a problem for accounts that authenticate with the `pam` authentication plugin, since MariaDB has no knowledge of the user's password. When a user tries to create an account that authenticates with the `pam` authentication plugin, the password validation plugin would throw an error, even with [strict\_password\_validation=OFF](../server-system-variables/index#strict_password_validation) set. The workaround is to uninstall the [password validation plugin](../password-validation-plugins/index) with [UNINSTALL PLUGIN](../uninstall-plugin/index), and then create the account, and then reinstall the [password validation plugin](../password-validation/index) with [INSTALL PLUGIN](../install-plugin/index). For example: ``` INSTALL PLUGIN simple_password_check SONAME 'simple_password_check'; Query OK, 0 rows affected (0.002 sec) SET GLOBAL strict_password_validation=OFF; Query OK, 0 rows affected (0.000 sec) CREATE USER ''@'%' IDENTIFIED VIA pam USING 'mariadb'; ERROR 1819 (HY000): Your password does not satisfy the current policy requirements UNINSTALL PLUGIN simple_password_check; Query OK, 0 rows affected (0.000 sec) CREATE USER ''@'%' IDENTIFIED VIA pam USING 'mariadb'; Query OK, 0 rows affected (0.000 sec) INSTALL PLUGIN simple_password_check SONAME 'simple_password_check'; Query OK, 0 rows affected (0.001 sec) ``` **MariaDB starting with [10.4.0](https://mariadb.com/kb/en/mariadb-1040-release-notes/)**Starting in [MariaDB 10.4.0](https://mariadb.com/kb/en/mariadb-1040-release-notes/), accounts that authenticate with the `pam` authentication plugin should be exempt from password validation checks. See [MDEV-12321](https://jira.mariadb.org/browse/MDEV-12321) and [MDEV-10457](https://jira.mariadb.org/browse/MDEV-10457) for more information. ### SELinux [SELinux](../selinux/index) may cause issues when using the `pam` authentication plugin. For example, using [pam\_unix](#pam_unix) with the `pam` authentication plugin while SELinux is enabled can sometimes lead to SELinux errors involving [unix\_chkpwd](https://linux.die.net/man/8/unix_chkpwd), such as the following:: ``` Apr 14 12:37:59 localhost setroubleshoot: Plugin Exception restorecon_source Apr 14 12:37:59 localhost setroubleshoot: SELinux is preventing /usr/sbin/unix_chkpwd from execute access on the file . For complete SELinux messages. run sealert -l c56fe6e0-c78c-4bdb-a80f-27ef86a1ea85 Apr 14 12:37:59 localhost python: SELinux is preventing /usr/sbin/unix_chkpwd from execute access on the file . ***** Plugin catchall (100. confidence) suggests ************************** If you believe that unix_chkpwd should be allowed execute access on the file by default. Then you should report this as a bug. You can generate a local policy module to allow this access. Do allow this access for now by executing: # grep unix_chkpwd /var/log/audit/audit.log | audit2allow -M mypol # semodule -i mypol.pp ``` Sometimes issues like this can be fixed by updating the system's SELinux policies. You may be able to update the policies using [audit2allow](https://linux.die.net/man/1/audit2allow). See [SELinux: Generating SELinux Policies with audit2allow](../selinux/index#generating-selinux-policies-with-audit2allow) for more information. If you can't get the `pam` authentication plugin to work with SELinux at all, then it can help to disable SELinux entirely. See [SELinux: Changing SELinux's Mode](../selinux/index#changing-selinuxs-mode) for information on how to do this. Tutorials --------- You may find the following PAM-related tutorials helpful: * [Configuring PAM Authentication and User Mapping with Unix Authentication](../configuring-pam-authentication-and-user-mapping-with-unix-authentication/index) * [Configuring PAM Authentication and User Mapping with LDAP Authentication](../configuring-pam-authentication-and-user-mapping-with-ldap-authentication/index) Versions -------- | Version | Status | Introduced | | --- | --- | --- | | 2.0 | Beta | [MariaDB 10.4.0](https://mariadb.com/kb/en/mariadb-1040-release-notes/) | | 1.0 | Stable | [MariaDB 10.0.10](https://mariadb.com/kb/en/mariadb-10010-release-notes/) | | 1.0 | Beta | [MariaDB 5.2.10](https://mariadb.com/kb/en/mariadb-5210-release-notes/) | System Variables ---------------- ### `pam_debug` * **Description:** Enables verbose debug logging to the [error log](../error-log/index) for all authentication handled by the plugin. + This system variable is only available when the plugin is a [debug build](../compiling-mariadb-for-debugging/index). * **Commandline:** `--pam-debug` * **Scope:** Global * **Dynamic:** No * **Data Type:** `boolean` * **Default Value:** `OFF` * **Introduced:** [MariaDB 10.2.2](https://mariadb.com/kb/en/mariadb-1022-release-notes/), [MariaDB 10.1.17](https://mariadb.com/kb/en/mariadb-10117-release-notes/) --- ### `pam_use_cleartext_plugin` * **Description:** Use the [mysql\_clear\_password](#mysql_clear_password) client authentication plugin instead of the [dialog](#dialog) client authentication plugin. This may be needed for compatibility reasons, but it only supports simple PAM configurations that don't require any input besides a password. * **Commandline:** `--pam-use-cleartext-plugin` * **Scope:** Global * **Dynamic:** No * **Data Type:** `boolean` * **Default Value:** `OFF` * **Introduced:** [MariaDB 10.1.1](https://mariadb.com/kb/en/mariadb-1011-release-notes/), [MariaDB 5.5.32](https://mariadb.com/kb/en/mariadb-5532-release-notes/) --- ### `pam_winbind_workaround` * **Description:** Configures the authentication plugin to compare the user name provided by the client with the user name returned by the PAM module in a case insensitive manner. This may be needed if you use the [pam\_winbind](#pam_winbind) PAM module, which is known to convert all user names to lowercase, and which does not allow this behavior to be disabled. * **Commandline:** `--pam-winbind-workaround` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `OFF` * **Introduced:** [MariaDB 10.4.5](https://mariadb.com/kb/en/mariadb-1045-release-notes/), [MariaDB 10.3.15](https://mariadb.com/kb/en/mariadb-10315-release-notes/), [MariaDB 10.2.24](https://mariadb.com/kb/en/mariadb-10224-release-notes/), [MariaDB 10.1.39](https://mariadb.com/kb/en/mariadb-10139-release-notes/) --- Options ------- ### `pam` * **Description:** Controls how the server should treat the plugin when the server starts up. + Valid values are: - `OFF` - Disables the plugin without removing it from the [mysql.plugins](../mysqlplugin-table/index) table. - `ON` - Enables the plugin. If the plugin cannot be initialized, then the server will still continue starting up, but the plugin will be disabled. - `FORCE` - Enables the plugin. If the plugin cannot be initialized, then the server will fail to start with an error. - `FORCE_PLUS_PERMANENT` - Enables the plugin. If the plugin cannot be initialized, then the server will fail to start with an error. In addition, the plugin cannot be uninstalled with [UNINSTALL SONAME](../uninstall-soname/index) or [UNINSTALL PLUGIN](../uninstall-plugin/index) while the server is running. + See [Plugin Overview: Configuring Plugin Activation at Server Startup](../plugin-overview/index#configuring-plugin-activation-at-server-startup) for more information. * **Commandline:** `--pam=value` * **Data Type:** `enumerated` * **Default Value:** `ON` * **Valid Values:** `OFF`, `ON`, `FORCE`, `FORCE_PLUS_PERMANENT` --- See Also -------- * [Writing a MariaDB PAM Authentication Plugin](https://mariadb.org/writing-a-mariadb-pam-authentication-plugin/) * [MariaDB: Improve Security with Two-Step Verification](https://mariadb.org/improve-security-with-two-step-verification/) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb Window Frames Window Frames ============= **MariaDB starting with [10.2](../what-is-mariadb-102/index)**[Window functions](../window-functions/index) were first introduced in [MariaDB 10.2.0](https://mariadb.com/kb/en/mariadb-1020-release-notes/). Syntax ------ ``` frame_clause: {ROWS | RANGE} {frame_border | BETWEEN frame_border AND frame_border} frame_border: | UNBOUNDED PRECEDING | UNBOUNDED FOLLOWING | CURRENT ROW | expr PRECEDING | expr FOLLOWING ``` Description ----------- A basic overview of [window functions](../window-functions/index) is described in [Window Functions Overview](../window-functions-overview/index). Window frames expand this functionality by allowing the function to include a specified a number of rows around the current row. These include: * All rows before the current row (UNBOUNDED PRECEDING), for example `RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW` * All rows after the current row (UNBOUNDED FOLLOWING), for example `RANGE BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING` * A set number of rows before the current row (expr PRECEDING) for example `RANGE BETWEEN 6 PRECEDING AND CURRENT ROW` * A set number of rows after the current row (expr PRECEDING AND expr FOLLOWING) for example `RANGE BETWEEN CURRENT ROW AND 2 FOLLOWING` * A specified number of rows both before and after the current row, for example `RANGE BETWEEN 6 PRECEDING AND 3 FOLLOWING` The following functions operate on window frames: * [AVG](../avg/index) * [BIT\_AND](../bit_and/index) * [BIT\_OR](../bit_or/index) * [BIT\_XOR](../bit_xor/index) * [COUNT](../count/index) * [LEAD](../lead/index) * [MAX](../max/index) * [MIN](../min/index) * [NTILE](../ntile/index) * [STD](../std/index) * [STDDEV](../stddev/index) * [STDDEV\_POP](../stddev_pop/index) * [STDDEV\_SAMP](../stddev_samp/index) * [SUM](../sum/index) * [VAR\_POP](../var_pop/index) * [VAR\_SAMP](../var_samp/index) * [VARIANCE](../variance/index) Window frames are determined by the *frame\_clause* in the window function request. Take the following example: ``` CREATE TABLE `student_test` ( name char(10), test char(10), score tinyint(4) ); INSERT INTO student_test VALUES ('Chun', 'SQL', 75), ('Chun', 'Tuning', 73), ('Esben', 'SQL', 43), ('Esben', 'Tuning', 31), ('Kaolin', 'SQL', 56), ('Kaolin', 'Tuning', 88), ('Tatiana', 'SQL', 87); SELECT name, test, score, SUM(score) OVER () AS total_score FROM student_test; +---------+--------+-------+-------------+ | name | test | score | total_score | +---------+--------+-------+-------------+ | Chun | SQL | 75 | 453 | | Chun | Tuning | 73 | 453 | | Esben | SQL | 43 | 453 | | Esben | Tuning | 31 | 453 | | Kaolin | SQL | 56 | 453 | | Kaolin | Tuning | 88 | 453 | | Tatiana | SQL | 87 | 453 | +---------+--------+-------+-------------+ ``` By not specifying an OVER clause, the [SUM](../sum/index) function is run over the entire dataset. However, if we specify an ORDER BY condition based on score (and order the entire result in the same way for clarity), the following result is returned: ``` SELECT name, test, score, SUM(score) OVER (ORDER BY score) AS total_score FROM student_test ORDER BY score; +---------+--------+-------+-------------+ | name | test | score | total_score | +---------+--------+-------+-------------+ | Esben | Tuning | 31 | 31 | | Esben | SQL | 43 | 74 | | Kaolin | SQL | 56 | 130 | | Chun | Tuning | 73 | 203 | | Chun | SQL | 75 | 278 | | Tatiana | SQL | 87 | 365 | | Kaolin | Tuning | 88 | 453 | +---------+--------+-------+-------------+ ``` The total\_score column represents a running total of the current row, and all previous rows. The window frame in this example expands as the function proceeds. The above query makes use of the default to define the window frame. It could be written explicitly as follows: ``` SELECT name, test, score, SUM(score) OVER (ORDER BY score RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS total_score FROM student_test ORDER BY score; +---------+--------+-------+-------------+ | name | test | score | total_score | +---------+--------+-------+-------------+ | Esben | Tuning | 31 | 31 | | Esben | SQL | 43 | 74 | | Kaolin | SQL | 56 | 130 | | Chun | Tuning | 73 | 203 | | Chun | SQL | 75 | 278 | | Tatiana | SQL | 87 | 365 | | Kaolin | Tuning | 88 | 453 | +---------+--------+-------+-------------+ ``` Let's look at some alternatives: Firstly, applying the window function to the current row and all following rows can be done with the use of UNBOUNDED FOLLOWING: ``` SELECT name, test, score, SUM(score) OVER (ORDER BY score RANGE BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING) AS total_score FROM student_test ORDER BY score; +---------+--------+-------+-------------+ | name | test | score | total_score | +---------+--------+-------+-------------+ | Esben | Tuning | 31 | 453 | | Esben | SQL | 43 | 422 | | Kaolin | SQL | 56 | 379 | | Chun | Tuning | 73 | 323 | | Chun | SQL | 75 | 250 | | Tatiana | SQL | 87 | 175 | | Kaolin | Tuning | 88 | 88 | +---------+--------+-------+-------------+ ``` It's possible to specify a number of rows, rather than the entire unbounded following or preceding set. The following example takes the current row, as well as the previous row: ``` SELECT name, test, score, SUM(score) OVER (ORDER BY score ROWS BETWEEN 1 PRECEDING AND CURRENT ROW) AS total_score FROM student_test ORDER BY score; +---------+--------+-------+-------------+ | name | test | score | total_score | +---------+--------+-------+-------------+ | Esben | Tuning | 31 | 31 | | Esben | SQL | 43 | 74 | | Kaolin | SQL | 56 | 99 | | Chun | Tuning | 73 | 129 | | Chun | SQL | 75 | 148 | | Tatiana | SQL | 87 | 162 | | Kaolin | Tuning | 88 | 175 | +---------+--------+-------+-------------+ ``` The current row and the following row: ``` SELECT name, test, score, SUM(score) OVER (ORDER BY score ROWS BETWEEN 1 PRECEDING AND 1 FOLLOWING) AS total_score FROM student_test ORDER BY score; +---------+--------+-------+-------------+ | name | test | score | total_score | +---------+--------+-------+-------------+ | Esben | Tuning | 31 | 74 | | Esben | SQL | 43 | 130 | | Kaolin | SQL | 56 | 172 | | Chun | Tuning | 73 | 204 | | Chun | SQL | 75 | 235 | | Tatiana | SQL | 87 | 250 | | Kaolin | Tuning | 88 | 175 | +---------+--------+-------+-------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Sequences Sequences ========== **MariaDB starting with [10.3](../what-is-mariadb-103/index)**CREATE SEQUENCE was introduced in [MariaDB 10.3](../what-is-mariadb-103/index). A sequence is an object that generates a sequence of numeric values, as specified by the [CREATE SEQUENCE](../create-sequence/index) statement. Sequences are an alternative to [AUTO\_INCREMENT](../auto_increment/index) when you want more control over how sequence numbers are generated. Since a `SEQUENCE` caches values, it can sometimes be faster. Also, you can access the last value generated by all used sequences; it's not subjected to limitations of [LAST\_INSERT\_ID( )](../last_insert_id/index). This section is about sequence objects. For details about the storage engine, see [Sequence Storage Engine](../sequence-storage-engine/index). | Title | Description | | --- | --- | | [Sequence Overview](../sequence-overview/index) | Object that generates a sequence of numeric values. | | [CREATE SEQUENCE](../create-sequence/index) | Creates a sequence that generates new values when called with NEXT VALUE FOR. | | [SHOW CREATE SEQUENCE](../show-create-sequence/index) | Shows the CREATE SEQUENCE statement that created the sequence. | | [ALTER SEQUENCE](../alter-sequence/index) | Change options for a SEQUENCE. | | [DROP SEQUENCE](../drop-sequence/index) | Deleting a SEQUENCE. | | [SEQUENCE Functions](../sequence-functions/index) | Functions that can be used on SEQUENCEs. | | [SHOW TABLES](../show-tables/index) | List of non-temporary tables, views or sequences. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb System Variables Added in MariaDB 10.9 System Variables Added in MariaDB 10.9 ====================================== This is a list of [system variables](../server-system-variables/index) that have been added in the [MariaDB 10.9](../what-is-mariadb-109/index) series. | Variable | Added | | --- | --- | | [rocksdb\_log\_dir](../myrocks-system-variables/index#rocksdb_log_dir) | [MariaDB 10.9.1](https://mariadb.com/kb/en/mariadb-1091-release-notes/) | See Also -------- * [System Variables Added in MariaDB 10.6](../system-variables-added-in-mariadb-106/index) * [System Variables Added in MariaDB 10.5](../system-variables-added-in-mariadb-105/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb REPLACE Function REPLACE Function ================ Syntax ------ ``` REPLACE(str,from_str,to_str) ``` Description ----------- Returns the string `str` with all occurrences of the string `from_str` replaced by the string `to_str`. REPLACE() performs a case-sensitive match when searching for `from_str`. Examples -------- ``` SELECT REPLACE('www.mariadb.org', 'w', 'Ww'); +---------------------------------------+ | REPLACE('www.mariadb.org', 'w', 'Ww') | +---------------------------------------+ | WwWwWw.mariadb.org | +---------------------------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb MariaDB Replication & Cluster Plugins MariaDB Replication & Cluster Plugins ====================================== | Title | Description | | --- | --- | | [Semisynchronous Replication](../semisynchronous-replication/index) | Semisynchronous replication. | | [WSREP\_INFO Plugin](../wsrep_info-plugin/index) | Adds two new Information Schema tables, WSREP\_MEMBERSHIP and WSREP\_STATUS. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Overview of the Binary Log Overview of the Binary Log ========================== The binary log contains a record of all changes to the databases, both data and structure, as well as how long each statement took to execute. It consists of a set of binary log files and an index. This means that statements such as [CREATE](../create/index), [ALTER](../alter/index), [INSERT](../insert/index), [UPDATE](../update/index) and [DELETE](../delete/index) will be logged, but statements that have no effect on the data, such as SELECT and SHOW, will not be logged. If you want to log these (at a cost in performance), use the [general query log](../general-query-log/index). If a statement may potentially have an effect, but doesn't, such as an UPDATE or DELETE that returns no rows, it will still be logged (this applies to the default statement-based logging, not to row-based logging - see [Binary Log Formats](../binary-log-formats/index)). The purpose of the binary log is to allow [replication](../replication/index), where data is sent from one or more masters to one or more slave servers based on the contents of the binary log, as well as assisting in backup operations. A MariaDB server with the binary log enabled will run slightly more slowly. It is important to protect the binary log, as it may contain sensitive information, including passwords. Binary logs are stored in a binary, not plain text, format, and so are not viewable with a regular editor. However, MariaDB includes [mysqlbinlog](../mysqlbinlog/index), a commandline tool for plain text processing of binary logs. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Information Schema INNODB_TRX Table Information Schema INNODB\_TRX Table ==================================== The [Information Schema](../information_schema/index) `INNODB_TRX` table stores information about all currently executing InnoDB transactions. It has the following columns: | Column | Description | | --- | --- | | `TRX_ID` | Unique transaction ID number. | | `TRX_STATE` | Transaction execution state; one of `RUNNING`, `LOCK WAIT`, `ROLLING BACK` or `COMMITTING`. | | `TRX_STARTED` | Time that the transaction started. | | `TRX_REQUESTED_LOCK_ID` | If `TRX_STATE` is `LOCK_WAIT`, the `[INNODB\_LOCKS.LOCK\_ID](../information-schema-innodb_locks-table/index)` value of the lock being waited on. `NULL` if any other state. | | `TRX_WAIT_STARTED` | If `TRX_STATE` is `LOCK_WAIT`, the time the transaction started waiting for the lock, otherwise `NULL`. | | `TRX_WEIGHT` | Transaction weight, based on the number of locked rows and the number of altered rows. To resolve deadlocks, lower weighted transactions are rolled back first. Transactions that have affected non-transactional tables are always treated as having a heavier weight. | | `TRX_MYSQL_THREAD_ID` | Thread ID from the `[PROCESSLIST](../information-schema-processlist-table/index)` table (note that the locking and transaction information schema tables use a different snapshot from the processlist, so records may appear in one but not the other). | | `TRX_QUERY` | SQL that the transaction is currently running. | | `TRX_OPERATION_STATE` | Transaction's current state, or `NULL`. | | `TRX_TABLES_IN_USE` | Number of InnoDB tables currently being used for processing the current SQL statement. | | `TRX_TABLES_LOCKED` | Number of InnoDB tables that that have row locks held by the current SQL statement. | | `TRX_LOCK_STRUCTS` | Number of locks reserved by the transaction. | | `TRX_LOCK_MEMORY_BYTES` | Total size in bytes of the memory used to hold the lock structures for the current transaction in memory. | | `TRX_ROWS_LOCKED` | Number of rows the current transaction has locked. locked by this transaction. An approximation, and may include rows not visible to the current transaction that are delete-marked but physically present. | | `TRX_ROWS_MODIFIED` | Number of rows added or changed in the current transaction. | | `TRX_CONCURRENCY_TICKETS` | Indicates how much work the current transaction can do before being swapped out, see the `[innodb\_concurrency\_tickets](../xtradbinnodb-server-system-variables/index#innodb_concurrency_tickets)` system variable. | | `TRX_ISOLATION_LEVEL` | [Isolation level](../set-transaction/index#isolation-levels) of the current transaction. | | `TRX_UNIQUE_CHECKS` | Whether unique checks are `on` or `off` for the current transaction. Bulk data are a case where unique checks would be off. | | `TRX_FOREIGN_KEY_CHECKS` | Whether foreign key checks are `on` or `off` for the current transaction. Bulk data are a case where foreign keys checks would be off. | | `TRX_LAST_FOREIGN_KEY_ERROR` | Error message for the most recent foreign key error, or `NULL` if none. | | `TRX_ADAPTIVE_HASH_LATCHED` | Whether the adaptive hash index is locked by the current transaction or not. One transaction at a time can change the adaptive hash index. | | `TRX_ADAPTIVE_HASH_TIMEOUT` | Whether the adaptive hash index search latch shoild be relinquished immediately or reserved across all MariaDB calls. `0` if there is no contention on the adaptive hash index, in which case the latch is reserved until completion, otherwise counts down to zero and the latch is released after each row lookup. | | `TRX_IS_READ_ONLY` | `1` if a read-only transaction, otherwise `0`. | | `TRX_AUTOCOMMIT_NON_LOCKING` | `1` if the transaction only contains this one statement, that is, a `[SELECT](../select/index)` statement not using `FOR UPDATE` or `LOCK IN SHARED MODE`, and with autocommit on. If this and `TRX_IS_READ_ONLY` are both 1, the transaction can be optimized by the storrage engine to reduce some overheads | The table is often used in conjunction with the [INNODB\_LOCKS](../information-schema-innodb_locks-table/index) and [INNODB\_LOCK\_WAITS](../information-schema-innodb_lock_waits-table/index) tables to diagnose problematic locks and transactions. [XA transactions](../xa-transactions/index) are not stored in this table. To see them, `XA RECOVER` can be used. Example ------- ``` -- session 1 START TRANSACTION; UPDATE t SET id = 15 WHERE id = 10; -- session 2 DELETE FROM t WHERE id = 10; -- session 1 USE information_schema; SELECT l.*, t.* FROM information_schema.INNODB_LOCKS l JOIN information_schema.INNODB_TRX t ON l.lock_trx_id = t.trx_id WHERE trx_state = 'LOCK WAIT' \G *************************** 1. row *************************** lock_id: 840:40:3:2 lock_trx_id: 840 lock_mode: X lock_type: RECORD lock_table: `test`.`t` lock_index: PRIMARY lock_space: 40 lock_page: 3 lock_rec: 2 lock_data: 10 trx_id: 840 trx_state: LOCK WAIT trx_started: 2019-12-23 18:43:46 trx_requested_lock_id: 840:40:3:2 trx_wait_started: 2019-12-23 18:43:46 trx_weight: 2 trx_mysql_thread_id: 46 trx_query: DELETE FROM t WHERE id = 10 trx_operation_state: starting index read trx_tables_in_use: 1 trx_tables_locked: 1 trx_lock_structs: 2 trx_lock_memory_bytes: 1136 trx_rows_locked: 1 trx_rows_modified: 0 trx_concurrency_tickets: 0 trx_isolation_level: REPEATABLE READ trx_unique_checks: 1 trx_foreign_key_checks: 1 trx_last_foreign_key_error: NULL trx_is_read_only: 0 trx_autocommit_non_locking: 0 ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb MySQL/MariaDB Spatial Support Matrix MySQL/MariaDB Spatial Support Matrix ==================================== This table shows when different spatial features were introduced into MySQL and MariaDB. | | | | --- | --- | | My | MySQL | | MDB | MariaDB | | x | This feature is supported. | | MBR | This feature is present, but operates on the Minimum Bounding Rectangle instead of the actual shape. | | d | This feature is present, but has been deprecated and will be removed in a future version. | | \* | This feature is present, but may not work the way you expect. | | - | This feature is not supported. | | | My 5.4.2 | My 5.5 | My 5.6.1 | My 5.7.4 | My 5.7.5 | My 5.7.6 | MDB 5.1 | MDB 5.3.3 | MDB 10.1.2 | MDB 10.2 | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | InnoDB Spatial Indexes | - | - | - | - | x | x | - | - | - | x | | [MyISAM Spatial Indexes](../spatial-index/index) | x | x | x | x | x | x | x | x | x | x | | [Aria Spatial Indexes](../spatial-index/index) | - | - | - | - | - | - | x | x | x | x | | [Area](../st_area/index) | x | x | x | x | x | d | x | x | x | x | | [AsBinary](../st_asbinary/index) | x | x | x | x | x | d | x | x | x | x | | [AsText](../st_astext/index) | x | x | x | x | x | d | x | x | x | x | | [AsWKB](../st_asbinary/index) | x | x | x | x | x | d | x | x | x | x | | [AsWKT](../st_astext/index) | x | x | x | x | x | d | x | x | x | x | | [Boundary](../st_boundary/index) | - | - | - | - | - | - | - | - | x | x | | [Buffer](../st_buffer/index) | - | - | x | x | x | d | x | x | x | x | | [Centroid](../st_centroid/index) | - | x | x | x | x | d | x | x | x | x | | [Contains](../contains/index) | MBR | MBR | MBR | MBR | MBR | d | MBR | MBR | MBR | MBR | | [ConvexHull](../st_convexhull/index) | - | - | - | - | x | d | - | - | x | x | | [Crosses](../st_crosses/index) | MBR | x | x | x | x | d | MBR | MBR | MBR | MBR | | [Dimension](../st_dimension/index) | x | x | x | x | x | d | x | x | x | x | | [Disjoint](../disjoint/index) | MBR | MBR | MBR | MBR | MBR | d | MBR | MBR | MBR | MBR | | Distance | MBR | - | - | x | x | d | - | - | - | - | | [EndPoint](../st_endpoint/index) | x | x | x | x | x | d | x | x | x | x | | [Envelope](../st_envelope/index) | x | x | x | x | x | d | x | x | x | x | | [Equals](../equals/index) | MBR | MBR | MBR | MBR | MBR | d | MBR | MBR | MBR | MBR | | | My 5.4.2 | My 5.5 | My 5.6.1 | My 5.7.4 | My 5.7.5 | My 5.7.6 | MDB 5.1 | MDB 5.3.3 | MDB 10.1.2 | MDB 10.2 | | [ExteriorRing](../st_exteriorring/index) | x | x | x | x | x | d | x | x | x | x | | [GeomCollFromText](../st_geomcollfromtext/index) | x | x | x | x | x | d | x | x | x | x | | [GeomCollFromWKB](../st_geomcollfromwkb/index) | x | x | x | x | x | d | x | x | x | x | | [GeometryCollection](../geometrycollection/index) | x | x | x | x | x | x | x | x | x | x | | [GeometryCollectionFromText](../st_geomcollfromtext/index) | x | x | x | x | x | d | x | x | x | x | | [GeometryCollectionFromWKB](../st_geomcollfromwkb/index) | x | x | x | x | x | d | x | x | x | x | | [GeometryFromText](../st_geomfromtext/index) | x | x | x | x | x | d | x | x | x | x | | [GeometryFromWKB](../st_geomfromwkb/index) | x | x | x | x | x | d | x | x | x | x | | [GeometryN](../st_geometryn/index) | x | x | x | x | x | d | x | x | x | x | | [GeometryType](../st_geometrytype/index) | x | x | x | x | x | d | x | x | x | x | | [GeomFromText](../st_geomfromtext/index) | x | x | x | x | x | d | x | x | x | x | | [GeomFromWKB](../st_geomfromwkb/index) | x | x | x | x | x | d | x | x | x | x | | [GLength](../glength/index) | x | x | x | x | x | d | x | x | x | x | | [InteriorRingN](../st_interiorringn/index) | x | x | x | x | x | d | x | x | x | x | | [Intersects](../intersects/index) | MBR | MBR | MBR | MBR | MBR | d | MBR | MBR | MBR | MBR | | [IsClosed](../st_isclosed/index) | x | x | x | x | x | d | x | x | x | x | | [IsEmpty](../st_isempty/index) | - | \* | \* | \* | \* | d | x | x | x | x | | [IsRing](../st_isring/index) | - | - | - | - | - | - | - | - | x | x | | [IsSimple](../st_issimple/index) | - | \* | \* | x | x | d | - | x | x | x | | [LineFromText](../st_linefromtext/index) | x | x | x | x | x | d | x | x | x | x | | | My 5.4.2 | My 5.5 | My 5.6.1 | My 5.7.4 | My 5.7.5 | My 5.7.6 | MDB 5.1 | MDB 5.3.3 | MDB 10.1.2 | MDB 10.2 | | [LineFromWKB](../st_linefromwkb/index) | x | x | x | x | x | d | x | x | x | x | | [LineString](../linestring/index) | x | x | x | x | x | x | x | x | x | x | | [LineStringFromText](../st_linefromtext/index) | x | x | x | x | x | d | x | x | x | x | | [LineStringFromWKB](../st_linefromwkb/index) | x | x | x | x | x | d | x | x | x | x | | [MBRContains](../mbrcontains/index) | MBR | MBR | MBR | MBR | MBR | MBR | MBR | MBR | MBR | MBR | | MBRCoveredBy | - | - | - | MBR | MBR | MBR | - | - | - | - | | [MBRDisjoint](../mbrdisjoint/index) | MBR | MBR | MBR | MBR | MBR | MBR | MBR | MBR | MBR | MBR | | [MBREqual](../mbrequal/index) | MBR | MBR | MBR | MBR | MBR | MBR | MBR | MBR | MBR | MBR | | [MBREquals](../equals/index) | - | - | - | MBR | MBR | MBR | - | - | - | MBR | | [MBRIntersects](../mbrintersects/index) | MBR | MBR | MBR | MBR | MBR | MBR | MBR | MBR | MBR | MBR | | [MBROverlaps](../mbroverlaps/index) | MBR | MBR | MBR | MBR | MBR | MBR | MBR | MBR | MBR | MBR | | [MBRTouches](../mbrtouches/index) | MBR | MBR | MBR | MBR | MBR | MBR | MBR | MBR | MBR | MBR | | [MBRWithin](../mbrwithin/index) | MBR | MBR | MBR | MBR | MBR | MBR | MBR | MBR | MBR | MBR | | [MLineFromText](../mlinefromtext/index) | x | x | x | x | x | d | x | x | x | x | | [MLineFromWKB](../linefromwkb/index) | x | x | x | x | x | d | x | x | x | x | | [MPointFromText](../mpointfromtext/index) | x | x | x | x | x | d | x | x | x | x | | [MPointFromWKB](../mpointfromwkb/index) | x | x | x | x | x | d | x | x | x | x | | [MPolyFromText](../mpolyfromtext/index) | x | x | x | x | x | d | x | x | x | x | | [MPolyFromWKB](../mpolyfromwkb/index) | x | x | x | x | x | d | x | x | x | x | | [MultiLineString](../multilinestring/index) | x | x | x | x | x | x | x | x | x | x | | | My 5.4.2 | My 5.5 | My 5.6.1 | My 5.7.4 | My 5.7.5 | My 5.7.6 | MDB 5.1 | MDB 5.3.3 | MDB 10.1.2 | MDB 10.2 | | [MultiLineStringFromText](../mlinefromtext/index) | x | x | x | x | x | d | x | x | x | x | | [MultiLineStringFromWKB](../mlinefromwkb/index) | x | x | x | x | x | d | x | x | x | x | | [MultiPoint](../multipoint/index) | x | x | x | x | x | x | x | x | x | x | | [MultiPointFromText](../mpointfromtext/index) | x | x | x | x | x | d | x | x | x | x | | [MultiPointFromWKB](../mpointfromwkb/index) | x | x | x | x | x | d | x | x | x | x | | [MultiPolygon](../multipolygon/index) | x | x | x | x | x | x | x | x | x | x | | [MultiPolygonFromText](../mpolyfromtext/index) | x | x | x | x | x | d | x | x | x | x | | [MultiPolygonFromWKB](../mpolyfromwkb/index) | x | x | x | x | x | d | x | x | x | x | | [NumGeometries](../st_numgeometries/index) | x | x | x | x | x | d | x | x | x | x | | [NumInteriorRings](../st_numinteriorrings/index) | x | x | x | x | x | d | x | x | x | x | | [NumPoints](../st_numpoints/index) | x | x | x | x | x | d | x | x | x | x | | [Overlaps](../overlaps/index) | MBR | MBR | MBR | MBR | MBR | d | MBR | MBR | MBR | MBR | | [Point](../point/index) | x | x | x | x | x | x | x | x | x | x | | [PointFromText](../st_pointfromtext/index) | x | x | x | x | x | d | x | x | x | x | | [PointFromWKB](../st_pointfromwkb/index) | x | x | x | x | x | d | x | x | x | x | | [PointOnSurface](../st_pointonsurface/index) | - | - | - | - | - | - | - | - | x | x | | [PointN](../st_pointn/index) | x | x | x | x | x | d | x | x | x | x | | [PolyFromText](../st_polyfromtext/index) | x | x | x | x | x | d | x | x | x | x | | [PolyFromWKB](../st_polyfromwkb/index) | x | x | x | x | x | d | x | x | x | x | | [Polygon](../polygon/index) | x | x | x | x | x | x | x | x | x | x | | | My 5.4.2 | My 5.5 | My 5.6.1 | My 5.7.4 | My 5.7.5 | My 5.7.6 | MDB 5.1 | MDB 5.3.3 | MDB 10.1.2 | MDB 10.2 | | [PolygonFromText](../st_polyfromtext/index) | x | x | x | x | x | d | x | x | x | x | | [PolygonFromWKB](../st_polyfromwkb/index) | x | x | x | x | x | d | x | x | x | x | | [SRID](../srid/index) | x | x | x | x | x | d | x | x | x | x | | [ST\_Area](../st_area/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_AsBinary](../st_asbinary/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_AsGeoJSON](../geojson-st_asgeojson/index) | - | - | - | x | x | x | - | - | - | x | | [ST\_AsText](../st_astext/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_AsWKB](../st_asbinary/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_AsWKT](../st_astext/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_Boundary](../st_boundary/index) | - | - | - | - | - | - | - | - | x | x | | [ST\_Buffer](../st_buffer/index) | - | - | x | x | x | x | - | x | x | x | | ST\_Buffer\_Strategy | - | - | - | x | x | x | - | - | - | - | | [ST\_Centroid](../st_centroid/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_Contains](../st_contains/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_ConvexHull](../st_convexhull/index) | - | - | - | - | x | x | - | - | x | x | | [ST\_Crosses](../st_crosses/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_Difference](../st_difference/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_Dimension](../st_dimension/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_Disjoint](../st_disjoint/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_Distance](../st_distance/index) | - | - | x | x | x | x | - | x | x | x | | | My 5.4.2 | My 5.5 | My 5.6.1 | My 5.7.4 | My 5.7.5 | My 5.7.6 | MDB 5.1 | MDB 5.3.3 | MDB 10.1.2 | MDB 10.2 | | ST\_Distance\_Sphere | - | - | - | - | - | x | - | - | - | - | | [ST\_EndPoint](../st_endpoint/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_Envelope](../st_envelope/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_Equals](../st_equals/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_ExteriorRing](../st_exteriorring/index) | - | - | x | x | x | x | - | x | x | x | | ST\_GeoHash | - | - | - | - | x | x | - | - | - | - | | [ST\_GeomCollFromText](../st_geomcollfromtext/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_GeomCollFromWKB](../st_geomcollfromwkb/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_GeometryCollectionFromText](../st_geomcollfromtext/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_GeometryCollectionFromWKB](../st_geomcollfromwkb/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_GeometryFromText](../st_geomfromtext/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_GeometryFromWKB](../st_geomfromwkb/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_GeometryN](../st_geometryn/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_GeometryType](../st_geometrytype/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_GeomFromGeoJSON](../st_geomfromgeojson/index) | - | - | - | - | x | x | - | - | - | x | | [ST\_GeomFromText](../st_geomfromtext/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_GeomFromWKB](../st_geomfromwkb/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_InteriorRingN](../st_interiorringn/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_Intersection](../st_intersection/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_Intersects](../st_intersects/index) | - | - | x | x | x | x | - | x | x | x | | | My 5.4.2 | My 5.5 | My 5.6.1 | My 5.7.4 | My 5.7.5 | My 5.7.6 | MDB 5.1 | MDB 5.3.3 | MDB 10.1.2 | MDB 10.2 | | [ST\_IsClosed](../st_isclosed/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_IsEmpty](../st_isempty/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_IsRing](../st_isring/index) | - | - | - | - | - | - | - | - | x | x | | [ST\_IsSimple](../st_issimple/index) | - | - | x | x | x | x | - | x | x | x | | ST\_IsValid | - | - | - | - | - | x | - | - | - | - | | ST\_LatFromGeoHash | - | - | - | - | x | x | - | - | - | - | | [ST\_Length](../st_length/index) | - | - | - | - | - | x | - | x | x | x | | [ST\_LineFromText](../st_linefromtext/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_LineFromWKB](../st_linefromwkb/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_LineStringFromText](../st_linefromtext/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_LineStringFromWKB](../st_linefromwkb/index) | - | - | x | x | x | x | - | x | x | x | | ST\_LongFromGeoHash | - | - | - | - | x | x | - | - | - | - | | [ST\_NumGeometries](../st_numgeometries/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_NumInteriorRings](../st_numinteriorrings/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_NumPoints](../st_numpoints/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_Overlaps](../st_overlaps/index) | - | - | x | x | x | x | - | x | x | x | | ST\_PointFromGeoHash | - | - | - | - | x | x | - | - | - | - | | [ST\_PointFromText](../st_pointfromtext/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_PointFromWKB](../st_pointfromwkb/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_PointOnSurface](../st_pointonsurface/index) | - | - | - | - | - | - | - | - | x | x | | | My 5.4.2 | My 5.5 | My 5.6.1 | My 5.7.4 | My 5.7.5 | My 5.7.6 | MDB 5.1 | MDB 5.3.3 | MDB 10.1.2 | MDB 10.2 | | [ST\_PointN](../st_pointn/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_PolyFromText](../st_polyfromtext/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_PolyFromWKB](../st_polyfromwkb/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_PolygonFromText](../st_polyfromtext/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_PolygonFromWKB](../st_polyfromwkb/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_Relate](../st_relate/index) | - | - | - | - | - | - | - | - | x | x | | ST\_Simplify | - | - | - | - | - | x | - | - | - | - | | [ST\_SRID](../st_srid/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_StartPoint](../st_startpoint/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_SymDifference](../st_symdifference/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_Touches](../st_touches/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_Union](../st_union/index) | - | - | x | x | x | x | - | x | x | x | | ST\_Validate | - | - | - | - | - | x | - | - | - | - | | [ST\_Within](../st_within/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_X](../st_x/index) | - | - | x | x | x | x | - | x | x | x | | [ST\_Y](../st_y/index) | - | - | x | x | x | x | - | x | x | x | | [StartPoint](../st_startpoint/index) | x | x | x | x | x | d | x | x | x | x | | [Touches](../touches/index) | MBR | x | x | x | x | d | MBR | MBR | MBR | MBR | | [Within](../within/index) | MBR | MBR | MBR | MBR | MBR | d | MBR | MBR | MBR | MBR | | [X](../st_x/index) | x | x | x | x | x | d | x | x | x | x | | [Y](../st_y/index) | x | x | x | x | x | d | x | x | x | x | | | My 5.4.2 | My 5.5 | My 5.6.1 | My 5.7.4 | My 5.7.5 | My 5.7.6 | MDB 5.1 | MDB 5.3.3 | MDB 10.1.2 | MDB 10.2 | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb Buildbot Setup for Virtual Machines - FreeBSD 9.2 Buildbot Setup for Virtual Machines - FreeBSD 9.2 ================================================= Base install ------------ ``` qemu-img create -f qcow2 /kvm/vms/vm-freebsd92-amd64-serial.qcow2 15G qemu-img create -f qcow2 /kvm/vms/vm-freebsd92-i386-serial.qcow2 15G ``` Start each VM booting from the server install iso one at a time and perform the following install steps: ``` kvm -m 2048 -hda /kvm/vms/vm-freebsd92-amd64-serial.qcow2 -cdrom /kvm/iso/freebsd/9.2/FreeBSD-9.2-RELEASE-amd64-dvd1.iso -boot d -smp 2 -cpu qemu64 -net nic,model=virtio -net user,hostfwd=tcp:127.0.0.1:2283-:22 kvm -m 2048 -hda /kvm/vms/vm-freebsd92-i386-serial.qcow2 -cdrom /kvm/iso/freebsd/9.2/FreeBSD-9.2-RELEASE-i386-dvd1.iso -boot d -smp 2 -cpu qemu64 -net nic,model=virtio -net user,hostfwd=tcp:127.0.0.1:2284-:22 ``` Once running you can connect to the VNC server from your local host with: ``` vncviewer -via ${remote_host} localhost ``` Replace `${remote\_host}` with the host the vm is running on. **Note:** When you activate the install, vncviewer will disconnect after a bit with a complaint about the rect being too large. This is fine. The installer has just resized the vnc screen. Simply reconnect. Install, picking default options mostly, with the following notes: * Keymap Selection: Do not set non-default key mapping * Hostname: to freebsd-92-amd64 or freebsd-92-i386 * Distribution Select: deselect "games", leave "ports" selected * Partitioning: Guided and use the entire disk + Accept the default partitioning (Finish then Commit) * Archive Extraction: *...wait while installer installs the OS...* * Network Configuration: choose `vtnet0` + configure ipv4 w/ DHCP + do not configure ipv6 * System Configuration: leave sshd selected, don't select the others * Dumpdev Configuration: do not enable crash dumps * add a buildbot user + add user to 'wheel' group * Final Configuration: Apply configuration and exit * Manual Configuration: yes to opening a shell + `echo 'console="comconsole"' >> /boot/loader.conf` + Edit /etc/ttys and change off to on and dialup to vt100 for the ttyu0 entry. + `shutdown -p now` Now that the VM is installed, it's time to configure it. If you have the memory you can do the following simultaneously: ``` kvm -m 2048 -hda /kvm/vms/vm-freebsd92-amd64-serial.qcow2 -boot c -smp 2 -cpu qemu64 -net nic,model=virtio -net user,hostfwd=tcp:127.0.0.1:2283-:22 -nographic kvm -m 2048 -hda /kvm/vms/vm-freebsd92-i386-serial.qcow2 -boot c -smp 2 -cpu qemu64 -net nic,model=virtio -net user,hostfwd=tcp:127.0.0.1:2284-:22 -nographic ssh -p 2283 localhost ssh -p 2284 localhost su - cd /usr/ports/security/sudo; make install clean # accept defaults visudo # uncomment the '# %wheel ALL=(ALL) NOPASSWD: ALL' line exit cd /usr/ports/ports-mgmt/portmaster; sudo make install clean # select both autocomplete options ssh hasky.askmonty.org exit sudo su buildbot - ssh hasky.askmonty.org exit exit exit scp -P 2283 /kvm/vms/authorized_keys localhost:.ssh/ scp -P 2283 /kvm/vms/authorized_keys buildbot@localhost:.ssh/ scp -P 2284 /kvm/vms/authorized_keys localhost:.ssh/ scp -P 2284 /kvm/vms/authorized_keys buildbot@localhost:.ssh/ ssh -p 2283 localhost ssh -p 2284 localhost sudo portsnap fetch extract sudo portsnap fetch update sudo portmaster -Da sudo shutdown -p now ``` VMs for building BSD bintars ---------------------------- ``` for i in '/kvm/vms/vm-freebsd92-amd64-serial.qcow2 2283 qemu64' '/kvm/vms/vm-freebsd92-i386-serial.qcow2 2284 qemu64' ; do \ set $i; \ runvm --user=buildbot --logfile=kernel_$2.log --base-image=$1 --port=$2 --cpu=$3 "$(echo $1 | sed -e 's/serial/build/')" \ "cd /usr/ports/devel/libevent; sudo make install clean BATCH=yes" \ "cd /usr/ports/devel/boost-all; sudo make install clean BATCH=yes" \ "cd /usr/ports/devel/cmake; sudo make install clean BATCH=yes" \ "cd /usr/ports/devel/thrift/; sudo make install clean BATCH=yes" \ "cd /usr/ports/devel/bzr/; sudo make install clean BATCH=yes" \ "cd /usr/ports/devel/bison/; sudo make install clean BATCH=yes" \ "cd /usr/ports/databases/unixODBC; sudo make install clean BATCH=yes" \ "cd /usr/ports/devel/doxygen; sudo make install clean BATCH=yes"; \ done ``` VMs for install testing. ------------------------ ``` qemu-img create -b /kvm/vms/vm-freebsd92-amd64-serial.qcow2 -f qcow2 /kvm/vms/vm-freebsd92-amd64-install.qcow2 qemu-img create -b /kvm/vms/vm-freebsd92-i386-serial.qcow2 -f qcow2 /kvm/vms/vm-freebsd92-i386-install.qcow2 for i in '/kvm/vms/vm-freebsd92-amd64-serial.qcow2 2283 qemu64' '/kvm/vms/vm-freebsd92-i386-serial.qcow2 2284 qemu64' ; do \ set $i; \ runvm --user=buildbot --logfile=kernel_$2.log --base-image=$1 --port=$2 --cpu=$3 "$(echo $1 | sed -e 's/serial/install/')" \ "sudo portsnap cron update"; \ done ``` VMs for MySQL upgrade testing ----------------------------- ``` for i in '/kvm/vms/vm-freebsd92-amd64-serial.qcow2 2283 qemu64' '/kvm/vms/vm-freebsd92-i386-serial.qcow2 2284 qemu64' ; do \ set $i; \ runvm --user=buildbot --logfile=kernel_$2.log --base-image=$1 --port=$2 --cpu=$3 "$(echo $1 | sed -e 's/serial/upgrade/')" \ "cd /usr/ports/databases/mysql55-server; sudo make install clean BATCH=yes" \ "sudo /usr/local/etc/rc.d/mysql-server onestart" \ 'mysql -uroot -e "create database mytest; use mytest; create table t(a int primary key); insert into t values (1); select * from t"' ;\ done ``` VMs for MariaDB upgrade testing ------------------------------- ``` for i in '/kvm/vms/vm-freebsd92-amd64-serial.qcow2 2283 qemu64' '/kvm/vms/vm-freebsd92-i386-serial.qcow2 2284 qemu64' ; do \ set $i; \ runvm --user=buildbot --logfile=kernel_$2.log --base-image=$1 --port=$2 --cpu=$3 "$(echo $1 | sed -e 's/serial/upgrade2/')" \ "cd /usr/ports/databases/mariadb55-server; sudo make install clean BATCH=yes" \ "sudo /usr/local/etc/rc.d/mysql-server onestart" \ 'mysql -uroot -e "create database mytest; use mytest; create table t(a int primary key); insert into t values (1); select * from t"'; \ done ``` Add Key to known\_hosts ----------------------- Do the following on each kvm host server (terrier, terrier2, i7, etc...) to add the VMs to known\_hosts. ``` # freebsd92-amd64 cp -avi /kvm/vms/vm-freebsd92-amd64-install.qcow2 /kvm/vms/vm-freebsd92-amd64-test.qcow2 kvm -m 1024 -hda /kvm/vms/vm-freebsd92-amd64-test.qcow2 -redir tcp:2283::22 -boot c -smp 2 -cpu qemu64 -net nic,model=virtio -net user -nographic sudo su - buildbot ssh -p 2283 buildbot@localhost sudo shutdown -p now # answer "yes" when prompted exit # the buildbot user rm -v /kvm/vms/vm-freebsd92-amd64-test.qcow2 # freebsd92-i386 cp -avi /kvm/vms/vm-freebsd92-i386-install.qcow2 /kvm/vms/vm-freebsd92-i386-test.qcow2 kvm -m 1024 -hda /kvm/vms/vm-freebsd92-i386-test.qcow2 -redir tcp:2284::22 -boot c -smp 2 -cpu qemu64 -net nic,model=virtio -net user -nographic sudo su - buildbot ssh -p 2284 buildbot@localhost sudo shutdown -p now # answer "yes" when prompted exit # the buildbot user rm -v /kvm/vms/vm-freebsd92-i386-test.qcow2 ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb ST_IsSimple ST\_IsSimple ============ Syntax ------ ``` ST_IsSimple(g) IsSimple(g) ``` Description ----------- Returns true if the given Geometry has no anomalous geometric points, false if it does, or NULL if given a NULL value. ST\_IsSimple() and IsSimple() are synonyms. Examples -------- A POINT is always simple. ``` SET @g = 'Point(1 2)'; SELECT ST_ISSIMPLE(GEOMFROMTEXT(@g)); +-------------------------------+ | ST_ISSIMPLE(GEOMFROMTEXT(@g)) | +-------------------------------+ | 1 | +-------------------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Installing and Configuring a Single Server ColumnStore System Installing and Configuring a Single Server ColumnStore System ============================================================= After the MariaDB ColumnStore server have been setup based on the Preparing for Installations Document and the required MariaDB ColumnStore Packages have been Installed, use of the following option to configure and install MariaDB ColumnStore: * MariaDB ColumnStore One Step Quick Installer Script - Release 1.1.6 and later * MariaDB ColumnStore Post Install Script This Article shows how to install on a single server system. If installing a single combined functionality server with no plans to add additional servers, Single Node should be chosen. Going from one configuration to another will require a re-installation of the MariaDB ColumnStore software. The following is a transcript of a typical runs of the MariaDB ColumnStore configuration/install scripts. Plain-text formatting indicates output from the script and bold text indicates responses to questions. After each question there is a short discussion of what the question is asking and what some typical answers might be. You will not see these discussions the running the actual configuration script. NOTE: You can install MariaDB ColumnStore as a root user or non-root user. This is based on how you setup the servers based on "Preparing for Installation Document". If installing as root, you need to be logged in as root user in a root login shell. If you are installing as non-root, you need to be logged in as a non-root user that was setup in the ["Preparing for Installation Document"](../preparing-for-columnstore-installation/index) MariaDB ColumnStore One Step Quick Installer Script, quick\_installer\_single\_server.sh ======================================================================================== MariaDB ColumnStore One Step Quick Installer Script, quick\_installer\_single\_server.sh, is used to perform a simple 1 command run to perform the configuration and startup of MariaDB ColumnStore package on a Single Server setup. This will work with both root and non-root installs. Available in Release 1.1.6 and later. It will perform an install with these defaults: * System-Name = columnstore-1 * Single-Server Install with 1 Performance Module * Storage - Internal * DBRoot - DBroot #1 assigned to Performance Module #1 Running quick\_installer\_single\_server.sh help as root user ------------------------------------------------------------- ``` /usr/local/mariadb/columnstore/bin/quick_installer_single_server.sh --help Usage ./quick_installer_multi_server.sh Quick Installer for a Single Server MariaDB ColumnStore Install ``` Running quick\_installer\_single\_server.sh as root user -------------------------------------------------------- ``` # /usr/local/mariadb/columnstore/bin/quick_installer_single_server.sh Run post-install script The next step is: If installing on a pm1 node: /usr/local/mariadb/columnstore/bin/postConfigure If installing on a non-pm1 using the non-distributed option: /usr/local/mariadb/columnstore/bin/columnstore start Run postConfigure script This is the MariaDB ColumnStore System Configuration and Installation tool. It will Configure the MariaDB ColumnStore System and will perform a Package Installation of all of the Servers within the System that is being configured. IMPORTANT: This tool requires to run on the Performance Module #1 With the no-Prompting Option being specified, you will be required to have the following: 1. Root user ssh keys setup between all nodes in the system or use the password command line option. 2. A Configure File to use to retrieve configure data, default to Columnstore.xml.rpmsave or use the '-c' option to point to a configuration file. ===== Quick Install Single-Server Configuration ===== Single-Server install is used when there will only be 1 server configured on the system. It can also be used for production systems, if the plan is to stay single-server. Enter System Name (columnstore-1) > Performing Configuration Setup and MariaDB ColumnStore Startup NOTE: Setting 'NumBlocksPct' to 50% Setting 'TotalUmMemory' to 25% of total memory. Running the MariaDB ColumnStore setup scripts post-mysqld-install Successfully Completed post-mysql-install Successfully Completed Starting MariaDB Columnstore Database Platform MariaDB ColumnStore Database Platform Starting, please wait ...... DONE System Catalog Successfull Created MariaDB ColumnStore Install Successfully Completed, System is Active Enter the following command to define MariaDB ColumnStore Alias Commands . /etc/profile.d/columnstoreAlias.sh Enter 'mcsmysql' to access the MariaDB ColumnStore SQL console Enter 'mcsadmin' to access the MariaDB ColumnStore Admin console NOTE: The MariaDB ColumnStore Alias Commands are in /etc/profile.d/columnstoreAlias.sh ``` Running quick\_installer\_single\_server.sh as non-root user ------------------------------------------------------------ ``` # /home/guest/mariadb/columnstore/bin/quick_installer_single_server.sh Run post-install script The next step is: If installing on a pm1 node: /home/guest/mariadb/columnstore/bin/postConfigure If installing on a non-pm1 using the non-distributed option: /home/guest/mariadb/columnstore/bin/columnstore start Run postConfigure script This is the MariaDB ColumnStore System Configuration and Installation tool. It will Configure the MariaDB ColumnStore System and will perform a Package Installation of all of the Servers within the System that is being configured. IMPORTANT: This tool requires to run on the Performance Module #1 With the no-Prompting Option being specified, you will be required to have the following: 1. Root user ssh keys setup between all nodes in the system or use the password command line option. 2. A Configure File to use to retrieve configure data, default to Columnstore.xml.rpmsave or use the '-c' option to point to a configuration file. ===== Quick Install Single-Server Configuration ===== Single-Server install is used when there will only be 1 server configured on the system. It can also be used for production systems, if the plan is to stay single-server. Enter System Name (columnstore-1) > Performing Configuration Setup and MariaDB ColumnStore Startup NOTE: Setting 'NumBlocksPct' to 50% Setting 'TotalUmMemory' to 25% of total memory. Running the MariaDB ColumnStore setup scripts post-mysqld-install Successfully Completed post-mysql-install Successfully Completed Starting MariaDB Columnstore Database Platform MariaDB ColumnStore Database Platform Starting, please wait ...... DONE System Catalog Successfull Created MariaDB ColumnStore Install Successfully Completed, System is Active Enter the following command to define MariaDB ColumnStore Alias Commands . /etc/profile.d/columnstoreAlias.sh Enter 'mcsmysql' to access the MariaDB ColumnStore SQL console Enter 'mcsadmin' to access the MariaDB ColumnStore Admin console NOTE: The MariaDB ColumnStore Alias Commands are in /etc/profile.d/columnstoreAlias.sh ``` MariaDB ColumnStore Post Install Script, postConfigure ====================================================== Run the script 'postConfigure' to complete the configuration and installation. Common Installation Examples ---------------------------- During postConfigure, this first question will be asked. Select 1 for a Single Server Install ``` Select the type of server install [1=single, 2=multi] (1) > 1 ``` Running postConfigure as root user: ----------------------------------- ``` /usr/local/mariadb/columnstore/bin/postConfigure ``` Running postConfigure as non-root user: --------------------------------------- ``` export COLUMNSTORE_INSTALL_DIR=/home/guest/mariadb/columnstore export LD_LIBRARY_PATH=/home/guest/mariadb/columnstore/lib:/home/guest/mariadb/columnstore/mysql/lib /home/guest/mariadb/columnstore/bin/postConfigure -i /home/guest/mariadb/columnstore ``` This is the MariaDB Columnstore System Configuration and Installation tool. It will Configure the MariaDB Columnstore System and will perform a Package Installation of all of the Servers within the System that is being configured. IMPORTANT: This tool should only be run on the Parent OAM Module which is a Performance Module, preferred Module #1 Prompting instructions: Press 'enter' to accept a value in (), if available or Enter one of the options within [], if available, or Enter a new value Setup System Server Type Configuration -------------------------------------- ``` There are 2 options when configuring the System Server Type: single and multi 'single' - Single-Server install is used when there will only be 1 server configured on the system. It can also be used for production systems, if the plan is to stay single-server. 'multi' - Multi-Server install is used when you want to configure multiple servers now or in the future. With Multi-Server install, you can still configure just 1 server now and add on addition servers/modules in the future. Select the type of System Server install [1=single, 2=multi] (2) > 1 Performing a Single Server Install. Enter System Name (columnstore-1) > mymcs1 ``` **Notes**: You should give this system a name that will appear in various Admin utilities, SNMP messages, etc. The name can be composed of any number of printable characters and spaces. Setup High Availability Data Storage Mount Configuration -------------------------------------------------------- ``` There are 2 options when configuring the storage: internal and external 'internal' - This is specified when a local disk is used for the DBRoot storage. High Availability Server Failover is not Supported in this mode 'external' - This is specified when the DBRoot directories are mounted. High Availability Server Failover is Supported in this mode. <<code>> Select the type of Data Storage [1=internal, 2=external] (1) > **<Enter>** ``` Notes: Choosing internal and using softlinks to point to an externally mounted storage will allow you to use any format (i.e., ext2, ext3, etc.). ``` Enter the list (Nx,Ny,Nz) or range (Nx-Nz) of dbroot IDs assigned to module 'pm1' (1) > 1 ``` **Notes**: The installer will set up the number of dbroot directories based on this answer. Performing Configuration Setup and MariaDB Columnstore Startup -------------------------------------------------------------- ``` NOTE: Setting 'NumBlocksPct' to 50% Setting 'TotalUmMemory' to 25% of total memory (Combined Server Install maximum value is 16G). Value set to 4G ``` **Notes**: The default maximum for a single server is 16Gb. ``` Running the MariaDB Columnstore MySQL setup scripts post-mysqld-install Successfully Completed post-mysql-install Successfully Completed Starting MariaDB ColumnStore Database Platform Starting MariaDB ColumnStore Database Platform, please wait......... DONE System Catalog Successfully Created MariaDB ColumnStore Install Successfully Completed, System is Active Enter the following command to define MariaDB ColumnStore Alias Commands . /usr/local/mariadb/columnstore/bin/columnstoreAlias Enter 'mcsmysql' to access the MariaDB Columnstore MySQL console Enter 'mcsadmin' to access the MariaDB Columnstore Admin console ``` MariaDB Columnstore Memory Configuration ---------------------------------------- During the installation process, postConfigure will set the 2 main Memory configuration settings based on the size of memory detected on the local node. The 2 settings are in the MariaDB Columnstore Configuration file, /usr/local/mariadb/columnstore/etc Columnstore.xml. These 2 settings are: ``` 'NumBlocksPct' - Performance Module Data cache memory setting TotalUmMemory - User Module memory setting, used as temporary memory for joins ``` On a Single Server Install, this is the default settings: ``` NumBlocksPct - 50% of total memory TotalUmMemory - 25% of total memory, default maximum the percentage equal to 16G ``` The user can choose to change these settings after the install is completed, if for instance they want to setup more memory for Joins to utilize. On a single server or combined UM/PM server, it is recommended to not have the combination of these 2 settings over 75% of total memory. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb FLOAT FLOAT ===== Syntax ------ ``` FLOAT[(M,D)] [SIGNED | UNSIGNED | ZEROFILL] ``` Description ----------- A small (single-precision) floating-point number (see [DOUBLE](../double/index) for a regular-size floating point number). Allowable values are: * -3.402823466E+38 to -1.175494351E-38 * 0 * 1.175494351E-38 to 3.402823466E+38. These are the theoretical limits, based on the IEEE standard. The actual range might be slightly smaller depending on your hardware or operating system. M is the total number of digits and D is the number of digits following the decimal point. If M and D are omitted, values are stored to the limits allowed by the hardware. A single-precision floating-point number is accurate to approximately 7 decimal places. UNSIGNED, if specified, disallows negative values. Using FLOAT might give you some unexpected problems because all calculations in MariaDB are done with double precision. See [Floating Point Accuracy](../floating-point-accuracy/index). For more details on the attributes, see [Numeric Data Type Overview](../numeric-data-type-overview/index). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb NOT LIKE NOT LIKE ======== Syntax ------ ``` expr NOT LIKE pat [ESCAPE 'escape_char'] ``` Description ----------- This is the same as [NOT (expr LIKE pat [ESCAPE 'escape\_char'])](../not/index). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Existing Puppet Modules for MariaDB Existing Puppet Modules for MariaDB =================================== This page contains links to Puppet modules that can be used to automate MariaDB deployment and configuration. The list is not meant to be exhaustive. Use it as a starting point, but then please do your own research. Puppet Forge ------------ Puppet Forge is the website to search for Puppet modules, maintained by the Puppet company. Modules are searched by the technology that needs to be automated, and the target operating system. Search criteria include whether the modules are supported by Puppet or its partners, and whether a module is approved by Puppet. Approved modules are certified by Puppet based on their quality and maintenance standards. Acceptance Tests ---------------- Some modules that support the Puppet Development Kit allow some types of acceptance tests. We can run a static analysis on a module's source code to find certain bad practices that are likely to be a source of bugs: ``` pdk validate ``` If a module's authors wrote unit tests, we can run them in this way: ``` pdk test unit ``` Supported Modules for MariaDB ----------------------------- At the time of writing, there are no supported or approved modules for MariaDB. However there is a [mysql module](https://forge.puppet.com/modules/puppetlabs/mysql) supported by Puppet, that supports the Puppet Development Kit. Though it doesn't support MariaDB-specific features, it works with MariaDB. Its documentation shows how to use the module to install MariaDB on certain operating systems. Several unsupported and not approved modules exist for MariaDB and MaxScale. Resources and References ------------------------ * [Puppet Forge](https://forge.puppet.com/) website. * [Puppet Development Kit](https://puppet.com/docs/pdk/1.x/pdk.html) documentation. * [Modules overview](https://puppet.com/docs/puppet/7.1/modules_fundamentals.html) in Puppet documentation. * [Beginner's guide to writing modules](https://puppet.com/docs/puppet/7.1/bgtm.html) in Puppet documentation. * [Puppet Supported Modules](https://forge.puppet.com/supported) page in Puppet Forge. --- Content initially contributed by [Vettabase Ltd](https://vettabase.com/). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Analyzing Queries in ColumnStore Analyzing Queries in ColumnStore ================================ Determining active queries ========================== show processlist ---------------- The MariaDB **show processlist** command may be used to see a list of active queries on that UM: ``` MariaDB [test]> show processlist; +----+------+-----------+-------+---------+------+-------+--------------+ | Id | User | Host | db | Command | Time | State | Info | +----+------+-----------+-------+---------+------+-------+--------------+ | 73 | root | localhost | ssb10 | Query | 0 | NULL | show processlist +----+------+-----------+-------+---------+------+-------+--------------+ 1 row in set (0.01 sec) ``` getActiveSQLStatements ---------------------- *getActiveSQLStatements* is a mcsadmin command that shows which SQL statements are currently being executed on the database: ``` mcsadmin> getActiveSQLStatements getactivesqlstatements Wed Oct 7 08:38:32 2015 Get List of Active SQL Statements ================================= Start Time Time (hh:mm:ss) Session ID SQL Statement ---------------- ---------------- -------------------- ------------------------------------------------------------ Oct 7 08:38:30 00:00:03 73 select c_name,sum(lo_revenue) from customer, lineorder where lo_custkey = c_custkey and c_custkey = 6 group by c_name ``` Analysis of individual queries ============================== Query statistics ---------------- The *calGetStats* function provides statistics about resources used on the [User Module](../columnstore-user-module/index) (UM) node, PM node, and network by the last run query. Example: ``` MariaDB [test]> select count(*) from wide2; +----------+ | count(*) | +----------+ | 5000000 | +----------+ 1 row in set (0.22 sec) MariaDB [test]> select calGetStats(); +---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ | calGetStats() | +---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ | Query Stats: MaxMemPct-0; NumTempFiles-0; TempFileSpace-0B; ApproxPhyI/O-1931; CacheI/O-2446; BlocksTouched-2443; PartitionBlocksEliminated-0; MsgBytesIn-73KB; MsgBytesOut-1KB; Mode-Distributed | +---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ 1 row in set (0.01 sec) ``` The output contains information on: * **MaxMemPct** - Peak memory utilization on the [User Module](../columnstore-user-module/index), likely in support of a large (User Module) based hash join operation. * **NumTempFiles** - Report on any temporary files created in support of query operations larger than available memory, typically for unusual join operations where the smaller table join cardinality exceeds some configurable threshold. * **TempFileSpace** - Report on space used by temporary files created in support of query operations larger than available memory, typically for unusual join operations where the smaller table join cardinality exceeds some configurable threshold. * **PhyI/O** - Number of 8k blocks read from disk, SSD, or other persistent storage. * **CacheI/O** - Approximate number of 8k blocks processed in memory, adjusted down by the number of discrete PhyI/O calls required. * **BlocksTouched** - Approximate number of 8k blocks processed in memory. * **PartitionBlocksEliminated** - The number of block touches eliminated via the Extent Map elimination behavior. * **MsgBytesIn, MsgByteOut** - Message size in MB sent between nodes in support of the query. The output is useful to determine how much physical I/O was required, how much data was cached, and how many partition blocks were eliminated through use of extent map elimination. The system maintains min / max values for each extent and uses these to help implement where clause filters to completely bypass extents where the value is outside of the min/max range. When a column is ordered (or semi-ordered) during load such as a time column this offer very large performance gains as the system can avoid scanning many extents for the column. Query plan / trace ================== While the MariaDB Server's [EXPLAIN](../explain/index) utility can be used to look at the query plan, it is somewhat less helpful for ColumnStore tables as ColumnStore does not use indexes or make use of MariaDB I/O functionality. The execution plan for a query on a ColumnStore table is made up of multiple steps. Each step in the query plan performs a set of operations that are issued from the [User Module](../columnstore-user-module/index) to the set of [Performance Modules](../columnstore-performance-module/index) in support of a given step in a query. * Full Column Scan - an operation that scans each entry in a column using all available threads on the Performance Modules. Speed of operation is generally related to the size of the data type and the total number of rows in the column. The closest analogy for a traditional system is an index scan operation. * Partitioned Column Scan - an operation that uses the Extent Map to identify that certain portions of the column do not contain any matching values for a given set of filters. The closest analogy for a traditional row-based DBMS is a partitioned index scan, or partitioned table scan operation. * Column lookup by row offset - once the set of matching filters have been applied and the minimal set of rows have been identified, additional blocks are requested using a calculation that determines exactly which block is required. The closest analogy for a traditional system is a lookup by rowid. These operations are automatically executed together in order to execute appropriate filters and column lookup by row offset. Viewing the ColumnStore query plan ---------------------------------- In MariaDB ColumnStore there is a set of SQL tracing stored functions provided to see the distributed query execution plan between the [UM](../columnstore-user-module/index) and the [PM](../columnstore-performance-module/index). The basic steps to using these SQL tracing stored functions are: 1. Start the trace for the particular session. 2. Execute the SQL statement in question. 3. Review the trace collected for the statement. As an example, the following session starts a trace, issues a query against a 6 million row fact table and 300,000 row dimension table, and then reviews the output from the trace: ``` MariaDB [test]> select calSetTrace(1); +----------------+ | calSetTrace(1) | +----------------+ | 0 | +----------------+ 1 row in set (0.00 sec) MariaDB [test]> select c_name, sum(o_totalprice) -> from customer, orders -> where o_custkey = c_custkey -> and c_custkey = 5 -> group by c_name; +--------------------+-------------------+ | c_name | sum(o_totalprice) | +--------------------+-------------------+ | Customer#000000005 | 684965.28 | +--------------------+-------------------+ 1 row in set, 1 warning (0.34 sec) MariaDB [test]> select calGetTrace(); +------------------------------------------------------------------------------------------------------------------------------------------------------------------- -------------------------------------------------------------------------------------------------------------------------------------------------------------------- ----------------------------------------------------------------------------------------------------------+ | calGetTrace() | +------------------------------------------------------------------------------------------------------------------------------------------------------------------- -------------------------------------------------------------------------------------------------------------------------------------------------------------------- ----------------------------------------------------------------------------------------------------------+ | Desc Mode Table TableOID ReferencedColumns PIO LIO PBE Elapsed Rows BPS PM customer 3024 (c_custkey,c_name) 0 43 36 0.006 1 BPS PM orders 3038 (o_custkey,o_totalprice) 0 766 0 0.032 3 HJS PM orders-customer 3038 - - - - ----- - TAS UM - - - - - - 0.021 1 | +------------------------------------------------------------------------------------------------------------------------------------------------------------------- -------------------------------------------------------------------------------------------------------------------------------------------------------------------- ----------------------------------------------------------------------------------------------------------+ 1 row in set (0.00 sec) ``` The columns headings in the output are as follows: * **Desc** – Operation being executed. Possible values: + **BPS** - Batch Primitive Step : scanning or projecting the column blocks. + **CES** - Cross Engine Step: Performing Cross engine join + **DSS** - Dictionary Structure Step : a dictionary scan for a particular variable length string value. + **HJS** - Hash Join Step : Performing a hash join between 2 tables + **HVS** - Having Step: Performing the having clause on the result set + **SQS** - Sub Query Step: Performaning a sub query + **TAS** - Tuple Aggregation step : the process of receiving intermediate aggregation results at the UM from the PM nodes. + **TNS** - Tuple Annexation Step : Query result finishing, e.g. filling in constant columns, limit, order by and final distinct cases. + **TUS** = Tuple Union step : Performing a SQL union of 2 sub queries. + **TCS** = Tuple Constant Step: Process Constant Value Columns + **WFS** = Window Function Step: Performing a window function. * **Mode** – Where the operation was performed: UM or PM * **Table** – Table for which columns may be scanned/projected. * **TableOID** – ObjectID for the table being scanned. * **ReferencedOIDs** – ObjectIDs for the columns required by the query. * **PIO** – Physical I/O (reads from storage) executed for the query. * **LIO** – Logical I/O executed for the query, also known as Blocks Touched. * **PBE** – Partition Blocks Eliminated identifies blocks eliminated by Extent Map min/max. * **Elapsed** – Elapsed time for a give step. * **Rows** – Intermediate rows returned **Note: The time recorded is the time from PrimProc and ExeMgr. Execution time from withing mysqld is not tracked here. There could be extra processing time in mysqld due to a number of factors such as ORDER BY.** Cache clearing to enable cold testing ===================================== Sometimes it can be useful to clear caches to allow understanding of uncached and cached query access. The calFlushCache() function will clear caches on all servers. This is only really useful for testing query performance: ``` MariaDB [test]> select calFlushCache(); ``` Viewing extent map information ============================== It can be useful to view details about the extent map for a given column. This can be achieved using the editem process on a PM server. Available arguments can be provided by using the -h flag. The most common use is to provide the column object id with the -o argument which will output details for the column and in this case the -t argument is provided to show min / max values as dates: ``` /usr/local/mariadb/columnstore/bin/editem -o 3032 -t Col OID = 3032, NumExtents = 10, width = 4 428032 - 432127 (4096) min: 1992-01-01, max: 1993-06-21, seqNum: 1, state: valid, fbo: 0, DBRoot: 1, part#: 0, seg#: 0, HWM: 0; status: avail 502784 - 506879 (4096) min: 1992-01-01, max: 1993-06-22, seqNum: 1, state: valid, fbo: 0, DBRoot: 2, part#: 0, seg#: 1, HWM: 0; status: unavail 708608 - 712703 (4096) min: 1993-06-21, max: 1994-12-11, seqNum: 1, state: valid, fbo: 0, DBRoot: 1, part#: 0, seg#: 2, HWM: 0; status: unavail 766976 - 771071 (4096) min: 1993-06-22, max: 1994-12-12, seqNum: 1, state: valid, fbo: 0, DBRoot: 2, part#: 0, seg#: 3, HWM: 0; status: unavail 989184 - 993279 (4096) min: 1994-12-11, max: 1996-06-01, seqNum: 1, state: valid, fbo: 4096, DBRoot: 1, part#: 0, seg#: 0, HWM: 8191; status: avail 1039360 - 1043455 (4096) min: 1994-12-12, max: 1996-06-02, seqNum: 1, state: valid, fbo: 4096, DBRoot: 2, part#: 0, seg#: 1, HWM: 8191; status: avail 1220608 - 1224703 (4096) min: 1996-06-01, max: 1997-11-22, seqNum: 1, state: valid, fbo: 4096, DBRoot: 1, part#: 0, seg#: 2, HWM: 8191; status: avail 1270784 - 1274879 (4096) min: 1996-06-02, max: 1997-11-22, seqNum: 1, state: valid, fbo: 4096, DBRoot: 2, part#: 0, seg#: 3, HWM: 8191; status: avail 1452032 - 1456127 (4096) min: 1997-11-22, max: 1998-08-02, seqNum: 1, state: valid, fbo: 0, DBRoot: 1, part#: 1, seg#: 0, HWM: 1930; status: avail 1510400 - 1514495 (4096) min: 1997-11-22, max: 1998-08-02, seqNum: 1, state: valid, fbo: 0, DBRoot: 2, part#: 1, seg#: 1, HWM: 1930; status: avail ``` Here it can be seen that the extent maps for the o\_orderdate (object id 3032) column are well partitioned since the order table source data was sorted by the order\_date. This example shows 2 seperate DBRoot values as the environment was a 2 node combined deployment. Column object ids may be found by querying the calpontsys.syscolumn metadata table (deprecated) or information\_schema.columnstore\_columns table (version 1.0.6+). Query statistics history ======================== MariaDB ColumnStore query statistics history can be retrieved for analysis. By default the query stats collection is disabled. To enable the collection of query stats, the <QueryStats><Enabled> element in the ColumnStore.XML configuration file should be set to Y (default is N). ``` <QueryStats> <Enabled>Y</Enabled> </QueryStats> ``` Cross Engine Support must also be enabled before enabling Query Statistics. See the [Cross Engine Configuration](../configuring-columnstore-cross-engine-joins/index) section. When enabled the history of query statistics across all sessions along with execution time, and those stats provided by calgetstats() is stored in a table in the infinidb\_querystats schema. Only queries in the following ColumnStore syntax are available for statistics monitoring: * SELECT * INSERT * UPDATE * DELETE * INSERT SELECT * LOAD DATA INFILE Query statistics table ---------------------- When QueryStats is enabled, the query statistics history is collected in the querystats table in the infinidb\_querystats schema. The columns of this table are: * **queryID** - A unique identifier assigned to the query * **Session ID (sessionID)** - The session number that executed the statement. * **queryType** - The type of the query whether insert, update, delete, select, delete, insert select or load data infile * **query** - The text of the query * **Host (host)** - The host that executed the statement. * **User ID (user)** - The user that executed the statement. * **Priority (priority)** The priority the user has for this statement. * **Query Execution Times (startTime, endTime)** Calculated as end time – start time. + **start time** - the time that the query gets to ExeMgr, DDLProc, or DMLProc + **end time** - the time that the last result packet exits ExeMgr, DDLProc or DMLProc * **Rows returned or affected (rows)** -The number of rows returned for SELECT queries, or the number of rows affected by DML queries. Not valid for DDL and other query types. * **Error Number (errNo)** - The IDB error number if this query failed, 0 if it succeeded. * **Physical I/O (phyIO)** - The number of blocks that the query accessed from the disk, including the pre-fetch blocks. This statistic is only valid for the queries that are processed by ExeMgr, i.e. SELECT, DML with WHERE clause, and INSERT SELECT. * **Cache I/O (cacheIO)** - The number of blocks that the query accessed from the cache. This statistic is only valid for queries that are processed by ExeMgr, i.e. SELECT, DML with WHERE clause, and INSERT SELECT. * **Blocks Touched (blocksTouched)** - The total number of blocks that the query accessed physically and from the cache. This should be equal or less than the sum of physical I/O and cache I/O. This statistic is only valid for queries that are processed by ExeMgr, i.e. SELECT, DML with WHERE clause, and INSERT SELECT. * **Partition Blocks Eliminated (CPBlocksSkipped)** - The number of blocks being eliminated by the extent map casual partition. This statistic is only valid for queries that are processed by ExeMgr, i.e. SELECT, DML with WHERE clause, and INSERT SELECT. * **Messages from [UM](../columnstore-user-module/index) to [PM](columnstore-performance-modulec) (msgOutUM)** - The number of messages in bytes that ExeMgr sends to the PrimProc. If a message needs to be distributed to all the PMs, the sum of all the distributed messages will be counted. Only valid for queries that are processed by ExeMgr, i.e. SELECT, DML with WHERE clause, and INSERT SELECT. * **Messages from PM to UM (msgInUM)** - The number of messages in bytes that PrimProc sends to the ExeMgr. Only valid for queries that are processed by ExeMgr, i.e. SELECT, DML with where clause, and INSERT SELECT. * **Memory Utilization (maxMemPct)** - This field shows memory utilization for the [User Module](../columnstore-user-module/index) (UM) in support of any UM join, group by, aggregation, distinct, or other operation. * **Blocks Changed (blocksChanged)** - Total number of blocks that queries physically changed on disk. This is only for delete/update statements. * **Temp Files (numTempFiles)** - This field shows any temporary file utilization for the User Module (UM) in support of any UM join, group by, aggregation, distinct, or other operation. * **Temp File Space (tempFileSpace)** - This shows the size of any temporary file utilization for the User Module (UM) in support of any UM join, group by, aggregation, distinct, or other operation. Query statistics viewing ------------------------ Users can view the query statistics by selecting the rows from the query stats table in the infinidb\_querystats schema. Examples listed below: * Example 1: List execution time, rows returned for all the select queries within the past 12 hours: ``` MariaDB [infinidb_querystats]> select queryid, query, endtime-starttime, rows from querystats where starttime >= now() - interval 12 hour and querytype = 'SELECT'; ``` * Example 2: List the three slowest running select queries of session 2 within the past 12 hours: ``` MariaDB [infinidb_querystats]> select a.* from (select endtime-starttime execTime, query from queryStats where sessionid = 2 and querytype = 'SELECT' and starttime >= now()-interval 12 hour order by 1 limit 3) a; ``` * Example 3: List the average, min and max running time of all the INSERT SELECT queries within the past 12 hours: ``` MariaDB [infinidb_querystats]> select min(endtime-starttime), max(endtime-starttime), avg(endtime-starttime) from querystats where querytype='INSERT SELECT' and starttime >= now() - interval 12 hour; ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb ST_ISCLOSED ST\_ISCLOSED ============ Syntax ------ ``` ST_IsClosed(g) IsClosed(g) ``` Description ----------- Returns 1 if a given [LINESTRING's](../linestring/index) start and end points are the same, or 0 if they are not the same. Before [MariaDB 10.1.5](https://mariadb.com/kb/en/mariadb-1015-release-notes/), returns NULL if not given a LINESTRING. After [MariaDB 10.1.5](https://mariadb.com/kb/en/mariadb-1015-release-notes/), returns -1. `ST_IsClosed()` and `IsClosed()` are synonyms. Examples -------- ``` SET @ls = 'LineString(0 0, 0 4, 4 4, 0 0)'; SELECT ST_ISCLOSED(GEOMFROMTEXT(@ls)); +--------------------------------+ | ST_ISCLOSED(GEOMFROMTEXT(@ls)) | +--------------------------------+ | 1 | +--------------------------------+ SET @ls = 'LineString(0 0, 0 4, 4 4, 0 1)'; SELECT ST_ISCLOSED(GEOMFROMTEXT(@ls)); +--------------------------------+ | ST_ISCLOSED(GEOMFROMTEXT(@ls)) | +--------------------------------+ | 0 | +--------------------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Common Table Expressions Common Table Expressions ========================= **MariaDB starting with [10.2.1](https://mariadb.com/kb/en/mariadb-1021-release-notes/)**Common table expressions were introduced in [MariaDB 10.2.1](https://mariadb.com/kb/en/mariadb-1021-release-notes/). | Title | Description | | --- | --- | | [WITH](../with/index) | Allows reference to subqueries as temporary tables within queries. | | [Non-Recursive Common Table Expressions Overview](../non-recursive-common-table-expressions-overview/index) | Common Table Expressions (CTEs) are essentially Temporary Named Result Sets. | | [Recursive Common Table Expressions Overview](../recursive-common-table-expressions-overview/index) | A recursive CTE will repeatedly execute subsets of the data until obtaining the complete results | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Buildbot Setup for Virtual Machines - Fedora 20 Buildbot Setup for Virtual Machines - Fedora 20 =============================================== Base install ------------ ``` qemu-img create -f qcow2 /kvm/vms/vm-fedora20-i386-serial.qcow2 20G qemu-img create -f qcow2 /kvm/vms/vm-fedora20-amd64-serial.qcow2 20G ``` Start each VM booting from the server install iso one at a time and perform the following install steps: ``` kvm -m 2048 -hda /kvm/vms/vm-fedora20-i386-serial.qcow2 -cdrom /ds413/iso/fedora/Fedora-20-i386-DVD.iso -redir tcp:2291::22 -boot d -smp 2 -cpu qemu64 -net nic,model=virtio -net user kvm -m 2048 -hda /kvm/vms/vm-fedora20-amd64-serial.qcow2 -cdrom /ds413/iso/fedora/Fedora-20-x86_64-DVD.iso -redir tcp:2292::22 -boot d -smp 2 -cpu qemu64 -net nic,model=virtio -net user ``` Once running you can connect to the VNC server from your local host with: ``` vncviewer -via ${remote-host} localhost ``` Replace ${remote-host} with the host the vm is running on. **Note:** When you activate the install, vncviewer may disconnect with a complaint about the rect being too large. This is fine. The Fedora installer has just resized the vnc screen. Simply reconnect. Install, picking default options mostly, with the following notes: * Set the language to English(US) * Set the timezone to Etc/Greenwich Mean Time timezone * Change "Software Selection" to "Minimal Install" (default is "Gnome Desktop") * Under "Network Configuration" set the hostnames to fedora20-amd64 and fedora20-i386 * For "Installation Destination" select the disk then click continue. + On "Installation Options" screen, select the "Partition scheme" drop-down menu and select "Standard Partition". We **do not** want LVM. + **do not** check the encryption checkbox * Select the "Begin installation" button to start the install * While installing, set the root password and an initial user. + Be sure the initial user is an administrator When the install is finished, you will be prompted to reboot. Go ahead and do so, but it will fail. Kill the VM after the reboot fails and start it up again with: ``` kvm -m 2048 -hda /kvm/vms/vm-fedora20-i386-serial.qcow2 -redir tcp:2291::22 -boot c -smp 2 -cpu qemu64 -net nic,model=virtio -net user kvm -m 2048 -hda /kvm/vms/vm-fedora20-amd64-serial.qcow2 -redir tcp:2292::22 -boot c -smp 2 -cpu qemu64 -net nic,model=virtio -net user ``` Log in using the initial user created during the install: ``` ssh -p 2291 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -i ~/.ssh/buildbot.id_dsa localhost ssh -p 2292 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -i ~/.ssh/buildbot.id_dsa localhost ``` After logging in, add the initial user to the "wheel" group. ``` sudo usermod -a -G wheel ${username} ``` Enable password-less sudo for the "wheel" group and serial console sudo: ``` sudo visudo # Uncomment the line "%wheel ALL=(ALL) NOPASSWD: ALL" # Comment out this line: # Defaults requiretty ``` Edit /boot/grub/menu.lst: ``` sudo vi /etc/default/grub # Add/edit these entries: GRUB_CMDLINE_LINUX_DEFAULT="console=tty0 console=ttyS0,115200n8" GRUB_TERMINAL="serial" GRUB_SERIAL_COMMAND="serial --unit=0 --speed=115200 --word=8 --parity=no --stop=1" sudo grub2-mkconfig -o /boot/grub2/grub.cfg ``` Logout and then, from the VM host server: Create a .ssh folder: ``` ssh -t -p 2291 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -i ~/.ssh/buildbot.id_dsa localhost "mkdir -v .ssh" ssh -t -p 2292 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -i ~/.ssh/buildbot.id_dsa localhost "mkdir -v .ssh" ``` Copy over the authorized keys file: ``` scp -P 2291 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no /kvm/vms/authorized_keys localhost:.ssh/ scp -P 2292 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no /kvm/vms/authorized_keys localhost:.ssh/ ``` Set permissions on the .ssh folder correctly: ``` ssh -t -p 2291 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -i ~/.ssh/buildbot.id_dsa localhost "chmod -vR go-rwx .ssh" ssh -t -p 2292 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -i ~/.ssh/buildbot.id_dsa localhost "chmod -vR go-rwx .ssh" ``` Create the buildbot user: ``` ssh -t -p 2291 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no localhost 'chmod -vR go-rwx .ssh; sudo adduser buildbot; sudo usermod -a -G wheel buildbot; sudo mkdir ~buildbot/.ssh; sudo cp -vi .ssh/authorized_keys ~buildbot/.ssh/; sudo chown -vR buildbot:buildbot ~buildbot/.ssh; sudo chmod -vR go-rwx ~buildbot/.ssh' ssh -t -p 2292 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no localhost 'chmod -vR go-rwx .ssh; sudo adduser buildbot; sudo usermod -a -G wheel buildbot; sudo mkdir ~buildbot/.ssh; sudo cp -vi .ssh/authorized_keys ~buildbot/.ssh/; sudo chown -vR buildbot:buildbot ~buildbot/.ssh; sudo chmod -vR go-rwx ~buildbot/.ssh' ``` su to the local buildbot user and ssh to the vm to put the key in known\_hosts: For i386: ``` sudo su - buildbot ssh -p 2291 buildbot@localhost # exit, then exit again ``` For amd64: ``` sudo su - buildbot ssh -p 2292 buildbot@localhost # exit, then exit again ``` Upload the ttyS0 file and put it where it goes: ``` scp -P 2291 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no /kvm/vms/ttyS0 buildbot@localhost: scp -P 2292 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no /kvm/vms/ttyS0 buildbot@localhost: ssh -t -p 2291 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no buildbot@localhost 'sudo mkdir -v /etc/event.d;sudo mv -vi ttyS0 /etc/event.d/;' ssh -t -p 2292 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no buildbot@localhost 'sudo mkdir -v /etc/event.d;sudo mv -vi ttyS0 /etc/event.d/;' ``` Update the VM: ``` ssh -t -p 2291 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no buildbot@localhost ssh -t -p 2292 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no buildbot@localhost ``` Once logged in: ``` sudo yum -y update ``` Change selinux policy to `permissive`: ``` sudo sed -i 's/SELINUX=enforcing/SELINUX=permissive/' /etc/selinux/config ``` After updating, exit, then shut down the VM: ``` exit ``` ``` ssh -t -p 2291 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no buildbot@localhost 'sudo shutdown -h now;exit' ssh -t -p 2292 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no buildbot@localhost 'sudo shutdown -h now;exit' ``` VMs for building .rpms ---------------------- ``` for i in '/kvm/vms/vm-fedora20-i386-serial.qcow2 2291 qemu64' '/kvm/vms/vm-fedora20-amd64-serial.qcow2 2292 qemu64' ; do \ set $i; \ runvm --user=buildbot --logfile=kernel_build_$2.log --base-image=$1 --port=$2 --cpu=$3 "$(echo $1 | sed -e 's/serial/build/')" \ "= scp -P $2 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no /kvm/thrift-0.9.0.tar.gz buildbot@localhost:/dev/shm/" \ "sudo yum -y groupinstall 'Development Tools'" \ "sudo yum -y install yum-utils" \ "sudo yum-builddep -y mariadb" \ "sudo yum -y install automake libtool flex pkgconfig gcc-c++ libevent-devel python-devel ruby-devel rpm-build Judy-devel" \ "sudo yum -y install cmake tar wget tree gperf readline-devel ncurses-devel zlib-devel pam-devel libaio-devel openssl-devel" \ "sudo yum -y install libxml2 libxml2-devel bison bison-devel boost-devel unixODBC-devel bzr perl perl\(DBI\)" \ "sudo yum -y remove systemtap-sdt-dev" \ "bzr co --lightweight lp:mariadb-native-client" \ "sudo mkdir -vp /usr/src/redhat/SOURCES /usr/src/redhat/SPECS /usr/src/redhat/RPMS /usr/src/redhat/SRPMS" \ "cd /usr/local/src;sudo tar zxf /dev/shm/thrift-0.9.0.tar.gz;pwd;ls" \ "cd /usr/local/src/thrift-0.9.0;echo;pwd;sudo ./configure --prefix=/usr --enable-shared=no --enable-static=yes CXXFLAGS=-fPIC CFLAGS=-fPIC && echo && echo 'now making' && echo && sleep 3 && sudo make && echo && echo 'now installing' && echo && sleep 3 && sudo make install" ; \ done ``` VMs for install testing. ------------------------ ``` for i in '/kvm/vms/vm-fedora20-i386-serial.qcow2 2291 qemu64' '/kvm/vms/vm-fedora20-amd64-serial.qcow2 2292 qemu64' ; do \ set $i; \ runvm --user=buildbot --logfile=kernel_install_$2.log --base-image=$1 --port=$2 --cpu=$3 "$(echo $1 | sed -e 's/serial/install/')" \ "sudo yum -y update" \ "sudo yum -y install patch tar libaio perl perl-Time-HiRes perl-DBI unixODBC Judy" ; \ done ``` VMs for MariaDB upgrade testing (Fedora repo) --------------------------------------------- ``` for i in '/kvm/vms/vm-fedora20-i386-serial.qcow2 2291 qemu64' '/kvm/vms/vm-fedora20-amd64-serial.qcow2 2292 qemu64' ; do \ set $i; \ runvm --user=buildbot --logfile=kernel_upgrade_$2.log --base-image=$1 --port=$2 --cpu=$3 "$(echo $1 | sed -e 's/serial/upgrade/')" \ "sudo yum -y update" \ "sudo yum -y install patch tar mariadb-server libtool-ltdl unixODBC Judy" \ "sudo systemctl enable mariadb.service" \ "sudo systemctl start mariadb.service" \ 'mysql -uroot -e "create database mytest; use mytest; create table t(a int primary key); insert into t values (1); select * from t"' ; \ done ``` VMs for MariaDB upgrade testing (MariaDB repo) ---------------------------------------------- ``` for i in '/kvm/vms/vm-fedora20-amd64-serial.qcow2 2292 qemu64' '/kvm/vms/vm-fedora20-i386-serial.qcow2 2291 qemu64' ; do \ set $i; \ runvm --user=buildbot --logfile=kernel_upgrade2_$2.log --base-image=$1 --port=$2 --cpu=$3 "$(echo $1 | sed -e 's/serial/upgrade2/')" \ 'sudo yum -y update' \ "= scp -P $2 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no /kvm/vms/MariaDB-${2}.repo buildbot@localhost:/tmp/MariaDB.repo" \ 'sudo rpm --verbose --import https://yum.mariadb.org/RPM-GPG-KEY-MariaDB' \ 'sudo mv -vi /tmp/MariaDB.repo /etc/yum.repos.d/' \ 'sudo yum -y remove mysql-libs' \ 'sudo yum -y install MariaDB-server MariaDB-client MariaDB-test libtool-ltdl unixODBC Judy' \ 'sudo yum -y install cronie cronie-anacron crontabs.noarch patch tar' \ 'sudo /etc/init.d/mysql start' \ 'mysql -uroot -e "create database mytest; use mytest; create table t(a int primary key); insert into t values (1); select * from t"' \ 'sudo rm -v /etc/yum.repos.d/MariaDB.repo' \ 'sudo yum -y update' \ "= scp -P $2 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no /kvm/vms/MariaDB.local.repo buildbot@localhost:/tmp/" \ 'sudo mv -vi /tmp/MariaDB.local.repo /etc/yum.repos.d/'; \ done ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb HOUR HOUR ==== Syntax ------ ``` HOUR(time) ``` Description ----------- Returns the hour for time. The range of the return value is 0 to 23 for time-of-day values. However, the range of `TIME` values actually is much larger, so HOUR can return values greater than 23. The return value is always positive, even if a negative `TIME` value is provided. Examples -------- ``` SELECT HOUR('10:05:03'); +------------------+ | HOUR('10:05:03') | +------------------+ | 10 | +------------------+ SELECT HOUR('272:59:59'); +-------------------+ | HOUR('272:59:59') | +-------------------+ | 272 | +-------------------+ ``` Difference between `[EXTRACT (HOUR FROM ...)](../extract/index)` (>= [MariaDB 10.0.7](https://mariadb.com/kb/en/mariadb-1007-release-notes/) and [MariaDB 5.5.35](https://mariadb.com/kb/en/mariadb-5535-release-notes/)) and `HOUR`: ``` SELECT EXTRACT(HOUR FROM '26:30:00'), HOUR('26:30:00'); +-------------------------------+------------------+ | EXTRACT(HOUR FROM '26:30:00') | HOUR('26:30:00') | +-------------------------------+------------------+ | 2 | 26 | +-------------------------------+------------------+ ``` See Also -------- * [Date and Time Units](../date-and-time-units/index) * [Date and Time Literals](../date-and-time-literals/index) * [EXTRACT()](../extract/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Benchmarks Benchmarks =========== Articles about the performance of MariaDB. | Title | Description | | --- | --- | | [mariadb-tools](../mariadb-tools/index) | Helper and wrapper scripts. | | [Recommended Settings for Benchmarks](../recommended-settings-for-benchmarks/index) | Best known settings and recommendations for benchmarks. | | [Benchmarking Aria](../benchmarking-aria/index) | Aria benchmarks | | [DBT-3 Dataset](../dbt-3-dataset/index) | This page describes our setup for DBT-3 tests. A very cogent resource on th... | | [DBT3 Automation Scripts](../dbt3-automation-scripts/index) | DBT-3 (OSDL Database Test 3) is a workload tool for the Linux kernel that ... | | [Segmented Key Cache Performance](../segmented-key-cache-performance/index) | Testing method for segmented key cache performance We used SysBench v0.5 f... | | [run-sql-bench.pl](../run-sql-benchpl/index) | run-sql-bench.pl is a perl script for automating runs of sql-bench (You can... | | [sysbench Benchmark Setup](../sysbench-benchmark-setup/index) | Basic parameters and configuration for sysbench | | [MariaDB 5.3 - Asynchronous I/O on Windows with InnoDB](../mariadb-53-asynchronous-io-on-windows-with-innodb/index) | MariaDB 5.3 - Asynchronous I/O on Windows with InnoDB | | [MariaDB 5.3/MySQL 5.5 Windows performance patches](../mariadb-53mysql-55-windows-performance-patches/index) | I just backported Windows performance patches I've done for 5.5 back to Mar... | | [Benchmark Builds](../benchmark-builds/index) | how to build with cmake and consistent settings (CFLAGS etc) | | [DBT3 Benchmark Results InnoDB](../dbt3-benchmark-results-innodb/index) | Results for DBT3 benchmarking with MariaDB 5.3 InnoDB | | [DBT3 Benchmark Results MyISAM](../dbt3-benchmark-results-myisam/index) | Results for DBT3 benchmarking with MariaDB 5.3/5/5 MyISAM | | [DBT3 Example Preparation Time](../dbt3-example-preparation-time/index) | Database preparation and creation times discovered while working on the DBT3 Automation Scripts | | [Performance of MEMORY Tables](../performance-of-memory-tables/index) | Up to 60% better performance with MariaDB 5.5.22 for inserting rows into MEMORY tables | | [RQG Performance Comparisons](../rqg-performance-comparisons/index) | Performance testing The performance/perfrun.pl executes each query against ... | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Downgrading between Major Versions of MariaDB Downgrading between Major Versions of MariaDB ============================================= Downgrading MariaDB is not supported. The only reliable way to downgrade is to [restore from a full backup](../backing-up-and-restoring-databases/index) made before upgrading, and start the old version of MariaDB. Some people have reported successfully downgrading, but there are many possible things that can go wrong, and downgrading is not tested in any way by the MariaDB developers. Between major releases, there are often substantial changes, even if none of the new features are used. For example, both [MariaDB 10.2](../what-is-mariadb-102/index) and [MariaDB 10.3](../what-is-mariadb-103/index) introduce new versions of the redo log. Even within minor releases, there may be problems, for example [MariaDB 10.1.21](https://mariadb.com/kb/en/mariadb-10121-release-notes/) fixed a file format incompatibility bug that prevents a downgrade to earlier [MariaDB 10.1](../what-is-mariadb-101/index) releases. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb JSON_LENGTH JSON\_LENGTH ============ **MariaDB starting with [10.2.3](https://mariadb.com/kb/en/mariadb-1023-release-notes/)**JSON functions were added in [MariaDB 10.2.3](https://mariadb.com/kb/en/mariadb-1023-release-notes/). Syntax ------ ``` JSON_LENGTH(json_doc[, path]) ``` Description ----------- Returns the length of a JSON document, or, if the optional path argument is given, the length of the value within the document specified by the path. Returns NULL if any of the arguments argument are null or the path argument does not identify a value in the document. An error will occur if the JSON document is invalid, the path is invalid or if the path contains a `*` or `**` wildcard. Length will be determined as follow: * A scalar's length is always 1. * If an array, the number of elements in the array. * If an object, the number of members in the object. The length of nested arrays or objects are not counted. Examples -------- Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb Invisible Columns Invisible Columns ================= **MariaDB starting with [10.3.3](https://mariadb.com/kb/en/mariadb-1033-release-notes/)**Invisible columns (sometimes also called hidden columns) first appeared in [MariaDB 10.3.3](https://mariadb.com/kb/en/mariadb-1033-release-notes/). Columns can be given an `INVISIBLE` attribute in a [CREATE TABLE](../create-table/index) or [ALTER TABLE](../alter-table/index) statement. These columns will then not be listed in the results of a [SELECT \*](../select/index) statement, nor do they need to be assigned a value in an [INSERT](../insert/index) statement, unless INSERT explicitly mentions them by name. Since `SELECT *` does not return the invisible columns, new tables or views created in this manner will have no trace of the invisible columns. If specifically referenced in the SELECT statement, the columns will be brought into the view/new table, but the INVISIBLE attribute will not. Invisible columns can be declared as `NOT NULL`, but then require a `DEFAULT` value. It is not possible for all columns in a table to be invisible. Examples -------- ``` CREATE TABLE t (x INT INVISIBLE); ERROR 1113 (42000): A table must have at least 1 column CREATE TABLE t (x INT, y INT INVISIBLE, z INT INVISIBLE NOT NULL); ERROR 4106 (HY000): Invisible column `z` must have a default value CREATE TABLE t (x INT, y INT INVISIBLE, z INT INVISIBLE NOT NULL DEFAULT 4); INSERT INTO t VALUES (1),(2); INSERT INTO t (x,y) VALUES (3,33); SELECT * FROM t; +------+ | x | +------+ | 1 | | 2 | | 3 | +------+ SELECT x,y,z FROM t; +------+------+---+ | x | y | z | +------+------+---+ | 1 | NULL | 4 | | 2 | NULL | 4 | | 3 | 33 | 4 | +------+------+---+ DESC t; +-------+---------+------+-----+---------+-----------+ | Field | Type | Null | Key | Default | Extra | +-------+---------+------+-----+---------+-----------+ | x | int(11) | YES | | NULL | | | y | int(11) | YES | | NULL | INVISIBLE | | z | int(11) | NO | | 4 | INVISIBLE | +-------+---------+------+-----+---------+-----------+ ALTER TABLE t MODIFY x INT INVISIBLE, MODIFY y INT, MODIFY z INT NOT NULL DEFAULT 4; DESC t; +-------+---------+------+-----+---------+-----------+ | Field | Type | Null | Key | Default | Extra | +-------+---------+------+-----+---------+-----------+ | x | int(11) | YES | | NULL | INVISIBLE | | y | int(11) | YES | | NULL | | | z | int(11) | NO | | 4 | | +-------+---------+------+-----+---------+-----------+ ``` Creating a view from a table with hidden columns: ``` CREATE VIEW v1 AS SELECT * FROM t; DESC v1; +-------+---------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-------+---------+------+-----+---------+-------+ | y | int(11) | YES | | NULL | | | z | int(11) | NO | | 4 | | +-------+---------+------+-----+---------+-------+ CREATE VIEW v2 AS SELECT x,y,z FROM t; DESC v2; +-------+---------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-------+---------+------+-----+---------+-------+ | x | int(11) | YES | | NULL | | | y | int(11) | YES | | NULL | | | z | int(11) | NO | | 4 | | +-------+---------+------+-----+---------+-------+ ``` Adding a Surrogate Primary Key: ``` create table t1 (x bigint unsigned not null, y varchar(16), z text); insert into t1 values (123, 'qq11', 'ipsum'); insert into t1 values (123, 'qq22', 'lorem'); alter table t1 add pkid serial primary key invisible first; insert into t1 values (123, 'qq33', 'amet'); select * from t1; +-----+------+-------+ | x | y | z | +-----+------+-------+ | 123 | qq11 | ipsum | | 123 | qq22 | lorem | | 123 | qq33 | amet | +-----+------+-------+ select pkid, z from t1; +------+-------+ | pkid | z | +------+-------+ | 1 | ipsum | | 2 | lorem | | 3 | amet | +------+-------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Database Design Phase 4: Testing Database Design Phase 4: Testing ================================ This article follows on from [Database Design Phase 3: Implementation](../database-design-phase-3-implementation/index). The testing phase is where the performance, security, and integrity of the data are tested. Usually this will occur in conjunctions with the applications that have been developed. You test the performance under various loads conditions to see how the database handles multiple concurrent connections or high volumes of updating and reading. Are the reports generated quickly enough? For example, an application designed with the old [MyISAM](../myisam/index) storage engine may prove to be too slow because the impact of the updates was underestimated. The storage engine may have to be changed to [XtraDB](../innodb/index) in response. Data integrity also needs to be tested, as the application may have logical flaws that result in transactions being lost or other inaccuracies. Further, security needs to be tested to ensure that users can access and change only the data they should. The logical or physical designs may have to be modified. Perhaps new indexes are required (which the tester may discover after careful use of MariaDB's [EXPLAIN](../explain/index) statement, for example). The testing and fine-tuning process is an iterative one, with multiple tests performed and changes implemented. The following are the steps in the testing phase: 1. Test the performance 2. Test the security 3. Test the data integrity 4. Fine-tune the parameters or modify the logical or physical designs in response to the tests. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Performance Schema events_waits_summary_by_account_by_event_name Table Performance Schema events\_waits\_summary\_by\_account\_by\_event\_name Table ============================================================================= The [Performance Schema](../performance-schema/index) `events_waits_summary_by_account_by_event_name` table contains wait events summarized by account and event name. It contains the following columns: | Column | Description | | --- | --- | | `USER` | User. Used together with `HOST` and `EVENT_NAME` for grouping events. | | `HOST` | Host. Used together with `USER` and `EVENT_NAME` for grouping events. | | `EVENT_NAME` | Event name. Used together with `USER` and `HOST` for grouping events. | | `COUNT_STAR` | Number of summarized events | | `SUM_TIMER_WAIT` | Total wait time of the summarized events that are timed. | | `MIN_TIMER_WAIT` | Minimum wait time of the summarized events that are timed. | | `AVG_TIMER_WAIT` | Average wait time of the summarized events that are timed. | | `MAX_TIMER_WAIT` | Maximum wait time of the summarized events that are timed. | The `*_TIMER_WAIT` columns only calculate results for timed events, as non-timed events have a `NULL` wait time. Example ------- ``` SELECT * FROM events_waits_summary_by_account_by_event_name\G ... *************************** 915. row *************************** USER: NULL HOST: NULL EVENT_NAME: wait/io/socket/sql/server_tcpip_socket COUNT_STAR: 0 SUM_TIMER_WAIT: 0 MIN_TIMER_WAIT: 0 AVG_TIMER_WAIT: 0 MAX_TIMER_WAIT: 0 *************************** 916. row *************************** USER: NULL HOST: NULL EVENT_NAME: wait/io/socket/sql/server_unix_socket COUNT_STAR: 0 SUM_TIMER_WAIT: 0 MIN_TIMER_WAIT: 0 AVG_TIMER_WAIT: 0 MAX_TIMER_WAIT: 0 *************************** 917. row *************************** USER: NULL HOST: NULL EVENT_NAME: wait/io/socket/sql/client_connection COUNT_STAR: 0 SUM_TIMER_WAIT: 0 MIN_TIMER_WAIT: 0 AVG_TIMER_WAIT: 0 MAX_TIMER_WAIT: 0 *************************** 918. row *************************** USER: NULL HOST: NULL EVENT_NAME: idle COUNT_STAR: 0 SUM_TIMER_WAIT: 0 MIN_TIMER_WAIT: 0 AVG_TIMER_WAIT: 0 MAX_TIMER_WAIT: 0 ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb BOOLEAN BOOLEAN ======= Syntax ------ ``` BOOL, BOOLEAN ``` Description ----------- These types are synonyms for [TINYINT(1)](../sql_language-data_types-tinyint/index). A value of zero is considered false. Non-zero values are considered true. However, the values TRUE and FALSE are merely aliases for 1 and 0. See [Boolean Literals](../sql-language-structure-boolean-literals/index), as well as the [IS operator](../is/index) for testing values against a boolean. Examples -------- ``` CREATE TABLE boo (i BOOLEAN); DESC boo; +-------+------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-------+------------+------+-----+---------+-------+ | i | tinyint(1) | YES | | NULL | | +-------+------------+------+-----+---------+-------+ ``` ``` SELECT IF(0, 'true', 'false'); +------------------------+ | IF(0, 'true', 'false') | +------------------------+ | false | +------------------------+ SELECT IF(1, 'true', 'false'); +------------------------+ | IF(1, 'true', 'false') | +------------------------+ | true | +------------------------+ SELECT IF(2, 'true', 'false'); +------------------------+ | IF(2, 'true', 'false') | +------------------------+ | true | +------------------------+ ``` TRUE and FALSE as aliases for 1 and 0: ``` SELECT IF(0 = FALSE, 'true', 'false'); +--------------------------------+ | IF(0 = FALSE, 'true', 'false') | +--------------------------------+ | true | +--------------------------------+ SELECT IF(1 = TRUE, 'true', 'false'); +-------------------------------+ | IF(1 = TRUE, 'true', 'false') | +-------------------------------+ | true | +-------------------------------+ SELECT IF(2 = TRUE, 'true', 'false'); +-------------------------------+ | IF(2 = TRUE, 'true', 'false') | +-------------------------------+ | false | +-------------------------------+ SELECT IF(2 = FALSE, 'true', 'false'); +--------------------------------+ | IF(2 = FALSE, 'true', 'false') | +--------------------------------+ | false | +--------------------------------+ ``` The last two statements display the results shown because 2 is equal to neither 1 nor 0. See Also -------- * [Boolean Literals](../sql-language-structure-boolean-literals/index) * [IS operator](../is/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb MariaDB Online Backup MariaDB Online Backup ===================== **Note:** This page is obsolete. The information is old, outdated, or otherwise currently incorrect. We are keeping the page for historical reasons only. **Do not** rely on the information in this article. Rumours have it that MySQL/Sun/Oracle are going to drop the MySQL online backup project, which was originally scheduled for MySQL 6.0. Given this, it makes sense to consider resurrecting the project for MariaDB. This page collects various resources related to this. Documentation ------------- * [MySQL Forge project page](http://forge.mysql.com/wiki/OnlineBackup) for Online Backup * [Online Backup reference manual](http://dev.mysql.com/doc/mysql-backup/en/index.html) * [tarball](http://hasky.askmonty.org/download/onlinebackup/backup-manual.tar.gz) containing self-contained copy of the Online Backup reference manual (the license allows to copy/distribute the manual together with the source tarball, but not to modify it). Source code ----------- * [mysql-6.0-backup branch](https://code.launchpad.net/~mysql/mysql-server/mysql-6.0-backup) on Launchpad * [mysql-6.0 branch](https://code.launchpad.net/~mysql/mysql-server/mysql-6.0) on Launchpad * [Source tarball](http://hasky.askmonty.org/download/onlinebackup/mysql-6.0.14-alpha.tar.gz) of mysql-6.0-backup Notes ----- ### Extracting a patch for merging It may not be trivial to extract a patch of MySQL Online Backup that can be used as a basis for merging into MariaDB. The problem is that we do not have a feature tree that contains only the backup feature over some base/parent tree. There was work done at MySQL to merge online backup into MySQL 5.5 using such a feature tree, but this tree is not public, and requests to make it public have not been answered positively so far. It may still be possible to extract the code, but it may be necessary to do it manually, by extracting relevant parts of the code from 6.0 without including other stuff that is not related to backup. It might also be useful to search the [bugs.mysql.com](http://bugs.mysql.com/) MySQL bug tracker for recently fixed online backup bugs, since recent fixes are not included in the publicly available trees on Launchpad. ### Comments on the code From looking at the documentation of Online Backup, it seems geared more towards an optimised mysqldump facility than towards an easy-to-use facility to back up a complete MySQL server: * The `BACKUP` command only allows to backup selected (or all) databases/schemas. * There seems to be no facility to backup the binary log * There seems to be no facility to backup `GRANT`s or other server-global configuration, using [mysqldump](../mysqldump/index) on the "mysql" schema/database is suggested * Restoring a new server from scratch seems to involve setting up a new server, including running [mysql\_install\_db](../mysql_install_db/index) and adding `GRANT`s, and only then restoring tables and other schema objects Compared to something like XtraBackup, full backup and restore seems to be somewhat more involved. It may be necessary to add extra facilities or wrapper scripts to enable to backup/restore a full database server. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Mariabackup Overview Mariabackup Overview ==================== **MariaDB starting with [10.1.23](https://mariadb.com/kb/en/mariadb-10123-release-notes/)**Mariabackup was first released in [MariaDB 10.1.23](https://mariadb.com/kb/en/mariadb-10123-release-notes/) and [MariaDB 10.2.7](https://mariadb.com/kb/en/mariadb-1027-release-notes/). It was first released as GA in [MariaDB 10.1.26](https://mariadb.com/kb/en/mariadb-10126-release-notes/) and [MariaDB 10.2.10](https://mariadb.com/kb/en/mariadb-10210-release-notes/). **Mariabackup** is an open source tool provided by MariaDB for performing physical online backups of [InnoDB](../innodb/index), [Aria](../aria/index) and [MyISAM](../myisam/index) tables. For InnoDB, “hot online” backups are possible. It was originally forked from [Percona XtraBackup](../backup-restore-and-import-clients-percona-xtrabackup/index) 2.3.8. It is available on Linux and Windows. Backup Support for MariaDB-Exclusive Features --------------------------------------------- [MariaDB 10.1](../what-is-mariadb-101/index) introduced features that are exclusive to MariaDB, such as [InnoDB Page Compression](innodb_compression) and [Data-at-Rest Encryption](../data-at-rest-encryption/index). These exclusive features have been very popular with MariaDB users. However, existing backup solutions from the MySQL ecosystem, such as [Percona XtraBackup](../backup-restore-and-import-clients-percona-xtrabackup/index), did not support full backup capability for these features. To address the needs of our users, we decided to develop a backup solution that would fully support these popular MariaDB-exclusive features. We did this by creating Mariabackup, which is based on the well-known and commonly used backup tool called [Percona XtraBackup](../backup-restore-and-import-clients-percona-xtrabackup/index). Mariabackup was originally extended from version 2.3.8. ### Supported Features Mariabackup supports all of the main features of [Percona XtraBackup](../backup-restore-and-import-clients-percona-xtrabackup/index) 2.3.8, plus: * Backup/Restore of tables using [Data-at-Rest Encryption](../data-at-rest-encryption/index). * Backup/Restore of tables using [InnoDB Page Compression](innodb_compression). * [mariabackup SST method](../mariabackup-sst-method/index) with Galera Cluster. * Microsoft Windows support. * Backup/Restore of tables using the [MyRocks](../myrocks/index) storage engine starting with [MariaDB 10.2.16](https://mariadb.com/kb/en/mariadb-10216-release-notes/) and [MariaDB 10.3.8](https://mariadb.com/kb/en/mariadb-1038-release-notes/). See [Files Backed up by Mariabackup: MyRocks Data Files](../files-backed-up-by-mariabackup/index#myrocks-data-files) for more information. #### Supported Features in MariaDB Enterprise Backup [MariaDB Enterprise Backup](https://mariadb.com/docs/usage/mariadb-enterprise-backup/) supports some additional features, such as: * Minimizes locks during the backup to permit more concurrency and to enable faster backups. + This relies on the usage of `[BACKUP STAGE](../backup-stage/index)` commands and DDL logging. + This includes no locking during the copy phase of `[ALTER TABLE](../alter-table/index)` statements, which tends to be the longest phase of these statements. * Provides optimal backup support for all storage engines that store things on local disk. ### Differences Compared to Percona XtraBackup * Percona XtraBackup copies its [InnoDB redo log](../xtradbinnodb-redo-log/index) files to the file `xtrabackup_logfile`, while Mariabackup uses the file `[ib\_logfile0](../files-created-by-mariabackup/index#ib_logfile0)`. * Percona XtraBackup's [libgcrypt-based encryption of backups](https://www.percona.com/doc/percona-xtrabackup/2.3/backup_scenarios/encrypted_backup.html) is not supported by Mariabackup. * There is no symbolic link from `mariabackup` to `[innobackupex](https://www.percona.com/doc/percona-xtrabackup/2.3/innobackupex/innobackupex_option_reference.html)`, as there is for `[xtrabackup](https://www.percona.com/doc/percona-xtrabackup/2.3/xtrabackup_bin/xbk_option_reference.html)`. Instead, `mariabackup` has the `[--innobackupex](../mariabackup-options/index#-innobackupex)` command-line option to enable innobackupex-compatible options. * The `[--compact](https://www.percona.com/doc/percona-xtrabackup/2.3/xtrabackup_bin/xbk_option_reference.html#cmdoption-xtrabackup-compact)` and `[--rebuild\_indexes](https://www.percona.com/doc/percona-xtrabackup/2.3/xtrabackup_bin/xbk_option_reference.html#cmdoption-xtrabackup-rebuild-indexes)` options are not supported. * Support for `[--stream=tar](https://www.percona.com/doc/percona-xtrabackup/2.3/howtos/recipes_ibkx_stream.html)` was removed from Mariabackup in [MariaDB 10.1.24](https://mariadb.com/kb/en/mariadb-10124-release-notes/). * The `[xbstream](https://www.percona.com/doc/percona-xtrabackup/2.3/xbstream/xbstream.html)` utility has been renamed to `mbstream`. However, to select this output format when creating a backup, Mariabackup's `[--stream](../mariabackup-options/index#-stream)` option still expects the `xbstream` value. * Mariabackup does not support [lockless binlog](https://www.percona.com/doc/percona-xtrabackup/2.3/advanced/lockless_bin-log.html). #### Difference in Versioning Schemes Each Percona XtraBackup release has two version numbers--the Percona XtraBackup version number and the version number of the MySQL Server release that it is based on. For example: ``` xtrabackup version 2.2.8 based on MySQL server 5.6.22 ``` Each Mariabackup release only has one version number, and it is the same as the version number of the MariaDB Server release that it is based on. For example: ``` mariabackup based on MariaDB server 10.2.15-MariaDB Linux (x86_64) ``` See [Compatibility of Mariabackup Releases with MariaDB Server Releases](#compatibility-of-mariabackup-releases-with-mariadb-server-releases) for more information on Mariabackup versions. Compatibility of Mariabackup Releases with MariaDB Server Releases ------------------------------------------------------------------ It is not generally possible, or supported, to prepare a backup in a different MariaDB version than the database version at the time when backup was taken. For example, if you backup [MariaDB 10.4](../what-is-mariadb-104/index), you should use mariabackup version 10.4, rather than e.g 10.5. A MariaDB Server version can often be backed up with most other Mariabackup releases in the same release series. For example, [MariaDB 10.2.21](https://mariadb.com/kb/en/mariadb-10221-release-notes/) and [MariaDB 10.2.22](https://mariadb.com/kb/en/mariadb-10222-release-notes/) are both in the [MariaDB 10.2](../what-is-mariadb-102/index) release series, so MariaDB Server from [MariaDB 10.2.21](https://mariadb.com/kb/en/mariadb-10221-release-notes/) could be backed up by Mariabackup from [MariaDB 10.2.22](https://mariadb.com/kb/en/mariadb-10222-release-notes/), or vice versa. However, occasionally, a MariaDB Server or Mariabackup release will include bug fixes that will break compatibility with previous releases. For example, the fix for [MDEV-13564](https://jira.mariadb.org/browse/MDEV-13564) changed the [InnoDB redo log](../innodb-redo-log/index) format in [MariaDB 10.2.19](https://mariadb.com/kb/en/mariadb-10219-release-notes/) which broke compatibility with previous releases. To be safest, a MariaDB Server release should generally be backed up with the Mariabackup release that has the same version number. Mariabackup from [MariaDB 10.1](../what-is-mariadb-101/index) releases may also be able to back up MariaDB Server from [MariaDB 5.5](../what-is-mariadb-55/index) and [MariaDB 10.0](../what-is-mariadb-100/index) releases in many cases. However, this is not fully supported. See [MDEV-14936](https://jira.mariadb.org/browse/MDEV-14936) for more information. Installing Mariabackup ---------------------- ### Installing on Linux The `mariabackup` executable is included in [binary tarballs](../installing-mariadb-binary-tarballs/index) on Linux. #### Installing with a Package Manager Mariabackup can also be installed via a package manager on Linux. In order to do so, your system needs to be configured to install from one of the MariaDB repositories. You can configure your package manager to install it from MariaDB Corporation's MariaDB Package Repository by using the [MariaDB Package Repository setup script](../mariadb-package-repository-setup-and-usage/index). You can also configure your package manager to install it from MariaDB Foundation's MariaDB Repository by using the [MariaDB Repository Configuration Tool](https://downloads.mariadb.org/mariadb/repositories/). ##### Installing with yum/dnf On RHEL, CentOS, Fedora, and other similar Linux distributions, it is highly recommended to install the relevant [RPM package](../rpm/index) from MariaDB's repository using `[yum](../yum/index)` or `[dnf](https://en.wikipedia.org/wiki/DNF_(software))`. Starting with RHEL 8 and Fedora 22, `yum` has been replaced by `dnf`, which is the next major version of `yum`. However, `yum` commands still work on many systems that use `dnf`. For example: ``` sudo yum install MariaDB-backup ``` ##### Installing with apt-get On Debian, Ubuntu, and other similar Linux distributions, it is highly recommended to install the relevant [DEB package](../installing-mariadb-deb-files/index) from MariaDB's repository using `[apt-get](https://wiki.debian.org/apt-get)`. For example: ``` sudo apt-get install mariadb-backup ``` ##### Installing with zypper On SLES, OpenSUSE, and other similar Linux distributions, it is highly recommended to install the relevant [RPM package](../rpm/index) from MariaDB's repository using `[zypper](../installing-mariadb-with-zypper/index)`. For example: ``` sudo zypper install MariaDB-backup ``` ### Installing on Windows The `mariabackup` executable is included in [MSI](../installing-mariadb-msi-packages-on-windows/index) and [ZIP](../installing-mariadb-windows-zip-packages/index) packages on Windows. When using the [Windows MSI installer](../installing-mariadb-msi-packages-on-windows/index), `mariabackup` can be installed by selecting *Backup utilities*: Using Mariabackup ----------------- The command to use `mariabackup` and the general syntax is: ``` mariabackup <options> ``` For in-depth explanations on how to use Mariabackup, see: * [Full Backup and Restore with Mariabackup](../full-backup-and-restore-with-mariabackup/index) * [Incremental Backup and Restore with Mariabackup](../incremental-backup-and-restore-with-mariabackup/index) * [Partial Backup and Restore with Mariabackup](../partial-backup-and-restore-with-mariabackup/index) * [Restoring Individual Tables and Partitions with Mariabackup](../restoring-individual-tables-and-partitions-with-mariabackup/index) * [Setting up a Replication Slave with Mariabackup](../setting-up-a-replication-slave-with-mariabackup/index) * [Using Encryption and Compression Tools With Mariabackup](../using-encryption-and-compression-tools-with-mariabackup/index) ### Options Options supported by Mariabackup can be found [here](../mariabackup-options/index). `mariabackup` will currently silently ignore unknown command-line options, so be extra careful about accidentally including typos in options or accidentally using options from later `mariabackup` versions. The reason for this is that `mariabackup` currently treats command-line options and options from [option files](../configuring-mariadb-with-option-files/index) equivalently. When it reads from these [option files](../configuring-mariadb-with-option-files/index), it has to read a lot of options from the [server option groups](#server-option-groups) read by `[mysqld](../mysqld-options/index)`. However, `mariabackup` does not know about many of the options that it normally reads in these option groups. If `mariabackup` raised an error or warning when it encountered an unknown option, then this process would generate a large amount of log messages under normal use. Therefore, `mariabackup` is designed to silently ignore the unknown options instead. See [MDEV-18215](https://jira.mariadb.org/browse/MDEV-18215) about that. ### Option Files In addition to reading options from the command-line, Mariabackup can also read options from [option files](../configuring-mariadb-with-option-files/index). The following options relate to how MariaDB command-line tools handles option files. They must be given as the first argument on the command-line: | Option | Description | | --- | --- | | `--print-defaults` | Print the program argument list and exit. | | `--no-defaults` | Don't read default options from any option file. | | `--defaults-file=#` | Only read default options from the given option file. | | `--defaults-extra-file=#` | Read this file after the global files are read. | | `--defaults-group-suffix=#` | In addition to the default option groups, also read option groups with this suffix. | #### Server Option Groups Mariabackup reads server options from the following [option groups](../configuring-mariadb-with-option-files/index#option-groups) from [option files](../configuring-mariadb-with-option-files/index): | Group | Description | | --- | --- | | `[mariabackup]` | Options read by Mariabackup. Available starting with [MariaDB 10.1.31](https://mariadb.com/kb/en/mariadb-10131-release-notes/) and [MariaDB 10.2.13](https://mariadb.com/kb/en/mariadb-10213-release-notes/). | | `[mariadb-backup]` | Options read by Mariabackup. Available starting with [MariaDB 10.4.14](https://mariadb.com/kb/en/mariadb-10414-release-notes/) and [MariaDB 10.5.4](https://mariadb.com/kb/en/mariadb-1054-release-notes/). | | `[xtrabackup]` | Options read by Mariabackup and [Percona XtraBackup](../percona-xtrabackup-overview/index). | | `[server]` | Options read by MariaDB Server. Available starting with [MariaDB 10.1.38](https://mariadb.com/kb/en/mariadb-10138-release-notes/), [MariaDB 10.2.22](https://mariadb.com/kb/en/mariadb-10222-release-notes/), and [MariaDB 10.3.13](https://mariadb.com/kb/en/mariadb-10313-release-notes/). | | `[mysqld]` | Options read by `mysqld`, which includes both MariaDB Server and MySQL Server. | | `[mysqld-X.Y]` | Options read by a specific version of `mysqld`, which includes both MariaDB Server and MySQL Server. For example, `[mysqld-10.4]`. Available starting with [MariaDB 10.1.38](https://mariadb.com/kb/en/mariadb-10138-release-notes/), [MariaDB 10.2.22](https://mariadb.com/kb/en/mariadb-10222-release-notes/), and [MariaDB 10.3.13](https://mariadb.com/kb/en/mariadb-10313-release-notes/). | | `[mariadb]` | Options read by MariaDB Server. Available starting with [MariaDB 10.1.38](https://mariadb.com/kb/en/mariadb-10138-release-notes/), [MariaDB 10.2.22](https://mariadb.com/kb/en/mariadb-10222-release-notes/), and [MariaDB 10.3.13](https://mariadb.com/kb/en/mariadb-10313-release-notes/). | | `[mariadb-X.Y]` | Options read by a specific version of MariaDB Server. For example, `[mariadb-10.4]`. Available starting with [MariaDB 10.1.38](https://mariadb.com/kb/en/mariadb-10138-release-notes/), [MariaDB 10.2.22](https://mariadb.com/kb/en/mariadb-10222-release-notes/), and [MariaDB 10.3.13](https://mariadb.com/kb/en/mariadb-10313-release-notes/). | | `[mariadbd]` | Options read by MariaDB Server. Available starting with [MariaDB 10.4.14](https://mariadb.com/kb/en/mariadb-10414-release-notes/) and [MariaDB 10.5.4](https://mariadb.com/kb/en/mariadb-1054-release-notes/). | | `[mariadbd-X.Y]` | Options read by a specific version of MariaDB Server. For example, `[mariadbd-10.4]`. Available starting with [MariaDB 10.4.14](https://mariadb.com/kb/en/mariadb-10414-release-notes/) and [MariaDB 10.5.4](https://mariadb.com/kb/en/mariadb-1054-release-notes/). | | `[client-server]` | Options read by all MariaDB [client programs](../clients-utilities/index) and the MariaDB Server. This is useful for options like socket and port, which is common between the server and the clients. Available starting with [MariaDB 10.1.38](https://mariadb.com/kb/en/mariadb-10138-release-notes/), [MariaDB 10.2.22](https://mariadb.com/kb/en/mariadb-10222-release-notes/), and [MariaDB 10.3.13](https://mariadb.com/kb/en/mariadb-10313-release-notes/). | | `[galera]` | Options read by MariaDB Server, but only if it is compiled with [Galera Cluster](../galera/index) support. In [MariaDB 10.1](../what-is-mariadb-101/index) and later, all builds on Linux are compiled with [Galera Cluster](../galera/index) support. When using one of these builds, options from this option group are read even if the [Galera Cluster](../galera/index) functionality is not enabled. Available starting with [MariaDB 10.1.38](https://mariadb.com/kb/en/mariadb-10138-release-notes/), [MariaDB 10.2.22](https://mariadb.com/kb/en/mariadb-10222-release-notes/), and [MariaDB 10.3.13](https://mariadb.com/kb/en/mariadb-10313-release-notes/) on systems compiled with [Galera Cluster](../galera/index) support. | #### Client Option Groups Mariabackup reads client options from the following [option groups](../configuring-mariadb-with-option-files/index#option-groups) from [option files](../configuring-mariadb-with-option-files/index): | Group | Description | | --- | --- | | `[mariabackup]` | Options read by Mariabackup. Available starting with [MariaDB 10.1.31](https://mariadb.com/kb/en/mariadb-10131-release-notes/) and [MariaDB 10.2.13](https://mariadb.com/kb/en/mariadb-10213-release-notes/). | | `[mariadb-backup]` | Options read by Mariabackup. Available starting with [MariaDB 10.4.14](https://mariadb.com/kb/en/mariadb-10414-release-notes/) and [MariaDB 10.5.4](https://mariadb.com/kb/en/mariadb-1054-release-notes/). | | `[xtrabackup]` | Options read by Mariabackup and [Percona XtraBackup](../percona-xtrabackup-overview/index). | | `[client]` | Options read by all MariaDB and MySQL [client programs](../clients-utilities/index), which includes both MariaDB and MySQL clients. For example, `mysqldump`. | | `[client-server]` | Options read by all MariaDB [client programs](../clients-utilities/index) and the MariaDB Server. This is useful for options like socket and port, which is common between the server and the clients. Available starting with [MariaDB 10.1.38](https://mariadb.com/kb/en/mariadb-10138-release-notes/), [MariaDB 10.2.22](https://mariadb.com/kb/en/mariadb-10222-release-notes/), and [MariaDB 10.3.13](https://mariadb.com/kb/en/mariadb-10313-release-notes/). | | `[client-mariadb]` | Options read by all MariaDB [client programs](../clients-utilities/index). Available starting with [MariaDB 10.1.38](https://mariadb.com/kb/en/mariadb-10138-release-notes/), [MariaDB 10.2.22](https://mariadb.com/kb/en/mariadb-10222-release-notes/), and [MariaDB 10.3.13](https://mariadb.com/kb/en/mariadb-10313-release-notes/). | ### Authentication and Privileges Mariabackup needs to authenticate with the database server when it performs a backup operation (i.e. when the `[--backup](../mariabackup-options/index#-backup)` option is specified). For most use cases, the user account that performs the backup needs to have the following [global privileges](../grant/index#global-privileges) on the database server. In 10.5 and later the required privileges are: ``` CREATE USER 'mariabackup'@'localhost' IDENTIFIED BY 'mypassword'; GRANT RELOAD, PROCESS, LOCK TABLES, BINLOG MONITOR ON *.* TO 'mariabackup'@'localhost'; ``` Prior to 10.5, the required privileges are: ``` CREATE USER 'mariabackup'@'localhost' IDENTIFIED BY 'mypassword'; GRANT RELOAD, PROCESS, LOCK TABLES, REPLICATION CLIENT ON *.* TO 'mariabackup'@'localhost'; ``` If your database server is also using the [MyRocks](../myrocks/index) storage engine, then the user account that performs the backup will also need the `SUPER` [global privilege](../grant/index#global-privileges). This is because Mariabackup creates a checkpoint of this data by setting the `[rocksdb\_create\_checkpoint](../myrocks-system-variables/index#rocksdb_create_checkpoint)` system variable, which requires this privilege. See [MDEV-20577](https://jira.mariadb.org/browse/MDEV-20577) for more information. To use the `[--history](../mariabackup-options/index#-history)` option, the backup user also needs to have the following privileges granted: ``` GRANT CREATE ON PERCONA_SCHEMA.* TO 'mariabackup'@'localhost'; GRANT INSERT ON PERCONA_SCHEMA.* TO 'mariabackup'@'localhost'; ``` The user account information can be specified with the `[--user](../mariabackup-options/index#-user)` and `[--password](../mariabackup-options/index#-p-password)` command-line options. For example: ``` $ mariabackup --backup \ --target-dir=/var/mariadb/backup/ \ --user=mariabackup --password=mypassword ``` The user account information can also be specified in a supported [client option group](#client-option-groups) in an [option file](../configuring-mariadb-with-option-files/index). For example: ``` [mariabackup] user=mariabackup password=mypassword ``` Mariabackup does not need to authenticate with the database server when preparing or restoring a backup. ### File System Permissions Mariabackup has to read MariaDB's files from the file system. Therefore, when you run Mariabackup as a specific operating system user, you should ensure that user account has sufficient permissions to read those files. If you are using Linux and if you installed MariaDB with a package manager, then MariaDB's files will probably be owned by the `mysql` user and the `mysql` group. ### Using Mariabackup with Data-at-Rest Encryption Mariabackup supports [Data-at-Rest Encryption](../data-at-rest-encryption/index). Mariabackup will query the server to determine which [key management and encryption plugin](../encryption-key-management/index) is being used, and then it will load that plugin itself, which means that Mariabackup needs to be able to load the key management and encryption plugin's shared library. Mariabackup will also query the server to determine which [encryption keys](../encryption-key-management/index#using-multiple-encryption-keys) it needs to use. In other words, Mariabackup is able to figure out a lot of encryption-related information on its own, so normally one doesn't need to provide any extra options to backup or restore encrypted tables. Mariabackup backs up encrypted and unencrypted tables as they are on the original server. If a table is encrypted, then the table will remain encrypted in the backup. Similarly, if a table is unencrypted, then the table will remain unencrypted in the backup. The primary reason that Mariabackup needs to be able to encrypt and decrypt data is that it needs to apply [InnoDB redo log](../xtradbinnodb-redo-log/index) records to make the data consistent when the backup is prepared. As a consequence, Mariabackup does not perform many encryption or decryption operations when the backup is initially taken. MariaDB performs more encryption and decryption operations when the backup is prepared. This means that some encryption-related problems (such as using the wrong encryption keys) may not become apparent until the backup is prepared. ### Using Mariabackup for Galera SSTs The `mariabackup` SST method uses the [Mariabackup](../backup-restore-and-import-clients-mariadb-backup/index) utility for performing SSTs. See [mariabackup SST method](../mariabackup-sst-method/index) for more information. Files Backed up by Mariabackup ------------------------------ Mariabackup backs up many different files in order to perform its backup operation. See [Files Backed up by Mariabackup](../files-backed-up-by-mariabackup/index) for a list of these files. Files Created by Mariabackup ---------------------------- Mariabackup creates several different types of files during the backup and prepare phases. See [Files Created by Mariabackup](../files-created-by-mariabackup/index) for a list of these files. Known Issues ------------ ### Unsupported Server Option Groups Mariabackup doesn't currently support the `[mariadbd]` and `[mariadbd-X.Y]` server option groups. See [MDEV-21298](https://jira.mariadb.org/browse/MDEV-21298) for more information. Mariabackup doesn't currently support the `[mariadb-backup]` server option group. See [MDEV-21301](https://jira.mariadb.org/browse/MDEV-21301) for more information. Prior to [MariaDB 10.1.38](https://mariadb.com/kb/en/mariadb-10138-release-notes/), [MariaDB 10.2.22](https://mariadb.com/kb/en/mariadb-10222-release-notes/), and [MariaDB 10.3.13](https://mariadb.com/kb/en/mariadb-10313-release-notes/), Mariabackup doesn't read server options from all [option groups](../configuring-mariadb-with-option-files/index#option-groups) supported by the server. In those versions, it only looks for server options in the following server option groups: | Group | Description | | --- | --- | | `[xtrabackup]` | Options read by Percona XtraBackup and Mariabackup. | | `[mariabackup]` | Options read by Percona XtraBackup and Mariabackup. Available starting with [MariaDB 10.1.31](https://mariadb.com/kb/en/mariadb-10131-release-notes/) and [MariaDB 10.2.13](https://mariadb.com/kb/en/mariadb-10213-release-notes/). | | `[mysqld]` | Options read by `mysqld`, which includes both MariaDB Server and MySQL Server. | Those versions do not read server options from the following option groups supported by the server: | Group | Description | | --- | --- | | `[server]` | Options read by MariaDB Server. Available starting with [MariaDB 10.1.38](https://mariadb.com/kb/en/mariadb-10138-release-notes/), [MariaDB 10.2.22](https://mariadb.com/kb/en/mariadb-10222-release-notes/), and [MariaDB 10.3.13](https://mariadb.com/kb/en/mariadb-10313-release-notes/). | | `[mysqld-X.Y]` | Options read by a specific version of `mysqld`, which includes both MariaDB Server and MySQL Server. For example, `[mysqld-5.5]` Available starting with [MariaDB 10.1.38](https://mariadb.com/kb/en/mariadb-10138-release-notes/), [MariaDB 10.2.22](https://mariadb.com/kb/en/mariadb-10222-release-notes/), and [MariaDB 10.3.13](https://mariadb.com/kb/en/mariadb-10313-release-notes/). | | `[mariadb]` | Options read by MariaDB Server. Available starting with [MariaDB 10.1.38](https://mariadb.com/kb/en/mariadb-10138-release-notes/), [MariaDB 10.2.22](https://mariadb.com/kb/en/mariadb-10222-release-notes/), and [MariaDB 10.3.13](https://mariadb.com/kb/en/mariadb-10313-release-notes/). | | `[mariadb-X.Y]` | Options read by a specific version of MariaDB Server. For example, `[mariadb-10.3]` Available starting with [MariaDB 10.1.38](https://mariadb.com/kb/en/mariadb-10138-release-notes/), [MariaDB 10.2.22](https://mariadb.com/kb/en/mariadb-10222-release-notes/), and [MariaDB 10.3.13](https://mariadb.com/kb/en/mariadb-10313-release-notes/). | | `[client-server]` | Options read by all MariaDB [client programs](../clients-utilities/index) and the MariaDB Server. This is useful for options like socket and port, which is common between the server and the clients. Available starting with [MariaDB 10.1.38](https://mariadb.com/kb/en/mariadb-10138-release-notes/), [MariaDB 10.2.22](https://mariadb.com/kb/en/mariadb-10222-release-notes/), and [MariaDB 10.3.13](https://mariadb.com/kb/en/mariadb-10313-release-notes/). | | `[galera]` | Options read by MariaDB Server, but only if it is compiled with [Galera Cluster](../galera/index) support. In [MariaDB 10.1](../what-is-mariadb-101/index) and later, all builds on Linux are compiled with [Galera Cluster](../galera/index) support. When using one of these builds, options from this option group are read even if the [Galera Cluster](../galera/index) functionality is not enabled. Available starting with [MariaDB 10.1.38](https://mariadb.com/kb/en/mariadb-10138-release-notes/), [MariaDB 10.2.22](https://mariadb.com/kb/en/mariadb-10222-release-notes/), and [MariaDB 10.3.13](https://mariadb.com/kb/en/mariadb-10313-release-notes/) on systems compiled with [Galera Cluster](../galera/index) support. | See [MDEV-18347](https://jira.mariadb.org/browse/MDEV-18347) for more information. ### No Default Datadir Prior to [MariaDB 10.1.36](https://mariadb.com/kb/en/mariadb-10136-release-notes/), [MariaDB 10.2.18](https://mariadb.com/kb/en/mariadb-10218-release-notes/), and [MariaDB 10.3.10](https://mariadb.com/kb/en/mariadb-10310-release-notes/), if you were performing a `[--copy-back](../mariabackup-options/index#-copy-back)` operation, and if you did not explicitly specify a value for the `[datadir](../mariabackup-options/index#datadir)` option either on the command line or one of the supported [server option groups](#server-option-group) in an [option file](../configuring-mariadb-with-option-files/index), then Mariabackup would not default to the server's default `datadir`. Instead, Mariabackup would fail with an error. For example: ``` Error: datadir must be specified. ``` The solution is to explicitly specify a value for the `[datadir](../mariabackup-options/index#datadir)` option either on the command line or in one of the supported [server option groups](#server-option-groups) in an [option file](../configuring-mariadb-with-option-files/index). For example: ``` [mysqld] datadir=/var/lib/mysql ``` In [MariaDB 10.1.36](https://mariadb.com/kb/en/mariadb-10136-release-notes/), [MariaDB 10.2.18](https://mariadb.com/kb/en/mariadb-10218-release-notes/), and [MariaDB 10.3.10](https://mariadb.com/kb/en/mariadb-10310-release-notes/) and later, Mariabackup will default to the server's default `[datadir](../server-system-variables/index#datadir)` value. See [MDEV-12956](https://jira.mariadb.org/browse/MDEV-12956) for more information. ### Concurrent DDL and Backup Issues Prior to [MariaDB 10.2.19](https://mariadb.com/kb/en/mariadb-10219-release-notes/) and [MariaDB 10.3.10](https://mariadb.com/kb/en/mariadb-10310-release-notes/), if concurrent DDL was executed while the backup was taken, then that could cause various kinds of problems to occur. One example is that if DDL caused any tablespace IDs to change (such as `[TRUNCATE TABLE](../truncate-table/index)` or `[RENAME TABLE](../rename-table/index)`), then that could cause the effected tables to be inconsistent in the backup. In this scenario, you might see errors about mismatched tablespace IDs when the backup is prepared. For example, the errors might look like this: ``` 2018-12-07 07:49:32 7f51b3184820 InnoDB: Error: table 'DB1/TAB_TEMP' InnoDB: in InnoDB data dictionary has tablespace id 1355633, InnoDB: but a tablespace with that id does not exist. There is InnoDB: a tablespace of name DB1/TAB_TEMP and id 1354713, though. Have InnoDB: you deleted or moved .ibd files? InnoDB: Please refer to InnoDB: http://dev.mysql.com/doc/refman/5.6/en/innodb-troubleshooting-datadict.html InnoDB: for how to resolve the issue. ``` Or they might look like this: ``` 2018-07-12 21:24:14 139666981324672 [Note] InnoDB: Ignoring data file 'db1/tab1.ibd' with space ID 200485, since the redo log references db1/tab1.ibd with space ID 200484. ``` Some of the problems related to concurrent DDL are described below. Problems solved by setting `[--lock-ddl-per-table](../mariabackup-options/index#-lock-ddl-per-table)` (Mariabackup command-line option added in [MariaDB 10.2.9](https://mariadb.com/kb/en/mariadb-1029-release-notes/)): * If a table is dropped during the backup, then it might still exists after the backup is prepared. * If a table exists when the backup starts, but it is dropped before the backup copies it, then the tablespace file can't be copied, so the backup would fail. Problems solved by setting `[innodb\_log\_optimize\_ddl=OFF](../innodb-system-variables/index#innodb_log_optimize_ddl)` (MariaDB Server system variable added in [MariaDB 10.2.17](https://mariadb.com/kb/en/mariadb-10217-release-notes/): * If the backup noticed concurrent DDL, then it might fail with "ALTER TABLE or OPTIMIZE TABLE was executed during backup". Problems solved by `[innodb\_safe\_truncate=ON](../innodb-system-variables/index#innodb_safe_truncate)` (MariaDB Server system variable in [MariaDB 10.2.19](https://mariadb.com/kb/en/mariadb-10219-release-notes/)): * If a table is created during the backup, then it might not exist in the backup after prepare. * If a table is renamed during the backup after the tablespace file was copied, then the table may not exist after the backup is prepared. * If a table is dropped and created under the same name during the backup after the tablespace file was copied, then the table will have the wrong tablespace ID when the backup is prepared. Problems solved by other bug fixes: * If `[--lock-ddl-per-table](../mariabackup-options/index#-lock-ddl-per-table)` is used and if a table is concurrently being dropped or renamed, then Mariabackup can fail to acquire the MDL lock. These problems are only fixed in [MariaDB 10.2](../what-is-mariadb-102/index) and later, so it is not recommended to execute concurrent DDL when using Mariabackup with [MariaDB 10.1](../what-is-mariadb-101/index). See [MDEV-13563](https://jira.mariadb.org/browse/MDEV-13563), [MDEV-13564](https://jira.mariadb.org/browse/MDEV-13564), [MDEV-16809](https://jira.mariadb.org/browse/MDEV-16809), and [MDEV-16791](https://jira.mariadb.org/browse/MDEV-16791) for more information. ### Manual Restore with Pre-existing InnoDB Redo Log files Prior to [MariaDB 10.2.10](https://mariadb.com/kb/en/mariadb-10210-release-notes/), Mariabackup users could run into issues if they restored a backup by manually copying the files from the backup into the `[datadir](../server-system-variables/index#datadir)` while the directory still contained pre-existing [InnoDB redo log](../xtradbinnodb-redo-log/index) files. The backup itself did not contain [InnoDB redo log](../xtradbinnodb-redo-log/index) files with the traditional `ib_logfileN` file names, so the pre-existing log files would remain in the `[datadir](../server-system-variables/index#datadir)`. If the server were started with these pre-existing log files, then it could perform crash recovery with them, which could cause the database to become inconsistent or corrupt. In these MariaDB versions, this problem could be avoided by not restoring the backup by manually copying the files and instead restoring the backup by using Mariabackup and providing the `[--copy-back](../mariabackup-options/index#-copy-back)` option, since Mariabackup deletes pre-existing [InnoDB redo log](../xtradbinnodb-redo-log/index) files from the `[datadir](../server-system-variables/index#datadir)` during the restore process. In [MariaDB 10.2.10](https://mariadb.com/kb/en/mariadb-10210-release-notes/) and later, Mariabackup prevents this issue by creating an empty [InnoDB redo log](../xtradbinnodb-redo-log/index) file called `[ib\_logfile0](../files-created-by-mariabackup/index#ib_logfile0)` as part of the `[--prepare](../mariabackup-options/index#-prepare)` stage. That way, if the backup is manually restored, any pre-existing [InnoDB redo log](../xtradbinnodb-redo-log/index) files would get overwritten by the empty one. See [MDEV-13311](https://jira.mariadb.org/browse/MDEV-13311) for more information. ### Too Many Open Files If Mariabackup uses more file descriptors than the system is configured to allow, then users can see errors like the following: ``` 2019-02-12 09:48:38 7ffff7fdb820 InnoDB: Operating system error number 23 in a file operation. InnoDB: Error number 23 means 'Too many open files in system'. InnoDB: Some operating system error numbers are described at InnoDB: http://dev.mysql.com/doc/refman/5.6/en/operating-system-error-codes.html InnoDB: Error: could not open single-table tablespace file ./db1/tab1.ibd InnoDB: We do not continue the crash recovery, because the table may become InnoDB: corrupt if we cannot apply the log records in the InnoDB log to it. InnoDB: To fix the problem and start mysqld: InnoDB: 1) If there is a permission problem in the file and mysqld cannot InnoDB: open the file, you should modify the permissions. InnoDB: 2) If the table is not needed, or you can restore it from a backup, InnoDB: then you can remove the .ibd file, and InnoDB will do a normal InnoDB: crash recovery and ignore that table. InnoDB: 3) If the file system or the disk is broken, and you cannot remove InnoDB: the .ibd file, you can set innodb_force_recovery > 0 in my.cnf InnoDB: and force InnoDB to continue crash recovery here. ``` Prior to [MariaDB 10.1.39](https://mariadb.com/kb/en/mariadb-10139-release-notes/), [MariaDB 10.2.24](https://mariadb.com/kb/en/mariadb-10224-release-notes/), and [MariaDB 10.3.14](https://mariadb.com/kb/en/mariadb-10314-release-notes/), Mariabackup would actually ignore the error and continue the backup. In some of those cases, Mariabackup would even report a successful completion of the backup to the user. In later versions, Mariabackup will properly throw an error and abort when this error is encountered. See [MDEV-19060](https://jira.mariadb.org/browse/MDEV-19060) for more information. When this error is encountered, one solution is to explicitly specify a value for the `[open-files-limit](../mariabackup-options/index#-open-files-limit)` option either on the command line or in one of the supported [server option groups](#server-option-groups) in an [option file](../configuring-mariadb-with-option-files/index). For example: ``` [mariabackup] open_files_limit=65535 ``` An alternative solution is to set the soft and hard limits for the user account that runs Mariabackup by adding new limits to `[/etc/security/limits.conf](https://linux.die.net/man/5/limits.conf)`. For example, if Mariabackup is run by the `mysql` user, then you could add lines like the following: ``` mysql soft nofile 65535 mysql hard nofile 65535 ``` After the system is rebooted, the above configuration should set new open file limits for the `mysql` user, and the user's `ulimit` output should look like the following: ``` $ ulimit -Sn 65535 $ ulimit -Hn 65535 ``` Versions -------- | Mariabackup/Server Version | Maturity | | --- | --- | | [MariaDB 10.2.10](https://mariadb.com/kb/en/mariadb-10210-release-notes/)+, [MariaDB 10.1.26](https://mariadb.com/kb/en/mariadb-10126-release-notes/)+ | Stable | | [MariaDB 10.2.7](https://mariadb.com/kb/en/mariadb-1027-release-notes/)+, [MariaDB 10.1.25](https://mariadb.com/kb/en/mariadb-10125-release-notes/) | Beta | | [MariaDB 10.1.23](https://mariadb.com/kb/en/mariadb-10123-release-notes/) | Alpha | See Also -------- * [mariadb-dump/mysqldump](../mysqldump/index) * [How to backup with MariaDB](https://www.youtube.com/watch?v=xB4ImmmzXqU) (video) * [MariaDB point-in-time recovery](https://www.youtube.com/watch?v=ezHmnNmmcDo) (video) * [Mariabackup and Restic](https://www.youtube.com/watch?v=b-KFj8GfvzE) (video) * [MariaDB Enterprise backup](https://mariadb.com/docs/usage/mariadb-enterprise-backup/). An updated version of mariabackup. * [Percona Xtrabackup 2.3 documentation](https://www.percona.com/doc/percona-xtrabackup/2.3/index.html/) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb Error Codes Error Codes ============ | Title | Description | | --- | --- | | [MariaDB Error Codes](../mariadb-error-codes/index) | MariaDB error codes reference list. | | [Operating System Error Codes](../operating-system-error-codes/index) | Linux and Windows operating system error codes. | | [SQLSTATE](../sqlstate/index) | A string which identifies a condition's class and subclass | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb GeometryCollectionFromWKB GeometryCollectionFromWKB ========================= A synonym for [ST\_GeomCollFromWKB](../st_geomcollfromwkb/index). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb MariaDB ColumnStore software upgrade 1.0.14 to 1.0.15 MariaDB ColumnStore software upgrade 1.0.14 to 1.0.15 ===================================================== MariaDB ColumnStore software upgrade 1.0.14 to 1.0.15 ----------------------------------------------------- Note: Columnstore.xml modifications you manually made are not automatically carried forward on an upgrade. These modifications will need to be incorporated back into .XML once the upgrade has occurred. The previous configuration file will be saved as /usr/local/mariadb/columnstore/etc/Columnstore.xml.rpmsave. If you have specified a root database password (which is good practice), then you must configure a .my.cnf file with user credentials for the upgrade process to use. Create a .my.cnf file in the user home directory with 600 file permissions with the following content (updating PASSWORD as appropriate): ``` [mysqladmin] user = root password = PASSWORD ``` ### Choosing the type of upgrade As noted on the Preparing guide, you can installing MariaDB ColumnStore with the use of soft-links. If you have the softlinks be setup at the Data Directory Levels, like mariadb/columnstore/data and mariadb/columnstore/dataX, then your upgrade will happen without any issues. In the case where you have a softlink at the top directory, like /usr/local/mariadb, you will need to upgrade using the binary package. If you updating using the rpm package and tool, this softlink will be deleted when you perform the upgrade process and the upgrade will fail. #### Root User Installs #### Upgrading MariaDB ColumnStore using RPMs Upgrade MariaDB ColumnStore as user root on the server designated as PM1: **Download the package mariadb-columnstore-1.0.15-1-centos#.x86\_64.rpm.tar.gz to the PM1 server where you are installing MariaDB ColumnStore.** Shutdown the MariaDB ColumnStore system: ``` # mcsadmin shutdownsystem y ``` * Unpack the tarball, which will generate a set of RPMs that will reside in the /root/ directory. ``` # tar -zxf mariadb-columnstore-1.0.15-1-centos#.x86_64.rpm.tar.gz ``` * Upgrade the RPMs. The MariaDB ColumnStore software will be installed in /usr/local/. ``` # rpm -e --nodeps $(rpm -qa | grep '^mariadb-columnstore') # rpm -ivh mariadb-columnstore-*1.0.15*rpm ``` * Run postConfigure using the upgrade option, which will utilize the configuration from the Columnstore.xml.rpmsave ``` # /usr/local/mariadb/columnstore/bin/postConfigure -u ``` For RPM Upgrade, the previous configuration file will be saved as: /usr/local/mariadb/columnstore/etc/Columnstore.xml.rpmsave ### Initial download/install of MariaDB ColumnStore binary package Upgrade MariaDB ColumnStore as user root on the server designated as PM1: * Download the package into the /usr/local directory -mariadb-columnstore-1.0.15-1.x86\_64.bin.tar.gz (Binary 64-BIT)to the server where you are installing MariaDB ColumnStore. * Shutdown the MariaDB ColumnStore system: ``` # mcsadmin shutdownsystem y ``` * Run pre-uninstall script ``` # /usr/local/mariadb/columnstore/bin/pre-uninstall ``` * Unpack the tarball, in the /usr/local/ directory. ``` # tar -zxvf -mariadb-columnstore-1.0.15-1.x86_64.bin.tar.gz ``` * Run post-install scripts ``` # /usr/local/mariadb/columnstore/bin/post-install ``` * Run postConfigure using the upgrade option, which will utilize the configuration from the Columnstore.xml,rpmsave ``` # /usr/local/mariadb/columnstore/bin/postConfigure -u ``` ### Upgrading MariaDB ColumnStore using the DEB package A DEB upgrade would be done on a system that supports DEBs like Debian or Ubuntu systems. Upgrade MariaDB ColumnStore as user root on the server designated as PM1: * Download the package into the /root directory mariadb-columnstore-1.0.15-1.amd64.deb.tar.gz (DEB 64-BIT) to the server where you are installing MariaDB ColumnStore. * Shutdown the MariaDB ColumnStore system: ``` # mcsadmin shutdownsystem y ``` * Unpack the tarball, which will generate DEBs. ``` # tar -zxf mariadb-columnstore-1.0.15-1.amd64.deb.tar.gz ``` * Remove, purge and install all MariaDB ColumnStore debs ``` # cd /root/ # dpkg -r $(dpkg --list | grep 'mariadb-columnstore' | awk '{print $2}') # dpkg -P $(dpkg --list | grep 'mariadb-columnstore' | awk '{print $2}') # dpkg --install mariadb-columnstore-*1.0.15-1*deb ``` * Run postConfigure using the upgrade option, which will utilize the configuration from the Columnstore.xml,rpmsave ``` # /usr/local/mariadb/columnstore/bin/postConfigure -u ``` #### Non-Root User Installs ### Initial download/install of MariaDB ColumnStore binary package Upgrade MariaDB ColumnStore as user root on the server designated as PM1: * Download the package into the /home/'non-root-user" directory mariadb-columnstore-1.0.15-1.x86\_64.bin.tar.gz (Binary 64-BIT)to the server where you are installing MariaDB ColumnStore. * Shutdown the MariaDB ColumnStore system: ``` # mcsadmin shutdownsystem y ``` * Run pre-uninstall script ``` # $HOME/mariadb/columnstore/bin/pre-uninstall --installdir= /home/guest/mariadb/columnstore ``` * Unpack the tarball, which will generate the $HOME/ directory. ``` # tar -zxvf -mariadb-columnstore-1.0.15-1.x86_64.bin.tar.gz ``` * Run post-install scripts ``` # $HOME/mariadb/columnstore/bin/post-install --installdir=/home/guest/mariadb/columnstore ``` * Run postConfigure using the upgrade option, which will utilize the configuration from the Columnstore.xml,rpmsave ``` # $HOME/mariadb/columnstore/bin/postConfigure -u -i /home/guest/mariadb/columnstore ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Subquery Optimizations Map Subquery Optimizations Map ========================== Below is a map showing all types of subqueries allowed in the SQL language, and the optimizer strategies available to handle them. * Uncolored areas represent different kinds of subqueries, for example: + Subqueries that have form `x IN (SELECT ...)` + Subqueries that are in the `FROM` clause + .. and so forth * The size of each uncolored area roughly corresponds to how important (i.e. frequently used) that kind of subquery is. For example, `x IN (SELECT ...)` queries are the most important, and `EXISTS (SELECT ...)` are relatively unimportant. * Colored areas represent optimizations/execution strategies that are applied to handle various kinds of subqueries. * The color of optimization indicates which version of MySQL/MariaDB it was available in (see legend below) Some things are not on the map: * MariaDB doesn't evaluate expensive subqueries when doing optimization (this means, EXPLAIN is always fast). MySQL 5.6 has made a progress in this regard but its optimizer will still evaluate certain kinds of subqueries (for example, scalar-context subqueries used in range predicates) Links to pages about individual optimizations: ---------------------------------------------- * [IN->EXISTS](../non-semi-join-subquery-optimizations/index#the-in-to-exists-transformation) * [Subquery Caching](../subquery-cache/index) * [Semi-join optimizations](../semi-join-subquery-optimizations/index) + [Table pullout](../table-pullout-optimization/index) + [FirstMatch](../firstmatch-strategy/index) + [Materialization, +scan, +lookup](../semi-join-materialization-strategy/index) + [LooseScan](../loosescan-strategy/index) + [DuplicateWeedout execution strategy](../duplicateweedout-strategy/index) * Non-semi-join [Materialization](../non-semi-join-subquery-optimizations/index#materialization-for-non-correlated-in-subqueries) (including NULL-aware and partial matching) * Derived table optimizations + [Derived table merge](../derived-table-merge-optimization/index) + [Derived table with keys](../derived-table-with-key-optimization/index) See also -------- * [Subquery optimizations in MariaDB 5.3](../what-is-mariadb-53/index#subquery-optimizations) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb SET DEFAULT ROLE SET DEFAULT ROLE ================ Syntax ------ ``` SET DEFAULT ROLE { role | NONE } [ FOR user@host ] ``` Description ----------- The `SET DEFAULT ROLE` statement sets a **default [role](../roles/index)** for a specified (or current) user. A default role is automatically enabled when a user connects (an implicit [SET ROLE](../set-role/index) statement is executed immediately after a connection is established). To be able to set a role as a default, the role must already have been granted to that user, and one needs the privileges to enable this role (if you cannot do `SET ROLE X`, you won't be able to do `SET DEFAULT ROLE X`). To set a default role for another user one needs to have write access to the `mysql` database. To remove a user's default role, use `SET DEFAULT ROLE NONE [ FOR user@host ]`. The record of the default role is not removed if the role is [dropped](../drop-role/index) or [revoked](../revoke/index#roles), so if the role is subsequently re-created or granted, it will again be the user's default role. The default role is stored in the `default_role` column in the [mysql.user](../mysqluser-table/index) table/view, as well as in the [Information Schema APPLICABLE\_ROLES table](../information-schema-applicable_roles-table/index), so these can be viewed to see which role has been assigned to a user as the default. Examples -------- Setting a default role for the current user: ``` SET DEFAULT ROLE journalist; ``` Removing a default role from the current user: ``` SET DEFAULT ROLE NONE; ``` Setting a default role for another user. The role has to have been granted to the user before it can be set as default: ``` CREATE ROLE journalist; CREATE USER taniel; SET DEFAULT ROLE journalist FOR taniel; ERROR 1959 (OP000): Invalid role specification `journalist` GRANT journalist TO taniel; SET DEFAULT ROLE journalist FOR taniel; ``` Viewing mysql.user: ``` select * from mysql.user where user='taniel'\G *************************** 1. row *************************** Host: % User: taniel ... is_role: N default_role: journalist ... ``` Removing a default role for another user ``` SET DEFAULT ROLE NONE FOR taniel; ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb CONNECT Zipped File Tables CONNECT Zipped File Tables ========================== **MariaDB starting with [10.2.4](https://mariadb.com/kb/en/mariadb-1024-release-notes/)**Connect can work on table files that are compressed in one or several zip files. The specific options used when creating tables based on zip files are: | Table Option | Type | Description | | --- | --- | --- | | ZIPPED | Boolean | Required to be set as true. | | ENTRY\* | String | The optional name or pattern of the zip entry or entries to be used with the table. If not specified, all entries or only the first one will be used depending on the *mulentries* option setting. | | MULENTRIES\* | Boolean | True if several entries are part of the table. If not specified, it defaults to false if the *entry* option is not specified. If the entry option is specified, it defaults to true if the entry name contains wildcard characters or false if it does not. | | APPEND\* | Boolean | Used when creating new zipped tables (see below) | | LOAD\* | String | Used when creating new zipped tables (see below) | Options marked with a ‘\*’ must be specified in the option list. Examples of use: #### Example 1: Single CSV File Included in a Single ZIP File Let's suppose you have a CSV file from which you would create a table by: ``` create table emp ... optional column definition engine=connect table_type=CSV file_name='E:/Data/employee.csv' sep_char=';' header=1; ``` If the CSV file is included in a ZIP file, the CREATE TABLE becomes: ``` create table empzip ... optional column definition engine=connect table_type=CSV file_name='E:/Data/employee.zip' sep_char=';' header=1 zipped=1 option_list='Entry=emp.csv'; ``` The *file\_name* option is the name of the zip file. The *entry* option is the name of the entry inside the zip file. If there is only one entry file inside the zip file, this option can be omitted. #### Example 2: Several CSV Files Included in a Single ZIP File If the table is made from several files such as emp01.csv, emp02.csv, etc., the standard create table would be: ``` create table empmul ( ... required column definition ) engine=connect table_type=CSV file_name='E:/Data/emp*.csv' sep_char=';' header=1 multiple=1; ``` But if these files are all zipped inside a unique zip file, it becomes: ``` create table empzmul ... required column definition engine=connect table_type=CSV file_name='E:/Data/emp.zip' sep_char=';' header=1 zipped=1 option_list='Entry=emp*.csv'; ``` Here the *entry* option is the pattern that the files inside the zip file must match. If all entry files are ok, the *entry* option can be omitted but the Boolean option *mulentries* must be specified as true. #### Example 3: Single CSV File included in Multiple ZIP Files (Without considering subfolders) If the table is created on several zip files, it is specified as for all other multiple tables: ``` create table zempmul ( ... required column definition ) engine=connect table_type=CSV file_name='E:/Data/emp*.zip' sep_char=';' header=1 multiple=1 zipped=yes option_list='Entry=employee.csv'; ``` Here again the *entry* option is used to restrict the entry file(s) to be used inside the zip files and can be omitted if all are ok. The column descriptions can be retrieved by the discovery process for table types allowing it. It cannot be done for multiple tables or multiple entries. A catalog table can be created by adding *catfunc=columns*. This can be used to show the column definitions of multiple tables. *Multiple* must be set to false and the column definitions will be the ones of the first table or entry. This first implementation has some restrictions: 1. Zipped tables are read-only. [UPDATE](../update/index) and [DELETE](../delete/index) are not supported. However, [INSERT](../insert/index) is supported in a specific way when making tables. 2. The inside files are decompressed into memory. Memory problems may arise with huge files. 3. Only file types that can be handled from memory are eligible for this. This includes [DOS](../connect-dos-and-fix-table-types/index), [FIX](../connect-dos-and-fix-table-types/index), [BIN](../connect-bin-table-type/index), [CSV](../connect-csv-and-fmt-table-types/index), [FMT](../connect-csv-and-fmt-table-types/index), [DBF](../connect-dbf-table-type/index), [JSON](../connect-json-table-type/index), and [XML](../connect-xml-table-type/index) table types, as well as types based on these such as [XCOL](../connect-xcol-table-type/index), [OCCUR](../connect-occur-table-type/index) and [PIVOT](../connect-pivot-table-type/index). Optimization by indexing or block indexing is possible for table types supporting it. However, it applies to the uncompressed table. This means that the whole table is always uncompressed. Partitioning is also supported. See how to do it in the section about partitioning. ### Creating New Zipped Tables Tables can be created to access already existing zip files. However, is it also possible to make the zip file from an existing file or table. Two ways are available to make the zip file: #### Insert Method insert can be used to make the table file for table types based on records (this excludes DBF, XML and JSON when pretty is not 0). However, the current implementation of the used package (minizip) does not support adding to an already existing zip entry. This means that when executing an insert statement the inserted records are not added but replace the existing ones. CONNECT protects existing data by not allowing such inserts, Therefore, only three ways are available to do so: 1. Using only one insert statement to make the whole table. This is possible only for small tables and is principally useful when making tests. 2. Making the table from the data of another table. This can be done by executing an “insert into table select \* from another\_table” or by specifying “as select \* from another\_table” in the create table statement. 3. Making the table from a file whose format enables to use the “load data infile” statement. To add a new entry in an existing zip file, specify “append=YES” in the option list. When inserting several entries, use ALTER to specify the required options, for instance: ``` create table znumul ( Chiffre int(3) not null, Lettre char(16) not null) engine=CONNECT table_type=CSV file_name='C:/Data/FMT/mnum.zip' header=1 lrecl=20 zipped=1 option_list='Entry=Num1'; insert into znumul select * from num1; alter table znumul option_list='Entry=Num2,Append=YES'; insert into znumul select * from num2; alter table znumul option_list='Entry=Num3,Append=YES'; insert into znumul select * from num3; alter table znumul option_list='Entry=Num*,Append=YES'; select * from znumul; ``` The last ALTER is needed to display all the entries. #### File Zipping Method This method enables to make the zip file from another file when creating the table. It applies to all table types including DBF, XML and JSON. It is specified in the create table statement with the load option. For example: ``` create table XSERVZIP ( NUMERO varchar(4) not null, LIEU varchar(15) not null, CHEF varchar(5) not null, FONCTION varchar(12) not null, NOM varchar(21) not null) engine=CONNECT table_type=XML file_name='E:/Xml/perso.zip' zipped=1 option_list='entry=services,load=E:/Xml/serv2.xml'; ``` When executing this statement, the *serv2.xml* file will be zipped as /perso.zip*. The entry name can be specified or defaults to the source file name.* If the column descriptions are specified, the table can be used later to read from the zipped table, but they are not used when creating the zip file. Thus, a fake column (there must be one) can be specified and another table created to read the zip file. This one can take advantage of the discovery process to avoid providing the columns description for table types allowing it. For instance: ``` create table mkzq (whatever int) engine=connect table_type=DBF zipped=1 file_name='C:/Data/EAUX/dbf/CQUART.ZIP' option_list='Load=C:/Data/EAUX/dbf/CQUART.DBF'; create table zquart engine=connect table_type=DBF zipped=1 file_name='C:/Data/EAUX/dbf/CQUART.ZIP'; ``` It is also possible to create a multi-entries table from several files: ``` CREATE TABLE znewcities ( _id char(5) NOT NULL, city char(16) NOT NULL, lat double(18,6) NOT NULL `FIELD_FORMAT`='loc:[0]', lng double(18,6) NOT NULL `FIELD_FORMAT`='loc:[1]', pop int(6) NOT NULL, state char(2) NOT NULL ) ENGINE=CONNECT TABLE_TYPE=JSON FILE_NAME='E:/Json/newcities.zip' ZIPPED=1 LRECL=1000 OPTION_LIST='Load=E:/Json/city_*.json,mulentries=YES,pretty=0'; ``` Here the files to load are specified with wildcard characters and the *mulentries* options must be specified. However, the *entry* option must not be specified, entry names will be made from the file names. Provide a fake column description if the files have different column layout, but specific tables will have to be created to read each of them. ### ZIP Table Type A ZIP table type is also available. It is not meant to read the inside files but to display information about the zip file contents. For instance: ``` create table xzipinfo2 ( entry varchar(256)not null, cmpsize bigint not null flag=1, uncsize bigint not null flag=2, method int not null flag=3, date datetime not null flag=4) engine=connect table_type=ZIP file_name='E:/Data/Json/cities.zip'; ``` This will display the name, compressed size, uncompressed size, and compress method of all entries inside the zip file. Column names are irrelevant; these are flag values that mean what information to retrieve. It is possible to retrieve this information from several zip files by specifying the multiple option: ``` create table TestZip1 ( entry varchar(260)not null, cmpsize bigint not null flag=1, uncsize bigint not null flag=2, method int not null flag=3, date datetime not null flag=4, zipname varchar(256) special='FILEID') engine=connect table_type=ZIP multiple=1 file_name='C:/Data/Ziptest/CCAM06300_DBF_PART*.zip'; ``` Here we added the special column zipname to get the name of the zip file for each entry. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb SHOW DATABASES SHOW DATABASES ============== Syntax ------ ``` SHOW {DATABASES | SCHEMAS} [LIKE 'pattern' | WHERE expr] ``` Description ----------- `SHOW DATABASES` lists the databases on the MariaDB server host. `SHOW SCHEMAS` is a synonym for `SHOW DATABASES`. The `LIKE` clause, if present on its own, indicates which database names to match. The `WHERE` and `LIKE` clauses can be given to select rows using more general conditions, as discussed in [Extended SHOW](../extended-show/index). You see only those databases for which you have some kind of privilege, unless you have the global [SHOW DATABASES privilege](../grant/index). You can also get this list using the [mysqlshow](../mysqlshow/index) command. If the server was started with the `--skip-show-database` option, you cannot use this statement at all unless you have the [SHOW DATABASES privilege](../grant/index). The list of results returned by `SHOW DATABASES` is based on directories in the data directory, which is how MariaDB implements databases. It's possible that output includes directories that do not correspond to actual databases. The [Information Schema SCHEMATA table](../information-schema-schemata-table/index) also contains database information. Examples -------- ``` SHOW DATABASES; +--------------------+ | Database | +--------------------+ | information_schema | | mysql | | performance_schema | | test | +--------------------+ ``` ``` SHOW DATABASES LIKE 'm%'; +---------------+ | Database (m%) | +---------------+ | mysql | +---------------+ ``` See Also -------- * [CREATE DATABASE](../create-database/index) * [ALTER DATABASE](../alter-database/index) * [DROP DATABASE](../drop-database/index) * [SHOW CREATE DATABASE](../show-create-database/index) * [Character Sets and Collations](../character-sets-and-collations/index) * [Information Schema SCHEMATA Table](../information-schema-schemata-table/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb 10.2.5 Pre-release Upgrade Tests 10.2.5 Pre-release Upgrade Tests ================================ Upgrade from 10.0 ----------------- ### Tested revision b56262f69677fdb158b3d19dd8848e5802b2dd27 ### Test date 2017-03-27 02:05:09 ### Summary (PASS) All tests passed ### Details | # | type | pagesize | OLD version | encrypted | compressed | | NEW version | encrypted | compressed | readonly | result | notes | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | 1 | normal | 4 | 10.0.29 (InnoDB plugin) | - | - | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 2 | normal | 4 | 10.0.29 (InnoDB plugin) | - | - | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 3 | normal | 8 | 10.0.29 (InnoDB plugin) | - | - | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 4 | normal | 8 | 10.0.29 (InnoDB plugin) | - | - | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 5 | normal | 16 | 10.0.29 (InnoDB plugin) | - | - | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 6 | normal | 16 | 10.0.29 (InnoDB plugin) | - | - | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 7 | normal | 4 | 10.0.29 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 8 | normal | 4 | 10.0.29 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 9 | normal | 8 | 10.0.29 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 10 | normal | 8 | 10.0.29 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 11 | normal | 16 | 10.0.29 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 12 | normal | 16 | 10.0.29 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | - | - | - | OK | | Upgrade from 10.1 ----------------- ### Tested revision b56262f69677fdb158b3d19dd8848e5802b2dd27 ### Test date 2017-03-27 02:31:34 ### Summary (FAIL) One test failed: [MDEV-12388](https://jira.mariadb.org/browse/MDEV-12388) ### Details | # | type | pagesize | OLD version | encrypted | compressed | | NEW version | encrypted | compressed | readonly | result | notes | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | 1 | normal | 64 | 10.1.20 (InnoDB plugin) | on | - | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 2 | normal | 64 | 10.1.20 (InnoDB plugin) | - | - | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 3 | normal | 64 | 10.1.20 (InnoDB plugin) | on | - | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 4 | normal | 64 | 10.1.20 (InnoDB plugin) | - | - | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 5 | normal | 64 | 10.1.20 (InnoDB plugin) | - | zlib | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 6 | normal | 64 | 10.1.20 (InnoDB plugin) | on | zlib | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 7 | normal | 64 | 10.1.20 (InnoDB plugin) | - | zlib | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 8 | normal | 64 | 10.1.20 (InnoDB plugin) | on | zlib | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 9 | normal | 64 | 10.1.20 (InnoDB plugin) | on | zlib | => | 10.2.5 (inbuilt) | on | zlib | - | OK | | | 10 | normal | 64 | 10.1.20 (InnoDB plugin) | - | zlib | => | 10.2.5 (inbuilt) | - | zlib | - | OK | | | 11 | normal | 64 | 10.1.20 (InnoDB plugin) | - | zlib | => | 10.2.5 (inbuilt) | on | zlib | - | OK | | | 12 | normal | 64 | 10.1.20 (InnoDB plugin) | on | zlib | => | 10.2.5 (inbuilt) | - | zlib | - | OK | | | 13 | normal | 64 | 10.1.20 (InnoDB plugin) | on | - | => | 10.2.5 (inbuilt) | - | zlib | - | OK | | | 14 | normal | 64 | 10.1.20 (InnoDB plugin) | on | - | => | 10.2.5 (inbuilt) | on | zlib | - | OK | | | 15 | normal | 64 | 10.1.20 (InnoDB plugin) | - | - | => | 10.2.5 (inbuilt) | on | zlib | - | OK | | | 16 | normal | 64 | 10.1.20 (InnoDB plugin) | - | - | => | 10.2.5 (inbuilt) | - | zlib | - | OK | | | 17 | normal | 8 | 10.1.20 (InnoDB plugin) | - | zlib | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 18 | normal | 8 | 10.1.20 (InnoDB plugin) | on | zlib | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 19 | normal | 8 | 10.1.20 (InnoDB plugin) | on | zlib | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 20 | normal | 8 | 10.1.20 (InnoDB plugin) | - | zlib | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 21 | normal | 8 | 10.1.20 (InnoDB plugin) | - | - | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 22 | normal | 8 | 10.1.20 (InnoDB plugin) | - | - | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 23 | normal | 8 | 10.1.20 (InnoDB plugin) | on | - | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 24 | normal | 8 | 10.1.20 (InnoDB plugin) | on | - | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 25 | normal | 8 | 10.1.20 (InnoDB plugin) | - | - | => | 10.2.5 (inbuilt) | on | zlib | - | OK | | | 26 | normal | 8 | 10.1.20 (InnoDB plugin) | on | - | => | 10.2.5 (inbuilt) | - | zlib | - | OK | | | 27 | normal | 8 | 10.1.20 (InnoDB plugin) | - | - | => | 10.2.5 (inbuilt) | - | zlib | - | OK | | | 28 | normal | 8 | 10.1.20 (InnoDB plugin) | on | - | => | 10.2.5 (inbuilt) | on | zlib | - | OK | | | 29 | normal | 8 | 10.1.20 (InnoDB plugin) | - | zlib | => | 10.2.5 (inbuilt) | on | zlib | - | OK | | | 30 | normal | 8 | 10.1.20 (InnoDB plugin) | - | zlib | => | 10.2.5 (inbuilt) | - | zlib | - | OK | | | 31 | normal | 8 | 10.1.20 (InnoDB plugin) | on | zlib | => | 10.2.5 (inbuilt) | - | zlib | - | OK | | | 32 | normal | 8 | 10.1.20 (InnoDB plugin) | on | zlib | => | 10.2.5 (inbuilt) | on | zlib | - | OK | | | 33 | normal | 16 | 10.1.20 (InnoDB plugin) | - | - | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 34 | normal | 16 | 10.1.20 (InnoDB plugin) | on | - | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 35 | normal | 16 | 10.1.20 (InnoDB plugin) | on | - | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 36 | normal | 16 | 10.1.20 (InnoDB plugin) | - | - | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 37 | normal | 16 | 10.1.20 (InnoDB plugin) | on | zlib | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 38 | normal | 16 | 10.1.20 (InnoDB plugin) | - | zlib | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 39 | normal | 16 | 10.1.20 (InnoDB plugin) | - | zlib | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 40 | normal | 16 | 10.1.20 (InnoDB plugin) | on | zlib | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 41 | normal | 16 | 10.1.20 (InnoDB plugin) | - | zlib | => | 10.2.5 (inbuilt) | - | zlib | - | OK | | | 42 | normal | 16 | 10.1.20 (InnoDB plugin) | on | zlib | => | 10.2.5 (inbuilt) | - | zlib | - | OK | | | 43 | normal | 16 | 10.1.20 (InnoDB plugin) | on | zlib | => | 10.2.5 (inbuilt) | on | zlib | - | OK | | | 44 | normal | 16 | 10.1.20 (InnoDB plugin) | - | zlib | => | 10.2.5 (inbuilt) | on | zlib | - | OK | | | 45 | normal | 16 | 10.1.20 (InnoDB plugin) | on | - | => | 10.2.5 (inbuilt) | - | zlib | - | OK | | | 46 | normal | 16 | 10.1.20 (InnoDB plugin) | - | - | => | 10.2.5 (inbuilt) | - | zlib | - | OK | | | 47 | normal | 16 | 10.1.20 (InnoDB plugin) | - | - | => | 10.2.5 (inbuilt) | on | zlib | - | OK | | | 48 | normal | 16 | 10.1.20 (InnoDB plugin) | on | - | => | 10.2.5 (inbuilt) | on | zlib | - | OK | | | 49 | normal | 32 | 10.1.20 (InnoDB plugin) | on | zlib | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 50 | normal | 32 | 10.1.20 (InnoDB plugin) | - | zlib | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 51 | normal | 32 | 10.1.20 (InnoDB plugin) | - | zlib | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 52 | normal | 32 | 10.1.20 (InnoDB plugin) | on | zlib | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 53 | normal | 32 | 10.1.20 (InnoDB plugin) | - | - | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 54 | normal | 32 | 10.1.20 (InnoDB plugin) | on | - | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 55 | normal | 32 | 10.1.20 (InnoDB plugin) | on | - | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 56 | normal | 32 | 10.1.20 (InnoDB plugin) | - | - | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 57 | normal | 32 | 10.1.20 (InnoDB plugin) | on | - | => | 10.2.5 (inbuilt) | on | zlib | - | OK | | | 58 | normal | 32 | 10.1.20 (InnoDB plugin) | - | - | => | 10.2.5 (inbuilt) | on | zlib | - | OK | | | 59 | normal | 32 | 10.1.20 (InnoDB plugin) | on | - | => | 10.2.5 (inbuilt) | - | zlib | - | OK | | | 60 | normal | 32 | 10.1.20 (InnoDB plugin) | - | - | => | 10.2.5 (inbuilt) | - | zlib | - | OK | | | 61 | normal | 32 | 10.1.20 (InnoDB plugin) | - | zlib | => | 10.2.5 (inbuilt) | on | zlib | - | OK | | | 62 | normal | 32 | 10.1.20 (InnoDB plugin) | on | zlib | => | 10.2.5 (inbuilt) | on | zlib | - | OK | | | 63 | normal | 32 | 10.1.20 (InnoDB plugin) | on | zlib | => | 10.2.5 (inbuilt) | - | zlib | - | OK | | | 64 | normal | 32 | 10.1.20 (InnoDB plugin) | - | zlib | => | 10.2.5 (inbuilt) | - | zlib | - | OK | | | 65 | normal | 4 | 10.1.20 (InnoDB plugin) | - | - | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 66 | normal | 4 | 10.1.20 (InnoDB plugin) | on | - | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 67 | normal | 4 | 10.1.20 (InnoDB plugin) | on | - | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 68 | normal | 4 | 10.1.20 (InnoDB plugin) | - | - | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 69 | normal | 4 | 10.1.20 (InnoDB plugin) | on | zlib | => | 10.2.5 (inbuilt) | - | zlib | - | OK | | | 70 | normal | 4 | 10.1.20 (InnoDB plugin) | - | zlib | => | 10.2.5 (inbuilt) | on | zlib | - | OK | | | 71 | normal | 4 | 10.1.20 (InnoDB plugin) | on | zlib | => | 10.2.5 (inbuilt) | on | zlib | - | **FAIL** | [MDEV-12388](https://jira.mariadb.org/browse/MDEV-12388) | | 72 | normal | 4 | 10.1.20 (InnoDB plugin) | - | zlib | => | 10.2.5 (inbuilt) | - | zlib | - | OK | | | 73 | normal | 4 | 10.1.20 (InnoDB plugin) | on | zlib | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 74 | normal | 4 | 10.1.20 (InnoDB plugin) | - | zlib | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 75 | normal | 4 | 10.1.20 (InnoDB plugin) | on | zlib | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 76 | normal | 4 | 10.1.20 (InnoDB plugin) | - | zlib | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 77 | normal | 4 | 10.1.20 (InnoDB plugin) | - | - | => | 10.2.5 (inbuilt) | - | zlib | - | OK | | | 78 | normal | 4 | 10.1.20 (InnoDB plugin) | on | - | => | 10.2.5 (inbuilt) | on | zlib | - | OK | | | 79 | normal | 4 | 10.1.20 (InnoDB plugin) | - | - | => | 10.2.5 (inbuilt) | on | zlib | - | OK | | | 80 | normal | 4 | 10.1.20 (InnoDB plugin) | on | - | => | 10.2.5 (inbuilt) | - | zlib | - | OK | | | 81 | normal | 8 | 10.1.20 (inbuilt) | - | zlib | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 82 | normal | 8 | 10.1.20 (inbuilt) | on | zlib | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 83 | normal | 8 | 10.1.20 (inbuilt) | on | zlib | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 84 | normal | 8 | 10.1.20 (inbuilt) | - | zlib | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 85 | normal | 8 | 10.1.20 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | on | zlib | - | OK | | | 86 | normal | 8 | 10.1.20 (inbuilt) | on | - | => | 10.2.5 (inbuilt) | on | zlib | - | OK | | | 87 | normal | 8 | 10.1.20 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | - | zlib | - | OK | | | 88 | normal | 8 | 10.1.20 (inbuilt) | on | - | => | 10.2.5 (inbuilt) | - | zlib | - | OK | | | 89 | normal | 8 | 10.1.20 (inbuilt) | on | - | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 90 | normal | 8 | 10.1.20 (inbuilt) | on | - | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 91 | normal | 8 | 10.1.20 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 92 | normal | 8 | 10.1.20 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 93 | normal | 8 | 10.1.20 (inbuilt) | on | zlib | => | 10.2.5 (inbuilt) | on | zlib | - | OK | | | 94 | normal | 8 | 10.1.20 (inbuilt) | - | zlib | => | 10.2.5 (inbuilt) | - | zlib | - | OK | | | 95 | normal | 8 | 10.1.20 (inbuilt) | - | zlib | => | 10.2.5 (inbuilt) | on | zlib | - | OK | | | 96 | normal | 8 | 10.1.20 (inbuilt) | on | zlib | => | 10.2.5 (inbuilt) | - | zlib | - | OK | | | 97 | normal | 64 | 10.1.20 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 98 | normal | 64 | 10.1.20 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 99 | normal | 64 | 10.1.20 (inbuilt) | on | - | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 100 | normal | 64 | 10.1.20 (inbuilt) | on | - | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 101 | normal | 64 | 10.1.20 (inbuilt) | - | zlib | => | 10.2.5 (inbuilt) | on | zlib | - | OK | | | 102 | normal | 64 | 10.1.20 (inbuilt) | on | zlib | => | 10.2.5 (inbuilt) | on | zlib | - | OK | | | 103 | normal | 64 | 10.1.20 (inbuilt) | on | zlib | => | 10.2.5 (inbuilt) | - | zlib | - | OK | | | 104 | normal | 64 | 10.1.20 (inbuilt) | - | zlib | => | 10.2.5 (inbuilt) | - | zlib | - | OK | | | 105 | normal | 64 | 10.1.20 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | - | zlib | - | OK | | | 106 | normal | 64 | 10.1.20 (inbuilt) | on | - | => | 10.2.5 (inbuilt) | on | zlib | - | OK | | | 107 | normal | 64 | 10.1.20 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | on | zlib | - | OK | | | 108 | normal | 64 | 10.1.20 (inbuilt) | on | - | => | 10.2.5 (inbuilt) | - | zlib | - | OK | | | 109 | normal | 64 | 10.1.20 (inbuilt) | on | zlib | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 110 | normal | 64 | 10.1.20 (inbuilt) | on | zlib | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 111 | normal | 64 | 10.1.20 (inbuilt) | - | zlib | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 112 | normal | 64 | 10.1.20 (inbuilt) | - | zlib | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 113 | normal | 16 | 10.1.20 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | - | zlib | - | OK | | | 114 | normal | 16 | 10.1.20 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | on | zlib | - | OK | | | 115 | normal | 16 | 10.1.20 (inbuilt) | on | - | => | 10.2.5 (inbuilt) | on | zlib | - | OK | | | 116 | normal | 16 | 10.1.20 (inbuilt) | on | - | => | 10.2.5 (inbuilt) | - | zlib | - | OK | | | 117 | normal | 16 | 10.1.20 (inbuilt) | - | zlib | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 118 | normal | 16 | 10.1.20 (inbuilt) | on | zlib | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 119 | normal | 16 | 10.1.20 (inbuilt) | - | zlib | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 120 | normal | 16 | 10.1.20 (inbuilt) | on | zlib | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 121 | normal | 16 | 10.1.20 (inbuilt) | on | - | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 122 | normal | 16 | 10.1.20 (inbuilt) | on | - | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 123 | normal | 16 | 10.1.20 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 124 | normal | 16 | 10.1.20 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 125 | normal | 16 | 10.1.20 (inbuilt) | on | zlib | => | 10.2.5 (inbuilt) | on | zlib | - | OK | | | 126 | normal | 16 | 10.1.20 (inbuilt) | - | zlib | => | 10.2.5 (inbuilt) | - | zlib | - | OK | | | 127 | normal | 16 | 10.1.20 (inbuilt) | - | zlib | => | 10.2.5 (inbuilt) | on | zlib | - | OK | | | 128 | normal | 16 | 10.1.20 (inbuilt) | on | zlib | => | 10.2.5 (inbuilt) | - | zlib | - | OK | | | 129 | normal | 4 | 10.1.20 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 130 | normal | 4 | 10.1.20 (inbuilt) | on | - | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 131 | normal | 4 | 10.1.20 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 132 | normal | 4 | 10.1.20 (inbuilt) | on | - | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 133 | normal | 4 | 10.1.20 (inbuilt) | - | zlib | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 134 | normal | 4 | 10.1.20 (inbuilt) | on | zlib | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 135 | normal | 4 | 10.1.20 (inbuilt) | - | zlib | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 136 | normal | 4 | 10.1.20 (inbuilt) | on | zlib | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 137 | normal | 4 | 10.1.20 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | on | zlib | - | OK | | | 138 | normal | 4 | 10.1.20 (inbuilt) | on | - | => | 10.2.5 (inbuilt) | - | zlib | - | OK | | | 139 | normal | 4 | 10.1.20 (inbuilt) | on | - | => | 10.2.5 (inbuilt) | on | zlib | - | OK | | | 140 | normal | 4 | 10.1.20 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | - | zlib | - | OK | | | 141 | normal | 4 | 10.1.20 (inbuilt) | - | zlib | => | 10.2.5 (inbuilt) | - | zlib | - | OK | | | 142 | normal | 4 | 10.1.20 (inbuilt) | - | zlib | => | 10.2.5 (inbuilt) | on | zlib | - | OK | | | 143 | normal | 4 | 10.1.20 (inbuilt) | on | zlib | => | 10.2.5 (inbuilt) | on | zlib | - | OK | | | 144 | normal | 4 | 10.1.20 (inbuilt) | on | zlib | => | 10.2.5 (inbuilt) | - | zlib | - | OK | | | 145 | normal | 32 | 10.1.20 (inbuilt) | - | zlib | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 146 | normal | 32 | 10.1.20 (inbuilt) | on | zlib | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 147 | normal | 32 | 10.1.20 (inbuilt) | on | zlib | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 148 | normal | 32 | 10.1.20 (inbuilt) | - | zlib | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 149 | normal | 32 | 10.1.20 (inbuilt) | on | zlib | => | 10.2.5 (inbuilt) | on | zlib | - | OK | | | 150 | normal | 32 | 10.1.20 (inbuilt) | - | zlib | => | 10.2.5 (inbuilt) | on | zlib | - | OK | | | 151 | normal | 32 | 10.1.20 (inbuilt) | on | zlib | => | 10.2.5 (inbuilt) | - | zlib | - | OK | | | 152 | normal | 32 | 10.1.20 (inbuilt) | - | zlib | => | 10.2.5 (inbuilt) | - | zlib | - | OK | | | 153 | normal | 32 | 10.1.20 (inbuilt) | on | - | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 154 | normal | 32 | 10.1.20 (inbuilt) | on | - | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 155 | normal | 32 | 10.1.20 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 156 | normal | 32 | 10.1.20 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 157 | normal | 32 | 10.1.20 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | - | zlib | - | OK | | | 158 | normal | 32 | 10.1.20 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | on | zlib | - | OK | | | 159 | normal | 32 | 10.1.20 (inbuilt) | on | - | => | 10.2.5 (inbuilt) | - | zlib | - | OK | | | 160 | normal | 32 | 10.1.20 (inbuilt) | on | - | => | 10.2.5 (inbuilt) | on | zlib | - | OK | | Upgrade from MySQL 5.6 ---------------------- ### Tested revision b56262f69677fdb158b3d19dd8848e5802b2dd27 ### Test date 2017-03-28 14:00:57 ### Summary (PASS) All tests passed ### Details | # | type | pagesize | OLD version | encrypted | compressed | | NEW version | encrypted | compressed | readonly | result | notes | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | 1 | normal | 16 | 5.6.35 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 2 | normal | 16 | 5.6.35 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 3 | normal | 4 | 5.6.35 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 4 | normal | 4 | 5.6.35 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 5 | normal | 8 | 5.6.35 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 6 | normal | 8 | 5.6.35 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | on | - | - | OK | | Upgrade from MySQL 5.7 ---------------------- ### Tested revision b56262f69677fdb158b3d19dd8848e5802b2dd27 ### Test date 2017-03-28 23:04:16 ### Summary (PASS) All tests passed ### Details | # | type | pagesize | OLD version | encrypted | compressed | | NEW version | encrypted | compressed | readonly | result | notes | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | 1 | normal | 8 | 5.7.17 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 2 | normal | 8 | 5.7.17 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 3 | normal | 64 | 5.7.17 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 4 | normal | 64 | 5.7.17 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 5 | normal | 16 | 5.7.17 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 6 | normal | 16 | 5.7.17 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 7 | normal | 32 | 5.7.17 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 8 | normal | 32 | 5.7.17 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 9 | normal | 4 | 5.7.17 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 10 | normal | 4 | 5.7.17 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 11 | crash | 64 | 5.7.17 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 12 | crash | 64 | 5.7.17 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 13 | crash | 16 | 5.7.17 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 14 | crash | 16 | 5.7.17 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 15 | crash | 8 | 5.7.17 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 16 | crash | 8 | 5.7.17 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 17 | crash | 32 | 5.7.17 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 18 | crash | 32 | 5.7.17 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 19 | crash | 4 | 5.7.17 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 20 | crash | 4 | 5.7.17 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 21 | normal | 32 | 5.7.17 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 22 | normal | 32 | 5.7.17 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 23 | normal | 4 | 5.7.17 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 24 | normal | 4 | 5.7.17 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 25 | normal | 16 | 5.7.17 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 26 | normal | 16 | 5.7.17 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 27 | normal | 64 | 5.7.17 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | on | - | - | OK | | | 28 | normal | 64 | 5.7.17 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 29 | normal | 8 | 5.7.17 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | - | - | - | OK | | | 30 | normal | 8 | 5.7.17 (inbuilt) | - | - | => | 10.2.5 (inbuilt) | on | - | - | OK | | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb JSON_QUERY JSON\_QUERY =========== **MariaDB starting with [10.2.3](https://mariadb.com/kb/en/mariadb-1023-release-notes/)**JSON functions were added in [MariaDB 10.2.3](https://mariadb.com/kb/en/mariadb-1023-release-notes/). Syntax ------ ``` JSON_QUERY(json_doc, path) ``` Description ----------- Given a JSON document, returns an object or array specified by the path. Returns NULL if not given a valid JSON document, or if there is no match. Examples -------- ``` select json_query('{"key1":{"a":1, "b":[1,2]}}', '$.key1'); +-----------------------------------------------------+ | json_query('{"key1":{"a":1, "b":[1,2]}}', '$.key1') | +-----------------------------------------------------+ | {"a":1, "b":[1,2]} | +-----------------------------------------------------+ select json_query('{"key1":123, "key1": [1,2,3]}', '$.key1'); +-------------------------------------------------------+ | json_query('{"key1":123, "key1": [1,2,3]}', '$.key1') | +-------------------------------------------------------+ | [1,2,3] | +-------------------------------------------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Stored Function Overview Stored Function Overview ======================== A Stored Function is a defined function that is called from within an SQL statement like a regular function, and returns a single value. Creating Stored Functions ------------------------- Here's a skeleton example to see a stored function in action: ``` DELIMITER // CREATE FUNCTION FortyTwo() RETURNS TINYINT DETERMINISTIC BEGIN DECLARE x TINYINT; SET x = 42; RETURN x; END // DELIMITER ; ``` First, the delimiter is changed, since the function definition will contain the regular semicolon delimiter. See [Delimiters in the mysql client](../delimiters-in-the-mysql-client/index) for more. Then the function is named `FortyTwo` and defined to return a `tinyin`. The `DETERMINISTIC` keyword is not necessary in all cases (although if binary logging is on, leaving it out will throw an error), and is to help the query optimizer choose a query plan. A deterministic function is one that, given the same arguments, will always return the same result. Next, the function body is placed between [BEGIN and END](../begin-end/index) statements. It declares a tinyint, `X`, which is simply set to 42, and this is the result returned. ``` SELECT FortyTwo(); +------------+ | FortyTwo() | +------------+ | 42 | +------------+ ``` Of course, a function that doesn't take any arguments is of little use. Here's a more complex example: ``` DELIMITER // CREATE FUNCTION VatCents(price DECIMAL(10,2)) RETURNS INT DETERMINISTIC BEGIN DECLARE x INT; SET x = price * 114; RETURN x; END // Query OK, 0 rows affected (0.04 sec) DELIMITER ; ``` This function takes an argument, `price` which is defined as a DECIMAL, and returns an INT. Take a look at the [CREATE FUNCTION](../create-function/index) page for more details. From [MariaDB 10.3.3](https://mariadb.com/kb/en/mariadb-1033-release-notes/), it is also possible to create [stored aggregate functions](../stored-aggregate-functions/index). Stored Function listings and definitions ---------------------------------------- To find which stored functions are running on the server, use [SHOW FUNCTION STATUS](../show-function-status/index). ``` SHOW FUNCTION STATUS\G *************************** 1. row *************************** Db: test Name: VatCents Type: FUNCTION Definer: root@localhost Modified: 2013-06-01 12:40:31 Created: 2013-06-01 12:40:31 Security_type: DEFINER Comment: character_set_client: utf8 collation_connection: utf8_general_ci Database Collation: latin1_swedish_ci 1 row in set (0.00 sec) ``` or query the [routines table](../information-schema-routines-table/index) in the INFORMATION\_SCHEMA database directly: ``` SELECT ROUTINE_NAME FROM INFORMATION_SCHEMA.ROUTINES WHERE ROUTINE_TYPE='FUNCTION'; +--------------+ | ROUTINE_NAME | +--------------+ | VatCents | +--------------+ ``` To find out what the stored function does, use [SHOW CREATE FUNCTION](../show-create-function/index). ``` SHOW CREATE FUNCTION VatCents\G *************************** 1. row *************************** Function: VatCents sql_mode: Create Function: CREATE DEFINER=`root`@`localhost` FUNCTION `VatCents`(price DECIMAL(10,2)) RETURNS int(11) DETERMINISTIC BEGIN DECLARE x INT; SET x = price * 114; RETURN x; END character_set_client: utf8 collation_connection: utf8_general_ci Database Collation: latin1_swedish_ci ``` Dropping and Updating Stored Functions -------------------------------------- To drop a stored function, use the [DROP FUNCTION](../drop-function/index) statement. ``` DROP FUNCTION FortyTwo; ``` To change the characteristics of a stored function, use [ALTER FUNCTION](../alter-function/index). Note that you cannot change the parameters or body of a stored function using this statement; to make such changes, you must drop and re-create the function using DROP FUNCTION and CREATE FUNCTION. Permissions in Stored Functions ------------------------------- See the article [Stored Routine Privileges](../stored-routine-privileges/index). See Also -------- * [CREATE FUNCTION](../create-function/index) * [SHOW CREATE FUNCTION](../show-create-function/index) * [DROP FUNCTION](../drop-function/index) * [Stored Routine Privileges](../stored-routine-privileges/index) * [SHOW FUNCTION STATUS](../show-function-status/index) * [Information Schema ROUTINES Table](../information-schema-routines-table/index) * [Stored Aggregate Functions](../stored-aggregate-functions/index). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Information Schema ROCKSDB_GLOBAL_INFO Table Information Schema ROCKSDB\_GLOBAL\_INFO Table ============================================== The [Information Schema](../information_schema/index) `ROCKSDB_GLOBAL_INFO` table is included as part of the [MyRocks](../myrocks/index) storage engine. The `PROCESS` [privilege](../grant/index) is required to view the table. It contains the following columns: | Column | Description | | --- | --- | | `TYPE` | | | `NAME` | | | `VALUE` | | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Logical Operators Logical Operators ================== NOT, AND, Exclusive OR and OR | Title | Description | | --- | --- | | [!](../not/index) | Logical NOT. | | [&&](../and/index) | Logical AND. | | [XOR](../xor/index) | Logical XOR. | | [||](../or/index) | Logical OR. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Semisynchronous Replication Plugin Status Variables Semisynchronous Replication Plugin Status Variables =================================================== This page documents status variables related to the [Semisynchronous Replication Plugin](../semisynchronous-replication/index) (which has been merged into the main server from [MariaDB 10.3.3](https://mariadb.com/kb/en/mariadb-1033-release-notes/)). See [Server Status Variables](../server-status-variables/index) for a complete list of status variables that can be viewed with [SHOW STATUS](../show-status/index). See also the [Full list of MariaDB options, system and status variables](../full-list-of-mariadb-options-system-and-status-variables/index). #### `Rpl_semi_sync_master_clients` * **Description:** Number of semisynchronous slaves. * **Data Type:** `numeric` --- #### `Rpl_semi_sync_master_net_avg_wait_time` * **Description:** Average time the master waited for a slave to reply, in microseconds. * **Data Type:** `numeric` --- #### `Rpl_semi_sync_master_net_wait_time` * **Description:** Total time the master waited for slave replies, in microseconds. * **Data Type:** `numeric` --- #### `Rpl_semi_sync_master_net_waits` * **Description:** Total number of times the master waited for slave replies. * **Data Type:** `numeric` --- #### `Rpl_semi_sync_master_no_times` * **Description:** Number of times the master turned off semisynchronous replication. The global value can be flushed by `[FLUSH STATUS](../flush/index)`. * **Data Type:** `numeric` --- #### `Rpl_semi_sync_master_no_tx` * **Description:** Number of commits that have not been successfully acknowledged by a slave. The global value can be flushed by `[FLUSH STATUS](../flush/index)`. * **Data Type:** `numeric` --- #### `Rpl_semi_sync_master_status` * **Description:** Whether or not semisynchronous replication is currently operating on the master. The value will be `ON` if both the plugin has been enabled and a commit acknowledgment has occurred. It will be `OFF` if either the plugin has not been enabled, or the master is replicating asynchronously due to a commit acknowledgment timeout. * **Data Type:** `boolean` --- #### `Rpl_semi_sync_master_timefunc_failures` * **Description:** Number of times the master failed when calling a time function, such as gettimeofday(). The global value can be flushed by `[FLUSH STATUS](../flush/index)`. * **Data Type:** `numeric` --- #### `Rpl_semi_sync_master_tx_avg_wait_time` * **Description:** Average time the master waited for each transaction, in microseconds. * **Data Type:** `numeric` --- #### `Rpl_semi_sync_master_tx_wait_time` * **Description:** Total time the master waited for transactions, in microseconds. * **Data Type:** `numeric` --- #### `Rpl_semi_sync_master_tx_waits` * **Description:** Total number of times the master waited for transactions. * **Data Type:** `numeric` --- #### `Rpl_semi_sync_master_wait_pos_backtraverse` * **Description:** Total number of times the master waited for an event that had binary coordinates lower than previous events waited for. Occurs if the order in which transactions start waiting for a reply is different from the order in which their binary log events were written. The global value can be flushed by `[FLUSH STATUS](../flush/index)`. * **Data Type:** `numeric` --- #### `Rpl_semi_sync_master_wait_sessions` * **Description:** Number of sessions that are currently waiting for slave replies. * **Data Type:** `numeric` --- #### `Rpl_semi_sync_master_yes_tx` * **Description:** Number of commits that have been successfully acknowledged by a slave. The global value can be flushed by `[FLUSH STATUS](../flush/index)`. * **Data Type:** `numeric` --- #### `Rpl_semi_sync_slave_status` * **Description:** Whether or not semisynchronous replication is currently operating on the slave. `ON` if both the plugin has been enabled and the slave I/O thread is running. * **Data Type:** `boolean` --- Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb myisampack myisampack ========== `myisampack` is a tool for compressing [MyISAM](../myisam/index) tables. The resulting tables are read-only, and usually about 40% to 70% smaller. It is run as follows: ``` myisampack [options] file_name [file_name2...] ``` The `file_name` is the `.MYI` index file. The extension can be omitted, although keeping it permits wildcards, such as: ``` myisampack *.MYI ``` ...to compress all the files. `myisampack` compresses each column separately, and, when the resulting data is read, only the individual rows and columns required need to be decompressed, allowing for quicker reading. Once a table has been packed, use `[myisamchk -rq](../myisamchk/index)` (the quick and recover options) to rebuild its indexes. `myisampack` does not support partitioned tables. Do not run myisampack if the tables could be updated during the operation, and [skip\_external\_locking](../server-system-variables/index#skip_external_locking) has been set. Options ------- The following variables can be set while passed as commandline options to `myisampack`, or set with a `[myisampack]` section in your [my.cnf](../configuring-mariadb-with-mycnf/index) file. | Option | Description | | --- | --- | | `-b`, `--backup` | Make a backup of the table as `table_name.OLD`. | | `--character-sets-dir=name` | Directory where character sets are. | | `-#` , `--debug[=name]` | Output debug log. Often this is `'d:t:o,filename'`. | | `-f`, `--force` | Force packing of table even if it gets bigger or if tempfile exists. | | `-j`, `--join=name` | Join all given tables into `'new_table_name'`. All tables **must** have identical layouts. | | `-?`, `--help` | Display help and exit. | | `-s`, `--silent` | Only write output when an error occurs | | `-T`, `--tmpdir=name` | Use temporary directory to store temporary table. | | `-t`, `--test` | Don't pack table, only test packing it. | | `-v`, `--verbose` | Write info about progress and packing result. Use multiple `-v` flags for more verbosity. | | `-V`, `--version` | Output version information and exit. | | `-w`, `--wait` | Wait and retry if table is in use. | Uncompressing ------------- To uncompress a table compressed with `myisampack`, use the `[myisamchk -u](../myisamchk/index)` option. Examples -------- ``` > myisampack /var/lib/mysql/test/posts Compressing /var/lib/mysql/test/posts.MYD: (1680 records) - Calculating statistics - Compressing file 37.71% > myisamchk -rq /var/lib/mysql/test/posts - check record delete-chain - recovering (with sort) MyISAM-table '/var/lib/mysql/test/posts' Data records: 1680 - Fixing index 1 - Fixing index 2 ``` See Also -------- * [FLUSH TABLES FOR EXPORT](../flush-tables-for-export/index) * [myisamchk](../myisamchk/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Installing MariaDB With the rpm Tool Installing MariaDB With the rpm Tool ==================================== This article describes how to download the RPM files and install them using the `rpm` command. It is highly recommended to [Install MariaDB with yum](../yum/index) where possible. Navigate to <http://downloads.mariadb.org> and choose the desired database version and then select the RPMs that match your Linux distribution and architecture. Clicking those links takes you to a local mirror. Choose the rpms link and download the desired packages. The packages will be similar to the following: ``` MariaDB-client-5.2.5-99.el5.x86_64.rpm MariaDB-debuginfo-5.2.5-99.el5.x86_64.rpm MariaDB-devel-5.2.5-99.el5.x86_64.rpm MariaDB-server-5.2.5-99.el5.x86_64.rpm MariaDB-shared-5.2.5-99.el5.x86_64.rpm MariaDB-test-5.2.5-99.el5.x86_64.rpm ``` For a standard server installation you will need to download at least the *client*, *shared*, and *server* RPM files. See [About the MariaDB RPM Files](../about-the-mariadb-rpm-files/index) for more information about what is included in each RPM package. After downloading the MariaDB RPM files, you might want to check their signatures. See [Checking MariaDB RPM Package Signatures](../checking-mariadb-rpm-package-signatures/index) for more information about checking signatures. ``` rpm --checksig $(find . -name '*.rpm') ``` Prior to installing MariaDB, be aware that it will conflict with an existing installation of MySQL. To check whether MySQL is already installed, issue the command: ``` rpm -qa 'mysql*' ``` If necessary, you can remove found MySQL packages before installing MariaDB. To install MariaDB, use the command: ``` rpm -ivh MariaDB-* ``` You should see output such as the following: ``` Preparing... ########################################### [100%] 1:MariaDB-shared ########################################### [ 14%] 2:MariaDB-client ########################################### [ 29%] 3:MariaDB-client ########################################### [ 43%] 4:MariaDB-debuginfo ########################################### [ 57%] 5:MariaDB-devel ########################################### [ 71%] 6:MariaDB-server ########################################### [ 86%] PLEASE REMEMBER TO SET A PASSWORD FOR THE MariaDB root USER ! To do so, start the server, then issue the following commands: /usr/bin/mysqladmin -u root password 'new-password' /usr/bin/mysqladmin -u root -h hostname password 'new-password' Alternatively you can run: /usr/bin/mysql_secure_installation which will also give you the option of removing the test databases and anonymous user created by default. This is strongly recommended for production servers. See the MySQL manual for more instructions. Please report any problems with the /usr/bin/mysqlbug script! The latest information about MariaDB is available at http://www.askmonty.org/. You can find additional information about the MySQL part at: http://dev.mysql.com Support MariaDB development by buying support/new features from Monty Program Ab. You can contact us about this at [email protected]. Alternatively consider joining our community based development effort: http://askmonty.org/wiki/index.php/MariaDB#How_can_I_participate_in_the_development_of_MariaDB Starting MySQL....[ OK ] Giving mysqld 2 seconds to start 7:MariaDB-test ########################################### [100%] ``` Be sure to follow the instructions given in the preceding output and create a password for the root user either by using mysqladmin or by running the /usr/bin/mysql\_secure\_installation script. Installing the MariaDB RPM files installs the MySQL tools in the `/usr/bin` directory. You can confirm that MariaDB has been installed by using the MySQL client program. Issuing the command `mysql` should give you the MariaDB cursor. See Also -------- * [Installing MariaDB with yum](../installing-mariadb-with-yum/index) * [Troubleshooting MariaDB Installs on RedHat/CentOS](../troubleshooting-mariadb-installs-on-redhatcentos/index) * [Checking MariaDB RPM Package Signatures](../checking-mariadb-rpm-package-signatures/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb MBRDisjoint MBRDisjoint =========== Syntax ------ ``` MBRDisjoint(g1,g2) ``` Description ----------- Returns 1 or 0 to indicate whether the Minimum Bounding Rectangles of the two geometries g1 and g2 are disjoint. Two geometries are disjoint if they do not intersect, that is touch or overlap. Examples -------- ``` SET @g1 = GeomFromText('Polygon((0 0,0 3,3 3,3 0,0 0))'); SET @g2 = GeomFromText('Polygon((4 4,4 7,7 7,7 4,4 4))'); SELECTmbrdisjoint(@g1,@g2); +----------------------+ | mbrdisjoint(@g1,@g2) | +----------------------+ | 1 | +----------------------+ SET @g1 = GeomFromText('Polygon((0 0,0 3,3 3,3 0,0 0))'); SET @g2 = GeomFromText('Polygon((3 3,3 6,6 6,6 3,3 3))'); SELECT mbrdisjoint(@g1,@g2); +----------------------+ | mbrdisjoint(@g1,@g2) | +----------------------+ | 0 | +----------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb Performance Schema status_by_user Table Performance Schema status\_by\_user Table ========================================= **MariaDB starting with [10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/)**The `status_by_account` table was added in [MariaDB 10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/). The `status_by_account` table contains status variable information by user. The table does not collect statistics for `Com_xxx` variables. The table contains the following columns: | Column | Description | | --- | --- | | USER | User for which the status variable is reported. | | VARIABLE\_NAME | Status variable name. | | VARIABLE\_VALUE | Aggregated status variable value | If [TRUNCATE TABLE](../truncate-table/index) is run, will reset the aggregated user status from terminated sessions. If [FLUSH STATUS](flush-status) is run, session status from all active sessions are added to the global status variables, the status of all active sessions are reset, and values aggregated from disconnected sessions are reset. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb ST_PointFromWKB ST\_PointFromWKB ================ Syntax ------ ``` ST_PointFromWKB(wkb[,srid]) PointFromWKB(wkb[,srid]) ``` Description ----------- Constructs a [POINT](../point/index) value using its [WKB](../well-known-binary-wkb-format/index) representation and [SRID](../srid/index). `ST_PointFromWKB()` and `PointFromWKB()` are synonyms. Examples -------- ``` SET @g = ST_AsBinary(ST_PointFromText('POINT(0 4)')); SELECT ST_AsText(ST_PointFromWKB(@g)) AS p; +------------+ | p | +------------+ | POINT(0 4) | +------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb YEAR YEAR ==== Syntax ------ ``` YEAR(date) ``` Description ----------- Returns the year for the given date, in the range 1000 to 9999, or 0 for the "zero" date. Examples -------- ``` CREATE TABLE t1 (d DATETIME); INSERT INTO t1 VALUES ("2007-01-30 21:31:07"), ("1983-10-15 06:42:51"), ("2011-04-21 12:34:56"), ("2011-10-30 06:31:41"), ("2011-01-30 14:03:25"), ("2004-10-07 11:19:34"); ``` ``` SELECT * FROM t1; +---------------------+ | d | +---------------------+ | 2007-01-30 21:31:07 | | 1983-10-15 06:42:51 | | 2011-04-21 12:34:56 | | 2011-10-30 06:31:41 | | 2011-01-30 14:03:25 | | 2004-10-07 11:19:34 | +---------------------+ SELECT * FROM t1 WHERE YEAR(d) = 2011; +---------------------+ | d | +---------------------+ | 2011-04-21 12:34:56 | | 2011-10-30 06:31:41 | | 2011-01-30 14:03:25 | +---------------------+ ``` ``` SELECT YEAR('1987-01-01'); +--------------------+ | YEAR('1987-01-01') | +--------------------+ | 1987 | +--------------------+ ``` See Also -------- * [YEAR data type](../year-data-type/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Performance Schema events_waits_summary_by_thread_by_event_name Table Performance Schema events\_waits\_summary\_by\_thread\_by\_event\_name Table ============================================================================ The [Performance Schema](../performance-schema/index) `events_waits_summary_by_thread_by_event_name` table contains wait events summarized by thread and event name. It contains the following columns: | Column | Description | | --- | --- | | `THREAD_ID` | Thread associated with the event. Together with `EVENT_NAME` uniquely identifies the row. | | `EVENT_NAME` | Event name. Used together with `THREAD_ID` for grouping events. | | `COUNT_STAR` | Number of summarized events | | `SUM_TIMER_WAIT` | Total wait time of the summarized events that are timed. | | `MIN_TIMER_WAIT` | Minimum wait time of the summarized events that are timed. | | `AVG_TIMER_WAIT` | Average wait time of the summarized events that are timed. | | `MAX_TIMER_WAIT` | Maximum wait time of the summarized events that are timed. | The `*_TIMER_WAIT` columns only calculate results for timed events, as non-timed events have a `NULL` wait time. Example ------- ``` SELECT * FROM events_waits_summary_by_thread_by_event_name\G ... *************************** 6424. row *************************** THREAD_ID: 64 EVENT_NAME: wait/io/socket/sql/server_unix_socket COUNT_STAR: 0 SUM_TIMER_WAIT: 0 MIN_TIMER_WAIT: 0 AVG_TIMER_WAIT: 0 MAX_TIMER_WAIT: 0 *************************** 6425. row *************************** THREAD_ID: 64 EVENT_NAME: wait/io/socket/sql/client_connection COUNT_STAR: 0 SUM_TIMER_WAIT: 0 MIN_TIMER_WAIT: 0 AVG_TIMER_WAIT: 0 MAX_TIMER_WAIT: 0 *************************** 6426. row *************************** THREAD_ID: 64 EVENT_NAME: idle COUNT_STAR: 73 SUM_TIMER_WAIT: 22005252162000000 MIN_TIMER_WAIT: 3000000 AVG_TIMER_WAIT: 301441810000000 MAX_TIMER_WAIT: 4912417573000000 ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Event Scheduler Event Scheduler ================ Events are named database objects containing SQL statements that are to be executed at a later stage, either once off, or at regular intervals. | Title | Description | | --- | --- | | [Events Overview](../events/index) | Scheduled events. | | [Event Limitations](../event-limitations/index) | Restrictions applying to events | | [CREATE EVENT](../create-event/index) | Create and schedule a new event. | | [ALTER EVENT](../alter-event/index) | Change an existing event. | | [DROP EVENT](../drop-event/index) | Removes an existing event. | | [Information Schema EVENTS Table](../information-schema-events-table/index) | Server event information | | [SHOW EVENTS](../show-events/index) | Shows information about events | | [SHOW CREATE EVENT](../show-create-event/index) | Displays the CREATE EVENT statement needed to re-create a given event | | [Automating MariaDB Tasks with Events](../automating-mariadb-tasks-with-events/index) | Using MariaDB events for automating tasks. | | [mysql.event Table](../mysqlevent-table/index) | Information about MariaDB events. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb mroonga_snippet mroonga\_snippet ================ Syntax ------ ``` mroonga_snippet document, max_length, max_count, encoding, skip_leading_spaces, html_escape, snippet_prefix, snippet_suffix, word1, word1_prefix, word1_suffix ... [wordN wordN_prefix wordN_suffix] ``` Description ----------- `mroonga_snippet` is a [user-defined function](../user-defined-functions/index) (UDF) included with the [Mroonga storage engine](../mroonga/index). It provides a keyword with surrounding text, or the keyword in context. See [Creating Mroonga User-Defined Functions](../creating-mroonga-user-defined-functions/index) for details on creating this UDF if required. The required parameters include: * `document` - Column name or string value. * `max_length` - Maximum length of the snippet, in bytes. * `max_count` - Maximum snippet elements (N word). * `encoding` - Encoding of the document, for example `cp932_japanese_ci` * `skip_leading_spaces` - `1` to skip leading spaces, `0` to not skip. * `html_escape` = `1` to enable HTML espape, `0` to disable. * `prefix` - Snippet start text. * `suffix` - Snippet end text. The optional parameters include: * `wordN` - A word. * `wordN_prefix` - wordN start text. * `wordN_suffix` - wordN end text It can be used in both storage and wrapper mode. Returns the snippet string. Example ------- See Also -------- * [Creating Mroonga User-Defined Functions](../creating-mroonga-user-defined-functions/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Introduction to State Snapshot Transfers (SSTs) Introduction to State Snapshot Transfers (SSTs) =============================================== In a State Snapshot Transfer (SST), the cluster provisions nodes by transferring a full data copy from one node to another. When a new node joins the cluster, the new node initiates a State Snapshot Transfer to synchronize its data with a node that is already part of the cluster. Types of SSTs ------------- There are two conceptually different ways to transfer a state from one MariaDB server to another: 1. **Logical** The only SST method of this type is the `mysqldump` SST method, which actually uses the `[mysqldump](../mysqldump/index)` utility to get a logical dump of the donor. This SST method requires the joiner node to be fully initialized and ready to accept connections before the transfer. This method is, by definition, blocking, in that it blocks the donor node from modifying its own state for the duration of the transfer. It is also the slowest of all, and that might be an issue in a cluster with a lot of load. 2. **Physical** SST methods of this type physically copy the data files from the donor node to the joiner node. This requires that the joiner node is initialized after the transfer. The `[mariabackup](../mariabackup-sst-method/index)` SST method and a few other SST methods fall into this category. These SST methods are much faster than the `mysqldump` SST method, but they have certain limitations. For example, they can be used only on server startup and the joiner node must be configured very similarly to the donor node (e.g. [innodb\_file\_per\_table](../innodb-system-variables/index#innodb_file_per_table) should be the same and so on). Some of the SST methods in this category are non-blocking on the donor node, meaning that the donor node is still able to process queries while donating the SST (e.g. the `[mariabackup](../mariabackup-sst-method/index)` SST method is non-blocking). SST Methods ----------- SST methods are supported via a scriptable interface. New SST methods could potentially be developed by creating new SST scripts. The scripts usually have names of the form `wsrep_sst_<method>` where `<method>` is one of the SST methods listed below. You can choose your SST method by setting the `[wsrep\_sst\_method](../galera-cluster-system-variables/index#wsrep_sst_method)` system variable. It can be changed dynamically with `[SET GLOBAL](../set/index#global-session)` on the node that you intend to be a SST donor. For example: ``` SET GLOBAL wsrep_sst_method='mariabackup'; ``` It can also be set in a server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index) prior to starting up a node: ``` [mariadb] ... wsrep_sst_method = mariabackup ``` For an SST to work properly, the donor and joiner node must use the same SST method. Therefore, it is recommended to set `[wsrep\_sst\_method](../galera-cluster-system-variables/index#wsrep_sst_method)` to the same value on all nodes, since any node will usually be a donor or joiner node at some point. MariaDB Galera Cluster comes with the following built-in SST methods: ### mariabackup This SST method uses the [Mariabackup](../backup-restore-and-import-clients-mariadb-backup/index) utility for performing SSTs. It is one of the two non-locking methods. This is the recommended SST method if you require the ability to run queries on the donor node during the SST. Note that if you use the `mariabackup` SST method, then you also need to have `socat` installed on the server. This is needed to stream the backup from the donor to the joiner. This is a limitation inherited from the `xtrabackup-v2` SST method. This SST method supports [GTID](../gtid/index). This SST method supports [Data at Rest Encryption](../data-at-rest-encryption/index). This SST method is available from [MariaDB 10.1.26](https://mariadb.com/kb/en/mariadb-10126-release-notes/) and [MariaDB 10.2.10](https://mariadb.com/kb/en/mariadb-10210-release-notes/). With this SST method, it is impossible to upgrade the cluster between some major versions; see [MDEV-27437](https://jira.mariadb.org/browse/MDEV-27437). See [mariabackup SST method](../mariabackup-sst-method/index) for more information. ### rsync / rsync\_wan `rsync` is the default method. This method uses the `[rsync](http://www.samba.org/rsync/)` utility to create a snapshot of the donor node. `rsync` should be available by default on all modern Linux distributions. The donor node is blocked with a read lock during the SST. This is the fastest SST method, especially for large datasets since it copies binary data. Because of that, this is the recommended SST method if you do not need to allow the donor node to execute queries during the SST. The `rsync` method runs `rsync` in `--whole-file` mode, assuming that nodes are connected by fast local network links so that the default delta transfer mode would consume more processing time than it may save on data transfer bandwidth. When having a distributed cluster with slow links between nodes, the `rsync_wan` method runs `rsync` in the default delta transfer mode, which may reduce data transfer time substantially when an older datadir state is already present on the joiner node. Both methods are actually implemented by the same script, `wsrep_sst_rsync_wan` is just a symlink to the `wsrep_sst_rsync` script and the actual `rsync` mode to use is determined by the name the script was called by. This SST method supports [GTID](../gtid/index). This SST method supports [Data at Rest Encryption](../data-at-rest-encryption/index). Use of this SST method **could result in data corruption** when using [innodb\_use\_native\_aio](../innodb-system-variables/index#innodb_use_native_aio) (the default) if the donor is older than [MariaDB 10.3.35](https://mariadb.com/kb/en/mariadb-10335-release-notes/), [MariaDB 10.4.25](https://mariadb.com/kb/en/mariadb-10425-release-notes/), [MariaDB 10.5.16](https://mariadb.com/kb/en/mariadb-10516-release-notes/), [MariaDB 10.6.8](https://mariadb.com/kb/en/mariadb-1068-release-notes/), or [MariaDB 10.7.4](https://mariadb.com/kb/en/mariadb-1074-release-notes/); see [MDEV-25975](https://jira.mariadb.org/browse/MDEV-25975). Starting with those donor versions, `wsrep_sst_method=rsync` is a reliable way to upgrade the cluster to a newer major version. As of [MariaDB 10.1.36](https://mariadb.com/kb/en/mariadb-10136-release-notes/), [MariaDB 10.2.18](https://mariadb.com/kb/en/mariadb-10218-release-notes/), and [MariaDB 10.3.10](https://mariadb.com/kb/en/mariadb-10310-release-notes/), `[stunnel](https://www.stunnel.org)` can be used to encrypt data over the wire. Be sure to have `stunnel` installed. You will also need to generate certificates and keys. See [the stunnel documentation](https://www.stunnel.org/howto.html) for information on how to do that. Once you have the keys, you will need to add the `tkey` and `tcert` options to the `[sst]` option group in your MariaDB configuration file, such as: ``` [sst] tkey = /etc/my.cnf.d/certificates/client-key.pem tcert = /etc/my.cnf.d/certificates/client-cert.pem ``` You also need to run the certificate directory through `[openssl rehash](https://www.openssl.org/docs/man1.1.0/apps/rehash.html)`. ### mysqldump This SST method runs `[mysqldump](../mysqldump/index)` on the donor node and pipes the output to the `[mysql](../mysql-client/index)` client connected to the joiner node. The `mysqldump` SST method needs a username/password pair set in the [wsrep\_sst\_auth](../galera-cluster-system-variables/index#wsrep_sst_auth) variable in order to get the dump. The donor node is blocked with a read lock during the SST. This is the slowest SST method. This SST method supports [GTID](../gtid/index). This SST method supports [Data at Rest Encryption](../data-at-rest-encryption/index). ### xtrabackup-v2 In [MariaDB 10.1](../what-is-mariadb-101/index) and later, [Mariabackup](../mariabackup/index) is the recommended backup method to use instead of Percona XtraBackup. In [MariaDB 10.3](../what-is-mariadb-103/index), Percona XtraBackup is **not supported**. See [Percona XtraBackup Overview: Compatibility with MariaDB](../percona-xtrabackup-overview/index#compatibility-with-mariadb) for more information. In [MariaDB 10.2](../what-is-mariadb-102/index) and [MariaDB 10.1](../what-is-mariadb-101/index), Percona XtraBackup is only **partially supported**. See [Percona XtraBackup Overview: Compatibility with MariaDB](../percona-xtrabackup-overview/index#compatibility-with-mariadb) for more information. This SST method uses the [Percona XtraBackup](../backup-restore-and-import-clients-percona-xtrabackup/index) utility for performing SSTs. It is one of the two non-blocking methods. Note that if you use the `xtrabackup-v2` SST method, you also need to have `socat` installed on the server. Since Percona XtraBackup is a third party product, this SST method requires an additional installation some additional configuration. Please refer to [Percona's xtrabackup SST documentation](http://www.percona.com/doc/percona-xtradb-cluster/5.7/manual/xtrabackup_sst.html) for information from the vendor. This SST method does **not** support [GTID](../gtid/index). This SST method does **not** support [Data at Rest Encryption](../data-at-rest-encryption/index). This SST method is available from MariaDB Galera Cluster 5.5.37 and MariaDB Galera Cluster 10.0.10. See [xtrabackup-v2 SST method](../xtrabackup-v2-sst-method/index) for more information. ### xtrabackup In [MariaDB 10.1](../what-is-mariadb-101/index) and later, [Mariabackup](../mariabackup/index) is the recommended backup method to use instead of Percona XtraBackup. In [MariaDB 10.3](../what-is-mariadb-103/index), Percona XtraBackup is **not supported**. See [Percona XtraBackup Overview: Compatibility with MariaDB](../percona-xtrabackup-overview/index#compatibility-with-mariadb) for more information. In [MariaDB 10.2](../what-is-mariadb-102/index) and [MariaDB 10.1](../what-is-mariadb-101/index), Percona XtraBackup is only **partially supported**. See [Percona XtraBackup Overview: Compatibility with MariaDB](../percona-xtrabackup-overview/index#compatibility-with-mariadb) for more information. This SST method is an older SST method that uses the [Percona XtraBackup](../backup-restore-and-import-clients-percona-xtrabackup/index) utility for performing SSTs. The `xtrabackup-v2` SST method should be used instead of the `xtrabackup` SST method starting from [MariaDB 5.5.33](https://mariadb.com/kb/en/mariadb-5533-release-notes/). This SST method does **not** support [GTID](../gtid/index). This SST method does **not** support [Data at Rest Encryption](../data-at-rest-encryption/index). Authentication -------------- All SST methods except `rsync` require authentication via username and password. You can tell the client what username and password to use by setting the `[wsrep\_sst\_auth](../galera-cluster-system-variables/index#wsrep_sst_auth)` system variable. It can be changed dynamically with `[SET GLOBAL](../set/index#global-session)` on the node that you intend to be a SST donor. For example: ``` SET GLOBAL wsrep_sst_auth = 'mariabackup:password'; ``` It can also be set in a server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index) prior to starting up a node: ``` [mariadb] ... wsrep_sst_auth = mariabackup:password ``` Some [authentication plugins](../authentication-plugins/index) do not require a password. For example, the `[unix\_socket](../authentication-plugin-unix-socket/index)` and `[gssapi](../authentication-plugin-gssapi/index)` authentication plugins do not require a password. If you are using a user account that does not require a password in order to log in, then you can just leave the password component of `[wsrep\_sst\_auth](../galera-cluster-system-variables/index#wsrep_sst_auth)` empty. For example: ``` [mariadb] ... wsrep_sst_auth = mariabackup: ``` See the relevant description or page for each SST method to find out what privileges need to be [granted](../grant/index) to the user and whether the privileges are needed on the donor node or joiner node for that method. SSTs and Systemd ---------------- MariaDB's `[systemd](../systemd/index)` unit file has a default startup timeout of about 90 seconds on most systems. If an SST takes longer than this default startup timeout on a joiner node, then `systemd` will assume that `mysqld` has failed to startup, which causes `systemd` to kill the `mysqld` process on the joiner node. To work around this, you can reconfigure the MariaDB `systemd` unit to have an infinite timeout, such as by executing one of the following commands: If you are using `systemd` 228 or older, then you can execute the following to set an infinite timeout: ``` sudo tee /etc/systemd/system/mariadb.service.d/timeoutstartsec.conf <<EOF [Service] TimeoutStartSec=0 EOF sudo systemctl daemon-reload ``` [Systemd 229 added the infinity option](https://lists.freedesktop.org/archives/systemd-devel/2016-February/035748.html), so if you are using `systemd` 229 or later, then you can execute the following to set an infinite timeout: ``` sudo tee /etc/systemd/system/mariadb.service.d/timeoutstartsec.conf <<EOF [Service] TimeoutStartSec=infinity EOF sudo systemctl daemon-reload ``` See [Configuring the Systemd Service Timeout](../systemd/index#configuring-the-systemd-service-timeout) for more details. Note that [systemd 236 added the `EXTEND_TIMEOUT_USEC` environment variable](https://lists.freedesktop.org/archives/systemd-devel/2017-December/039996.html) that allows services to extend the startup timeout during long-running processes. Starting with [MariaDB 10.1.35](https://mariadb.com/kb/en/mariadb-10135-release-notes/), [MariaDB 10.2.17](https://mariadb.com/kb/en/mariadb-10217-release-notes/), and [MariaDB 10.3.8](https://mariadb.com/kb/en/mariadb-1038-release-notes/), on systems with systemd versions that support it, MariaDB uses this feature to extend the startup timeout during long SSTs. Therefore, if you are using `systemd` 236 or later, then you should not need to manually override `TimeoutStartSec`, even if your SSTs run for longer than the configured value. See [MDEV-15607](https://jira.mariadb.org/browse/MDEV-15607) for more information. SST Failure ----------- An SST failure generally renders the joiner node unusable. Therefore, when an SST failure is detected, the joiner node will abort. Restarting a node after a `mysqldump` SST failure may require manual restoration of the administrative tables. SSTs and Data at Rest Encryption -------------------------------- Look at the description of each SST method to determine which methods support [Data at Rest Encryption](../data-at-rest-encryption/index). For logical SST methods like `mysqldump`, each node should be able to have different [encryption keys](../data-at-rest-encryption/index#encryption-key-management). For physical SST methods, all nodes need to have the same [encryption keys](../data-at-rest-encryption/index#encryption-key-management), since the donor node will copy encrypted data files to the joiner node, and the joiner node will need to be able to decrypt them. Minimal Cluster Size -------------------- In order to avoid a split-brain condition, the minimum recommended number of nodes in a cluster is 3. When using an SST method that blocks the donor, there is yet another reason to require a minimum of 3 nodes. In a 3-node cluster, if one node is acting as an SST joiner and one other node is acting as an SST donor, then there is still one more node to continue executing queries. Manual SSTs ----------- In some cases, if Galera Cluster's automatic SSTs repeatedly fail, then it can be helpful to perform a "manual SST". See the following pages on how to do that: * [Manual SST of Galera Cluster node with Mariabackup](../manual-sst-of-galera-cluster-node-with-mariabackup/index) * [Manual SST of Galera Cluster node with Percona XtraBackup](../manual-sst-of-galera-cluster-node-with-percona-xtrabackup/index) Known Issues ------------ ### mysqld\_multi SST scripts can't currently read the `[mysqldN]` [option groups](../configuring-mariadb-with-option-files/index#option-groups) in [option files](../configuring-mariadb-with-option-files/index) that are read by instances managed by `[mysqld\_multi](../mysqld_multi/index)`. See [MDEV-18863](https://jira.mariadb.org/browse/MDEV-18863) for more information. See Also -------- * [Galera Cluster documentation: STATE SNAPSHOT TRANSFERS](https://galeracluster.com/library/documentation/sst.html) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb Mariabackup Mariabackup ============ Mariabackup is an open source tool provided by MariaDB for performing physical online backups of InnoDB, MyRocks, Aria and MyISAM tables. | Title | Description | | --- | --- | | [Mariabackup Overview](../mariabackup-overview/index) | The Mariabackup utility performs physical backups and supports Data-at-Rest... | | [Mariabackup Options](../mariabackup-options/index) | Options for Mariabackup. | | [Full Backup and Restore with Mariabackup](../full-backup-and-restore-with-mariabackup/index) | Taking complete backups of databases and restoring from a complete backup. | | [Incremental Backup and Restore with Mariabackup](../incremental-backup-and-restore-with-mariabackup/index) | Backing up incremental changes of a database | | [Partial Backup and Restore with Mariabackup](../partial-backup-and-restore-with-mariabackup/index) | Taking partial backups of databases and restoring from a partial backup. | | [Restoring Individual Tables and Partitions with Mariabackup](../restoring-individual-tables-and-partitions-with-mariabackup/index) | Restoring individual tables and partitions from a backup. | | [Setting up a Replica with Mariabackup](../setting-up-a-replica-with-mariabackup/index) | Setting up a replica with Mariabackup. | | [Files Backed Up By Mariabackup](../files-backed-up-by-mariabackup/index) | Mariabackup backs up many different files in order to perform its operations. | | [Files Created by Mariabackup](../files-created-by-mariabackup/index) | Mariabackup creates many different files in order to perform its operations. | | [Using Encryption and Compression Tools With Mariabackup](../using-encryption-and-compression-tools-with-mariabackup/index) | Mariabackup supports streaming to stdout, allowing easy integration with popular tools. | | [How Mariabackup Works](../how-mariabackup-works/index) | Description of the different Mariabackup stages, what they do and why they are needed. | | [Mariabackup and BACKUP STAGE Commands](../mariabackup-and-backup-stage-commands/index) | How Mariabackup could use BACKUP STAGE commands. | | [mariabackup SST Method](../mariabackup-sst-method/index) | The mariabackup SST method uses the Mariabackup utility for performing SSTs. | | [Manual SST of Galera Cluster Node With Mariabackup](../manual-sst-of-galera-cluster-node-with-mariabackup/index) | It can be helpful to perform a "manual SST" with Mariabackup when Galera's normal SSTs fail. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Information Schema THREAD_POOL_QUEUES Table Information Schema THREAD\_POOL\_QUEUES Table ============================================= **MariaDB starting with [10.5](../what-is-mariadb-105/index)**The [Information Schema](../information_schema/index) `THREAD_POOL_QUEUES` table was introduced in [MariaDB 10.5.0](https://mariadb.com/kb/en/mariadb-1050-release-notes/). The table provides information about [thread pool](../thread-pool-in-mariadb/index) queues, and contains the following columns: | Column | Description | | --- | --- | | `POSITION` | | | `PRIORITY` | | | `CONNECTION_ID` | | | `QUEUEING_TIME_MICROSECONDS` | | Setting [thread\_poll\_exact\_stats](../thread-pool-system-status-variables/index#thread_pool_exact_stats) will provides better queueing time statistics by using a high precision timestamp, at a small performance cost, for the time when the connection was added to the queue. This timestamp helps calculate the queuing time shown in the table. Setting [thread\_pool\_dedicated\_listener](../thread-pool-system-status-variables/index#thread_pool_dedicated_listener) will give each group its own dedicated listener, and the listener thread will not pick up work items. As a result, the queueing time in the table will be more exact, since IO requests are immediately dequeued from poll, without delay. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb TRIM_ORACLE TRIM\_ORACLE ============ **MariaDB starting with [10.3.6](https://mariadb.com/kb/en/mariadb-1036-release-notes/)**`TRIM_ORACLE` is a synonym for the [Oracle mode](../sql_modeoracle/index) version of the [TRIM function](../trim/index), and is available in all modes. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Buildbot Setup for Virtual Machines - Fedora 18 Buildbot Setup for Virtual Machines - Fedora 18 =============================================== Base install ------------ ``` qemu-img create -f qcow2 /kvm/vms/vm-fedora18-i386-serial.qcow2 10G qemu-img create -f qcow2 /kvm/vms/vm-fedora18-amd64-serial.qcow2 10G ``` Start each VM booting from the server install iso one at a time and perform the following install steps: ``` kvm -m 2048 -hda /kvm/vms/vm-fedora18-i386-serial.qcow2 -cdrom /kvm/iso/fedora/Fedora-18-i386-DVD.iso -redir tcp:2277::22 -boot d -smp 2 -cpu qemu64 -net nic,model=virtio -net user kvm -m 2048 -hda /kvm/vms/vm-fedora18-amd64-serial.qcow2 -cdrom /kvm/iso/fedora/Fedora-18-x86_64-DVD.iso -redir tcp:2278::22 -boot d -smp 2 -cpu qemu64 -net nic,model=virtio -net user ``` Once running you can connect to the VNC server from your local host with: ``` vncviewer -via ${remote-host} localhost ``` Replace ${remote-host} with the host the vm is running on. **Note:** When you activate the install, vncviewer may disconnect with a complaint about the rect being too large. This is fine. The Fedora installer has just resized the vnc screen. Simply reconnect. Install, picking default options mostly, with the following notes: * Under "Network Configuration" set the hostnames to fedora18-amd64 and fedora18-i386 * Change "Software Selection" to "Minimal Install" (default is "Gnome Desktop") * For "Installation Destination" select the disk then click continue. * **do not** check the encryption checkbox * On "Installation Options" screen, expand the "Partition scheme configuration" box and select a "Partition type" of "Standard Partition" * While installing, set the root password When the install is finished, you will be prompted to reboot. Go ahead and do so, but it will fail. Kill the VM (after the reboot fails) and start it up again: ``` kvm -m 2048 -hda /kvm/vms/vm-fedora18-i386-serial.qcow2 -redir tcp:2277::22 -boot c -smp 2 -cpu qemu64 -net nic,model=virtio -net user kvm -m 2048 -hda /kvm/vms/vm-fedora18-amd64-serial.qcow2 -redir tcp:2278::22 -boot c -smp 2 -cpu qemu64 -net nic,model=virtio -net user ``` Until a non-root user is installed you must connect as root. SSH is preferred, so that's what we'll do first. Login as root. ``` ssh -p 2277 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -i ~/.ssh/buildbot.id_dsa root@localhost ssh -p 2278 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -i ~/.ssh/buildbot.id_dsa root@localhost ``` After logging in as root, install proper ssh and then create a local user: ``` adduser ${username} usermod -a -G wheel ${username} passwd ${username} ``` Enable password-less sudo and serial console: ``` visudo # Uncomment the line "%wheel ALL=(ALL) NOPASSWD: ALL" # Comment out this line: # Defaults requiretty ``` Still logged in as root, add to /boot/grub/menu.lst: Editing /boot/grub/menu.lst: ``` sudo vi /etc/default/grub # Add/edit these entries: GRUB_CMDLINE_LINUX_DEFAULT="console=tty0 console=ttyS0,115200n8" GRUB_TERMINAL="serial" GRUB_SERIAL_COMMAND="serial --unit=0 --speed=115200 --word=8 --parity=no --stop=1" grub2-mkconfig -o /boot/grub2/grub.cfg ``` Logout as root, and then, from the VM host server: Create a .ssh folder: ``` ssh -t -p 2277 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -i ~/.ssh/buildbot.id_dsa localhost "mkdir -v .ssh" ssh -t -p 2278 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -i ~/.ssh/buildbot.id_dsa localhost "mkdir -v .ssh" ``` Copy over the authorized keys file: ``` scp -P 2277 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no /kvm/vms/authorized_keys localhost:.ssh/ scp -P 2278 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no /kvm/vms/authorized_keys localhost:.ssh/ ``` Set permissions on the .ssh folder correctly: ``` ssh -t -p 2277 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -i ~/.ssh/buildbot.id_dsa localhost "chmod -R go-rwx .ssh" ssh -t -p 2278 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -i ~/.ssh/buildbot.id_dsa localhost "chmod -R go-rwx .ssh" ``` Create the buildbot user: ``` ssh -p 2277 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no localhost 'chmod -R go-rwx .ssh; sudo adduser buildbot; sudo usermod -a -G wheel buildbot; sudo mkdir ~buildbot/.ssh; sudo cp -vi .ssh/authorized_keys ~buildbot/.ssh/; sudo chown -vR buildbot:buildbot ~buildbot/.ssh; sudo chmod -vR go-rwx ~buildbot/.ssh' ssh -p 2278 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no localhost 'chmod -R go-rwx .ssh; sudo adduser buildbot; sudo usermod -a -G wheel buildbot; sudo mkdir ~buildbot/.ssh; sudo cp -vi .ssh/authorized_keys ~buildbot/.ssh/; sudo chown -vR buildbot:buildbot ~buildbot/.ssh; sudo chmod -vR go-rwx ~buildbot/.ssh' ``` su to the local buildbot user and ssh to the vm to put the key in known\_hosts: For i386: ``` sudo su - buildbot ssh -p 2277 buildbot@localhost # exit, then exit again ``` For amd64: ``` sudo su - buildbot ssh -p 2278 buildbot@localhost # exit, then exit again ``` Upload the ttyS0 file and put it where it goes: ``` scp -P 2277 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no /kvm/vms/ttyS0 buildbot@localhost: scp -P 2278 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no /kvm/vms/ttyS0 buildbot@localhost: ssh -p 2277 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no buildbot@localhost 'sudo mkdir -v /etc/event.d;sudo mv -vi ttyS0 /etc/event.d/;' ssh -p 2278 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no buildbot@localhost 'sudo mkdir -v /etc/event.d;sudo mv -vi ttyS0 /etc/event.d/;' ``` Update the VM: ``` ssh -p 2277 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no buildbot@localhost ssh -p 2278 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no buildbot@localhost ``` Once logged in: ``` sudo yum update ``` After updating, shut down the VM: ``` sudo shutdown -h now ``` VMs for building .rpms ---------------------- ``` for i in '/kvm/vms/vm-fedora18-i386-serial.qcow2 2277 qemu64' '/kvm/vms/vm-fedora18-amd64-serial.qcow2 2278 qemu64' ; do \ set $i; \ runvm --user=buildbot --logfile=kernel_$2.log --base-image=$1 --port=$2 --cpu=$3 "$(echo $1 | sed -e 's/serial/build/')" \ "= scp -P $2 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no /kvm/boost_1_49_0.tar.gz buildbot@localhost:/dev/shm/" \ "= scp -P $2 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no /kvm/thrift-0.9.0.tar.gz buildbot@localhost:/dev/shm/" \ "sudo yum -y groupinstall 'Development Tools'" \ "sudo yum -y install cmake tar wget tree gperf readline-devel ncurses-devel zlib-devel pam-devel libaio-devel openssl-devel libxml2 libxml2-devel unixODBC-devel bzr perl perl\(DBI\)" \ "sudo yum -y remove systemtap-sdt-dev" \ "bzr co --lightweight lp:mariadb-native-client" \ "sudo mkdir -vp /usr/src/redhat/SOURCES /usr/src/redhat/SPECS /usr/src/redhat/RPMS /usr/src/redhat/SRPMS" \ "cd /usr/local/src;sudo tar zxf /dev/shm/thrift-0.9.0.tar.gz;pwd;ls" \ "cd /usr/local/src/thrift-0.9.0;echo;pwd;sudo ./configure --prefix=/usr --enable-shared=no --enable-static=yes CXXFLAGS=-fPIC CFLAGS=-fPIC && echo && echo 'now making' && echo && sleep 3 && sudo make && echo && echo 'now installing' && echo && sleep 3 && sudo make install" \ "cd /usr/local/src;sudo tar zxf /dev/shm/boost_1_49_0.tar.gz;cd /usr/local/include/;sudo ln -vs ../src/boost_1_49_0/boost ." ; \ done ``` VMs for install testing. ------------------------ ``` for i in '/kvm/vms/vm-fedora18-i386-serial.qcow2 2277 qemu64' '/kvm/vms/vm-fedora18-amd64-serial.qcow2 2278 qemu64' ; do \ set $i; \ runvm --user=buildbot --logfile=kernel_$2.log --base-image=$1 --port=$2 --cpu=$3 "$(echo $1 | sed -e 's/serial/install/')" \ "sudo yum -y update" \ "sudo yum -y install patch tar libaio perl perl-Time-HiRes perl-DBI" ; \ done ``` VMs for MySQL upgrade testing ----------------------------- ``` for i in '/kvm/vms/vm-fedora18-i386-serial.qcow2 2277 qemu64' '/kvm/vms/vm-fedora18-amd64-serial.qcow2 2278 qemu64' ; do \ set $i; \ runvm --user=buildbot --logfile=kernel_$2.log --base-image=$1 --port=$2 --cpu=$3 "$(echo $1 | sed -e 's/serial/upgrade/')" \ "sudo yum -y update" \ "sudo yum -y install patch tar mysql-server libtool-ltdl unixODBC" \ "sudo systemctl enable mysqld.service" \ "sudo systemctl start mysqld.service" \ 'mysql -uroot -e "create database mytest; use mytest; create table t(a int primary key); insert into t values (1); select * from t"' ; \ done ``` VMs for MariaDB upgrade testing ------------------------------- ``` for i in '/kvm/vms/vm-fedora18-amd64-serial.qcow2 2278 qemu64' '/kvm/vms/vm-fedora18-i386-serial.qcow2 2277 qemu64' ; do \ set $i; \ runvm --user=buildbot --logfile=kernel_$2.log --base-image=$1 --port=$2 --cpu=$3 "$(echo $1 | sed -e 's/serial/upgrade2/')" \ 'sudo yum -y update' \ "= scp -P $2 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no /kvm/vms/MariaDB-${2}.repo buildbot@localhost:/tmp/MariaDB.repo" \ 'sudo rpm --verbose --import https://yum.mariadb.org/RPM-GPG-KEY-MariaDB' \ 'sudo mv -vi /tmp/MariaDB.repo /etc/yum.repos.d/' \ 'sudo yum -y remove mysql-libs' \ 'sudo yum -y install MariaDB-server MariaDB-client MariaDB-test libtool-ltdl unixODBC' \ 'sudo yum -y install cronie cronie-anacron crontabs.noarch postfix patch tar' \ 'sudo /etc/init.d/mysqld start' \ 'mysql -uroot -prootpass -e "create database mytest; use mytest; create table t(a int primary key); insert into t values (1); select * from t"' \ 'sudo rm -v /etc/yum.repos.d/MariaDB.repo' \ 'sudo yum -y update' \ "= scp -P $2 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no /kvm/vms/MariaDB.local.repo buildbot@localhost:/tmp/" \ 'sudo mv -vi /tmp/MariaDB.local.repo /etc/yum.repos.d/'; \ done ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Plans for MariaDB 10.7 Plans for MariaDB 10.7 ====================== [MariaDB 10.7](../what-is-mariadb-107/index) is stable, so no new features will be added. See [Plans for MariaDB 10.8](../plans-for-mariadb-108/index) instead. JIRA ---- We manage our development plans in JIRA, so the definitive list will be there. [This search](https://jira.mariadb.org/issues/?jql=project+%3D+MDEV+AND+issuetype+%3D+Task+AND+fixVersion+in+%2810.7%29+ORDER+BY+priority+DESC) shows what we **currently** plan for 10.7. It shows all tasks with the **Fix-Version** being 10.7. Not all these tasks will really end up in 10.7 but tasks with the "red" priorities have a much higher chance of being done in time for 10.7. Practically, you can think of these tasks as "features that **will** be in 10.7". Tasks with the "green" priorities probably won't be in 10.7. Think of them as "bonus features that would be **nice to have** in 10.7". Contributing ------------ If you want to be part of developing any of these features, see [Contributing to the MariaDB Project](../contributing-to-the-mariadb-project/index). You can also add new features to this list or to [JIRA](../jira-project-planning-and-tracking/index). See Also -------- * [Current tasks for 10.7](https://jira.mariadb.org/issues/?jql=project%20%3D%20MDEV%20AND%20issuetype%20%3D%20Task%20AND%20fixVersion%20in%20(10.7)%20ORDER%20BY%20priority%20DESC) * [10.7 Features/fixes by vote](https://jira.mariadb.org/issues/?jql=project%20%3D%20MDEV%20AND%20issuetype%20%3D%20Task%20AND%20fixVersion%20in%20(10.7)%20ORDER%20BY%20votes%20DESC%2C%20priority%20DESC) * [What is MariaDB 10.7?](../what-is-mariadb-107/index) * [What is MariaDB 10.6?](../what-is-mariadb-106/index) * [What is MariaDB 10.5?](../what-is-mariadb-105/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Full-Text Index Overview Full-Text Index Overview ======================== MariaDB has support for full-text indexing and searching: * A full-text index in MariaDB is an index of type FULLTEXT, and it allows more options when searching for portions of text from a field. * Full-text indexes can be used only with [MyISAM](../myisam/index), [Aria](../aria/index), [InnoDB](../innodb/index) and [Mroonga](../mroonga/index) tables, and can be created only for [CHAR](../char/index), [VARCHAR](../varchar/index), or [TEXT](../text/index) columns. * [Partitioned tables](../managing-mariadb-partitioning/index) cannot contain fulltext indexes, even if the storage engine supports them. * A FULLTEXT index definition can be given in the [CREATE TABLE](../create-table/index) statement when a table is created, or added later using [ALTER TABLE](../alter-table/index) or [CREATE INDEX](../create-index/index). * For large data sets, it is much faster to load your data into a table that has no FULLTEXT index and then create the index after that, than to load data into a table that has an existing FULLTEXT index. Full-text searching is performed using [MATCH() ... AGAINST](../match-against/index) syntax. MATCH() takes a comma-separated list that names the columns to be searched. AGAINST takes a string to search for, and an optional modifier that indicates what type of search to perform. The search string must be a literal string, not a variable or a column name. ``` MATCH (col1,col2,...) AGAINST (expr [search_modifier]) ``` Excluded Results ---------------- * Partial words are excluded. * Words less than 4 characters in length (3 or less) will not be stored in the fulltext index. This value can be adjusted by changing the [ft\_min\_word\_length](../server-system-variables/index#ft_min_word_len) system variable (or, for [InnoDB](../innodb/index), [innodb\_ft\_min\_token\_size](../xtradbinnodb-server-system-variables/index#innodb_ft_min_token_size)). * Words longer than 84 characters in length will also not be stored in the fulltext index. This values can be adjusted by changing the [ft\_max\_word\_length](../server-system-variables/index#ft_max_word_len) system variable (or, for [InnoDB](../innodb/index), [innodb\_ft\_max\_token\_size](../xtradbinnodb-server-system-variables/index#innodb_ft_max_token_size)). * Stopwords are a list of common words such as "once" or "then" that do not reflect in the search results unless IN BOOLEAN MODE is used. The stopword list for MyISAM/Aria tables and InnoDB tables can differ. See [stopwords](../stopwords/index) for details and a full list, as well as for details on how to change the default list. * For MyISAM/Aria fulltext indexes only, if a word appears in more than half the rows, it is also excluded from the results of a fulltext search. * For InnoDB indexes, only committed rows appear - modifications from the current transaction do not apply. Relevance --------- MariaDB calculates a relevance for each result, based on a number of factors, including the number of words in the index, the number of unique words in a row, the total number of words in both the index and the result, and the weight of the word. In English, 'cool' will be weighted less than 'dandy', at least at present! The relevance can be returned as part of a query simply by using the MATCH function in the field list. Types of Full-Text search ------------------------- ### IN NATURAL LANGUAGE MODE IN NATURAL LANGUAGE MODE is the default type of full-text search, and the keywords can be omitted. There are no special operators, and searches consist of one or more comma-separated keywords. Searches are returned in descending order of relevance. ### IN BOOLEAN MODE Boolean search permits the use of a number of special operators: | Operator | Description | | --- | --- | | + | The word is mandatory in all rows returned. | | - | The word cannot appear in any row returned. | | < | The word that follows has a lower relevance than other words, although rows containing it will still match | | > | The word that follows has a higher relevance than other words. | | () | Used to group words into subexpressions. | | ~ | The word following contributes negatively to the relevance of the row (which is different to the '-' operator, which specifically excludes the word, or the '<' operator, which still causes the word to contribute positively to the relevance of the row. | | \* | The wildcard, indicating zero or more characters. It can only appear at the end of a word. | | " | Anything enclosed in the double quotes is taken as a whole (so you can match phrases, for example). | Searches are not returned in order of relevance, and nor does the 50% limit apply. Stopwords and word minimum and maximum lengths still apply as usual. ### WITH QUERY EXPANSION A query expansion search is a modification of a natural language search. The search string is used to perform a regular natural language search. Then, words from the most relevant rows returned by the search are added to the search string and the search is done again. The query returns the rows from the second search. The IN NATURAL LANGUAGE MODE WITH QUERY EXPANSION or WITH QUERY EXPANSION modifier specifies a query expansion search. It can be useful when relying on implied knowledge within the data, for example that MariaDB is a database. Examples -------- Creating a table, and performing a basic search: ``` CREATE TABLE ft_myisam(copy TEXT,FULLTEXT(copy)) ENGINE=MyISAM; INSERT INTO ft_myisam(copy) VALUES ('Once upon a time'), ('There was a wicked witch'), ('Who ate everybody up'); SELECT * FROM ft_myisam WHERE MATCH(copy) AGAINST('wicked'); +--------------------------+ | copy | +--------------------------+ | There was a wicked witch | +--------------------------+ ``` Multiple words: ``` SELECT * FROM ft_myisam WHERE MATCH(copy) AGAINST('wicked,witch'); +---------------------------------+ | copy | +---------------------------------+ | There was a wicked witch | +---------------------------------+ ``` Since 'Once' is a [stopword](../stopwords/index), no result is returned: ``` SELECT * FROM ft_myisam WHERE MATCH(copy) AGAINST('Once'); Empty set (0.00 sec) ``` Inserting the word 'wicked' into more than half the rows excludes it from the results: ``` INSERT INTO ft_myisam(copy) VALUES ('Once upon a wicked time'), ('There was a wicked wicked witch'), ('Who ate everybody wicked up'); SELECT * FROM ft_myisam WHERE MATCH(copy) AGAINST('wicked'); Empty set (0.00 sec) ``` Using IN BOOLEAN MODE to overcome the 50% limitation: ``` SELECT * FROM ft_myisam WHERE MATCH(copy) AGAINST('wicked' IN BOOLEAN MODE); +---------------------------------+ | copy | +---------------------------------+ | There was a wicked witch | | Once upon a wicked time | | There was a wicked wicked witch | | Who ate everybody wicked up | +---------------------------------+ ``` Returning the relevance: ``` SELECT copy,MATCH(copy) AGAINST('witch') AS relevance FROM ft_myisam WHERE MATCH(copy) AGAINST('witch'); +---------------------------------+--------------------+ | copy | relevance | +---------------------------------+--------------------+ | There was a wicked witch | 0.6775632500648499 | | There was a wicked wicked witch | 0.5031757950782776 | +---------------------------------+--------------------+ ``` WITH QUERY EXPANSION. In the following example, 'MariaDB' is always associated with the word 'database', so it is returned when query expansion is used, even though not explicitly requested. ``` CREATE TABLE ft2(copy TEXT,FULLTEXT(copy)) ENGINE=MyISAM; INSERT INTO ft2(copy) VALUES ('MySQL vs MariaDB database'), ('Oracle vs MariaDB database'), ('PostgreSQL vs MariaDB database'), ('MariaDB overview'), ('Foreign keys'), ('Primary keys'), ('Indexes'), ('Transactions'), ('Triggers'); SELECT * FROM ft2 WHERE MATCH(copy) AGAINST('database'); +--------------------------------+ | copy | +--------------------------------+ | MySQL vs MariaDB database | | Oracle vs MariaDB database | | PostgreSQL vs MariaDB database | +--------------------------------+ 3 rows in set (0.00 sec) SELECT * FROM ft2 WHERE MATCH(copy) AGAINST('database' WITH QUERY EXPANSION); +--------------------------------+ | copy | +--------------------------------+ | MySQL vs MariaDB database | | Oracle vs MariaDB database | | PostgreSQL vs MariaDB database | | MariaDB overview | +--------------------------------+ 4 rows in set (0.00 sec) ``` Partial word matching with IN BOOLEAN MODE: ``` SELECT * FROM ft2 WHERE MATCH(copy) AGAINST('Maria*' IN BOOLEAN MODE); +--------------------------------+ | copy | +--------------------------------+ | MySQL vs MariaDB database | | Oracle vs MariaDB database | | PostgreSQL vs MariaDB database | | MariaDB overview | +--------------------------------+ ``` Using boolean operators ``` SELECT * FROM ft2 WHERE MATCH(copy) AGAINST('+MariaDB -database' IN BOOLEAN MODE); +------------------+ | copy | +------------------+ | MariaDB overview | +------------------+ ``` See Also -------- * For simpler searches of a substring in text columns, see the [LIKE](../like/index) operator. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
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mariadb 10.0.32 Release Upgrade Tests 10.0.32 Release Upgrade Tests ============================= Upgrade from 10.0 ----------------- ### Tested revision d85d6c9c416aab85f1ded344a5b870d4cc56f9f6 ### Test date 2017-08-03 19:25:53 ### Summary (PASS) All tests passed ### Details | # | type | pagesize | OLD version | file format | encrypted | compressed | | NEW version | file format | encrypted | compressed | readonly | result | notes | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | 1 | crash | 4 | 10.0.28 (inbuilt) | Antelope | - | - | => | 10.0.32 (inbuilt) | Antelope | - | - | - | OK | | | 2 | crash | 4 | 10.0.28 (inbuilt) | Barracuda | - | - | => | 10.0.32 (inbuilt) | Barracuda | - | - | - | OK | | | 3 | crash | 8 | 10.0.28 (inbuilt) | Antelope | - | - | => | 10.0.32 (inbuilt) | Antelope | - | - | - | OK | | | 4 | crash | 8 | 10.0.28 (inbuilt) | Barracuda | - | - | => | 10.0.32 (inbuilt) | Barracuda | - | - | - | OK | | | 5 | crash | 16 | 10.0.28 (inbuilt) | Antelope | - | - | => | 10.0.32 (inbuilt) | Antelope | - | - | - | OK | | | 6 | crash | 16 | 10.0.28 (inbuilt) | Barracuda | - | - | => | 10.0.32 (inbuilt) | Barracuda | - | - | - | OK | | | 7 | normal | 4 | 10.0.28 (inbuilt) | Barracuda | - | - | => | 10.0.32 (inbuilt) | Barracuda | - | - | - | OK | | | 8 | normal | 4 | 10.0.28 (inbuilt) | Antelope | - | - | => | 10.0.32 (inbuilt) | Antelope | - | - | - | OK | | | 9 | normal | 8 | 10.0.28 (inbuilt) | Antelope | - | - | => | 10.0.32 (inbuilt) | Antelope | - | - | - | OK | | | 10 | normal | 8 | 10.0.28 (inbuilt) | Barracuda | - | - | => | 10.0.32 (inbuilt) | Barracuda | - | - | - | OK | | | 11 | normal | 16 | 10.0.28 (inbuilt) | Barracuda | - | - | => | 10.0.32 (inbuilt) | Barracuda | - | - | - | OK | | | 12 | normal | 16 | 10.0.28 (inbuilt) | Antelope | - | - | => | 10.0.32 (inbuilt) | Antelope | - | - | - | OK | | Upgrade from MySQL 5.6 ---------------------- ### Tested revision d85d6c9c416aab85f1ded344a5b870d4cc56f9f6 ### Test date 2017-08-03 19:45:21 ### Summary (PASS) All tests passed ### Details | # | type | pagesize | OLD version | file format | encrypted | compressed | | NEW version | file format | encrypted | compressed | readonly | result | notes | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | 1 | normal | 16 | 5.6.35 (inbuilt) | Antelope | - | - | => | 10.0.32 (inbuilt) | Antelope | - | - | - | OK | | | 2 | normal | 16 | 5.6.35 (inbuilt) | Barracuda | - | - | => | 10.0.32 (inbuilt) | Barracuda | - | - | - | OK | | | 3 | normal | 4 | 5.6.35 (inbuilt) | Barracuda | - | - | => | 10.0.32 (inbuilt) | Barracuda | - | - | - | OK | | | 4 | normal | 4 | 5.6.35 (inbuilt) | Antelope | - | - | => | 10.0.32 (inbuilt) | Antelope | - | - | - | OK | | | 5 | normal | 8 | 5.6.35 (inbuilt) | Antelope | - | - | => | 10.0.32 (inbuilt) | Antelope | - | - | - | OK | | | 6 | normal | 8 | 5.6.35 (inbuilt) | Barracuda | - | - | => | 10.0.32 (inbuilt) | Barracuda | - | - | - | OK | | Crash Recovery -------------- ### Tested revision d85d6c9c416aab85f1ded344a5b870d4cc56f9f6 ### Test date 2017-08-03 19:55:23 ### Summary (PASS) All tests passed ### Details | # | type | pagesize | OLD version | file format | encrypted | compressed | | NEW version | file format | encrypted | compressed | readonly | result | notes | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | 1 | crash | 16 | 10.0.32 (inbuilt) | Antelope | - | - | => | 10.0.32 (inbuilt) | Antelope | - | - | - | OK | | | 2 | crash | 16 | 10.0.32 (inbuilt) | Barracuda | - | - | => | 10.0.32 (inbuilt) | Barracuda | - | - | - | OK | | | 3 | crash | 4 | 10.0.32 (inbuilt) | Barracuda | - | - | => | 10.0.32 (inbuilt) | Barracuda | - | - | - | OK | | | 4 | crash | 4 | 10.0.32 (inbuilt) | Antelope | - | - | => | 10.0.32 (inbuilt) | Antelope | - | - | - | OK | | | 5 | crash | 8 | 10.0.32 (inbuilt) | Antelope | - | - | => | 10.0.32 (inbuilt) | Antelope | - | - | - | OK | | | 6 | crash | 8 | 10.0.32 (inbuilt) | Barracuda | - | - | => | 10.0.32 (inbuilt) | Barracuda | - | - | - | OK | | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb CREATE VIEW CREATE VIEW =========== Syntax ------ ``` CREATE [OR REPLACE] [ALGORITHM = {UNDEFINED | MERGE | TEMPTABLE}] [DEFINER = { user | CURRENT_USER | role | CURRENT_ROLE }] [SQL SECURITY { DEFINER | INVOKER }] VIEW [IF NOT EXISTS] view_name [(column_list)] AS select_statement [WITH [CASCADED | LOCAL] CHECK OPTION] ``` Description ----------- The CREATE VIEW statement creates a new [view](../views/index), or replaces an existing one if the OR REPLACE clause is given. If the view does not exist, CREATE OR REPLACE VIEW is the same as CREATE VIEW. If the view does exist, CREATE OR REPLACE VIEW is the same as [ALTER VIEW](../alter-view/index). The select\_statement is a [SELECT](../select/index) statement that provides the definition of the view. (When you select from the view, you select in effect using the SELECT statement.) select\_statement can select from base tables or other views. The view definition is "frozen" at creation time, so changes to the underlying tables afterwards do not affect the view definition. For example, if a view is defined as SELECT \* on a table, new columns added to the table later do not become part of the view. A [SHOW CREATE VIEW](../show-create-view/index) shows that such queries are rewritten and column names are included in the view definition. The view definition must be a query that does not return errors at view creation times. However, the base tables used by the views might be altered later and the query may not be valid anymore. In this case, querying the view will result in an error. [CHECK TABLE](../check-table/index) helps in finding this kind of problems. The [ALGORITHM clause](../view-algorithms/index) affects how MariaDB processes the view. The DEFINER and SQL SECURITY clauses specify the security context to be used when checking access privileges at view invocation time. The WITH CHECK OPTION clause can be given to constrain inserts or updates to rows in tables referenced by the view. These clauses are described later in this section. The CREATE VIEW statement requires the CREATE VIEW privilege for the view, and some privilege for each column selected by the SELECT statement. For columns used elsewhere in the SELECT statement you must have the SELECT privilege. If the OR REPLACE clause is present, you must also have the DROP privilege for the view. A view belongs to a database. By default, a new view is created in the default database. To create the view explicitly in a given database, specify the name as db\_name.view\_name when you create it. ``` CREATE VIEW test.v AS SELECT * FROM t; ``` Base tables and views share the same namespace within a database, so a database cannot contain a base table and a view that have the same name. Views must have unique column names with no duplicates, just like base tables. By default, the names of the columns retrieved by the SELECT statement are used for the view column names. To define explicit names for the view columns, the optional column\_list clause can be given as a list of comma-separated identifiers. The number of names in column\_list must be the same as the number of columns retrieved by the SELECT statement. **MySQL until 5.1.28**Prior to MySQL 5.1.29, When you modify an existing view, the current view definition is backed up and saved. It is stored in that table's database directory, in a subdirectory named arc. The backup file for a view v is named v.frm-00001. If you alter the view again, the next backup is named v.frm-00002. The three latest view backup definitions are stored. Backed up view definitions are not preserved by [mysqldump](../mysqldump/index), or any other such programs, but you can retain them using a file copy operation. However, they are not needed for anything but to provide you with a backup of your previous view definition. It is safe to remove these backup definitions, but only while mysqld is not running. If you delete the arc subdirectory or its files while mysqld is running, you will receive an error the next time you try to alter the view: ``` MariaDB [test]> ALTER VIEW v AS SELECT * FROM t; ERROR 6 (HY000): Error on delete of '.\test\arc/v.frm-0004' (Errcode: 2) ``` Columns retrieved by the SELECT statement can be simple references to table columns. They can also be expressions that use functions, constant values, operators, and so forth. Unqualified table or view names in the SELECT statement are interpreted with respect to the default database. A view can refer to tables or views in other databases by qualifying the table or view name with the proper database name. A view can be created from many kinds of SELECT statements. It can refer to base tables or other views. It can use joins, UNION, and subqueries. The SELECT need not even refer to any tables. The following example defines a view that selects two columns from another table, as well as an expression calculated from those columns: ``` CREATE TABLE t (qty INT, price INT); INSERT INTO t VALUES(3, 50); CREATE VIEW v AS SELECT qty, price, qty*price AS value FROM t; SELECT * FROM v; +------+-------+-------+ | qty | price | value | +------+-------+-------+ | 3 | 50 | 150 | +------+-------+-------+ ``` A view definition is subject to the following restrictions: * The SELECT statement cannot contain a subquery in the FROM clause. * The SELECT statement cannot refer to system or user variables. * Within a stored program, the definition cannot refer to program parameters or local variables. * The SELECT statement cannot refer to prepared statement parameters. * Any table or view referred to in the definition must exist. However, after a view has been created, it is possible to drop a table or view that the definition refers to. In this case, use of the view results in an error. To check a view definition for problems of this kind, use the CHECK TABLE statement. * The definition cannot refer to a TEMPORARY table, and you cannot create a TEMPORARY view. * Any tables named in the view definition must exist at definition time. * You cannot associate a trigger with a view. * For valid identifiers to use as view names, see [Identifier Names](../identifier-names/index). ORDER BY is allowed in a view definition, but it is ignored if you select from a view using a statement that has its own ORDER BY. For other options or clauses in the definition, they are added to the options or clauses of the statement that references the view, but the effect is undefined. For example, if a view definition includes a LIMIT clause, and you select from the view using a statement that has its own LIMIT clause, it is undefined which limit applies. This same principle applies to options such as ALL, DISTINCT, or SQL\_SMALL\_RESULT that follow the SELECT keyword, and to clauses such as INTO, FOR UPDATE, and LOCK IN SHARE MODE. The PROCEDURE clause cannot be used in a view definition, and it cannot be used if a view is referenced in the FROM clause. If you create a view and then change the query processing environment by changing system variables, that may affect the results that you get from the view: ``` CREATE VIEW v (mycol) AS SELECT 'abc'; SET sql_mode = ''; SELECT "mycol" FROM v; +-------+ | mycol | +-------+ | mycol | +-------+ SET sql_mode = 'ANSI_QUOTES'; SELECT "mycol" FROM v; +-------+ | mycol | +-------+ | abc | +-------+ ``` The DEFINER and SQL SECURITY clauses determine which MariaDB account to use when checking access privileges for the view when a statement is executed that references the view. They were added in MySQL 5.1.2. The legal SQL SECURITY characteristic values are DEFINER and INVOKER. These indicate that the required privileges must be held by the user who defined or invoked the view, respectively. The default SQL SECURITY value is DEFINER. If a user value is given for the DEFINER clause, it should be a MariaDB account in 'user\_name'@'host\_name' format (the same format used in the GRANT statement). The user\_name and host\_name values both are required. The definer can also be given as CURRENT\_USER or CURRENT\_USER(). The default DEFINER value is the user who executes the CREATE VIEW statement. This is the same as specifying DEFINER = CURRENT\_USER explicitly. If you specify the DEFINER clause, these rules determine the legal DEFINER user values: * If you do not have the [SUPER](../grant/index#super) privilege, or, from [MariaDB 10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/), the [SET USER](../grant/index#set-user) privilege, the only legal user value is your own account, either specified literally or by using CURRENT\_USER. You cannot set the definer to some other account. * If you have the [SUPER](../grant/index#super) privilege, or, from [MariaDB 10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/), the [SET USER](../grant/index#set-user) privilege, you can specify any syntactically legal account name. If the account does not actually exist, a warning is generated. * If the SQL SECURITY value is DEFINER but the definer account does not exist when the view is referenced, an error occurs. Within a view definition, CURRENT\_USER returns the view's DEFINER value by default. For views defined with the SQL SECURITY INVOKER characteristic, CURRENT\_USER returns the account for the view's invoker. For information about user auditing within views, see <http://dev.mysql.com/doc/refman/5.1/en/account-activity-auditing.html>. Within a stored routine that is defined with the SQL SECURITY DEFINER characteristic, CURRENT\_USER returns the routine's DEFINER value. This also affects a view defined within such a program, if the view definition contains a DEFINER value of CURRENT\_USER. View privileges are checked like this: * At view definition time, the view creator must have the privileges needed to use the top-level objects accessed by the view. For example, if the view definition refers to table columns, the creator must have privileges for the columns, as described previously. If the definition refers to a stored function, only the privileges needed to invoke the function can be checked. The privileges required when the function runs can be checked only as it executes: For different invocations of the function, different execution paths within the function might be taken. * When a view is referenced, privileges for objects accessed by the view are checked against the privileges held by the view creator or invoker, depending on whether the SQL SECURITY characteristic is DEFINER or INVOKER, respectively. * If reference to a view causes execution of a stored function, privilege checking for statements executed within the function depend on whether the function is defined with a SQL SECURITY characteristic of DEFINER or INVOKER. If the security characteristic is DEFINER, the function runs with the privileges of its creator. If the characteristic is INVOKER, the function runs with the privileges determined by the view's SQL SECURITY characteristic. Example: A view might depend on a stored function, and that function might invoke other stored routines. For example, the following view invokes a stored function f(): ``` CREATE VIEW v AS SELECT * FROM t WHERE t.id = f(t.name); Suppose that f() contains a statement such as this: IF name IS NULL then CALL p1(); ELSE CALL p2(); END IF; ``` The privileges required for executing statements within f() need to be checked when f() executes. This might mean that privileges are needed for p1() or p2(), depending on the execution path within f(). Those privileges must be checked at runtime, and the user who must possess the privileges is determined by the SQL SECURITY values of the view v and the function f(). The DEFINER and SQL SECURITY clauses for views are extensions to standard SQL. In standard SQL, views are handled using the rules for SQL SECURITY INVOKER. If you invoke a view that was created before MySQL 5.1.2, it is treated as though it was created with a SQL SECURITY DEFINER clause and with a DEFINER value that is the same as your account. However, because the actual definer is unknown, MySQL issues a warning. To make the warning go away, it is sufficient to re-create the view so that the view definition includes a DEFINER clause. The optional ALGORITHM clause is an extension to standard SQL. It affects how MariaDB processes the view. ALGORITHM takes three values: MERGE, TEMPTABLE, or UNDEFINED. The default algorithm is UNDEFINED if no ALGORITHM clause is present. See [View Algorithms](../view-algorithms/index) for more information. Some views are updatable. That is, you can use them in statements such as UPDATE, DELETE, or INSERT to update the contents of the underlying table. For a view to be updatable, there must be a one-to-one relationship between the rows in the view and the rows in the underlying table. There are also certain other constructs that make a view non-updatable. See [Inserting and Updating with Views](../inserting-and-updating-with-views/index). ### WITH CHECK OPTION The WITH CHECK OPTION clause can be given for an updatable view to prevent inserts or updates to rows except those for which the WHERE clause in the select\_statement is true. In a WITH CHECK OPTION clause for an updatable view, the LOCAL and CASCADED keywords determine the scope of check testing when the view is defined in terms of another view. The LOCAL keyword restricts the CHECK OPTION only to the view being defined. CASCADED causes the checks for underlying views to be evaluated as well. When neither keyword is given, the default is CASCADED. For more information about updatable views and the WITH CHECK OPTION clause, see [Inserting and Updating with Views](../inserting-and-updating-with-views/index). ### IF NOT EXISTS **MariaDB starting with [10.1.3](https://mariadb.com/kb/en/mariadb-1013-release-notes/)**The `IF NOT EXISTS` clause was added in [MariaDB 10.1.3](https://mariadb.com/kb/en/mariadb-1013-release-notes/) When the IF NOT EXISTS clause is used, MariaDB will return a warning instead of an error if the specified view already exists. Cannot be used together with the `OR REPLACE` clause. ### Atomic DDL **MariaDB starting with [10.6.1](https://mariadb.com/kb/en/mariadb-1061-release-notes/)**[MariaDB 10.6.1](https://mariadb.com/kb/en/mariadb-1061-release-notes/) supports [Atomic DDL](../atomic-ddl/index) and `CREATE VIEW` is atomic. Examples -------- ``` CREATE TABLE t (a INT, b INT) ENGINE = InnoDB; INSERT INTO t VALUES (1,1), (2,2), (3,3); CREATE VIEW v AS SELECT a, a*2 AS a2 FROM t; SELECT * FROM v; +------+------+ | a | a2 | +------+------+ | 1 | 2 | | 2 | 4 | | 3 | 6 | +------+------+ ``` OR REPLACE and IF NOT EXISTS: ``` CREATE VIEW v AS SELECT a, a*2 AS a2 FROM t; ERROR 1050 (42S01): Table 'v' already exists CREATE OR REPLACE VIEW v AS SELECT a, a*2 AS a2 FROM t; Query OK, 0 rows affected (0.04 sec) CREATE VIEW IF NOT EXISTS v AS SELECT a, a*2 AS a2 FROM t; Query OK, 0 rows affected, 1 warning (0.01 sec) SHOW WARNINGS; +-------+------+--------------------------+ | Level | Code | Message | +-------+------+--------------------------+ | Note | 1050 | Table 'v' already exists | +-------+------+--------------------------+ ``` See Also -------- * [Identifier Names](../identifier-names/index) * [ALTER VIEW](../alter-view/index) * [DROP VIEW](../drop-view/index) * [SHOW CREATE VIEWS](show-create-views) * [INFORMATION SCHEMA VIEWS Table](../information-schema-views-table/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb Writing Plugins for MariaDB Writing Plugins for MariaDB =========================== About ----- Generally speaking, writing plugins for MariaDB is very similar to [writing plugins for MySQL](http://dev.mysql.com/doc/en/writing-plugins.html). Authentication Plugins ---------------------- See [Pluggable Authentication](../pluggable-authentication/index). Storage Engine Plugins ---------------------- Storage engines can extend `CREATE TABLE` syntax with optional index, field, and table attribute clauses. See [Extending CREATE TABLE](../extending-create-table/index) for more information. See [Storage Engine Development](../storage-engines-storage-engine-development/index). Information Schema Plugins -------------------------- Information Schema plugins can have their own [FLUSH](../flush/index) and [SHOW](../show/index) statements. See [FLUSH and SHOW for Information Schema plugins](../information-schema-plugins-show-and-flush-statements/index). Encryption Plugins ------------------ [Encryption plugins](../encryption-plugins/index) in MariaDB are used for the [data at rest encryption](../data-at-rest-encryption/index) feature. They are responsible for both key management and for the actual encryption and decryption of data. Plugin Declaration Structure ---------------------------- The MariaDB plugin declaration differs from the MySQL plugin declaration in the following ways: 1. it has no useless 'reserved' field (the very last field in the MySQL plugin declaration) 2. it has a 'maturity' declaration 3. it has a field for a text representation of the version field MariaDB can load plugins that only have the MySQL plugin declaration but both `PLUGIN_MATURITY` and `PLUGIN_AUTH_VERSION` will show up as 'Unknown' in the [INFORMATION\_SCHEMA.PLUGINS table](../information_schemaplugins-table/index). For compiled-in (not dynamically loaded) plugins, the presence of the MariaDB plugin declaration is mandatory. ### Example Plugin Declaration The MariaDB plugin declaration looks like this: ``` /* MariaDB plugin declaration */ maria_declare_plugin(example) { MYSQL_STORAGE_ENGINE_PLUGIN, /* the plugin type (see include/mysql/plugin.h) */ &example_storage_engine_info, /* pointer to type-specific plugin descriptor */ "EXAMPLEDB", /* plugin name */ "John Smith", /* plugin author */ "Example of plugin interface", /* the plugin description */ PLUGIN_LICENSE_GPL, /* the plugin license (see include/mysql/plugin.h) */ example_init_func, /* Pointer to plugin initialization function */ example_deinit_func, /* Pointer to plugin deinitialization function */ 0x0001 /* Numeric version 0xAABB means AA.BB version */, example_status_variables, /* Status variables */ example_system_variables, /* System variables */ "0.1 example", /* String version representation */ MariaDB_PLUGIN_MATURITY_EXPERIMENTAL /* Maturity (see include/mysql/plugin.h)*/ } maria_declare_plugin_end; ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb SHA1 SHA1 ==== Syntax ------ ``` SHA1(str), SHA(str) ``` Description ----------- Calculates an SHA-1 160-bit checksum for the string *`str`*, as described in RFC 3174 (Secure Hash Algorithm). The value is returned as a string of 40 hex digits, or NULL if the argument was NULL. As of [MariaDB 5.5](../what-is-mariadb-55/index), the return value is a nonbinary string in the connection [character set and collation](../data-types-character-sets-and-collations/index), determined by the values of the [character\_set\_connection](../server-system-variables/index#character_set_connection) and [collation\_connection](../server-system-variables/index#collation_connection) system variables. Before 5.5, the return value was a binary string. Examples -------- ``` SELECT SHA1('some boring text'); +------------------------------------------+ | SHA1('some boring text') | +------------------------------------------+ | af969fc2085b1bb6d31e517d5c456def5cdd7093 | +------------------------------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb mysql.plugin Table mysql.plugin Table ================== The `mysql.plugin` table can be queried to get information about installed [plugins](../plugins/index). This table only contains information about [plugins](../plugins/index) that have been installed via the following methods: * The `[INSTALL SONAME](../install-soname/index)` statement. * The `[INSTALL PLUGIN](../install-plugin/index)` statement. * The `[mysql\_plugin](../mysql_plugin/index)` utility. This table does not contain information about: * Built-in plugins. * Plugins loaded with the `[--plugin-load-add](../mysqld-options/index#-plugin-load-add)` option. * Plugins loaded with the `[--plugin-load](../mysqld-options/index#-plugin-load)` option. This table only contains enough information to reload the plugin when the server is restarted, which means it only contains the plugin name and the plugin library. **MariaDB starting with [10.4](../what-is-mariadb-104/index)**In [MariaDB 10.4](../what-is-mariadb-104/index) and later, this table uses the [Aria](../aria/index) storage engine. **MariaDB until [10.3](../what-is-mariadb-103/index)**In [MariaDB 10.3](../what-is-mariadb-103/index) and before, this table uses the [MyISAM](../myisam-storage-engine/index) storage engine. The `mysql.plugin` table contains the following fields: | Field | Type | Null | Key | Default | Description | | --- | --- | --- | --- | --- | --- | | `name` | `varchar(64)` | NO | PRI | | Plugin name. | | `dl` | `varchar(128)` | NO | | | Name of the plugin library. | Example ------- ``` SELECT * FROM mysql.plugin; +---------------------------+------------------------+ | name | dl | +---------------------------+------------------------+ | spider | ha_spider.so | | spider_alloc_mem | ha_spider.so | | METADATA_LOCK_INFO | metadata_lock_info.so | | OQGRAPH | ha_oqgraph.so | | cassandra | ha_cassandra.so | | QUERY_RESPONSE_TIME | query_response_time.so | | QUERY_RESPONSE_TIME_AUDIT | query_response_time.so | | LOCALES | locales.so | | sequence | ha_sequence.so | +---------------------------+------------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Performance Schema events_stages_summary_by_user_by_event_name Table Performance Schema events\_stages\_summary\_by\_user\_by\_event\_name Table =========================================================================== The table lists stage events, summarized by user and event name. It contains the following columns: | Column | Description | | --- | --- | | `USER` | User. Used together with `EVENT_NAME` for grouping events. | | `EVENT_NAME` | Event name. Used together with `USER` for grouping events. | | `COUNT_STAR` | Number of summarized events, which includes all timed and untimed events. | | `SUM_TIMER_WAIT` | Total wait time of the timed summarized events. | | `MIN_TIMER_WAIT` | Minimum wait time of the timed summarized events. | | `AVG_TIMER_WAIT` | Average wait time of the timed summarized events. | | `MAX_TIMER_WAIT` | Maximum wait time of the timed summarized events. | Example ------- ``` SELECT * FROM events_stages_summary_by_user_by_event_name\G ... *************************** 325. row *************************** USER: NULL EVENT_NAME: stage/sql/Waiting for event metadata lock COUNT_STAR: 0 SUM_TIMER_WAIT: 0 MIN_TIMER_WAIT: 0 AVG_TIMER_WAIT: 0 MAX_TIMER_WAIT: 0 *************************** 326. row *************************** USER: NULL EVENT_NAME: stage/sql/Waiting for commit lock COUNT_STAR: 0 SUM_TIMER_WAIT: 0 MIN_TIMER_WAIT: 0 AVG_TIMER_WAIT: 0 MAX_TIMER_WAIT: 0 *************************** 327. row *************************** USER: NULL EVENT_NAME: stage/aria/Waiting for a resource COUNT_STAR: 0 SUM_TIMER_WAIT: 0 MIN_TIMER_WAIT: 0 AVG_TIMER_WAIT: 0 MAX_TIMER_WAIT: 0 ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb HandlerSocket Installation HandlerSocket Installation ========================== After MariaDB is installed, use the [INSTALL PLUGIN](../install-plugin/index) command (as the root user) to install the HandlerSocket plugin. This command only needs to be run once, like so: ``` INSTALL PLUGIN handlersocket SONAME 'handlersocket.so'; ``` After installing the plugin, [SHOW PROCESSLIST](../show-processlist/index) you first need to configure some settings. All [HandlerSocket configuration options](../handlersocket-configuration-options/index) are placed in the [mysqld] section of your my.cnf file. At least the [handlersocket\_address](../handlersocket-configuration-options/index#handlersocket_address), [handlersocket\_port](../handlersocket-configuration-options/index#handlersocket_port) and [handlersocket\_port\_wr](../handlersocket-configuration-options/index#handlersocket_port_wr) options need to be set. For example: ``` handlersocket_address="127.0.0.1" handlersocket_port="9998" handlersocket_port_wr="9999" ``` After updating the configuration options, restart MariaDB. On the client side, to make use of the plugin you will need to install the appropriate client library (i.e. libhsclient for C++ applications and perl-Net-HandlerSocket for perl applications). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb MariaDB ColumnStore 1.1 Upgrades MariaDB ColumnStore 1.1 Upgrades ================================= | Title | Description | | --- | --- | | [MariaDB ColumnStore software upgrade 1.1.6 GA to 1.1.7 GA](../mariadb-columnstore-software-upgrade-116-ga-to-117-ga/index) | MariaDB ColumnStore software upgrade 1.1.6 GA to 1.1.7 GA Additional Depen... | | [MariaDB ColumnStore software upgrade 1.1.5 GA to 1.1.6 GA](../mariadb-columnstore-software-upgrade-115-ga-to-116-ga/index) | MariaDB ColumnStore software upgrade 1.1.5 GA to 1.1.6 GA Additional Depen... | | [MariaDB ColumnStore software upgrade 1.1.4 GA to 1.1.5 GA](../mariadb-columnstore-software-upgrade-114-ga-to-115-ga/index) | MariaDB ColumnStore software upgrade 1.1.4 GA to 1.1.5 GA Additional Depen... | | [MariaDB ColumnStore software upgrade 1.1.3 GA to 1.1.4 GA](../mariadb-columnstore-software-upgrade-113-ga-to-114-ga/index) | MariaDB ColumnStore software upgrade 1.1.3 GA to 1.1.4 GA Additional Depen... | | [MariaDB ColumnStore software upgrade 1.1.2 GA to 1.1.3 GA](../mariadb-columnstore-software-upgrade-112-ga-to-113-ga/index) | MariaDB ColumnStore software upgrade 1.1.2 GA to 1.1.3 GA Additional Depen... | | [MariaDB ColumnStore software upgrade 1.1.1 RC to 1.1.2 GA](../mariadb-columnstore-software-upgrade-111-rc-to-112-ga/index) | MariaDB ColumnStore software upgrade 1.1.1 RC to 1.1.2 GA Additional Depen... | | [MariaDB ColumnStore software upgrade 1.1.0 Beta to 1.1.1 RC](../mariadb-columnstore-software-upgrade-110-beta-to-111-rc/index) | MariaDB ColumnStore software upgrade 1.1.0 Beta to 1.1.1 RC Additional Dep... | | [MariaDB ColumnStore software upgrade 1.0.11 to 1.1.0 Beta](../mariadb-columnstore-software-upgrade-1011-to-110-beta/index) | MariaDB ColumnStore software upgrade 1.0.11 to 1.1.0 Beta Additional Depen... | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb InnoDB Versions InnoDB Versions =============== **MariaDB starting with [10.3.7](https://mariadb.com/kb/en/mariadb-1037-release-notes/)**In [MariaDB 10.3.7](https://mariadb.com/kb/en/mariadb-1037-release-notes/) and later, the InnoDB implementation has diverged substantially from the InnoDB in MySQL. Therefore, in these versions, the InnoDB version is no longer associated with a MySQL release version. **MariaDB starting with [10.2](../what-is-mariadb-102/index)**In [MariaDB 10.2](../what-is-mariadb-102/index) and later, the default InnoDB implementation is based on InnoDB from MySQL 5.7. See [Why MariaDB uses InnoDB instead of XtraDB from MariaDB 10.2](../why-does-mariadb-102-use-innodb-instead-of-xtradb/index) for more information. **MariaDB until [10.1](../what-is-mariadb-101/index)**In [MariaDB 10.1](../what-is-mariadb-101/index) and before, the default InnoDB implementation is based on Percona's XtraDB. XtraDB is a performance enhanced fork of InnoDB. For compatibility reasons, the [system variables](../xtradbinnodb-server-system-variables/index) still retain their original `innodb` prefixes. If the documentation says that something applies to InnoDB, then it usually also applies to the XtraDB fork, unless explicitly stated otherwise. In these versions, it is still possible to use InnoDB instead of XtraDB. See [Using InnoDB instead of XtraDB](../using-innodb-instead-of-xtradb/index) for more information. Divergences ----------- Some examples of divergences between MariaDB's InnoDB and MySQL's InnoDB are: * [MariaDB 10.1](../what-is-mariadb-101/index) (which is based on MySQL 5.6) included encryption and variable-size page compression before MySQL 5.7 introduced them. * [MariaDB 10.2](../what-is-mariadb-102/index) (based on MySQL 5.7) introduced persistent AUTO\_INCREMENT ([MDEV-6076](https://jira.mariadb.org/browse/MDEV-6076)) in a GA release before MySQL 8.0. * [MariaDB 10.3](../what-is-mariadb-103/index) (based on MySQL 5.7) introduced instant ADD COLUMN ([MDEV-11369](https://jira.mariadb.org/browse/MDEV-11369)) before MySQL. InnoDB Versions Included in MariaDB Releases -------------------------------------------- ### [MariaDB 10.3](../what-is-mariadb-103/index) | InnoDB Version | Introduced | | --- | --- | | No longer reported | [MariaDB 10.3.7](https://mariadb.com/kb/en/mariadb-1037-release-notes/) | | InnoDB 5.7.20 | [MariaDB 10.3.3](https://mariadb.com/kb/en/mariadb-1033-release-notes/) | | InnoDB 5.7.19 | [MariaDB 10.3.1](https://mariadb.com/kb/en/mariadb-1031-release-notes/) | | InnoDB 5.7.14 | [MariaDB 10.3.0](https://mariadb.com/kb/en/mariadb-1030-release-notes/) | ### [MariaDB 10.2](../what-is-mariadb-102/index) | InnoDB Version | Introduced | | --- | --- | | InnoDB 5.7.29 | [MariaDB 10.2.33](https://mariadb.com/kb/en/mariadb-10233-release-notes/) | | InnoDB 5.7.23 | [MariaDB 10.2.17](https://mariadb.com/kb/en/mariadb-10217-release-notes/) | | InnoDB 5.7.22 | [MariaDB 10.2.15](https://mariadb.com/kb/en/mariadb-10215-release-notes/) | | InnoDB 5.7.21 | [MariaDB 10.2.13](https://mariadb.com/kb/en/mariadb-10213-release-notes/) | | InnoDB 5.7.20 | [MariaDB 10.2.10](https://mariadb.com/kb/en/mariadb-10210-release-notes/) | | InnoDB 5.7.19 | [MariaDB 10.2.8](https://mariadb.com/kb/en/mariadb-1028-release-notes/) | | InnoDB 5.7.18 | [MariaDB 10.2.7](https://mariadb.com/kb/en/mariadb-1027-release-notes/) | | InnoDB 5.7.14 | [MariaDB 10.2.2](https://mariadb.com/kb/en/mariadb-1022-release-notes/) | ### [MariaDB 10.1](../what-is-mariadb-101/index) | InnoDB Version | Introduced | | --- | --- | | InnoDB 5.6.49 | [MariaDB 10.1.46](https://mariadb.com/kb/en/mariadb-10146-release-notes/) | | InnoDB 5.6.47 | [MariaDB 10.1.44](https://mariadb.com/kb/en/mariadb-10144-release-notes/) | | InnoDB 5.6.44 | [MariaDB 10.1.39](https://mariadb.com/kb/en/mariadb-10139-release-notes/) | | InnoDB 5.6.42 | [MariaDB 10.1.37](https://mariadb.com/kb/en/mariadb-10137-release-notes/) | | InnoDB 5.6.39 | [MariaDB 10.1.31](https://mariadb.com/kb/en/mariadb-10131-release-notes/) | | InnoDB 5.6.37 | [MariaDB 10.1.26](https://mariadb.com/kb/en/mariadb-10126-release-notes/) | | InnoDB 5.6.36 | [MariaDB 10.1.24](https://mariadb.com/kb/en/mariadb-10124-release-notes/) | | InnoDB 5.6.35 | [MariaDB 10.1.21](https://mariadb.com/kb/en/mariadb-10121-release-notes/) | | InnoDB 5.6.33 | [MariaDB 10.1.18](https://mariadb.com/kb/en/mariadb-10118-release-notes/) | | InnoDB 5.6.32 | [MariaDB 10.1.17](https://mariadb.com/kb/en/mariadb-10117-release-notes/) | | InnoDB 5.6.31 | [MariaDB 10.1.16](https://mariadb.com/kb/en/mariadb-10116-release-notes/) | | InnoDB 5.6.30 | [MariaDB 10.1.14](https://mariadb.com/kb/en/mariadb-10114-release-notes/) | | InnoDB 5.6.29 | [MariaDB 10.1.12](https://mariadb.com/kb/en/mariadb-10112-release-notes/) | ### [MariaDB 10.0](../what-is-mariadb-100/index) | InnoDB Version | Introduced | | --- | --- | | InnoDB 5.6.43 | [MariaDB 10.0.38](https://mariadb.com/kb/en/mariadb-10038-release-notes/) | | InnoDB 5.6.42 | [MariaDB 10.0.37](https://mariadb.com/kb/en/mariadb-10037-release-notes/) | | InnoDB 5.6.40 | [MariaDB 10.0.35](https://mariadb.com/kb/en/mariadb-10035-release-notes/) | | InnoDB 5.6.39 | [MariaDB 10.0.34](https://mariadb.com/kb/en/mariadb-10034-release-notes/) | | InnoDB 5.6.38 | [MariaDB 10.0.33](https://mariadb.com/kb/en/mariadb-10033-release-notes/) | | InnoDB 5.6.37 | [MariaDB 10.0.32](https://mariadb.com/kb/en/mariadb-10032-release-notes/) | | InnoDB 5.6.36 | [MariaDB 10.0.31](https://mariadb.com/kb/en/mariadb-10031-release-notes/) | | InnoDB 5.6.35 | [MariaDB 10.0.29](https://mariadb.com/kb/en/mariadb-10029-release-notes/) | | InnoDB 5.6.33 | [MariaDB 10.0.28](https://mariadb.com/kb/en/mariadb-10028-release-notes/) | | InnoDB 5.6.32 | [MariaDB 10.0.27](https://mariadb.com/kb/en/mariadb-10027-release-notes/) | | InnoDB 5.6.31 | [MariaDB 10.0.26](https://mariadb.com/kb/en/mariadb-10026-release-notes/) | | InnoDB 5.6.30 | [MariaDB 10.0.25](https://mariadb.com/kb/en/mariadb-10025-release-notes/) | | InnoDB 5.6.29 | [MariaDB 10.0.24](https://mariadb.com/kb/en/mariadb-10024-release-notes/) | | InnoDB 5.6.28 | [MariaDB 10.0.23](https://mariadb.com/kb/en/mariadb-10023-release-notes/) | | InnoDB 5.6.27 | [MariaDB 10.0.22](https://mariadb.com/kb/en/mariadb-10022-release-notes/) | | InnoDB 5.6.26 | [MariaDB 10.0.21](https://mariadb.com/kb/en/mariadb-10021-release-notes/) | | InnoDB 5.6.25 | [MariaDB 10.0.20](https://mariadb.com/kb/en/mariadb-10020-release-notes/) | | InnoDB 5.6.24 | [MariaDB 10.0.18](https://mariadb.com/kb/en/mariadb-10018-release-notes/) | | InnoDB 5.6.23 | [MariaDB 10.0.17](https://mariadb.com/kb/en/mariadb-10017-release-notes/) | | InnoDB 5.6.22 | [MariaDB 10.0.16](https://mariadb.com/kb/en/mariadb-10016-release-notes/) | | InnoDB 5.6.21 | [MariaDB 10.0.15](https://mariadb.com/kb/en/mariadb-10015-release-notes/) | | InnoDB 5.6.20 | [MariaDB 10.0.14](https://mariadb.com/kb/en/mariadb-10014-release-notes/) | | InnoDB 5.6.19 | [MariaDB 10.0.13](https://mariadb.com/kb/en/mariadb-10013-release-notes/) | | InnoDB 5.6.17 | [MariaDB 10.0.11](https://mariadb.com/kb/en/mariadb-10011-release-notes/) | | InnoDB 5.6.15 | [MariaDB 10.0.9](https://mariadb.com/kb/en/mariadb-1009-release-notes/) | | InnoDB 5.6.14 | [MariaDB 10.0.8](https://mariadb.com/kb/en/mariadb-1008-release-notes/) | See Also -------- * [Why MariaDB uses InnoDB instead of XtraDB from MariaDB 10.2](../why-does-mariadb-102-use-innodb-instead-of-xtradb/index) * [XtraDB Versions](../about-xtradb/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb MariaDB ColumnStore 1.0 Upgrades MariaDB ColumnStore 1.0 Upgrades ================================= | Title | Description | | --- | --- | | [MariaDB ColumnStore software upgrade 1.0.15 to 1.0.16](../mariadb-columnstore-software-upgrade-1015-to-1016/index) | MariaDB ColumnStore software upgrade 1.0.15 to 1.0.16 Note: Columnstore.xm... | | [MariaDB ColumnStore software upgrade 1.0.14 to 1.0.15](../mariadb-columnstore-software-upgrade-1014-to-1015/index) | MariaDB ColumnStore software upgrade 1.0.14 to 1.0.15 Note: Columnstore.xm... | | [MariaDB ColumnStore software upgrade 1.0.13 to 1.0.14](../mariadb-columnstore-software-upgrade-1013-to-1014/index) | MariaDB ColumnStore software upgrade 1.0.13 to 1.0.14 Note: Columnstore.xm... | | [MariaDB ColumnStore software upgrade 1.0.12 to 1.0.13](../mariadb-columnstore-software-upgrade-1012-to-1013/index) | MariaDB ColumnStore software upgrade 1.0.12 to 1.0.13 Note: Columnstore.xm... | | [MariaDB ColumnStore software upgrade 1.0.11 to 1.0.12](../mariadb-columnstore-software-upgrade-1011-to-1012/index) | MariaDB ColumnStore software upgrade 1.0.11 to 1.0.12 Note: Columnstore.xm... | | [MariaDB ColumnStore software upgrade 1.0.10 to 1.0.11](../mariadb-columnstore-software-upgrade-1010-to-1011/index) | MariaDB ColumnStore software upgrade 1.0.10 to 1.0.11 Note: Columnstore.xm... | | [MariaDB ColumnStore software upgrade 1.0.9 to 1.0.10](../mariadb-columnstore-software-upgrade-109-to-1010/index) | MariaDB ColumnStore software upgrade 1.0.9 to 1.0.10 Note: Columnstore.xml... | | [MariaDB ColumnStore software upgrade 1.0.8 to 1.0.9](../mariadb-columnstore-software-upgrade-108-to-109/index) | MariaDB ColumnStore software upgrade 1.0.8 to 1.0.9 Note: Columnstore.xml ... | | [MariaDB ColumnStore software upgrade 1.0.7 to 1.0.8](../mariadb-columnstore-software-upgrade-107-to-108/index) | MariaDB ColumnStore software upgrade 1.0.7 to 1.0.8 Note: Columnstore.xml ... | | [MariaDB ColumnStore software upgrade 1.0.6 to 1.0.7](../mariadb-columnstore-software-upgrade-106-to-107/index) | MariaDB ColumnStore software upgrade 1.0.6 to 1.0.7 Note: Columnstore.xml ... | | [MariaDB ColumnStore software upgrade 1.0.5 to 1.0.6](../mariadb-columnstore-software-upgrade-105-to-106/index) | MariaDB ColumnStore software upgrade 1.0.5 to 1.0.6 Note: Columnstore.xml ... | | [MariaDB ColumnStore software upgrade 1.0.4 to 1.0.6](../mariadb-columnstore-software-upgrade-104-to-106/index) | MariaDB ColumnStore software upgrade 1.0.4 to 1.0.6 Note: Columnstore.xml ... | | [Upgrading MariaDB ColumnStore from 1.0.4 to 1.0.5](../upgrading-mariadb-columnstore-from-104-to-105/index) | MariaDB ColumnStore software upgrade 1.0.4 to 1.0.5 Note: Columnstore.xml ... | | [Upgrading MariaDB ColumnStore from 1.0.3 to 1.0.4](../upgrading-mariadb-columnstore-from-103-to-104/index) | MariaDB ColumnStore software upgrade 1.0.3 to 1.0.4 Note: Columnstore.xml ... | | [Upgrading MariaDB ColumnStore from 1.0.2 to 1.0.3](../upgrading-mariadb-columnstore-from-102-to-103/index) | MariaDB ColumnStore software upgrade 1.0.2 to 1.0.3 Note: Columnstore.xml ... | | [Upgrading MariaDB ColumnStore from 1.0.1 to 1.0.2](../mariadb-columnstore-10-upgrades-upgrading-mariadb-columnstore-from-101-to-1/index) | MariaDB ColumnStore single server software upgrade from 1.0.1 to 1.0.2 Not... | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb STR_TO_DATE STR\_TO\_DATE ============= Syntax ------ ``` STR_TO_DATE(str,format) ``` Description ----------- This is the inverse of the [DATE\_FORMAT](../date_format/index)() function. It takes a string `str` and a format string `format`. `STR_TO_DATE()` returns a `DATETIME` value if the format string contains both date and time parts, or a `DATE` or `TIME` value if the string contains only date or time parts. The date, time, or datetime values contained in `str` should be given in the format indicated by format. If str contains an illegal date, time, or datetime value, `STR_TO_DATE()` returns `NULL`. An illegal value also produces a warning. The options that can be used by STR\_TO\_DATE(), as well as its inverse [DATE\_FORMAT()](../date_format/index) and the [FROM\_UNIXTIME()](../from_unixtime/index) function, are: | Option | Description | | --- | --- | | `%a` | Short weekday name in current locale (Variable [lc\_time\_names](../server-system-variables/index#lc_time_names)). | | `%b` | Short form month name in current locale. For locale en\_US this is one of: Jan,Feb,Mar,Apr,May,Jun,Jul,Aug,Sep,Oct,Nov or Dec. | | `%c` | Month with 1 or 2 digits. | | `%D` | Day with English suffix 'th', 'nd', 'st' or 'rd''. (1st, 2nd, 3rd...). | | `%d` | Day with 2 digits. | | `%e` | Day with 1 or 2 digits. | | `%f` | [Microseconds](../microseconds-in-mariadb/index) 6 digits. | | `%H` | Hour with 2 digits between 00-23. | | `%h` | Hour with 2 digits between 01-12. | | `%I` | Hour with 2 digits between 01-12. | | `%i` | Minute with 2 digits. | | `%j` | Day of the year (001-366) | | `%k` | Hour with 1 digits between 0-23. | | `%l` | Hour with 1 digits between 1-12. | | `%M` | Full month name in current locale (Variable [lc\_time\_names](../server-system-variables/index#lc_time_names)). | | `%m` | Month with 2 digits. | | `%p` | AM/PM according to current locale (Variable [lc\_time\_names](../server-system-variables/index#lc_time_names)). | | `%r` | Time in 12 hour format, followed by AM/PM. Short for '%I:%i:%S %p'. | | `%S` | Seconds with 2 digits. | | `%s` | Seconds with 2 digits. | | `%T` | Time in 24 hour format. Short for '%H:%i:%S'. | | `%U` | Week number (00-53), when first day of the week is Sunday. | | `%u` | Week number (00-53), when first day of the week is Monday. | | `%V` | Week number (01-53), when first day of the week is Sunday. Used with %X. | | `%v` | Week number (01-53), when first day of the week is Monday. Used with %x. | | `%W` | Full weekday name in current locale (Variable [lc\_time\_names](../server-system-variables/index#lc_time_names)). | | `%w` | Day of the week. 0 = Sunday, 6 = Saturday. | | `%X` | Year with 4 digits when first day of the week is Sunday. Used with %V. | | `%x` | Year with 4 digits when first day of the week is Monday. Used with %v. | | `%Y` | Year with 4 digits. | | `%y` | Year with 2 digits. | | `%#` | For [str\_to\_date](index)(), skip all numbers. | | `%.` | For [str\_to\_date](index)(), skip all punctation characters. | | `%@` | For [str\_to\_date](index)(), skip all alpha characters. | | `%%` | A literal `%` character. | Examples -------- ``` SELECT STR_TO_DATE('Wednesday, June 2, 2014', '%W, %M %e, %Y'); +---------------------------------------------------------+ | STR_TO_DATE('Wednesday, June 2, 2014', '%W, %M %e, %Y') | +---------------------------------------------------------+ | 2014-06-02 | +---------------------------------------------------------+ SELECT STR_TO_DATE('Wednesday23423, June 2, 2014', '%W, %M %e, %Y'); +--------------------------------------------------------------+ | STR_TO_DATE('Wednesday23423, June 2, 2014', '%W, %M %e, %Y') | +--------------------------------------------------------------+ | NULL | +--------------------------------------------------------------+ 1 row in set, 1 warning (0.00 sec) SHOW WARNINGS; +---------+------+-----------------------------------------------------------------------------------+ | Level | Code | Message | +---------+------+-----------------------------------------------------------------------------------+ | Warning | 1411 | Incorrect datetime value: 'Wednesday23423, June 2, 2014' for function str_to_date | +---------+------+-----------------------------------------------------------------------------------+ SELECT STR_TO_DATE('Wednesday23423, June 2, 2014', '%W%#, %M %e, %Y'); +----------------------------------------------------------------+ | STR_TO_DATE('Wednesday23423, June 2, 2014', '%W%#, %M %e, %Y') | +----------------------------------------------------------------+ | 2014-06-02 | +----------------------------------------------------------------+ ``` See Also -------- * [DATE\_FORMAT()](../date_format/index) * [FROM\_UNIXTIME()](../from_unixtime/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb DATE_FORMAT DATE\_FORMAT ============ Syntax ------ ``` DATE_FORMAT(date, format[, locale]) ``` Description ----------- Formats the date value according to the format string. The language used for the names is controlled by the value of the [lc\_time\_names](../server-system-variables/index#lc_time_names) system variable. See [server locale](../server-locale/index) for more on the supported locales. The options that can be used by DATE\_FORMAT(), as well as its inverse [STR\_TO\_DATE](../str_to_date/index)() and the [FROM\_UNIXTIME()](../from_unixtime/index) function, are: | Option | Description | | --- | --- | | `%a` | Short weekday name in current locale (Variable [lc\_time\_names](../server-system-variables/index#lc_time_names)). | | `%b` | Short form month name in current locale. For locale en\_US this is one of: Jan,Feb,Mar,Apr,May,Jun,Jul,Aug,Sep,Oct,Nov or Dec. | | `%c` | Month with 1 or 2 digits. | | `%D` | Day with English suffix 'th', 'nd', 'st' or 'rd''. (1st, 2nd, 3rd...). | | `%d` | Day with 2 digits. | | `%e` | Day with 1 or 2 digits. | | `%f` | [Microseconds](../microseconds-in-mariadb/index) 6 digits. | | `%H` | Hour with 2 digits between 00-23. | | `%h` | Hour with 2 digits between 01-12. | | `%I` | Hour with 2 digits between 01-12. | | `%i` | Minute with 2 digits. | | `%j` | Day of the year (001-366) | | `%k` | Hour with 1 digits between 0-23. | | `%l` | Hour with 1 digits between 1-12. | | `%M` | Full month name in current locale (Variable [lc\_time\_names](../server-system-variables/index#lc_time_names)). | | `%m` | Month with 2 digits. | | `%p` | AM/PM according to current locale (Variable [lc\_time\_names](../server-system-variables/index#lc_time_names)). | | `%r` | Time in 12 hour format, followed by AM/PM. Short for '%I:%i:%S %p'. | | `%S` | Seconds with 2 digits. | | `%s` | Seconds with 2 digits. | | `%T` | Time in 24 hour format. Short for '%H:%i:%S'. | | `%U` | Week number (00-53), when first day of the week is Sunday. | | `%u` | Week number (00-53), when first day of the week is Monday. | | `%V` | Week number (01-53), when first day of the week is Sunday. Used with %X. | | `%v` | Week number (01-53), when first day of the week is Monday. Used with %x. | | `%W` | Full weekday name in current locale (Variable [lc\_time\_names](../server-system-variables/index#lc_time_names)). | | `%w` | Day of the week. 0 = Sunday, 6 = Saturday. | | `%X` | Year with 4 digits when first day of the week is Sunday. Used with %V. | | `%x` | Year with 4 digits when first day of the week is Monday. Used with %v. | | `%Y` | Year with 4 digits. | | `%y` | Year with 2 digits. | | `%#` | For [str\_to\_date](../str_to_date/index)(), skip all numbers. | | `%.` | For [str\_to\_date](../str_to_date/index)(), skip all punctation characters. | | `%@` | For [str\_to\_date](../str_to_date/index)(), skip all alpha characters. | | `%%` | A literal `%` character. | To get a date in one of the standard formats, `[GET\_FORMAT()](../get_format/index)` can be used. Examples -------- ``` SELECT DATE_FORMAT('2009-10-04 22:23:00', '%W %M %Y'); +------------------------------------------------+ | DATE_FORMAT('2009-10-04 22:23:00', '%W %M %Y') | +------------------------------------------------+ | Sunday October 2009 | +------------------------------------------------+ SELECT DATE_FORMAT('2007-10-04 22:23:00', '%H:%i:%s'); +------------------------------------------------+ | DATE_FORMAT('2007-10-04 22:23:00', '%H:%i:%s') | +------------------------------------------------+ | 22:23:00 | +------------------------------------------------+ SELECT DATE_FORMAT('1900-10-04 22:23:00', '%D %y %a %d %m %b %j'); +------------------------------------------------------------+ | DATE_FORMAT('1900-10-04 22:23:00', '%D %y %a %d %m %b %j') | +------------------------------------------------------------+ | 4th 00 Thu 04 10 Oct 277 | +------------------------------------------------------------+ SELECT DATE_FORMAT('1997-10-04 22:23:00', '%H %k %I %r %T %S %w'); +------------------------------------------------------------+ | DATE_FORMAT('1997-10-04 22:23:00', '%H %k %I %r %T %S %w') | +------------------------------------------------------------+ | 22 22 10 10:23:00 PM 22:23:00 00 6 | +------------------------------------------------------------+ SELECT DATE_FORMAT('1999-01-01', '%X %V'); +------------------------------------+ | DATE_FORMAT('1999-01-01', '%X %V') | +------------------------------------+ | 1998 52 | +------------------------------------+ SELECT DATE_FORMAT('2006-06-00', '%d'); +---------------------------------+ | DATE_FORMAT('2006-06-00', '%d') | +---------------------------------+ | 00 | +---------------------------------+ ``` **MariaDB starting with [10.3.2](https://mariadb.com/kb/en/mariadb-1032-release-notes/)**Optionally, the locale can be explicitly specified as the third DATE\_FORMAT() argument. Doing so makes the function independent from the session settings, and the three argument version of DATE\_FORMAT() can be used in virtual indexed and persistent [generated-columns](../generated-columns/index): ``` SELECT DATE_FORMAT('2006-01-01', '%W', 'el_GR'); +------------------------------------------+ | DATE_FORMAT('2006-01-01', '%W', 'el_GR') | +------------------------------------------+ | Κυριακή | +------------------------------------------+ ``` See Also -------- * [STR\_TO\_DATE()](../str_to_date/index) * [FROM\_UNIXTIME()](../from_unixtime/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb SHOW BINLOG EVENTS SHOW BINLOG EVENTS ================== Syntax ------ ``` SHOW BINLOG EVENTS [IN 'log_name'] [FROM pos] [LIMIT [offset,] row_count] ``` Description ----------- Shows the events in the [binary log](../binary-log/index). If you do not specify '`log_name`', the first binary log is displayed. Requires the [BINLOG MONITOR](../grant/index#binlog-monitor) privilege (>= [MariaDB 10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/)) or the [REPLICATION SLAVE](../grant/index#replication-slave) privilege (<= [MariaDB 10.5.1](https://mariadb.com/kb/en/mariadb-1051-release-notes/)). Example ------- ``` SHOW BINLOG EVENTS IN 'mysql_sandbox10019-bin.000002'; +-------------------------------+-----+-------------------+-----------+-------------+------------------------------------------------+ | Log_name | Pos | Event_type | Server_id | End_log_pos | Info | +-------------------------------+-----+-------------------+-----------+-------------+------------------------------------------------+ | mysql_sandbox10019-bin.000002 | 4 | Format_desc | 1 | 248 | Server ver: 10.0.19-MariaDB-log, Binlog ver: 4 | | mysql_sandbox10019-bin.000002 | 248 | Gtid_list | 1 | 273 | [] | | mysql_sandbox10019-bin.000002 | 273 | Binlog_checkpoint | 1 | 325 | mysql_sandbox10019-bin.000002 | | mysql_sandbox10019-bin.000002 | 325 | Gtid | 1 | 363 | GTID 0-1-1 | | mysql_sandbox10019-bin.000002 | 363 | Query | 1 | 446 | CREATE DATABASE blog | | mysql_sandbox10019-bin.000002 | 446 | Gtid | 1 | 484 | GTID 0-1-2 | | mysql_sandbox10019-bin.000002 | 484 | Query | 1 | 571 | use `blog`; CREATE TABLE bb (id INT) | +-------------------------------+-----+-------------------+-----------+-------------+------------------------------------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Vagrant Security Concerns Vagrant Security Concerns ========================= Databases typically contain information to which access should be restricted. For this reason, it's worth discussing some security concerns that Vagrant users should be aware of. Access to the Vagrant Machine ----------------------------- By default, Vagrant machines are only accessible from the localhost. SSH access uses randomly generated key pairs, and therefore it is secure. The password for `root` and `vagrant` is "vagrant" by default. Consider changing it. Synced Folders -------------- By default, the project folder in the host system is shared with the machine, which sees it as `/vagrant`. This means that whoever has access to the project folder also has read and write access to the synced folder. If this is a problem, make sure to properly restrict the access to the synced folder. If we need to exchange files between the host system and the Vagrant machine, it is not advisable to disable the synced folder. This is because the only alternative is to use the `file` provider, which works by copying files to the machine via ssh. The problem is that the default ssh user does not have permissions to write to any directory by default, and changing this would be less secure than using a synced folder. When a machine is provisioned, it should read the needed files from the synced folder or copy them to other places. Files in the synced folder should not be accessed by the Vagrant machine during its normal activities. For example, it is fine to load a dump from the synced folder during provisioning; and it is fine to copy configuration files from the synced folder to directories in `/etc` during provisioning. But it is a bad practice to let MariaDB use table files located in the synced folder. Reporting Security Bugs ----------------------- Note that security bugs are not reported as normal bugs. Information about security bugs are not public. See [Security at HashiCorp](https://www.hashicorp.com/security) for details. --- Content initially contributed by [Vettabase Ltd](https://vettabase.com/). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Thread Pool in MariaDB Thread Pool in MariaDB ====================== Problem That Thread Pools Solve ------------------------------- The task of scalable server software (and a DBMS like MariaDB is an example of such software) is to maintain top performance with an increasing number of clients. MySQL traditionally assigned a thread for every client connection, and as the number of concurrent users grows this model shows performance drops. Many active threads are a performance killer, because increasing the number of threads leads to extensive context switching, bad locality for CPU caches, and increased contention for hot locks. An ideal solution that would help to reduce context switching is to maintain a lower number of threads than the number of clients. But this number should not be too low either, since we also want to utilize CPUs to their fullest, so ideally, there should be a single active thread for each CPU on the machine. MariaDB Thread Pool Features ---------------------------- The current MariaDB thread pool was implemented in [MariaDB 5.5](../what-is-mariadb-55/index). It replaced the legacy thread pool that was introduced in [MariaDB 5.1](../what-is-mariadb-51/index). The main drawback of the previous solution was that this pool was static–it had a fixed number of threads. Static thread pools can have their merits, for some limited use cases, such as cases where callbacks executed by the threads never block and do not depend on each other. For example, iimagine something like an echo server. However, DBMS clients are more complicated. For example, a thread may depend on another thread's completion, and they may block each other via locks and/or I/O. Thus it is very hard, and sometimes impossible, to predict how many threads would be ideal or even sufficient to prevent deadlocks in every situation. [MariaDB 5.5](../what-is-mariadb-55/index) implements a dynamic/adaptive pool that itself takes care of creating new threads in times of high demand and retiring threads if they have nothing to do. This is a complete reimplementation of the legacy `pool-of-threads` scheduler, with the following goals: * Make the pool dynamic, so that it will grow and shrink whenever required. * Minimize the amount of overhead that is required to maintain the thread pool itself. * Make the best use of underlying OS capabilities. For example, if a native thread pool implementation is available, then it should be used, and if not, then the best I/O multiplexing method should be used. * Limit the resources used by threads. There are currently two different low-level implementations – depending on OS. One implementation is designed specifically for Windows which utilizes a native `[CreateThreadpool](https://docs.microsoft.com/en-us/windows/desktop/api/threadpoolapiset/nf-threadpoolapiset-createthreadpool)` API. The second implementation is primarily intended to be used in Unix-like systems. Because the implementations are different, some system variables differ between Windows and Unix. When to Use the Thread Pool --------------------------- Thread pools are most efficient in situations where queries are relatively short and the load is CPU-bound, such as in OLTP workloads. If the workload is not CPU-bound, then you might still benefit from limiting the number of threads to save memory for the database memory buffers. When the Thread Pool is Less Efficient -------------------------------------- There are special, rare cases where the thread pool is likely to be less efficient. * If you have a **very bursty workload**, then the thread pool may not work well for you. These tend to be workloads in which there are long periods of inactivity followed by short periods of very high activity by many users. These also tend to be workloads in which delays cannot be tolerated, so the throttling of thread creation that the thread pool uses is not ideal. Even in this situation, performance can be improved by tweaking how often threads are retired. For example, with `[thread\_pool\_idle\_timeout](../thread-pool-system-and-status-variables/index#thread_pool_idle_timeout)` on Unix, or with `[thread\_pool\_min\_threads](../thread-pool-system-and-status-variables/index#thread_pool_min_threads)` on Windows. * If you have **many concurrent, long, non-yielding** queries, then the thread pool may not work well for you. In this context, a "non-yielding" query is one that never waits or which does not indicate waits to the thread pool. These kinds of workloads are mostly used in data warehouse scenarios. Long-running, non-yielding queries will delay execution of other queries. However, the thread pool has stall detection to prevent them from totally monopolizing the thread pool. See [Thread Groups in the Unix Implementation of the Thread Pool: Thread Group Stalls](../thread-groups-in-the-unix-implementation-of-the-thread-pool/index#thread-group-stalls) for more information. Even when the whole thread pool is blocked by non-yielding queries, you can still connect to the server through the `[extra-port](../thread-pool-system-and-status-variables/index#extra_port)` TCP/IP port. * If you rely on the fact that **simple queries always finish quickly**, no matter how loaded your database server is, then the thread pool may not work well for you. When the thread pool is enabled on a busy server, even simple queries might be queued to be executed later. This means that even if the statement itself doesn't take much time to execute, even a simple `SELECT 1`, might take a bit longer when the thread pool is enabled than with `one-thread-per-connection` if it gets queued. Configuring the Thread Pool --------------------------- The `[thread\_handling](../thread-pool-system-and-status-variables/index#thread_handling)` system variable is the primary system variable that is used to configure the thread pool. There are several other system variables as well, which are described in the sections below. Many of the system variables documented below are dynamic, meaning that they can be changed with `[SET GLOBAL](../set/index#global-session)` on a running server. Generally, there is no need to tweak many of these system variables. The goal of the thread pool was to provide good performance out-of-the box. However, the system variable values can be changed, and we intended to expose as many knobs from the underlying implementation as we could. Feel free to tweak them as you see fit. If you find any issues with any of the default behavior, then we encourage you to [submit a bug report](../reporting-bugs/index). See [Thread Pool System and Status Variables](../thread-pool-system-status-variables/index) for the full list of the thread pool's system variables. ### Configuring the Thread Pool on Unix On Unix, if you would like to use the thread pool, then you can use the thread pool by setting the `[thread\_handling](../thread-pool-system-and-status-variables/index#thread_handling)` system variable to `pool-of-threads` in a server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index) prior to starting up the server. For example: ``` [mariadb] ... thread_handling=pool-of-threads ``` The following system variables can also be configured on Unix: * `[thread\_pool\_size](../thread-pool-system-and-status-variables/index#thread_pool_size)` – The number of [thread groups](../thread-groups-in-the-unix-implementation-of-the-thread-pool/index) in the thread pool, which determines how many statements can execute simultaneously. The default value is the number of CPUs on the system. When setting this system variable's value at system startup, the max value is 100000. However, it is not a good idea to set it that high. When setting this system variable's value dynamically, the max value is either 128 or the value that was set at system startup--whichever value is higher. See [Thread Groups in the Unix Implementation of the Thread Pool](../thread-groups-in-the-unix-implementation-of-the-thread-pool/index) for more information. * `[thread\_pool\_max\_threads](../thread-pool-system-and-status-variables/index#thread_pool_max_threads)` – The maximum number of threads in the thread pool. Once this limit is reached, no new threads will be created in most cases. In rare cases, the actual number of threads can slightly exceed this, because each [thread group](../thread-groups-in-the-unix-implementation-of-the-thread-pool/index) needs at least two threads (i.e. at least one worker thread and at least one listener thread) to prevent deadlocks. The default value in [MariaDB 5.5](../what-is-mariadb-55/index) and [MariaDB 10.0](../what-is-mariadb-100/index) is `500`. The default value in [MariaDB 10.1](../what-is-mariadb-101/index) is `1000` in [MariaDB 10.1](../what-is-mariadb-101/index). The default value in [MariaDB 10.2](../what-is-mariadb-102/index) and later is `65536`. * `[thread\_pool\_stall\_limit](../thread-pool-system-and-status-variables/index#thread_pool_stall_limit)` – The number of milliseconds between each stall check performed by the timer thread. The default value is `500`. Stall detection is used to prevent a single client connection from monopolizing a thread group. When the timer thread detects that a thread group is stalled, it wakes up a sleeping worker thread in the thread group, if one is available. If there isn't one, then it creates a new worker thread in the thread group. This temporarily allows several client connections in the thread group to run in parallel. However, note that the timer thread will not create a new worker thread if the number of threads in the thread pool is already greater than or equal to the maximum defined by the `[thread\_pool\_max\_threads](../thread-pool-system-status-variables/index#thread_pool_max_threads)` variable, unless the thread group does not already have a listener thread. See [Thread Groups in the Unix Implementation of the Thread Pool: Thread Group Stalls](../thread-groups-in-the-unix-implementation-of-the-thread-pool/index#thread-group-stalls) for more information. * `[thread\_pool\_oversubscribe](../thread-pool-system-and-status-variables/index#thread_pool_oversubscribe)` – Determines how many worker threads in a thread group can remain active at the same time once a thread group is oversubscribed due to stalls. The default value is `3`. Usually, a thread group only has one active worker thread at a time. However, the timer thread can add more active worker threads to a thread group if it detects a stall. There are trade-offs to consider when deciding whether to allow **only one** thread per CPU to run at a time, or whether to allow **more than one** thread per CPU to run at a time. Allowing only one thread per CPU means that the thread can have unrestricted access to the CPU while its running, but it also means that there is additional overhead from putting threads to sleep or waking them up more frequently. Allowing more than one thread per CPU means that the threads have to share the CPU, but it also means that there is less overhead from putting threads to sleep or waking them up. This is primarily for **internal** use, and it is **not** meant to be changed for most users. See [Thread Groups in the Unix Implementation of the Thread Pool: Thread Group Oversubscription](../thread-groups-in-the-unix-implementation-of-the-thread-pool/index#thread-group-oversubscription) for more information. * `[thread\_pool\_idle\_timeout](../thread-pool-system-and-status-variables/index#thread_pool_idle_timeout)` – The number of seconds before an idle worker thread exits. The default value is `60`. If there is currently no work to do, how long should an idle thread wait before exiting? ### Configuring the Thread Pool on Windows The Windows implementation of the thread pool uses a native thread pool created with the `[CreateThreadpool](https://docs.microsoft.com/en-us/windows/desktop/api/threadpoolapiset/nf-threadpoolapiset-createthreadpool)` API. On Windows, if you would like to use the thread pool, then you do not need to do anything, because the default for the `[thread\_handling](../thread-pool-system-and-status-variables/index#thread_handling)` system variable is already preset to `pool-of-threads`. However, if you would like to use the old one thread per-connection behavior on Windows, then you can use use that by setting the `[thread\_handling](../thread-pool-system-and-status-variables/index#thread_handling)` system variable to `one-thread-per-connection` in a server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index) prior to starting up the server. For example: ``` [mariadb] ... thread_handling=one-thread-per-connection ``` On older versions of Windows, such as XP and 2003, `pool-of-threads` is not implemented, and the server will silently switch to using the legacy `one-thread-per-connection` method. The native `[CreateThreadpool](https://docs.microsoft.com/en-us/windows/desktop/api/threadpoolapiset/nf-threadpoolapiset-createthreadpool)` API allows applications to set the minimum and maximum number of threads in the pool. The following system variables can be used to configure those values on Windows: * `[thread\_pool\_min\_threads](../thread-pool-system-and-status-variables/index#thread_pool_min_threads)` – The minimum number of threads in the pool. Default is 1. This applicable in a special case of very “bursty” workloads. Imagine having longer periods of inactivity after periods of high activity. While the thread pool is idle, Windows would decide to retire pool threads (based on experimentation, this seems to happen after thread had been idle for 1 minute). Next time high load comes, it could take some milliseconds or seconds until the thread pool size stabilizes again to optimal value. To avoid thread retirement, one could set the parameter to a higher value. * `[thread\_pool\_max\_threads](../thread-pool-system-and-status-variables/index#thread_pool_max_threads)` – The maximum number of threads in the pool. Threads are not created when this value is reached. The default from [MariaDB 5.5](../what-is-mariadb-55/index) to [MariaDB 10.0](../what-is-mariadb-100/index) is 500 (this has been increased to 1000 in [MariaDB 10.1](../what-is-mariadb-101/index)). This parameter can be used to prevent the creation of new threads if the pool can have short periods where many or all clients are blocked (for example, with “FLUSH TABLES WITH READ LOCK”, high contention on row locks, or similar). New threads are created if a blocking situation occurs (such as after a throttling interval), but sometimes you want to cap the number of threads, if you’re familiar with the application and need to, for example, save memory. If your application constantly pegs at 500 threads, it might be a strong indicator for high contention in the application, and the thread pool does not help much. ### Configuring Priority Scheduling Starting with [MariaDB 10.2.2](https://mariadb.com/kb/en/mariadb-1022-release-notes/), it is possible to configure connection prioritization. The priority behavior is configured by the `[thread\_pool\_priority](../thread-pool-system-and-status-variables/index#thread_pool_priority)` system variable. By default, if `[thread\_pool\_priority](../thread-pool-system-and-status-variables/index#thread_pool_priority)` is set to `auto`, then queries would be given a higher priority, in case the current connection is inside a transaction. This allows the running transaction to finish faster, and has the effect of lowering the number of transactions running in parallel. The default setting will generally improve throughput for transactional workloads. But it is also possible to explicitly set the priority for the current connection to either 'high' or 'low'. There is also a mechanism in place to ensure that higher priority connections are not monopolizing the worker threads in the pool (which would cause indefinite delays for low priority connections). On Unix, low priority connections are put into the high priority queue after the timeout specified by the `[thread\_pool\_prio\_kickup\_timer](../thread-pool-system-and-status-variables/index#thread_pool_prio_kickup_timer)` system variable. ### Configuring the Extra Port MariaDB allows you to configure an extra port for administrative connections. This is primarily intended to be used in situations where all threads in the thread pool are blocked, and you still need a way to access the server. However, it can also be used to ensure that monitoring systems (including MaxScale's monitors) always have access to the system, even when all connections on the main port are used. This extra port uses the old `one-thread-per-connection` thread handling. You can enable this and configure a specific port by setting the `[extra\_port](../thread-pool-system-status-variables/index#extra_port)` system variable. You can configure a specific number of connections for this port by setting the `[extra\_max\_connections](../thread-pool-system-status-variables/index#extra_max_connections)` system variable. These system variables can be set in a server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index) prior to starting up the server. For example: ``` [mariadb] ... extra_port = 8385 extra_max_connections = 10 ``` Once you have the extra port configured, you can use the `[mysql](../mysql-command-line-client/index)` client with the `-P` option to connect to the port. ``` $ mysql -u root -P 8385 -p ``` Monitoring Thread Pool Activity ------------------------------- Currently there are two status variables exposed to monitor pool activity. | Variable | Description | | --- | --- | | `[Threadpool\_threads](../thread-pool-system-and-status-variables/index#threadpool_threads)` | Number of threads in the thread pool. In rare cases, this can be slightly higher than `[thread\_pool\_max\_threads](../thread-pool-system-status-variables/index#thread_pool_max_threads)`, because each thread group needs at least two threads (i.e. at least one worker thread and at least one listener thread) to prevent deadlocks. | | `[Threadpool\_idle\_threads](../thread-pool-system-and-status-variables/index#threadpool_idle_threads)` | Number of inactive threads in the thread pool. Threads become inactive for various reasons, such as by waiting for new work. However, an inactive thread is not necessarily one that has not been assigned work. Threads are also considered inactive if they are being blocked while waiting on disk I/O, or while waiting on a lock, etc. This status variable is only meaningful on **Unix**. | Thread Groups in the Unix Implementation of the Thread Pool ----------------------------------------------------------- On Unix, the thread pool implementation uses objects called thread groups to divide up client connections into many independent sets of threads. See [Thread Groups in the Unix Implementation of the Thread Pool](../thread-groups-in-the-unix-implementation-of-the-thread-pool/index) for more information. Fixing a Blocked Thread Pool ---------------------------- When using global locks, even with a high value on the `[thread\_pool\_max\_threads](../thread-pool-system-status-variables/index#thread_pool_max_threads)` system variable, it is still possible to block the entire pool. Imagine the case where a client performs `[FLUSH TABLES WITH READ LOCK](../flush/index)` then pauses. If then the number of other clients connecting to the server to start write operations exceeds the maximum number of threads allowed in the pool, it can block the Server. This makes it impossible to issue the `[UNLOCK TABLES](lock-and-unlock-tables)` statement. It can also block MaxScale from monitoring the Server. To mitigate the issue, MariaDB allows you to configure an extra port for administrative connections. See [Configuring the Extra Port](#configuring-the-extra-port) for information on how to configure this. Once you have the extra port configured, you can use the `[mysql](../mysql-command-line-client/index)` client with the `-P` option to connect to the port. ``` $ mysql -u root -P 8385 -p ``` This ensures that your administrators can access the server in cases where the number of threads is already equal to the configured value of the `[thread\_pool\_max\_threads](../thread-pool-system-status-variables/index#thread_pool_max_threads)` system variable, and all threads are blocked. It also ensures that MaxScale can still access the server in such situations for monitoring information. Once you are connected to the extra port, you can solve the issue by increasing the value on the `[thread\_pool\_max\_threads](../thread-pool-system-status-variables/index#thread_pool_max_threads)` system variable, or by killing the offending connection, (that is, the connection that holds the global lock, which would be in the `sleep` state). MariaDB Thread Pool vs Oracle MySQL Enterprise Thread Pool ---------------------------------------------------------- Commercial editions of MySQL since 5.5 include an Oracle MySQL Enterprise thread pool implemented as a plugin, which delivers similar functionality. Official documentation of the feature can be found in the [MySQL Reference Manual](http://dev.mysql.com/doc/refman/5.5/en/thread-pool-plugin.html) and a detailed discussion about the design of the feature is at [Mikael Ronstrom's blog](http://mikaelronstrom.blogspot.com/2011/10/mysql-thread-pool-summary.html). Here is the summary of similarities and differences, based on the above materials. ### Similarities * On Unix, both MariaDB and Oracle MySQL Enterprise Threadpool will partition client connections into groups. The [thread\_pool\_size](../thread-pool-system-and-status-variables/index#thread_pool_size) parameter thus has the same meaning for both MySQL and MariaDB. * Both implementations use similar schema checking for thread stalls, and both have the same parameter name for [thread\_pool\_stall\_limit](../thread-pool-system-and-status-variables/index#thread_pool_stall_limit) (though in MariaDB it is measured using millisecond units, not 10ms units like in Oracle MySQL). ### Differences * The Windows implementation is completely different – MariaDB's uses native Windows threadpooling, while Oracle's implementation includes a convenience function *WSAPoll()* (provided for convenience to port Unix applications). As a consequence of relying on *WSAPoll()*, Oracle's implementation will not work with named pipes and shared memory connections. * MariaDB uses the most efficient I/O multiplexing facilities for each operating system: Windows (the I/O completion port is used internally by the native threadpool), Linux (epoll), Solaris (event ports), FreeBSD and OSX (kevent). Oracle uses optimized I/O multiplexing only on Linux, with epoll, and uses poll() otherwise. * Unlike Oracle MySQL Enterprise Threadpool, MariaDB's one is builtin, not a plugin. MariaDB Thread Pool vs Percona Thread Pool ------------------------------------------ [Percona's implementation](https://www.percona.com/doc/percona-server/5.7/performance/threadpool.html) is a port of the MariaDB's threadpool with some added features. In particular, Percona added priority scheduling to its 5.5-5.7 releases. [MariaDB 10.2](../what-is-mariadb-102/index) and Percona priority scheduling work in a similar fashion, but there are some differences in details. * MariaDB's 10.2 thread\_pool\_priority=auto,high, low correspond to Percona's thread\_pool\_high\_prio\_mode=transactions,statements,none * Percona has a thread\_pool\_high\_prio\_tickets connection variable to allow every nth low priority query to be put into the high priority queue. MariaDB does not have corresponding settings. * MariaDB has a thread\_pool\_prio\_kickup\_timer setting, which Percona does not have. Thread Pool Internals --------------------- Low-level implementation details are documented in the [WL#246](http://askmonty.org/worklog/Server-BackLog/?tid=246) Running Benchmarks ------------------ When running sysbench and maybe other benchmarks, that create many threads on the same machine as the server, it is advisable to run benchmark driver and server on different CPUs to get the realistic results. Running lots of driver threads and only several server threads on the same CPUs will have the effect that OS scheduler will schedule benchmark driver threads to run with much higher probability than the server threads, that is driver will pre-empt the server. Use "taskset –c" on Linuxes, and "set /affinity" on Windows to separate benchmark driver and server CPUs, as the preferred method to fix this situation. A possible alternative on Unix (if taskset or a separate machine running the benchmark is not desired for some reason) would be to increase thread\_pool\_size to make the server threads more "competitive" against the client threads. When running sysbench, a good rule of thumb could be to give 1/4 of all CPUs to the sysbench, and 3/4 of CPUs to mysqld. It is also good idea to run sysbench and mysqld on different NUMA nodes, if possible. Notes ----- The [thread\_cache\_size](../server-system-variables/index#thread_cache_size) system variable is not used when the thread pool is used and the [Threads\_cached](../server-status-variables/index#threads_cached) status variable will have a value of 0. See Also -------- * [Thread Pool System and Status Variables](../thread-pool-system-and-status-variables/index) * [Threadpool Benchmarks](../threadpool-benchmarks/index) * [Thread Pool in MariaDB 5.1 - 5.3](../thread-pool-in-mariadb-51-53/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb mariadb-binlog mariadb-binlog ============== **MariaDB starting with [10.4.6](https://mariadb.com/kb/en/mariadb-1046-release-notes/)**From [MariaDB 10.4.6](https://mariadb.com/kb/en/mariadb-1046-release-notes/), `mariadb-binlog` is a symlink to `mysqlbinlog`. **MariaDB starting with [10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/)**From [MariaDB 10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/), `mariadb-binlog` is the name of the tool, with `mysqlbinlog` a symlink . See [mysqlbinlog](../mysqlbinlog/index) for details. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb SESSION_USER SESSION\_USER ============= Syntax ------ ``` SESSION_USER() ``` Description ----------- SESSION\_USER() is a synonym for [USER()](../user/index). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Distributions Which Include MariaDB Distributions Which Include MariaDB =================================== The following is a partial list of distributions which include MariaDB in their package repositories. For these you can use the distribution's management system to install MariaDB. The term "default" in the list below refers to the distribution's default relational or MySQL-type database. Linux Distributions ------------------- * [Alpine Linux](https://www.alpinelinux.org/) — Defaults to MariaDB. [MariaDB 10.6](../what-is-mariadb-106/index) has been available 3.12.11 * [4mLinux](https://4mlinux.com) — Defaults to MariaDB. [MariaDB 10.7](../what-is-mariadb-107/index) has been available [since 39.0](http://4mlinux-releases.blogspot.com/2022/03/4mlinux-390-stable-released.html) * [ALT Linux](https://packages.altlinux.org/en/Sisyphus/srpms/mariadb) — [MariaDB 5.5](../what-is-mariadb-55/index) included in 7.0.0, MariaDB is default from 8.1, which includes [MariaDB 10.1](../what-is-mariadb-101/index), 9.1 includes [MariaDB 10.4](../what-is-mariadb-104/index) * [Arch Linux](https://www.archlinux.org/news/mariadb-replaces-mysql-in-repositories/) — Features [MariaDB 10.8](../what-is-mariadb-108/index), and replaced MySQL as a default * [Asianux](https://www.asianux.com/) — [MariaDB 5.5](../what-is-mariadb-55/index) replaced MySQL in 7. * [Austrumi](http://cyti.latgola.lv/ruuni/)— Defaulted to [MariaDB 5.3](../what-is-mariadb-53/index) in 2.4.8, 3.5.8 includes [MariaDB 10.1](../what-is-mariadb-101/index) * [BlackArch](http://blackarch.org/) — Defaulted to [MariaDB 5.5](../what-is-mariadb-55/index) in 2014.07.01, 2020.12.01 includes [MariaDB 10.5](../what-is-mariadb-105/index) * [BlueOnyx](http://www.blueonyx.it/) — 5209 defaults to [MariaDB 5.5](../what-is-mariadb-55/index), 5210R to [MariaDB 10.3](../what-is-mariadb-103/index) * [BlueStar](http://bluestarlinux.sourceforge.net/) — 4.8.4 defaults to [MariaDB 10.1](../what-is-mariadb-101/index), 5.4.2 to [MariaDB 10.5](../what-is-mariadb-105/index) * [CentOS](https://wiki.centos.org/About/Product/) — [MariaDB 5.5](../what-is-mariadb-55/index) replaced MySQL in CentOS 7 * [The Chakra Project](https://chakraos.org/) — MariaDB replaced MySQL as default in 2013.05. 2016.02 includes [MariaDB 10.1](../what-is-mariadb-101/index) * [Debian](https://www.debian.org/) — Debian 8 "Jessie" includes [MariaDB 10.0](../what-is-mariadb-100/index), Debian 9 "Stretch" [MariaDB 10.1](../what-is-mariadb-101/index), Debian 10 "Buster" [MariaDB 10.3](../what-is-mariadb-103/index), Debian 11 "Bullseye" [MariaDB 10.5](../what-is-mariadb-105/index) as default. * [Elastix](http://www.elastix.org/) —Defaulted to [MariaDB 5.5](../what-is-mariadb-55/index) in 4.0.76 * [Exherbo](http://exherbo.org/) —Includes [MariaDB 10.4](../what-is-mariadb-104/index) * [Fedora](https://getfedora.org/) — [MariaDB 5.5](../what-is-mariadb-55/index) became the default relational database in Fedora 19. Fedora 30 [includes MariaDB 10.3](https://bodhi.fedoraproject.org/updates/?packages=mariadb&page=1), Fedora 34 [includes MariaDB 10.5](https://fedoraproject.org/wiki/Releases/34/ChangeSet#MariaDB_10.5). * [Funtoo](http://www.funtoo.org/) —Includes [MariaDB 5.5](../what-is-mariadb-55/index) * [Gentoo Linux](https://packages.gentoo.org/packages/dev-db/mariadb) * [Guix](https://www.gnu.org/software/guix/)—11.2.0 includes [MariaDB 10.1](../what-is-mariadb-101/index) * [Hanthana](http://www.hanthana.org/)— 19.1 defaulted to [MariaDB 5.5](../what-is-mariadb-55/index), 21 includes [MariaDB 10.0](../what-is-mariadb-100/index), 28.1.2 includes [MariaDB 10.2](../what-is-mariadb-102/index), 30 includes [MariaDB 10.3](../what-is-mariadb-103/index) * [KaOS](http://kaosx.us/) —Defaulted to [MariaDB 5.5](../what-is-mariadb-55/index) in 2014.12, 2019.04 includes [MariaDB 10.3](../what-is-mariadb-103/index) * [Kali Linux](https://www.kali.org/) —2017.3 Included [MariaDB 10.1](../what-is-mariadb-101/index), 2021.1 includes [MariaDB 10.5](../what-is-mariadb-105/index) * [GNU/Linux KDu](http://www.linux-kdu.com.br/) — [MariaDB 5.5](../what-is-mariadb-55/index) replaced MySQL as a default in 2.0 Final. * [Korora](https://kororaproject.org/) —Defaulted to MariaDB in 19.1, 26 includes [MariaDB 10.1](../what-is-mariadb-101/index) * [Linux from Scratch](http://www.linuxfromscratch.org/) —10.1-BLFS defaults to [MariaDB 10.5](../what-is-mariadb-105/index) * [Lunar](http://www.lunar-linux.org/) —1.7.0 includes [MariaDB 5.5](../what-is-mariadb-55/index), Moonbase includes [MariaDB 10.5](../what-is-mariadb-105/index) * [Mageia](https://www.mageia.org/) — [MariaDB 5.5](../what-is-mariadb-55/index) replaced MySQL as default in version 3, [MariaDB 10.3](../what-is-mariadb-103/index) from version 7.1, [MariaDB 10.5](../what-is-mariadb-105/index) from 8. * [Manjaro Linux](https://manjaro.github.io/) — Defaulted to [MariaDB 5.5](../what-is-mariadb-55/index) in 0.8.11, 16.10.3 includes [MariaDB 10.1](../what-is-mariadb-101/index). * [NixOS](http://nixos.org/) —14.0.4.630 included [MariaDB 10.0](../what-is-mariadb-100/index), 18.09 includes [MariaDB 10.2](../what-is-mariadb-102/index), Stable includes [MariaDB 10.5](../what-is-mariadb-105/index) * [Network Security Toolkit](http://www.networksecuritytoolkit.org/) —20-5663 defaulted to [MariaDB 5.5](../what-is-mariadb-55/index), 32-11992 includes [MariaDB 10.4](../what-is-mariadb-104/index) * [NuTyX](http://www.nutyx.org/) —14.11 included [MariaDB 10.0](../what-is-mariadb-100/index), defaulted to [MariaDB 10.1](../what-is-mariadb-101/index) in 8.2.1, 20.12.1 includes [MariaDB 10.5](../what-is-mariadb-105/index) * [OpenELEC](http://news.softpedia.com/news/openelec-8-0-3-embedded-linux-entertainment-os-adds-mesa-17-0-5-and-linux-4-9-25-515302.shtml) * [OpenEuler](https://openeuler.org/en/) —21.9 includes [10.5](https://repo.openeuler.org/openEuler-21.09/source/Packages/), 22.03 LTS [includes MariaDB 10.5](https://repo.openeuler.org/openEuler-22.03-LTS/source/Packages/) * [Open Mandriva](http://openmandriva.org/) —Defaulted to [MariaDB 10.0](../what-is-mariadb-100/index) in 2014.2, includes [MariaDB 10.5](../what-is-mariadb-105/index) in 4.2 * [openSUSE](https://en.opensuse.org/Portal:MySQL) — [MariaDB 5.5](../what-is-mariadb-55/index) became the default relational database in [openSUSE 12.3](https://blog.mariadb.org/opensuse-12-3-released-with-mariadb-as-default), and [MariaDB 10.4](../what-is-mariadb-104/index) the default since 15.2 * [Oracle Linux](http://www.oracle.com/us/technologies/linux/index.html) — 7.3 includes [MariaDB 5.5](../what-is-mariadb-55/index). 8.0 includes [MariaDB 10.3](../what-is-mariadb-103/index) * [Paldo](http://www.paldo.org/) —Defaults to [MariaDB 10.5](../what-is-mariadb-105/index) in Stable * [Parabola GNU/Linux](https://www.parabola.nu/packages/?q=mariadb) —Includes [MariaDB 10.1](../what-is-mariadb-101/index) since 3.7 * [Parrot Security](http://www.parrotsec.org/) —Based on Debian's testing branch (stretch), Parrot Security switched from MySQL to [MariaDB 10.0](../what-is-mariadb-100/index) in 3.1, 4.7 includes [MariaDB 10.3](../what-is-mariadb-103/index) * [Parted Magic](http://partedmagic.com/) —Defaulted to [MariaDB 5.5](../what-is-mariadb-55/index) in 2015\_11\_13 * [PCLinuxOS](http://www.pclinuxos.com/forum/index.php?topic=140029.0) —Replaced MySQL with [MariaDB 10.1](../what-is-mariadb-101/index) in 2017.03 * [Pisi Linux](http://www.pisilinux.org/) —Defaulted to [MariaDB 10.0](../what-is-mariadb-100/index) in 1.1 * [Plamo](http://www.plamolinux.org/) —Defaulted to [MariaDB 5.5](../what-is-mariadb-55/index) in 5.3.1, 7.3 includes [MariaDB 10.2](../what-is-mariadb-102/index) * [PoliArch](http://www.poliarch.org/) —Defaulted to [MariaDB 5.5](../what-is-mariadb-55/index) in 13.1, 15.1 includes [MariaDB 10.0](../what-is-mariadb-100/index) * [Red Hat Enterprise Linux](https://www.redhat.com/en/technologies/linux-platforms/enterprise-linux) — [MariaDB 5.5](../what-is-mariadb-55/index) was included as the default "MySQL" database since RHEL 7, RHEL 9 includes [MariaDB 10.5](../what-is-mariadb-105/index) * [ROSA](http://www.rosalab.com/) —Defaulted to [MariaDB 10.0](../what-is-mariadb-100/index) in R4 and [MariaDB 10.1](../what-is-mariadb-101/index) in R9. * [Sabayon](http://www.sabayon.org/) —Included [MariaDB 10.0](../what-is-mariadb-100/index) in 14.12, includes [MariaDB 10.3](../what-is-mariadb-103/index) since 19.03 * [Scientific Linux](https://www.scientificlinux.org/) —Defaulted to [MariaDB 5.5](../what-is-mariadb-55/index) in 7.3 * [Slackware](https://slackbuilds.org/apps/mariadb/) — [MariaDB 5.5](../what-is-mariadb-55/index) replaced MySQL as default in 14.1. 14.2 includes [MariaDB 10.0](../what-is-mariadb-100/index), current includes [MariaDB 10.5](../what-is-mariadb-105/index) * [SliTaz GNU/Linux](http://www.slitaz.org/) —Includes [MariaDB 10.0](../what-is-mariadb-100/index) in 5.0-rolling * [SME Server](https://wiki.contribs.org/SME_Server:10.0)— started to use [MariaDB 5.5](../what-is-mariadb-55/index) from 10.0 * [Springdale Linux](http://springdale.math.ias.edu/) —Defaulted to [MariaDB 5.5](../what-is-mariadb-55/index) in 7.2, 8.1 includes [MariaDB 10.3](../what-is-mariadb-103/index) * [SuliX](http://www.sulix.hu/) — Defaults to [MariaDB 5.5](../what-is-mariadb-55/index) in 8. * [SUSE Linux Enterprise](https://www.suse.com) — [MariaDB 10.0](../what-is-mariadb-100/index) is the default relational database option on 12-SP2, 15-SP2 includes [MariaDB 10.4](../what-is-mariadb-104/index) * [Ubuntu](https://wiki.ubuntu.com/Releases/) —[MariaDB 5.5](../what-is-mariadb-55/index) was included in Trusty Tahr 14.04. 20.04 [includes MariaDB 10.3](http://packages.ubuntu.com/focal/mariadb-server-10.3), and 22.04 [includes 10.6](https://packages.ubuntu.com/jammy/database/). * [Void](http://www.voidlinux.eu/) — [Includes MariaDB 10.5 in current](https://voidlinux.org/packages/) * [Wifislax](http://www.wifislax.com/) — Defaulted to [MariaDB 10.0](../what-is-mariadb-100/index) in 4.11.1 BSD Distributions ----------------- * [Dragonfly BSD](https://www.dragonflybsd.org/) — 3.8 included [MariaDB 5.5](../what-is-mariadb-55/index). 5.8.0 includes [MariaDB 10.4](../what-is-mariadb-104/index). * [FreeBSD](https://svnweb.freebsd.org/ports/head/databases/#mariadb100-client) — MariaDB is available in the ports tree and the FreeBSD Manual has instructions on [Installing Applications: Packages and Ports](https://www.freebsd.org/doc/en/books/handbook/ports.html). [MariaDB 10.5](../what-is-mariadb-105/index) is included in 12.2 + [MariaDB on FreshPorts](https://www.freshports.org/search.php?query=mariadb) * [NetBSD](https://www.netbsd.org/) — 6.1 and 7.0 include [MariaDB 5.5](../what-is-mariadb-55/index). * [OpenBSD](https://marc.info/?m=141063182731679) — [MariaDB 10.0](../what-is-mariadb-100/index) was included in 5.7, 6.8 includes [MariaDB 10.5](../what-is-mariadb-105/index). macOS ----- * [Homebrew](http://brew.sh/) — If you have Homebrew installed, you can install MariaDB Server by executing `brew install mariadb`. Find out more at [Installing MariaDB Server on macOS Using Homebrew](../installing-mariadb-on-macos-using-homebrew/index). * [MacPorts](https://www.macports.org/) —This provides [mariadb and mariadb-server](https://trac.macports.org/browser/trunk/dports/databases/mariadb/Portfile). A [quick guide](http://yosun.me/2012/04/13/mariadb-via-macports-on-mac-os-x-10-6/) on how to install it. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Optimizations for Derived Tables Optimizations for Derived Tables ================================= Derived tables are subqueries in the `FROM` clause. Prior to [MariaDB 5.3](../what-is-mariadb-53/index)/MySQL 5.6, they were too slow to be usable. In [MariaDB 5.3](../what-is-mariadb-53/index)/MySQL 5.6, there are two optimizations which provide adequate performance: | Title | Description | | --- | --- | | [Condition Pushdown into Derived Table Optimization](../condition-pushdown-into-derived-table-optimization/index) | If a query uses a derived table (or a view), the first action that the que... | | [Derived Table Merge Optimization](../derived-table-merge-optimization/index) | MariaDB 5.3 introduced the derived table merge optimization. | | [Derived Table with Key Optimization](../derived-table-with-key-optimization/index) | Since MariaDB 5.3, the optimizer can create an index and use it for joins with other tables. | | [Lateral Derived Optimization](../lateral-derived-optimization/index) | Lateral Derived optimization, also referred to as "Split Grouping Optimization". | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Installing MariaDB Server PKG packages on macOS Installing MariaDB Server PKG packages on macOS =============================================== MariaDB Server does not currently provide a `.pkg` installer for macOS. For information about how to install MariaDB Server on macOS using Homebrew, see [Installing MariaDB Server on macOS Using Homebrew](../installing-mariadb-on-macos-using-homebrew/index). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Introduction to the CONNECT Engine Introduction to the CONNECT Engine ================================== CONNECT is not just a new “YASE” (Yet another Storage Engine) that provides another way to store data with additional features. It brings a new dimension to MariaDB, already one of the best products to deal with traditional database transactional applications, further into the world of business intelligence and data analysis, including NoSQL facilities. Indeed, BI is the set of techniques and tools for the transformation of raw data into meaningful and useful information. And where is this data? "It's amazing in an age where relational databases reign supreme when it comes to managing data that so much information still exists outside RDBMS engines in the form of flat files and other such constructs. In most enterprises, data is passed back and forth between disparate systems in a fashion and speed that would rival the busiest expressways in the world, with much of this data existing in common, delimited files. Target systems intercept these source files and then typically proceed to load them via ETL (extract, transform, load) processes into databases that then utilize the information for business intelligence, transactional functions, or other standard operations. ETL tasks and data movement jobs can consume quite a bit of time and resources, especially if large volumes of data are present that require loading into a database. This being the case, many DBAs welcome alternative means of accessing and managing data that exists in file format." This has been written by Robin Schumacher.[[1](#_note-0)] What he describes is known as MED (Management of External Data) enabling the handling of data not stored in a DBMS database as if it were stored in tables. An ISO standard exists that describes one way to implement and use MED in SQL by defining foreign tables for which an external FDW (Foreign Data Wrapper) has been developed in C. However, since this was written, a new source of data was developed as the “cloud”. Data are existing worldwide and, in particular, can be obtained in JSON or XML format in answer to REST queries. From [Connect 1.06.0010](../connect/index), it is possible to create JSON, XML or CSV tables based on data retrieved from such REST queries. MED as described above is a rather complex way to achieve this goal and MariaDB does not support the ISO SQL/MED standard. But, to cover the need, possibly in transactional but mostly in decision support applications, the CONNECT storage engine supports MED in a much simpler way. The main features of CONNECT are: 1. No need for additional SQL language extensions. 2. Embedded wrappers for many external data types (files, data sources, virtual). 3. NoSQL query facilities for [JSON](../connect-json-table-type/index), [XML](../connect-xml-table-type/index), HTML files and using JSON UDFs. 4. NoSQL data obtained from REST queries (requires cpprestsdk). 5. NoSQL new data type [MONGO](../connect-mongo-table-type/index) accessing MongoDB collections as relational tables. 6. Read/Write access to external files of most commonly used formats. 7. Direct access to most external data sources via ODBC, JDBC and MySQL or MongoDB API. 8. Only used columns are retrieved from external scan. 9. Push-down WHERE clauses when appropriate. 10. Support of special and virtual columns. 11. Parallel execution of multi-table tables (currently unavailable). 12. Supports partitioning by sub-files or by sub-tables (enabling table sharding). 13. Support of MRR for SELECT, UPDATE and DELETE. 14. Provides remote, block, dynamic and virtual indexing. 15. Can execute complex queries on remote servers. 16. Provides an API that allows writing additional FDW in C++. With CONNECT, MariaDB has one of the most advanced implementations of MED and NoSQL, without the need for complex additions to the SQL syntax (foreign tables are "normal" tables using the CONNECT engine). Giving MariaDB easy and natural access to external data enables the use of all of its powerful functions and SQL-handling abilities for developing business intelligence applications. With version 1.07 of CONNECT, retrieving data from REST queries is available in all binary distributed version of MariaDB, and, from 1.07.002, CONNECT allows workspaces greater than 4GB. --- 1. [↑](#_ref-0) Robin Schumacher is Vice President Products at DataStax and former Director of Product Management at MySQL. He has over 13 years of database experience in DB2, MySQL, Oracle, SQL Server and other database engines. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb ST_GeometryFromWKB ST\_GeometryFromWKB =================== A synonym for [ST\_GeomFromWKB](../st_geomfromwkb/index). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb Upgrading from MariaDB 10.1 to MariaDB 10.2 with Galera Cluster Upgrading from MariaDB 10.1 to MariaDB 10.2 with Galera Cluster =============================================================== **MariaDB starting with [10.1](../what-is-mariadb-101/index)**Since [MariaDB 10.1](../what-is-mariadb-101/index), the [MySQL-wsrep](https://github.com/codership/mysql-wsrep) patch has been merged into MariaDB Server. Therefore, in [MariaDB 10.1](../what-is-mariadb-101/index) and above, the functionality of MariaDB Galera Cluster can be obtained by installing the standard MariaDB Server packages and the Galera wsrep provider library package. Beginning in [MariaDB 10.1](../what-is-mariadb-101/index), [Galera Cluster](../what-is-mariadb-galera-cluster/index) ships with the MariaDB Server. Upgrading a Galera Cluster node is very similar to upgrading a server from [MariaDB 10.1](../what-is-mariadb-101/index) to [MariaDB 10.2](../what-is-mariadb-102/index). For more information on that process as well as incompatibilities between versions, see the [Upgrade Guide](../upgrading-from-mariadb-101-to-mariadb-102/index). Performing a Rolling Upgrade ---------------------------- The following steps can be used to perform a rolling upgrade from [MariaDB 10.1](../what-is-mariadb-101/index) to [MariaDB 10.2](../what-is-mariadb-102/index) when using Galera Cluster. In a rolling upgrade, each node is upgraded individually, so the cluster is always operational. There is no downtime from the application's perspective. First, before you get started: 1. First, take a look at [Upgrading from MariaDB 10.1 to MariaDB 10.2](../upgrading-from-mariadb-101-to-mariadb-102/index) to see what has changed between the major versions. 1. Check whether any system variables or options have been changed or removed. Make sure that your server's configuration is compatible with the new MariaDB version before upgrading. 2. Check whether replication has changed in the new MariaDB version in any way that could cause issues while the cluster contains upgraded and non-upgraded nodes. 3. Check whether any new features have been added to the new MariaDB version. If a new feature in the new MariaDB version cannot be replicated to the old MariaDB version, then do not use that feature until all cluster nodes have been upgrades to the new MariaDB version. 2. Next, make sure that the Galera version numbers are compatible. 1. If you are upgrading from the most recent [MariaDB 10.1](../what-is-mariadb-101/index) release to [MariaDB 10.2](../what-is-mariadb-102/index), then the versions will be compatible. Both [MariaDB 10.1](../what-is-mariadb-101/index) and [MariaDB 10.2](../what-is-mariadb-102/index) use Galera 3 (i.e. Galera wsrep provider versions 25.3.x), so they should be compatible. 2. See [What is MariaDB Galera Cluster?: Galera wsrep provider Versions](../what-is-mariadb-galera-cluster/index#galera-wsrep-provider-versions) for information on which MariaDB releases uses which Galera wsrep provider versions. 3. Ideally, you want to have a large enough gcache to avoid a [State Snapshot Transfer (SST)](../introduction-to-state-snapshot-transfers-ssts/index) during the rolling upgrade. The gcache size can be configured by setting `[gcache.size](../wsrep_provider_options/index#gcachesize)` For example: `wsrep_provider_options="gcache.size=2G"` Before you upgrade, it would be best to take a backup of your database. This is always a good idea to do before an upgrade. We would recommend [Mariabackup](../mariabackup/index). Then, for each node, perform the following steps: 1. Modify the repository configuration, so the system's package manager installs [MariaDB 10.2](../what-is-mariadb-102/index). For example, * On Debian, Ubuntu, and other similar Linux distributions, see [Updating the MariaDB APT repository to a New Major Release](../installing-mariadb-deb-files/index#updating-the-mariadb-apt-repository-to-a-new-major-release) for more information. * On RHEL, CentOS, Fedora, and other similar Linux distributions, see [Updating the MariaDB YUM repository to a New Major Release](../yum/index#updating-the-mariadb-yum-repository-to-a-new-major-release) for more information. * On SLES, OpenSUSE, and other similar Linux distributions, see [Updating the MariaDB ZYpp repository to a New Major Release](../installing-mariadb-with-zypper/index#updating-the-mariadb-zypp-repository-to-a-new-major-release) for more information. 2. If you use a load balancing proxy such as MaxScale or HAProxy, make sure to drain the server from the pool so it does not receive any new connections. 3. Set `[innodb\_fast\_shutdown](../xtradbinnodb-server-system-variables/index#innodb_fast_shutdown)` to `0`. It can be changed dynamically with `[SET GLOBAL](../set/index#global-session)`. For example: `SET GLOBAL innodb_fast_shutdown=0;` * This step is not necessary when upgrading to [MariaDB 10.2.5](https://mariadb.com/kb/en/mariadb-1025-release-notes/) or later. Omitting it can make the upgrade process far faster. See [MDEV-12289](https://jira.mariadb.org/browse/MDEV-12289) for more information. 4. [Stop MariaDB](../starting-and-stopping-mariadb-starting-and-stopping-mariadb/index). 5. Uninstall the old version of MariaDB and the Galera wsrep provider. * On Debian, Ubuntu, and other similar Linux distributions, execute the following: `sudo apt-get remove mariadb-server galera` * On RHEL, CentOS, Fedora, and other similar Linux distributions, execute the following: `sudo yum remove MariaDB-server galera` * On SLES, OpenSUSE, and other similar Linux distributions, execute the following: `sudo zypper remove MariaDB-server galera` 6. Install the new version of MariaDB and the Galera wsrep provider. * On Debian, Ubuntu, and other similar Linux distributions, see [Installing MariaDB Packages with APT](../installing-mariadb-deb-files/index#installing-mariadb-packages-with-apt) for more information. * On RHEL, CentOS, Fedora, and other similar Linux distributions, see [Installing MariaDB Packages with YUM](../yum/index#installing-mariadb-packages-with-yum) for more information. * On SLES, OpenSUSE, and other similar Linux distributions, see [Installing MariaDB Packages with ZYpp](../installing-mariadb-with-zypper/index#installing-mariadb-packages-with-zypp) for more information. 7. Make any desired changes to configuration options in [option files](../configuring-mariadb-with-option-files/index), such as `my.cnf`. This includes removing any system variables or options that are no longer supported. * In order to use Galera Cluster without problems in [MariaDB 10.2](../what-is-mariadb-102/index), the `[innodb\_lock\_schedule\_algorithm](../xtradbinnodb-server-system-variables/index#innodb_lock_schedule_algorithm)` system variable must be set to `FCFS`. In [MariaDB 10.2.12](https://mariadb.com/kb/en/mariadb-10212-release-notes/) and later, this system variable is automatically set to this value when Galera Cluster is enabled. In [MariaDB 10.2.11](https://mariadb.com/kb/en/mariadb-10211-release-notes/) and before, this system variable must be set to this value manually. See [MDEV-12837](https://jira.mariadb.org/browse/MDEV-12837) for more information. 8. On Linux distributions that use `systemd` you may need to increase the service startup timeout as the default timeout of 90 seconds may not be sufficient. See [Systemd: Configuring the Systemd Service Timeout](../systemd/index#configuring-the-systemd-service-timeout) for more information. 9. [Start MariaDB](../starting-and-stopping-mariadb-starting-and-stopping-mariadb/index). 10. Run `[mysql\_upgrade](../mysql_upgrade/index)` with the `--skip-write-binlog` option. * `mysql_upgrade` does two things: 1. Ensures that the system tables in the `[mysq](../the-mysql-database-tables/index)l` database are fully compatible with the new version. 2. Does a very quick check of all tables and marks them as compatible with the new version of MariaDB . When this process is done for one node, move onto the next node. Note that when upgrading the Galera wsrep provider, sometimes the Galera protocol version can change. The Galera wsrep provider should not start using the new protocol version until all cluster nodes have been upgraded to the new version, so this is not generally an issue during a rolling upgrade. However, this can cause issues if you restart a non-upgraded node in a cluster where the rest of the nodes have been upgraded. ### Additional details #### Checking Status of the State Transfer When a node rejoins the cluster after being upgraded, it may have to perform a state transfer, such as an [Incremental State Transfer (IST)](../getting-started-with-mariadb-galera-cluster/index#incremental-state-transfers-ists) or a [State Snapshot Transfer(SST)](../introduction-to-state-snapshot-transfers-ssts/index). It is recommended to ensure that the node's state transfer is complete before upgrading the next node in the cluster. ##### State Transfers that Provide Access to the Server If the node is synchronizing with the cluster by performing a state transfer that allows access to the server, such as an [Incremental State Transfer (IST)](../getting-started-with-mariadb-galera-cluster/index#incremental-state-transfers-ists) or a [State Snapshot Transfer(SST)](../introduction-to-state-snapshot-transfers-ssts/index) that uses the `[mysqldump](../mysqldump/index)` SST method, then you can check the status of the state transfer by connecting to the server through the `mysql` client, then checking the `[wsrep\_local\_state\_uuid](../galera-cluster-status-variables/index#wsrep_local_state_uuid)` and `[wsrep\_cluster\_state\_uuid](../galera-cluster-status-variables/index#wsrep_cluster_state_uuid)` status variables. When they equal each other, the node is in sync with the cluster. ``` select if((SELECT VARIABLE_VALUE AS "uuid" FROM information_schema.GLOBAL_STATUS WHERE VARIABLE_NAME = "wsrep_cluster_state_uuid")=(SELECT VARIABLE_VALUE AS "uuid" FROM information_schema.GLOBAL_STATUS WHERE VARIABLE_NAME = "wsrep_local_state_uuid"), "Synced", "Not Synced") as "Cluster Status"; +----------------+ | Cluster Status | +----------------+ | Synced | +----------------+ ``` When the local and cluster UUID's come into sync, the node is again online and functioning as a part of the cluster. ##### State Transfers that Require the Server to be Down Some state transfers require the server to be unavailable, such as all [State Snapshot Transfer(SST)](../introduction-to-state-snapshot-transfers-ssts/index) methods other than `mysqldump`, so `mysql` client access is unavailable while the state transfer is happening. In those cases, you may have to monitor the progress of the state transfer in the [error log](../error-log/index). You'll know when the SST is complete when the joiner node changes its state to `SYNCED`. For example: ``` 2018-08-30 14:44:15 140694729484032 [Note] WSREP: Shifting JOINED -> SYNCED (TO: 210248566) ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Plans for MariaDB 10.9 Plans for MariaDB 10.9 ====================== [MariaDB 10.9](../what-is-mariadb-109/index) is an upcoming major development release. JIRA ---- We manage our development plans in JIRA, so the definitive list will be there. [This search](https://jira.mariadb.org/issues/?jql=project+%3D+MDEV+AND+issuetype+%3D+Task+AND+fixVersion+in+%2810.9%29+ORDER+BY+priority+DESC) shows what we **currently** plan for 10.9. It shows all tasks with the **Fix-Version** being 10.9. Not all these tasks will really end up in 10.9 but tasks with the "red" priorities have a much higher chance of being done in time for 10.9. Practically, you can think of these tasks as "features that **will** be in 10.9". Tasks with the "green" priorities probably won't be in 10.9. Think of them as "bonus features that would be **nice to have** in 10.9". Contributing ------------ If you want to be part of developing any of these features, see [Contributing to the MariaDB Project](../contributing-to-the-mariadb-project/index). You can also add new features to this list or to [JIRA](../jira-project-planning-and-tracking/index). See Also -------- * [Current tasks for 10.9](https://jira.mariadb.org/issues/?jql=project%20%3D%20MDEV%20AND%20issuetype%20%3D%20Task%20AND%20fixVersion%20in%20(10.9)%20ORDER%20BY%20priority%20DESC) * [10.9 Features/fixes by vote](https://jira.mariadb.org/issues/?jql=project%20%3D%20MDEV%20AND%20issuetype%20%3D%20Task%20AND%20fixVersion%20in%20(10.9)%20ORDER%20BY%20votes%20DESC%2C%20priority%20DESC) * [What is MariaDB 10.9?](../what-is-mariadb-109/index) * [What is MariaDB 10.8?](../what-is-mariadb-108/index) * [What is MariaDB 10.7?](../what-is-mariadb-107/index) * [What is MariaDB 10.6?](../what-is-mariadb-106/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Buildbot Setup for Virtual Machines - General Principles Buildbot Setup for Virtual Machines - General Principles ======================================================== The installations are kept minimal, picking mostly default options. This helps ensure our stuff works on default installs, and also saves effort during the creation of the virtual machines. Since most of the logic happens in the Buildbot slave on a host machine, and inside the Buildbot master, there is no need to install Buildbot or other similar complex stuff inside the VMs. ssh --- The virtual machines are configured with ssh access. An account called 'buildbot' is created, with passwordless login (using ssh public key authentication), and with passwordless sudo access (needed for automated scripting). The public key for user buildbot is installed in every VM, and the private key is added to the account running the Buildbot master on the host machine. To generate the ssh keys: ``` ssh-keygen -t dsa ``` Leave the passphrase empty. Run this as the user running the Buildbot slave on the KVM host machine. The resulting /.ssh/id\_dsa.pub will be needed below for each virtual machine install. Serial port ----------- The vms are configured to use the (emulated) serial port as the console. When running KVM on the host, the console then maps to the stdin/stdout. This is useful to get kernel log messages available to easier debug any problems. The bootloader Grub is similarly configured to use the serial port. The vms are also set up to give a login prompt on the serial port (running getty). In retrospect this has proven not really needed, as if needing to manually log in and investigate things, it is often as easy to just run KVM in graphics mode. It may be useful in cases where the host machine is remote though (in this case graphics mode does still work but can be a bit slow). To configure for serial console, the following two files are referenced below, and should be prepared in advance: ### `ttyS0` ``` # ttyS0 - getty # # This service maintains a getty on ttyS0 from the point the system is # started until it is shut down again. start on stopped rc2 start on stopped rc3 start on stopped rc4 start on stopped rc5 stop on runlevel 0 stop on runlevel 1 stop on runlevel 6 respawn exec /sbin/getty 115200 ttyS0 ``` ### `ttyS0.conf` ``` # ttyS0 - getty # # This service maintains a getty on ttyS0 from the point the system is # started until it is shut down again. start on stopped rc RUNLEVEL=[2345] stop on runlevel [!2345] respawn exec /sbin/getty -L 115200 ttyS0 vt102 ``` Unattended MariaDB install on Debian/Ubuntu ------------------------------------------- ### my.seed The MariaDB (and MySQL) package on Debian and Ubuntu prompts the user about the root password to set. We want to test this important step, but we do not want the prompt of course. To do this we use the following configuration file for defaults for debconf. This file is needed in the steps below under the name "my.seed" (be careful to preserve it exactly as here, including trailing space and tab characters!) ``` mariadb-server-5.1 mysql-server/root_password_again password rootpass mariadb-server-5.1 mysql-server/root_password password rootpass mariadb-server-5.1 mysql-server/error_setting_password error mariadb-server-5.1 mysql-server-5.1/nis_warning note mariadb-server-5.1 mysql-server-5.1/really_downgrade boolean false mariadb-server-5.1 mysql-server-5.1/start_on_boot boolean true mariadb-server-5.1 mysql-server-5.1/postrm_remove_databases boolean false mariadb-server-5.1 mysql-server/password_mismatch error mariadb-server-5.1 mysql-server/no_upgrade_when_using_ndb error ``` For some background see [here](http://blog.hjksolutions.com/articles/2007/07/27/unattended-package-installation-with-debian-and-ubuntu). The file my.seed can be generated from an existing install using debconf-get-selections. ### sources.append For Debian/Ubuntu, we add a local repository to the list of apt source to be able to test `apt-get install`. For this, the following file "sources.append" must be prepared: ``` deb file:///home/buildbot/buildbot/debs binary/ deb-src file:///home/buildbot/buildbot/debs source/ ``` Emulation options ----------------- The default network card emulated by KVM has poor performance. To solve this we instead use the "virtio" network device, using the KVM options "-net nic,model=virtio -net user". Except on Debian 4, which has an old kernel without support for virtio. Background info [here](http://episteme.arstechnica.com/eve/forums/a/tpc/f/96509133/m/303006642931). A detail is that some 32-bit vms crashed during boot with default options. This was fixed by using the kvm "-cpu qemu32,-nx" option. Some background information [here](https://bugs.launchpad.net/ubuntu/+source/kvm/+bug/396219). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Numeric Literals Numeric Literals ================ Numeric literals are written as a sequence of digits from `0` to `9`. Initial zeros are ignored. A sign can always precede the digits, but it is optional for positive numbers. In decimal numbers, the integer part and the decimal part are divided with a dot (`.`). If the integer part is zero, it can be omitted, but the literal must begin with a dot. The notation with exponent can be used. The exponent is preceded by an `E` or `e` character. The exponent can be preceded by a sign and must be an integer. A number `N` with an exponent part `X`, is calculated as `N * POW(10, X)`. In some cases, adding zeroes at the end of a decimal number can increment the precision of the expression where the number is used. For example, `[PI()](../pi/index)` by default returns a number with 6 decimal digits. But the `PI()+0.0000000000` expression (with 10 zeroes) returns a number with 10 decimal digits. [Hexadecimal literals](../hexadecimal-literals/index) are interpreted as numbers when used in numeric contexts. Examples -------- ``` 10 +10 -10 ``` All these literals are equivalent: ``` 0.1 .1 +0.1 +.1 ``` With exponents: ``` 0.2E3 -- 0.2 * POW(10, 3) = 200 .2e3 .2e+2 1.1e-10 -- 0.00000000011 -1.1e10 -- -11000000000 ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb SQL Server Features Not Available in MariaDB SQL Server Features Not Available in MariaDB ============================================ When planning a migration between different DBMSs, one of the most important aspects to consider is that the new database system will probably miss some features supported by the old one. This is not relevant for all users. The most widely used features are supported by most DBMSs. However, it is important to make a list of unsupported features and check which of them are currently used by applications. In most cases it is possible to implement such features on the application side, or simply stop using them. This page has a list of SQL Server features that are not supported in MariaDB. The list is not exhaustive. Introduced in SQL Server versions older than 2016 ------------------------------------------------- * Full outer joins. * `GROUP BY CUBE` syntax. * `MERGE` statement. * In MariaDB, indexes are always ascending. Defining them as `ASC` or `DESC` has no effect. + For single-column indexes, the performance difference between an `ORDER BY ... ASC` and `DESC` is negligible. + For multiple-column indexes, an index may be unusable for certain queries because `DESC` is not supported. In some cases, a [generated column](../generated-columns/index) can be used to invert the order of an index (for example, the expression `0 - price` can be indexed to index the prices in a descending order). * The [WITH](../with/index) syntax is currently only supported for the `SELECT` statement. * Filtered indexes (`CREATE INDEX ... WHERE`). * Autonomous transactions. * User-defined types. * Rules. * [Triggers](../triggers/index) don't support the following features: + Triggers on DDL and login. + `INSTEAD OF` triggers. + The `DISABLE TRIGGER` syntax. * [Cursors](../programmatic-compound-statements-cursors/index) advanced features. + Global cursors. + `DELETE ... CURRENT OF`, `UPDATE ... CURRENT OF` statements: MariaDB cursors are read-only. + Specifying a direction (MariaDB cursors can only advance by one row). * Synonyms. * Table variables. * Queues. * XML indexes, XML schema collection, XQuery. * User access to system functionalities, for example: + Running system commands (`xp_cmdshell()`). + Sending emails (`sp_send_dbmail()`). + Sending HTTP requests. * External languages, external libraries (MariaDB only supports procedural SQL and PL/SQL). * Negative permissions (the `DENY` command). * Snapshot replication. See [Provisioning a Slave](../mariadb-replication-overview-for-sql-server-users/index#provisioning-a-slave). Introduced in SQL Server 2016 ----------------------------- * Native data masking * PolyBase (however, [MariaDB 10.5](../what-is-mariadb-105/index) supports accessing Amazon S3 via the [S3 storage engine](../s3-storage-engine/index) and several DBMSs via [CONNECT](../connect/index)) * R and Python services * ColumnStore indexes. MariaDB has a storage engine called [ColumnStore](../mariadb-columnstore/index), but this is a completely different feature. Introduced in SQL Server 2017 ----------------------------- * Adaptive joins * Graph SQL See Also -------- * [SQL Server Features Implemented Differently in MariaDB](../sql-server-features-implemented-differently-in-mariadb/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb DATEDIFF DATEDIFF ======== Syntax ------ ``` DATEDIFF(expr1,expr2) ``` Description ----------- `DATEDIFF()` returns (*expr1* – *expr2*) expressed as a value in days from one date to the other. *expr1* and *expr2* are date or date-and-time expressions. Only the date parts of the values are used in the calculation. Examples -------- ``` SELECT DATEDIFF('2007-12-31 23:59:59','2007-12-30'); +----------------------------------------------+ | DATEDIFF('2007-12-31 23:59:59','2007-12-30') | +----------------------------------------------+ | 1 | +----------------------------------------------+ SELECT DATEDIFF('2010-11-30 23:59:59','2010-12-31'); +----------------------------------------------+ | DATEDIFF('2010-11-30 23:59:59','2010-12-31') | +----------------------------------------------+ | -31 | +----------------------------------------------+ ``` ``` CREATE TABLE t1 (d DATETIME); INSERT INTO t1 VALUES ("2007-01-30 21:31:07"), ("1983-10-15 06:42:51"), ("2011-04-21 12:34:56"), ("2011-10-30 06:31:41"), ("2011-01-30 14:03:25"), ("2004-10-07 11:19:34"); ``` ``` SELECT NOW(); +---------------------+ | NOW() | +---------------------+ | 2011-05-23 10:56:05 | +---------------------+ SELECT d, DATEDIFF(NOW(),d) FROM t1; +---------------------+-------------------+ | d | DATEDIFF(NOW(),d) | +---------------------+-------------------+ | 2007-01-30 21:31:07 | 1574 | | 1983-10-15 06:42:51 | 10082 | | 2011-04-21 12:34:56 | 32 | | 2011-10-30 06:31:41 | -160 | | 2011-01-30 14:03:25 | 113 | | 2004-10-07 11:19:34 | 2419 | +---------------------+-------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Inserting and Updating with Views Inserting and Updating with Views ================================= A [view](../views/index) can be used for inserting or updating. However, there are certain limitations. Updating with views ------------------- A view cannot be used for updating if it uses any of the following: * ALGORITHM=TEMPTABLE (see [View Algorithms](../view-algorithms/index)) * [HAVING](../select/index) * [GROUP BY](../select/index#group-by) * [DISTINCT](../select/index#distinct) * [UNION](../union/index) * [UNION ALL](../union/index) * An aggregate function, such as [MAX()](../max/index), [MIN()](../min/index), [SUM()](../sum/index) or [COUNT()](../count/index) * subquery in the SELECT list * subquery in the WHERE clause referring to a table in the FROM clause * if it has no underlying table because it refers only to literal values * the FROM clause contains a non-updatdable view. * multiple references to any base table column * an outer join * an inner join where more than one table in the view definition is being updated * if there's a LIMIT clause, the view does not contain all primary or not null unique key columns from the underlying table and the [updatable\_views\_with\_limit](../server-system-variables/index#updatable_views_with_limit) system variable is set to `0`. Inserting with views -------------------- A view cannot be used for inserting if it fails any of the criteria for [updating](#updating-with-views), and must also meet the following conditions: * the view contains all base table columns that don't have default values * there are no duplicate view column names * the view columns are all simple columns, and not derived in any way. The following are examples of derived columns + column\_name + 25 + LOWER(column\_name) + (subquery) + 9.5 + column1 / column2 Checking whether a view is updatable ------------------------------------ MariaDB stores an IS\_UPDATABLE flag with each view, so it is always possible to see if MariaDB considers a view updatable (although not necessarily insertable) by querying the IS\_UPDATABLE column in the INFORMATION\_SCHEMA.VIEWS table. WITH CHECK OPTION ----------------- The WITH CHECK OPTION clause is used to prevent updates or inserts to views unless the WHERE clause in the SELECT statement is true. There are two keywords that can be applied. WITH LOCAL CHECK OPTION restricts the CHECK OPTION to only the view being defined, while WITH CASCADED CHECK OPTION checks all underlying views as well. CASCADED is treated as default if neither keyword is given. If a row is rejected because of the CHECK OPTION, an error similar to the following is produced: ``` ERROR 1369 (HY000): CHECK OPTION failed 'db_name.view_name' ``` A view with a WHERE which is always false (like `WHERE 0`) and WITH CHECK OPTION is similar to a [BLACKHOLE](../blackhole/index) table: no row is ever inserted and no row is ever returned. An insertable view with a WHERE which is always false but no CHECK OPTION is a view that accepts data but does not show them. Examples -------- ``` CREATE TABLE table1 (x INT); CREATE VIEW view1 AS SELECT x, 99 AS y FROM table1; ``` Checking whether the view is updateable: ``` SELECT TABLE_NAME,IS_UPDATABLE FROM INFORMATION_SCHEMA.VIEWS; +------------+--------------+ | TABLE_NAME | IS_UPDATABLE | +------------+--------------+ | view1 | YES | +------------+--------------+ ``` This query works, as the view is updateable: ``` UPDATE view1 SET x = 5; ``` This query fails, since column `y` is a literal. ``` UPDATE view1 SET y = 5; ERROR 1348 (HY000): Column 'y' is not updatable ``` Here are three views to demonstrate the WITH CHECK OPTION clause. ``` CREATE VIEW view_check1 AS SELECT * FROM table1 WHERE x < 100 WITH CHECK OPTION; CREATE VIEW view_check2 AS SELECT * FROM view_check1 WHERE x > 10 WITH LOCAL CHECK OPTION; CREATE VIEW view_check3 AS SELECT * FROM view_check1 WHERE x > 10 WITH CASCADED CHECK OPTION; ``` This insert succeeds, as `view_check2` only checks the insert against `view_check2`, and the WHERE clause evaluates to true (`150` is `>10`). ``` INSERT INTO view_check2 VALUES (150); ``` This insert fails, as `view_check3` checks the insert against both `view_check3` and the underlying views. The WHERE clause for `view_check1` evaluates as false (`150` is `>10`, but `150` is not `<100`), so the insert fails. ``` INSERT INTO view_check3 VALUES (150); ERROR 1369 (HY000): CHECK OPTION failed 'test.view_check3' ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb LineStringFromWKB LineStringFromWKB ================= A synonym for [ST\_LineFromWKB](../st_linefromwkb/index). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Replication with Secure Connections Replication with Secure Connections =================================== The terms *master* and *slave* have historically been used in replication, but the terms terms *primary* and *replica* are now preferred. The old terms are used still used in parts of the documentation, and in MariaDB commands, although [MariaDB 10.5](../what-is-mariadb-105/index) has begun the process of renaming. The documentation process is ongoing. See [MDEV-18777](https://jira.mariadb.org/browse/MDEV-18777) to follow progress on this effort. By default, MariaDB replicates data between masters and slaves without encrypting it. This is generally acceptable when the master and slave run are in networks where security is guaranteed through other means. However, in cases where the master and slave exist on separate networks or they are in a high-risk network, the lack of encryption does introduce security concerns as a malicious actor could potentially eavesdrop on the traffic as it is sent over the network between them. To mitigate this concern, MariaDB allows you to encrypt replicated data in transit between masters and slaves using the Transport Layer Security (TLS) protocol. TLS was formerly known as Secure Socket Layer (SSL), but strictly speaking the SSL protocol is a predecessor to TLS and, that version of the protocol is now considered insecure. The documentation still uses the term SSL often and for compatibility reasons TLS-related server system and status variables still use the prefix `ssl_`, but internally, MariaDB only supports its secure successors. In order to secure connections between the master and slave, you need to ensure that both servers were compiled with TLS support. See [Secure Connections Overview](../secure-connections-overview/index) to determine how to check whether a server was compiled with TLS support. You also need an X509 certificate, a private key, and the Certificate Authority (CA) chain to verify the X509 certificate for the master. If you want to use two-way TLS, then you will also an X509 certificate, a private key, and the Certificate Authority (CA) chain to verify the X509 certificate for the slave. If you want to use self-signed certificates that are created with OpenSSL, then see [Certificate Creation with OpenSSL](../certificate-creation-with-openssl/index) for information on how to create those. Securing Replication Traffic ---------------------------- In order to secure replication traffic, you will need to ensure that TLS is enabled on the master. If you want to use two-way TLS, then you will also need to ensure that TLS is enabled on the slave. See [Securing Connections for Client and Server](../securing-connections-for-client-and-server/index) for information on how to do that. For example, to set the TLS system variables for each server, add them to a relevant server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index) on each server: ``` [mariadb] ... ssl_cert = /etc/my.cnf.d/certificates/server-cert.pem ssl_key = /etc/my.cnf.d/certificates/server-key.pem ssl_ca = /etc/my.cnf.d/certificates/ca.pem ``` And then [restart the server](../starting-and-stopping-mariadb-starting-and-stopping-mariadb/index) to make the changes persistent. At this point, you can reconfigure the slaves to use TLS to encrypt replicated data in transit. There are two methods available to do this: * Executing the `[CHANGE MASTER](../change-master-to/index)` statement to set the relevant TLS options. * Setting TLS client options in an [option file](../configuring-mariadb-with-option-files/index). ### Executing CHANGE MASTER TLS can be enabled on a replication slave by executing the `[CHANGE MASTER](../change-master-to/index)` statement. In order to do so, there are a number of options that you would need to set. The specific options that you would need to set would depend on whether you want one-way TLS or two-way TLS, and whether you want to verify the server certificate. #### Enabling Two-Way TLS with CHANGE MASTER Two-way TLS means that both the client and server provide a private key and an X509 certificate. It is called "two-way" TLS because both the client and server can be authenticated. In this case, the "client" is the slave. To configure two-way TLS, you would need to set the following options: * You need to set the path to the server's certificate by setting the `[MASTER\_SSL\_CERT](../change-master-to/index#master_ssl_cert)` option. * You need to set the path to the server's private key by setting the `[MASTER\_SSL\_KEY](../change-master-to/index#master_ssl_key)` option. * You need to set the path to the certificate authority (CA) chain that can verify the server's certificate by setting either the `[MASTER\_SSL\_CA](../change-master-to/index#master_ssl_ca)` or the `[MASTER\_SSL\_CAPATH](../change-master-to/index#master_ssl_capath)` options. * If you want [server certificate verification](../secure-connections-overview/index#server-certificate-verification), then you also need to set the `[MASTER\_SSL\_VERIFY\_SERVER\_CERT](../change-master-to/index#master_ssl_verify_server_cert)` option. * If you want to restrict the server to certain ciphers, then you also need to set the `[MASTER\_SSL\_CIPHER](../change-master-to/index#master_ssl_cipher)` option. If the [slave threads](../replication-threads/index#threads-on-the-slave) are currently running, you first need to stop them by executing the `[STOP SLAVE](../stop-slave/index)` statement. For example: ``` STOP SLAVE; ``` Then, execute the `[CHANGE MASTER](../change-master-to/index)` statement to configure the slave to use TLS. For example: ``` CHANGE MASTER TO MASTER_SSL_CERT = '/path/to/client-cert.pem', MASTER_SSL_KEY = '/path/to/client-key.pem', MASTER_SSL_CA = '/path/to/ca/ca.pem', MASTER_SSL_VERIFY_SERVER_CERT=1; ``` At this point, you can start replication by executing the `[START SLAVE](../start-slave/index)` statement. For example: ``` START SLAVE; ``` The slave now uses TLS to encrypt data in transit as it replicates it from the master. #### Enabling One-Way TLS with CHANGE MASTER ##### Enabling One-Way TLS with CHANGE MASTER with Server Certificate Verification One-way TLS means that only the server provides a private key and an X509 certificate. When TLS is used without a client certificate, it is called "one-way" TLS, because only the server can be authenticated, so authentication is only possible in one direction. However, encryption is still possible in both directions. [Server certificate verification](../secure-connections-overview/index#server-certificate-verification) means that the client verifies that the certificate belongs to the server. In this case, the "client" is the slave. To configure one-way TLS, you would need to set the following options: * You need to set the path to the certificate authority (CA) chain that can verify the server's certificate by setting either the `[MASTER\_SSL\_CA](../change-master-to/index#master_ssl_ca)` or the `[MASTER\_SSL\_CAPATH](../change-master-to/index#master_ssl_capath)` options. * If you want [server certificate verification](../secure-connections-overview/index#server-certificate-verification), then you also need to set the `[MASTER\_SSL\_VERIFY\_SERVER\_CERT](../change-master-to/index#master_ssl_verify_server_cert)` option. * If you want to restrict the server to certain ciphers, then you also need to set the `[MASTER\_SSL\_CIPHER](../change-master-to/index#master_ssl_cipher)` option. If the [slave threads](../replication-threads/index#threads-on-the-slave) are currently running, you first need to stop them by executing the `[STOP SLAVE](../stop-slave/index)` statement. For example: ``` STOP SLAVE; ``` Then, execute the `[CHANGE MASTER](../change-master-to/index)` statement to configure the slave to use TLS. For example: ``` CHANGE MASTER TO MASTER_SSL_CA = '/path/to/ca/ca.pem', MASTER_SSL_VERIFY_SERVER_CERT=1; ``` At this point, you can start replication by executing the `[START SLAVE](../start-slave/index)` statement. For example: ``` START SLAVE; ``` The slave now uses TLS to encrypt data in transit as it replicates it from the master. ##### Enabling One-Way TLS with CHANGE MASTER without Server Certificate Verification One-way TLS means that only the server provides a private key and an X509 certificate. When TLS is used without a client certificate, it is called "one-way" TLS, because only the server can be authenticated, so authentication is only possible in one direction. However, encryption is still possible in both directions. In this case, the "client" is the slave. To configure two-way TLS without server certificate verification, you would need to set the following options: * You need to configure the slave to use TLS by setting the `[MASTER\_SSL](../change-master-to/index#master_ssl)` option. * If you want to restrict the server to certain ciphers, then you also need to set the `[MASTER\_SSL\_CIPHER](../change-master-to/index#master_ssl_cipher)` option. If the [slave threads](../replication-threads/index#threads-on-the-slave) are currently running, you first need to stop them by executing the `[STOP SLAVE](../stop-slave/index)` statement. For example: ``` STOP SLAVE; ``` Then, execute the `[CHANGE MASTER](../change-master-to/index)` statement to configure the slave to use TLS. For example: ``` CHANGE MASTER TO MASTER_SSL=1; ``` At this point, you can start replication by executing the `[START SLAVE](../start-slave/index)` statement. For example: ``` START SLAVE; ``` The slave now uses TLS to encrypt data in transit as it replicates it from the master. ### Setting TLS Client Options in an Option File In cases where you don't mind restarting the server or you are setting the server up from scratch for the first time, you may find it more convenient to configure TLS options for replication through an [option file](../configuring-mariadb-with-option-files/index). This is done the same way as it is for other clients. The specific options that you would need to set would depend on whether you want one-way TLS or two-way TLS, and whether you want to verify the server certificate. See [Securing Connections for Client and Server: Enabling TLS for MariaDB Clients](../securing-connections-for-client-and-server/index#enabling-tls-for-mariadb-clients) for more information. For example, to enable two-way TLS with [server certificate verification](../secure-connections-overview/index#server-certificate-verification), then you could specify the following options in a a relevant client [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index): ``` [client-mariadb] ... ssl_cert = /etc/my.cnf.d/certificates/client-cert.pem ssl_key = /etc/my.cnf.d/certificates/client-key.pem ssl_ca = /etc/my.cnf.d/certificates/ca.pem ssl-verify-server-cert ``` Before you restart the server, you may also want to set the `[--skip-slave-start](../mysqld-options/index#-skip-slave-start)` option in a server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index). This option prevents the [slave threads](../replication-threads/index#threads-on-the-slave) from restarting automatically when the server starts. Instead, they will have to be restarted manually. After these changes have been made, you can [restart the server](../starting-and-stopping-mariadb-starting-and-stopping-mariadb/index). Once the server is back online, set the `[MASTER\_SSL](../change-master-to/index#master_ssl)` option by executing the `[CHANGE MASTER](../change-master-to/index)` statement. This will enable TLS. For example: ``` CHANGE MASTER TO MASTER_SSL=1; ``` The certificate and keys will be read from the option file. At this point, you can start replication by executing the `[START SLAVE](../start-slave/index)` statement. ``` START SLAVE; ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb ST_POINTN ST\_POINTN ========== Syntax ------ ``` ST_PointN(ls,N) PointN(ls,N) ``` Description ----------- Returns the N-th [Point](../point/index) in the [LineString](../linestring/index) value `ls`. Points are numbered beginning with `1`. `ST_PointN()` and `PointN()` are synonyms. Examples -------- ``` SET @ls = 'LineString(1 1,2 2,3 3)'; SELECT AsText(PointN(GeomFromText(@ls),2)); +-------------------------------------+ | AsText(PointN(GeomFromText(@ls),2)) | +-------------------------------------+ | POINT(2 2) | +-------------------------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Buildbot Setup for Virtual Machines - Fedora 16 Buildbot Setup for Virtual Machines - Fedora 16 =============================================== Base install ------------ ``` qemu-img create -f qcow2 /kvm/vms/vm-fedora16-i386-serial.qcow2 10G qemu-img create -f qcow2 /kvm/vms/vm-fedora16-amd64-serial.qcow2 10G ``` Start each VM booting from the server install iso one at a time and perform the following install steps: ``` kvm -m 1024 -hda /kvm/vms/vm-fedora16-i386-serial.qcow2 -cdrom /kvm/iso/fedora/Fedora-16-i386-DVD.iso -redir tcp:2263::22 -boot d -smp 2 -cpu qemu32,-nx -net nic,model=virtio -net user kvm -m 1024 -hda /kvm/vms/vm-fedora16-amd64-serial.qcow2 -cdrom /kvm/iso/fedora/Fedora-16-x86_64-DVD.iso -redir tcp:2264::22 -boot d -smp 2 -cpu qemu64 -net nic,model=virtio -net user ``` Once running you can connect to the VNC server from your local host with: ``` vncviewer -via ${remote-host} localhost ``` Replace ${remote-host} with the host the vm is running on. **Note:** When you activate the install, vncviewer may disconnect with a complaint about the rect being too large. This is fine. The Fedora installer has just resized the vnc screen. Simply reconnect. Install, picking default options mostly, with the following notes: * The Installer will throw up a "Storage Device Warning", choose "Yes, discard any data" * Set the hostname to fedora16-amd64 (or fedora16-i386) * Click the "Configure Network" button on the Hostname screen. + Edit System eth0 to "connect automatically" + Apply and then close the "Network Connections" window * When partitioning disks, choose "Use All Space" + **uncheck** the "Use LVM" checkbox + **do not** check the "Encrypt system" checkbox * Minimal install * Customize Later When the install is finished, you will be prompted to reboot. Go ahead and do so, but it will fail. Kill the VM (after the reboot fails) and start it up again: ``` kvm -m 1024 -hda /kvm/vms/vm-fedora16-i386-serial.qcow2 -redir tcp:2263::22 -boot c -smp 2 -cpu qemu32,-nx -net nic,model=virtio -net user kvm -m 1024 -hda /kvm/vms/vm-fedora16-amd64-serial.qcow2 -redir tcp:2264::22 -boot c -smp 2 -cpu qemu64 -net nic,model=virtio -net user ``` Until the extra user is installed you must connect via VNC as before. SSH is preferred, so that's what we'll do first. Login as root. ``` ssh -p 2263 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -i ~/.ssh/buildbot.id_dsa root@localhost ssh -p 2264 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -i ~/.ssh/buildbot.id_dsa root@localhost ``` After logging in as root, install proper ssh and then create a local user: ``` /sbin/chkconfig --level 35 network on ifup eth0 yum install openssh-server openssh-clients adduser ${username} usermod -a -G wheel ${username} passwd ${username} ``` Enable password-less sudo and serial console: ``` visudo # Uncomment the line "%wheel ALL=(ALL) NOPASSWD: ALL" # Comment out this line: # Defaults requiretty ``` Still logged in as root, add to /boot/grub/menu.lst: Editing /boot/grub/menu.lst: ``` sudo vi /etc/default/grub # Add/edit these entries: GRUB_CMDLINE_LINUX_DEFAULT="console=tty0 console=ttyS0,115200n8" GRUB_TERMINAL="serial" GRUB_SERIAL_COMMAND="serial --unit=0 --speed=115200 --word=8 --parity=no --stop=1" grub2-mkconfig -o /boot/grub2/grub.cfg ``` Logout as root, and then, from the VM host server: Create a .ssh folder: ``` ssh -t -p 2263 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -i ~/.ssh/buildbot.id_dsa localhost "mkdir -v .ssh" ssh -t -p 2264 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -i ~/.ssh/buildbot.id_dsa localhost "mkdir -v .ssh" ``` Copy over the authorized keys file: ``` scp -P 2263 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no /kvm/vms/authorized_keys localhost:.ssh/ scp -P 2264 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no /kvm/vms/authorized_keys localhost:.ssh/ ``` Set permissions on the .ssh folder correctly: ``` ssh -t -p 2263 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -i ~/.ssh/buildbot.id_dsa localhost "chmod -R go-rwx .ssh" ssh -t -p 2264 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -i ~/.ssh/buildbot.id_dsa localhost "chmod -R go-rwx .ssh" ``` Create the buildbot user: ``` ssh -p 2263 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no localhost 'chmod -R go-rwx .ssh; sudo adduser buildbot; sudo usermod -a -G wheel buildbot; sudo mkdir ~buildbot/.ssh; sudo cp -vi .ssh/authorized_keys ~buildbot/.ssh/; sudo chown -vR buildbot:buildbot ~buildbot/.ssh; sudo chmod -vR go-rwx ~buildbot/.ssh' ssh -p 2264 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no localhost 'chmod -R go-rwx .ssh; sudo adduser buildbot; sudo usermod -a -G wheel buildbot; sudo mkdir ~buildbot/.ssh; sudo cp -vi .ssh/authorized_keys ~buildbot/.ssh/; sudo chown -vR buildbot:buildbot ~buildbot/.ssh; sudo chmod -vR go-rwx ~buildbot/.ssh' ``` su to the local buildbot user and ssh to the vm to put the key in known\_hosts: For i386: ``` sudo su - buildbot ssh -p 2263 buildbot@localhost # exit, then exit again ``` For amd64: ``` sudo su - buildbot ssh -p 2264 buildbot@localhost # exit, then exit again ``` Upload the ttyS0 file and put it where it goes: ``` scp -P 2263 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no /kvm/vms/ttyS0 buildbot@localhost: scp -P 2264 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no /kvm/vms/ttyS0 buildbot@localhost: ssh -p 2263 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no buildbot@localhost 'sudo mv -vi ttyS0 /etc/event.d/;' ssh -p 2264 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no buildbot@localhost 'sudo mv -vi ttyS0 /etc/event.d/;' ``` Update the VM: ``` ssh -p 2263 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no buildbot@localhost ssh -p 2264 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no buildbot@localhost ``` Once logged in: ``` sudo yum update ``` After updating, shut down the VM: ``` sudo shutdown -h now ``` VMs for building .rpms ---------------------- ``` for i in '/kvm/vms/vm-fedora16-amd64-serial.qcow2 2264 qemu64' '/kvm/vms/vm-fedora16-i386-serial.qcow2 2263 qemu64' ; do \ set $i; \ runvm --user=buildbot --logfile=kernel_$2.log --base-image=$1 --port=$2 --cpu=$3 "$(echo $1 | sed -e 's/serial/build/')" \ "sudo yum -y groupinstall 'Development Tools'" \ "sudo yum -y install wget tree gperf readline-devel ncurses-devel zlib-devel pam-devel libaio-devel openssl-devel perl perl\(DBI\)" \ "sudo yum -y remove systemtap-sdt-dev" \ "sudo mkdir -vp /usr/src/redhat/SOURCES /usr/src/redhat/SPECS /usr/src/redhat/RPMS /usr/src/redhat/SRPMS" \ "wget http://www.cmake.org/files/v2.8/cmake-2.8.8.tar.gz;tar -zxvf cmake-2.8.8.tar.gz;cd cmake-2.8.8;./configure;make;sudo make install"; \ done ``` Also: * [Installing the Boost library needed for the OQGraph storage engine](../installing-the-boost-library-needed-for-the-oqgraph-storage-engine/index) VMs for install testing. ------------------------ `MariaDB.local.repo` points at a local directory on the VM. `MariaDB.repo` points at the real MariaDB YUM repository. ``` for i in '/kvm/vms/vm-fedora16-amd64-serial.qcow2 2264 qemu64' '/kvm/vms/vm-fedora16-i386-serial.qcow2 2263 qemu64' ; do \ set $i; \ runvm --user=buildbot --logfile=kernel_$2.log --base-image=$1 --port=$2 --cpu=$3 "$(echo $1 | sed -e 's/serial/install/')" \ "sudo yum -y update" \ "sudo yum -y install libaio perl perl-Time-HiRes perl-DBI" \ "= scp -P $2 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no /kvm/vms/MariaDB.local.repo buildbot@localhost:/tmp/" \ "sudo mv -vi /tmp/MariaDB.local.repo /etc/yum.repos.d/"; \ done ``` VMs for MySQL upgrade testing ----------------------------- ``` for i in '/kvm/vms/vm-fedora16-amd64-serial.qcow2 2264 qemu64' '/kvm/vms/vm-fedora16-i386-serial.qcow2 2263 qemu64' ; do \ set $i; \ runvm --user=buildbot --logfile=kernel_$2.log --base-image=$1 --port=$2 --cpu=$3 "$(echo $1 | sed -e 's/serial/upgrade/')" \ "sudo yum -y update" \ 'sudo yum -y install mysql-server' \ 'sudo systemctl enable mysqld.service' \ 'sudo systemctl start mysqld.service' \ 'mysql -uroot -e "create database mytest; use mytest; create table t(a int primary key); insert into t values (1); select * from t"' \ "= scp -P $2 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no /kvm/vms/MariaDB.local.repo buildbot@localhost:/tmp/" \ "sudo mv -vi /tmp/MariaDB.local.repo /etc/yum.repos.d/"; \ done ``` The MariaDB upgrade testing VMs were not built. Once we have MariaDB Fedora 16 RPMs, then I will attempt building this VM. For now, the placeholder text below is copied from the [Buildbot Setup for Virtual Machines - CentOS 6.2](../buildbot-setup-for-virtual-machines-centos-62/index) page. VMs for MariaDB upgrade testing ------------------------------- ``` for i in '/kvm/vms/vm-fedora16-amd64-serial.qcow2 2264 qemu64' '/kvm/vms/vm-fedora16-i386-serial.qcow2 2263 qemu64' ; do \ set $i; \ runvm --user=buildbot --logfile=kernel_$2.log --base-image=$1 --port=$2 --cpu=$3 "$(echo $1 | sed -e 's/serial/upgrade2/')" \ 'sudo yum -y update' \ "= scp -P $2 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no /kvm/vms/MariaDB.repo buildbot@localhost:/tmp/" \ 'sudo rpm --verbose --import http://downloads.mariadb.org/repo/RPM-GPG-KEY-MariaDB' \ 'sudo mv -vi /tmp/MariaDB.repo /etc/yum.repos.d/' \ 'sudo yum -y remove mysql-libs' \ 'sudo yum -y install MariaDB-server MariaDB-client MariaDB-test' \ 'sudo yum -y install cronie cronie-anacron crontabs.noarch postfix' \ 'sudo /etc/init.d/mysqld start' \ 'mysql -uroot -prootpass -e "create database mytest; use mytest; create table t(a int primary key); insert into t values (1); select * from t"' \ 'sudo rm -v /etc/yum.repos.d/MariaDB.repo' \ "= scp -P $2 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no /kvm/vms/MariaDB.local.repo buildbot@localhost:/tmp/" \ 'sudo mv -vi /tmp/MariaDB.local.repo /etc/yum.repos.d/'; \ done ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Compression Compression ============ There are a number of different kinds of compression in MariaDB | Title | Description | | --- | --- | | [Encryption, Hashing and Compression Functions](../encryption-hashing-and-compression-functions/index) | Functions used for encryption, hashing and compression. | | [Storage-Engine Independent Column Compression](../storage-engine-independent-column-compression/index) | Storage-engine independent support for column compression. | | [InnoDB Page Compression](../innodb-page-compression/index) | InnoDB page compression, which is more sophisticated than the COMPRESSED row format. | | [Compression Plugins](../compression-plugins/index) | Five MariaDB compression libraries are available as plugins. | | [Compressing Events to Reduce Size of the Binary Log](../compressing-events-to-reduce-size-of-the-binary-log/index) | Binlog events can be compressed to save space on disk and in network transfers | | [InnoDB COMPRESSED Row Format](../innodb-compressed-row-format/index) | Similar to the COMPACT row format, but can store even more data on overflow pages. | | [ColumnStore Compression Mode](../columnstore-compression-mode/index) | ColumnStore has the ability to compress data | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb HASH Partitioning Type HASH Partitioning Type ====================== ### Syntax ``` PARTITION BY HASH (partitioning_expression) [PARTITIONS(number_of_partitions)] ``` ### Description HASH partitioning is a form of [partitioning](../partitioning-tables/index) in which the server takes care of the partition in which to place the data, ensuring an even distribution among the partitions. It requires a column value, or an expression based on a column value, which is hashed, as well as the number of partitions into which to divide the table. *partitioning\_expression* needs to return a non-constant, deterministic integer. It is evaluated for each insert and update, so overly complex expressions can lead to performance issues. *number\_of\_partitions* is a positive integer specifying the number of partitions into which to divide the table. If the `PARTITIONS` clause is omitted, the default number of partitions is one. ### Examples ``` CREATE OR REPLACE TABLE t1 (c1 INT, c2 DATETIME) PARTITION BY HASH(TO_DAYS(c2)) PARTITIONS 5; ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Information Schema COLLATION_CHARACTER_SET_APPLICABILITY Table Information Schema COLLATION\_CHARACTER\_SET\_APPLICABILITY Table ================================================================= The [Information Schema](../information_schema/index) `COLLATION_CHARACTER_SET_APPLICABILITY` table shows which [character sets](../data-types-character-sets-and-collations/index) are associated with which collations. It contains the following columns: | Column | Description | | --- | --- | | `COLLATION_NAME` | Collation name. | | `CHARACTER_SET_NAME` | Name of the associated character set. | `COLLATION_CHARACTER_SET_APPLICABILITY` is essentially a subset of the `[COLLATIONS](../information-schema-collations-table/index)` table. ``` SELECT COLLATION_NAME,CHARACTER_SET_NAME FROM information_schema.COLLATIONS; ``` and ``` SELECT * FROM information_schema.COLLATION_CHARACTER_SET_APPLICABILITY; ``` will return identical results. See [Setting Character Sets and Collations](../setting-character-sets-and-collations/index) for details on specifying the character set at the server, database, table and column levels. Example ------- ``` SELECT * FROM information_schema.COLLATION_CHARACTER_SET_APPLICABILITY WHERE CHARACTER_SET_NAME='utf32'; +---------------------+--------------------+ | COLLATION_NAME | CHARACTER_SET_NAME | +---------------------+--------------------+ | utf32_general_ci | utf32 | | utf32_bin | utf32 | | utf32_unicode_ci | utf32 | | utf32_icelandic_ci | utf32 | | utf32_latvian_ci | utf32 | | utf32_romanian_ci | utf32 | | utf32_slovenian_ci | utf32 | | utf32_polish_ci | utf32 | | utf32_estonian_ci | utf32 | | utf32_spanish_ci | utf32 | | utf32_swedish_ci | utf32 | | utf32_turkish_ci | utf32 | | utf32_czech_ci | utf32 | | utf32_danish_ci | utf32 | | utf32_lithuanian_ci | utf32 | | utf32_slovak_ci | utf32 | | utf32_spanish2_ci | utf32 | | utf32_roman_ci | utf32 | | utf32_persian_ci | utf32 | | utf32_esperanto_ci | utf32 | | utf32_hungarian_ci | utf32 | | utf32_sinhala_ci | utf32 | | utf32_german2_ci | utf32 | | utf32_croatian_ci | utf32 | +---------------------+--------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb MariaDB Developer Meeting - Athens - Friday, 11 Nov 2011 MariaDB Developer Meeting - Athens - Friday, 11 Nov 2011 ========================================================= Agenda and notes from day 1 of the MariaDB Developer Meeting in Athens, Greece. Agenda ------ | Time | Main Track | | --- | --- | | 09:00‑10:00 | Email & Hacking time (Public) | | 10:00‑10:15 | Welcome session (Public) | | 10:15‑11:00 | MariaDB Development Procedures (should we try to adopt more Agile techniques?) (Public) | | 11:00‑11:15 | Small break | | 11:15‑12:30 | MariaDB Quality (Philip) (Public) | | 12:30‑13:30 | Lunch | | 13:30‑15:15 | Plans for [MariaDB 5.6](../what-is-mariadb-56/index) (Public) | | 15:15‑15:45 | Coffee break | | 15:45‑17:00 | [MariaDB 5.6](../what-is-mariadb-56/index) Merge Planning (Public) | | 17:00‑17:45 | [MariaDB 5.6](../what-is-mariadb-56/index) Merge Planning (Public) | [Printed Schedule](http://askmonty.org/blog/wp-content/uploads/2011/11/MariaDB-%CE%B5%CF%86%CE%B7%CE%BC%CE%B5%CF%81%CE%AF%CE%B4%CE%B1-11-Nov-2011.pdf) (pdf) Notes ----- | Title | Description | | --- | --- | | [Plans for 5.6](../plans-for-56/index) | The information on this page is obsolete. Current information can be found... | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb CONNECT System Variables CONNECT System Variables ======================== This page documents system variables related to the [CONNECT storage engine](../connect/index). See [Server System Variables](../server-system-variables/index) for a complete list of system variables and instructions on setting them. See also the [Full list of MariaDB options, system and status variables](../full-list-of-mariadb-options-system-and-status-variables/index). #### `connect_class_path` * **Description:** Java class path * **Commandline:** `--connect-class-path=value` * **Scope:** Global * **Dynamic:** * **Data Type:** `string` * **Default Value:** --- #### `connect_cond_push` * **Description:** Enable condition pushdown * **Commandline:** `--connect-cond-push={0|1}` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `ON` * **Introduced:** [MariaDB 10.3.6](https://mariadb.com/kb/en/mariadb-1036-release-notes/), [MariaDB 10.2.14](https://mariadb.com/kb/en/mariadb-10214-release-notes/) --- #### `connect_conv_size` * **Description:** The size of the [VARCHAR](../varchar/index) created when converting from a [TEXT](../text/index) type. See [connect\_type\_conv](#connect_type_conv). * **Commandline:** `--connect-conv-size=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** + >= [MariaDB 10.4.8](https://mariadb.com/kb/en/mariadb-1048-release-notes/), [MariaDB 10.3.18](https://mariadb.com/kb/en/mariadb-10318-release-notes/), [MariaDB 10.2.27](https://mariadb.com/kb/en/mariadb-10227-release-notes/): `1024` + <= [MariaDB 10.4.7](https://mariadb.com/kb/en/mariadb-1047-release-notes/), [MariaDB 10.3.17](https://mariadb.com/kb/en/mariadb-10317-release-notes/), [MariaDB 10.2.26](https://mariadb.com/kb/en/mariadb-10226-release-notes/): `8192` * **Range:** `0` to `65500` --- #### `connect_default_depth` * **Description:** Default depth used by Json, XML and Mongo discovery. * **Commandline:** `--connect-default-depth=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:**`5` * **Range:** `-1` to `16` * **Introduced:** [MariaDB 10.5.7](https://mariadb.com/kb/en/mariadb-1057-release-notes/), [MariaDB 10.4.16](https://mariadb.com/kb/en/mariadb-10416-release-notes/), [MariaDB 10.3.26](https://mariadb.com/kb/en/mariadb-10326-release-notes/), [MariaDB 10.2.35](https://mariadb.com/kb/en/mariadb-10235-release-notes/) --- #### `connect_default_prec` * **Description:** Default precision used for doubles. * **Commandline:** `--connect-default-prec=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:**`6` * **Range:** `0` to `16` * **Introduced:** [MariaDB 10.5.9](https://mariadb.com/kb/en/mariadb-1059-release-notes/), [MariaDB 10.4.18](https://mariadb.com/kb/en/mariadb-10418-release-notes/), [MariaDB 10.3.28](https://mariadb.com/kb/en/mariadb-10328-release-notes/), [MariaDB 10.2.37](https://mariadb.com/kb/en/mariadb-10237-release-notes/) --- #### `connect_enable_mongo` * **Description:** Enable the [Mongo table type](../connect-mongo-table-type/index). * **Commandline:** `--connect-enable-mongo={0|1}` * **Scope:** Global, Session * **Dynamic:** * **Data Type:** `boolean` * **Default Value:** `OFF` * **Introduced:** [MariaDB 10.3.2](https://mariadb.com/kb/en/mariadb-1032-release-notes/), [MariaDB 10.2.9](https://mariadb.com/kb/en/mariadb-1029-release-notes/) * **Removed:** [MariaDB 10.3.3](https://mariadb.com/kb/en/mariadb-1033-release-notes/) --- #### `connect_exact_info` * **Description:** Whether the CONNECT engine should return an exact record number value to information queries. It is OFF by default because this information can take a very long time for large variable record length tables or for remote tables, especially if the remote server is not available. It can be set to ON when exact values are desired, for instance when querying the repartition of rows in a partition table. * **Commandline:** `--connect-exact-info={0|1}` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `OFF` --- #### `connect_force_bson` * **Description:** Force using BSON for JSON tables. Starting with these releases, the internal way JSON was parsed and handled was changed. The main advantage of the new way is to reduce the memory required to parse JSON (from 6 to 10 times the size of the JSON source to now only 2 to 4 times). However, this is in Beta mode and JSON tables are still handled using the old mode. To use the new mode, tables should be created with TABLE\_TYPE=BSON, or by setting this session variable to 1 or ON. Then, all JSON tables will be handled as BSON. This is temporary until the new way replaces the old way by default. * **Commandline:** `--connect-force-bson={0|1}` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `OFF` * **Introduced:** [MariaDB 10.5.9](https://mariadb.com/kb/en/mariadb-1059-release-notes/), [MariaDB 10.4.18](https://mariadb.com/kb/en/mariadb-10418-release-notes/), [MariaDB 10.3.28](https://mariadb.com/kb/en/mariadb-10328-release-notes/), [MariaDB 10.2.37](https://mariadb.com/kb/en/mariadb-10237-release-notes/) --- #### `connect_indx_map` * **Description:** Enable file mapping for index files. To accelerate the indexing process, CONNECT makes an index structure in memory from the index file. This can be done by reading the index file or using it as if it was in memory by “file mapping”. Set to 0 (file read, the default) or 1 (file mapping). * **Commandline:** `--connect-indx-map=#` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `boolean` * **Default Value:** `OFF` --- #### `connect_java_wrapper` * **Description:** Java wrapper. * **Commandline:** `--connect-java-wrapper=val` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `string` * **Default Value:** `wrappers/JdbcInterface` * **Introduced:** Connect 1.05.0001, [MariaDB 10.2.4](https://mariadb.com/kb/en/mariadb-1024-release-notes/) --- #### `connect_json_all_path` * **Description:** Discovery to generate json path for all columns if ON (the default) or do not when the path is the column name. * **Commandline:** `--connect-json-all-path={0|1}` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Data Type:** `boolean` * **Default Value:** `ON` * **Introduced:** [MariaDB 10.5.7](https://mariadb.com/kb/en/mariadb-1057-release-notes/), [MariaDB 10.4.16](https://mariadb.com/kb/en/mariadb-10416-release-notes/), [MariaDB 10.3.26](https://mariadb.com/kb/en/mariadb-10326-release-notes/), [MariaDB 10.2.35](https://mariadb.com/kb/en/mariadb-10235-release-notes/) --- #### `connect_json_grp_size` * **Description:** Max number of rows for JSON aggregate functions. * **Commandline:** `--connect-json-grp-size=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `50` (>= Connect 1.7.0003), `10` (<= Connect 1.7.0002) * **Range:** `1` to `2147483647` --- #### `connect_json_null` * **Description:** Representation of JSON null values. * **Commandline:** `--connect-json-null=value` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `string` * **Default Value:** `<null>` * **Introduced:** [MariaDB 10.2.8](https://mariadb.com/kb/en/mariadb-1028-release-notes/) --- #### `connect_jvm_path` * **Description:** Path to JVM library. * **Commandline:** `--connect-jvm_path=value` * **Scope:** Global * **Dynamic:** * **Data Type:** `string` * **Default Value:** * **Introduced:** Connect 1.04.0006 --- #### `connect_type_conv` * **Description:** Determines the handling of [TEXT](../text/index) columns. + `NO`: The default until Connect 1.06.005, no conversion takes place, and a TYPE\_ERROR is returned, resulting in a “not supported” message. + `YES`: The default from Connect 1.06.006. The column is internally converted to a column declared as VARCHAR(n), `n` being the value of [connect\_conv\_size](#connect_conv_size). + `FORCE` (>= Connect 1.06.006): Also convert ODBC blob columns to TYPE\_STRING. + `SKIP`: No conversion. When the column declaration is provided via Discovery (meaning the CONNECT table is created without a column description), this column is not generated. Also applies to ODBC tables. * **Commandline:** `--connect-type-conv=#` * **Scope:** Global, Session * **Dynamic:** Yes * **Data Type:** `enum` * **Valid Values:** `NO`, `YES`, `FORCE` or `SKIP` * **Default Value:** `YES` --- #### `connect_use_tempfile` * **Description:** + `NO`: The first algorithm is always used. Because it can cause errors when updating variable record length tables, this value should be set only for testing. + `AUTO`: This is the default value. It leaves CONNECT to choose the algorithm to use. Currently it is equivalent to `NO`, except when updating variable record length tables ([DOS](../connect-table-types-data-files/index#dos-and-fix-table-types), [CSV](../connect-table-types-data-files/index#csv-and-fmt-table-types) or [FMT](../connect-table-types-data-files/index#fmt-type)) with file mapping forced to OFF. + `YES`: Using a temporary file is chosen with some exceptions. These are when file mapping is ON, for [VEC](../connect-table-types-data-files/index#vec-table-type-vector) tables and when deleting from [DBF](../connect-table-types-data-files/index#dbf-type) tables (soft delete). For variable record length tables, file mapping is forced to OFF. + `FORCE`: Like YES but forces file mapping to be OFF for all table types. + `TEST`: Reserved for CONNECT development. * **Commandline:** `--connect-use-tempfile=#` * **Scope:** Session * **Dynamic:** Yes * **Data Type:** `enum` * **Default Value:** `AUTO` --- #### `connect_work_size` * **Description:** Size of the CONNECT work area used for memory allocation. Permits allocating a larger memory sub-allocation space when dealing with very large if sub-allocation fails. If the specified value is too big and memory allocation fails, the size of the work area remains but the variable value is not modified and should be reset. * **Commandline:** `--connect-work-size=#` * **Scope:** Global, Session (Session-only from CONNECT 1.03.005) * **Dynamic:** Yes * **Data Type:** `numeric` * **Default Value:** `67108864` * **Range:** `4194304` upwards, depending on the physical memory size --- #### `connect_xtrace` * **Description:** Console trace value. Set to `0` (no trace), or to other values if a console tracing is desired. Note that to test this handler, MariaDB should be executed with the [--console](../mysqld-options/index#-console) parameter because CONNECT prints some error and trace messages on the console. In some Linux versions, this is re-routed into the error log file. Console tracing can be set on the command line or later by names or values. Valid values (from Connect 1.06.006) include: + `0`: No trace + `YES` or `1`: Basic trace + `MORE` or `2`: More tracing + `INDEX` or `4`: Index construction + `MEMORY` or `8`: Allocating and freeing memory + `SUBALLOC` or `16`: Sub-allocating in work area + `QUERY` or `32`: Constructed query sent to external server + `STMT` or `64`: Currently executing statement + `HANDLER` or `128`: Creating and dropping CONNECT handlers + `BLOCK` or `256`: Creating and dropping CONNECT objects + `MONGO` or `512`: Mongo and REST (from [Connect 1.06.0010](../connect/index)) tracing * For example: + `set global connect_xtrace=0; *No trace*` + `set global connect_xtrace='YES'; *By name*` + `set global connect_xtrace=1; *By value*` + `set global connect_xtrace='QUERY,STMT'; *By name*` + `set global connect_xtrace=96; *By value*` + `set global connect_xtrace=1023; *Trace all*` * **Commandline:** `--connect-xtrace=#` * **Scope:** Global * **Dynamic:** Yes * **Data Type:** `set` * **Default Value:** `0` * **Valid Values:** See description --- Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb mysql_embedded mysql\_embedded =============== **MariaDB starting with [10.4.6](https://mariadb.com/kb/en/mariadb-1046-release-notes/)**From [MariaDB 10.4.6](https://mariadb.com/kb/en/mariadb-1046-release-notes/), `mariadb-embedded` is a symlink to `mysql_embedded`. **MariaDB starting with [10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/)**From [MariaDB 10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/), `mariadb-embedded` is the name of the tool, with `mysql_embedded` a symlink. `mysql_embedded` is a [mysql client](../mysql-command-line-client/index) statically linked to libmysqld, the embedded server. Upon execution, an embedded MariaDB server is instantiated and you can execute statements just as you would using the normal mysql client, using the same options. Do not run *mysql\_embedded* while MariaDB is running, as effectively it starts a new instance of the server. Examples -------- ``` sudo mysql_embedded -e 'select user, host, password from mysql.user where user="root"' +------+-----------+-------------------------------------------+ | user | host | password | +------+-----------+-------------------------------------------+ | root | localhost | *196BDEDE2AE4F84CA44C47D54D78478C7E2BD7B7 | | root | db1 | *196BDEDE2AE4F84CA44C47D54D78478C7E2BD7B7 | | root | 127.0.0.1 | *196BDEDE2AE4F84CA44C47D54D78478C7E2BD7B7 | | root | ::1 | *196BDEDE2AE4F84CA44C47D54D78478C7E2BD7B7 | +------+-----------+-------------------------------------------+ ``` Sending options with `--server-arg`: ``` sudo mysql_embedded --server-arg='--skip-innodb' --server-arg='--default-storage-engine=myisam' --server-arg='--log-error=/tmp/mysql.err' -e 'select user, host, password from mysql.user where user="root"' +------+-----------+-------------------------------------------+ | user | host | password | +------+-----------+-------------------------------------------+ | root | localhost | *196BDEDE2AE4F84CA44C47D54D78478C7E2BD7B7 | | root | db1 | *196BDEDE2AE4F84CA44C47D54D78478C7E2BD7B7 | | root | 127.0.0.1 | *196BDEDE2AE4F84CA44C47D54D78478C7E2BD7B7 | | root | ::1 | *196BDEDE2AE4F84CA44C47D54D78478C7E2BD7B7 | +------+-----------+-------------------------------------------+ ``` See Also -------- * [Using mysql\_embedded and mysqld --bootstrap to tinker with privilege tables](using_mysql_embedded_and_mysqld_--bootstrap_to_tinker_with_privilege_tables) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Performance Schema session_connect_attrs Table Performance Schema session\_connect\_attrs Table ================================================ Description ----------- The `session_connect_attrs` table shows connection attributes for all sessions. Applications can pass key/value connection attributes to the server when a connection is made. The `session_connect_attrs` and [session\_account\_connect\_attrs](../performance-schema-session_account_connect_attrs-table/index) tables provide access to this information, for all sessions and the current session respectively. The C API functions [mysql\_options()](../mysql_options/index) and [mysql\_optionsv()](../mysql_optionsv/index) are used for passing connection attributes to the server. `session_connect_attrs` contains the following columns: | Column | Description | | --- | --- | | `PROCESSLIST_ID` | Session connection identifier. | | `ATTR_NAME` | Attribute name. | | `ATTR_VALUE` | Attribute value. | | `ORDINAL_POSITION` | Order in which attribute was added to the connection attributes. | Example ------- Returning the current connection's attributes: ``` SELECT * FROM performance_schema.session_connect_attrs WHERE processlist_id=CONNECTION_ID(); +----------------+-----------------+------------------+------------------+ | PROCESSLIST_ID | ATTR_NAME | ATTR_VALUE | ORDINAL_POSITION | +----------------+-----------------+------------------+------------------+ | 45 | _os | debian-linux-gnu | 0 | | 45 | _client_name | libmysql | 1 | | 45 | _pid | 7711 | 2 | | 45 | _client_version | 10.0.5 | 3 | | 45 | _platform | x86_64 | 4 | | 45 | program_name | mysql | 5 | +----------------+-----------------+------------------+------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb MariaDB ColumnStore Cluster Test Tool MariaDB ColumnStore Cluster Test Tool ===================================== Introduction ------------ MariaDB ColumnStore Cluster Test Tool is used to validate that the server(s)/node(s) are setup and configured correctly to allow a install of the MariaDB ColumnStore Product. It is packaged with the MariaDB ColumnStore package starting at 1.0.10 . It should be run after the "Preparing For ColumnStore Installation" steps are performed on the server(s)/node(s) that are being used for the MariaDB ColumnStore Product. When to use the Tool: * This script can be run from PM1 after the packages has been installed. It can be run on single-server installs and it will validate that the correct dependent packages are installed on the system. * It can be run on PM1 on multi-server installs to validate the local PM1 and the other servers that will make up the cluster are configured correctly according to the setup guide. * On multi-server installs that are going to be configured to support Server Failover, the script can be run on the other PM servers to validate that those nodes can access the PM1. Here is a link to the "Preparing For ColumnStore Installation" document: [https://mariadb.com/kb/en/mariadb/preparing-for-columnstore-installation](../mariadb/preparing-for-columnstore-installation) Here are the items that are tested/check during the running of this tool: * Node Ping test - ping test to remote nodes * Node SSH test -- SSH login test to remote nodes * ColumnStore Port (8600-8630,8700,8800,3306) test - use 'nmap' to check connectivity on ColumnStore ports to remote Nodes * OS version - Detect, Validate, and Compare OS version to make sure they match on remote nodes with local node * Locale settings - Compare Locale setting to make sure they match on remote nodes with local node * Firewall settings - Verify that certain firewalls are disabled on all nodes. * Date/Time settings - Compare Date/Time settings to make sure they match on remote nodes with local node * MariaDB port usage - Checks that he MariaDB default port of 3306 is not in use * Dependent packages installed - Checks that all dependency packages are installed on all nodes * For non-root user install - test permissions on /tmp and /dev/shm This tool can be used on single-server installs also, not just clusters with multiple nodes On single-server installs, the following items will be tested: * Dependent packages installed * For non-root user install - test permissions on /tmp and /dev/shm Tool Installation ----------------- To perform testing on a multi-node system, these 2 packages are required to be installed before the tool is run. * expect * nmap MariaDB ColumnStore Cluster Test Tool is a tar package that consist of mutliple files. It can be download from here: Tool Usage ---------- Here is how to execute the tool. Example is showing a root install ``` cd /usr/local/mariadb/columnstore/bin ./columnstoreClusterTester.sh 'options' ``` Addition information from the tool can be obtained by running 'help' ``` # cd ClusterTesterTool # ./columnstoreClusterTester.sh -h This is the MariaDB ColumnStore Cluster System Test tool. It will run a set of test to validate the setup of the MariaDB Columnstore system. This can be run prior to running MariaDB ColumnStore 'postConfigure' tool to verify servers/nodes are configured properly. It should be run as the user of the planned install. Meaning if MariaDB ColumnStore is going to be installed as root user, then run from root user. Also the assumption is that the servers/node have be setup based on the Preparing for ColumnStore Installation. It should also be run on the server that is designated as Performance Module #1. Items that are checked: Node Ping test Node SSH test ColumnStore Port test OS version Locale settings Firewall settings Date/Time Settings MariaDB port 3306 availability Dependent packages installed For non-root user install - test permissions on /tmp and /dev/shm Usage: ./columnstoreClusterTester.sh [options] OPTIONS: -h,--help Help --ipaddr=[ipaddresses] Remote Node IP Addresses, if not provide, will only check local node --os=[os] Optional: Set OS Version (centos6, centos7, debian8, debian9, suse12, ubuntu16). --password=[password] Provide a user password. (Default: ssh-keys setup will be assumed) -c,--continue Continue on failures --logfile=[filename] Optional: Output results to a log file NOTE: Dependent package : 'nmap' and 'expect' packages need to be installed locally ``` ### Options: 'ipaddr' - This is the list of IP Addresses or hostname of the other server/nodes that make up the MariaDB ColumnStore Cluster. If this is not provide, just the Single-Server Local node tests will be performed. You don't need to provide the IP address/hostname of the local node. You can enter multiple using one of these formats: --ipaddr=192.168.1.1,192.196.1.2 --ipaddr=serverum1,serverpm2 'os' - This os optional. Tool will determine the Local OS version and validate it againest the supported OS. This is the list of support versions: * centos6 * centos7 * debian8 * debian9 * suse12 * ubuntu16 'password' - The tool will log into the other server/nodes that make up the MariaDB ColumnStore Cluster to perform test. So the user password or ssh-key setup is required. NOTE: If no 'password' is provided, the tool will assume ssh-keys are setup between the local node and the other server/nodes that make up the MariaDB ColumnStore Cluster. 'continue' - This option allows the user to run the tool to completion while reporting test/check failures. When this option is not used, then a prompt will be issued allowing the user to stop and fix the issue or continue. Here is an example where an error is detected. When the 'continue' option is not specified, a prompt is given to the user to exit or continue the test once an error has been detected. ``` ./columnstoreClusterTester.sh --ipaddr=x.x.x.x *** This is the MariaDB Columnstore Cluster System test tool *** ** Run Ping access Test to remote nodes x.x.x.x Node Passed ping test ** Run SSH Login access Test to remote nodes x.x.x.x Node Passed SSH login test ** Run OS check - OS version needs to be the same on all nodes Local Node OS Version : Linux Debian stretch/sid x.x.x.x Node OS Version : Linux RedHat 6.9 Failed, x.x.x.x has a different OS than local node Failure occurred, do you want to continue? (y,n) > n ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Information Schema PLUGINS Table Information Schema PLUGINS Table ================================ The [Information Schema](../information_schema/index) `PLUGINS` table contains information about [server plugins](../mariadb-plugins/index). It contains the following columns: | Column | Description | | --- | --- | | `PLUGIN_NAME` | Name of the plugin. | | `PLUGIN_VERSION` | Version from the plugin's general type descriptor. | | `PLUGIN_STATUS` | Plugin status, one of `ACTIVE`, `INACTIVE`, `DISABLED` or `DELETED`. | | `PLUGIN_TYPE` | Plugin type; `STORAGE ENGINE`, `INFORMATION_SCHEMA`, `AUTHENTICATION`, `REPLICATION`, `DAEMON` or `AUDIT`. | | `PLUGIN_TYPE_VERSION` | Version from the plugin's type-specific descriptor. | | `PLUGIN_LIBRARY` | Plugin's shared object file name, located in the directory specified by the [plugin\_dir](../server-system-variables/index#plugin_dir) system variable, and used by the [INSTALL PLUGIN](../install-plugin/index) and [UNINSTALL PLUGIN](../uninstall-plugin/index) statements. `NULL` if the plugin is complied in and cannot be uninstalled. | | `PLUGIN_LIBRARY_VERSION` | Version from the plugin's API interface. | | `PLUGIN_AUTHOR` | Author of the plugin. | | `PLUGIN_DESCRIPTION` | Description. | | `PLUGIN_LICENSE` | Plugin's licence. | | `LOAD_OPTION` | How the plugin was loaded; one of `OFF`, `ON`, `FORCE` or `FORCE_PLUS_PERMANENT`. See [Installing Plugins](../plugin-overview/index#installing-plugins). | | `PLUGIN_MATURITY` | Plugin's maturity level; one of `Unknown`, `Experimental`, `Alpha`, `Beta`,`'Gamma`, and `Stable`. | | `PLUGIN_AUTH_VERSION` | Plugin's version as determined by the plugin author. An example would be '0.99 beta 1'. | It provides a superset of the information shown by the [SHOW PLUGINS](../show-plugins/index) statement. For specific information about storage engines (a particular type of plugins), see the [information\_schema.ENGINES](../information-schema-engines-table/index) table and the [SHOW ENGINES](../show-engines/index) statement. This table provides a subset of the Information Schema [information\_schema.ALL\_PLUGINS](../information-schema-all_plugins-table/index) table, which contains all available plugins, installed or not. The table is not a standard Information Schema table, and is a MariaDB extension. #### Examples The easiest way to get basic information on plugins is with [SHOW PLUGINS](../show-plugins/index): ``` SHOW PLUGINS; +----------------------------+----------+--------------------+-------------+---------+ | Name | Status | Type | Library | License | +----------------------------+----------+--------------------+-------------+---------+ | binlog | ACTIVE | STORAGE ENGINE | NULL | GPL | | mysql_native_password | ACTIVE | AUTHENTICATION | NULL | GPL | | mysql_old_password | ACTIVE | AUTHENTICATION | NULL | GPL | | MRG_MyISAM | ACTIVE | STORAGE ENGINE | NULL | GPL | | MyISAM | ACTIVE | STORAGE ENGINE | NULL | GPL | | CSV | ACTIVE | STORAGE ENGINE | NULL | GPL | | MEMORY | ACTIVE | STORAGE ENGINE | NULL | GPL | | FEDERATED | ACTIVE | STORAGE ENGINE | NULL | GPL | | PERFORMANCE_SCHEMA | ACTIVE | STORAGE ENGINE | NULL | GPL | | Aria | ACTIVE | STORAGE ENGINE | NULL | GPL | | InnoDB | ACTIVE | STORAGE ENGINE | NULL | GPL | | INNODB_TRX | ACTIVE | INFORMATION SCHEMA | NULL | GPL | | INNODB_LOCKS | ACTIVE | INFORMATION SCHEMA | NULL | GPL | | INNODB_LOCK_WAITS | ACTIVE | INFORMATION SCHEMA | NULL | GPL | | INNODB_CMP | ACTIVE | INFORMATION SCHEMA | NULL | GPL | | INNODB_CMP_RESET | ACTIVE | INFORMATION SCHEMA | NULL | GPL | | INNODB_CMPMEM | ACTIVE | INFORMATION SCHEMA | NULL | GPL | | INNODB_CMPMEM_RESET | ACTIVE | INFORMATION SCHEMA | NULL | GPL | | INNODB_BUFFER_PAGE | ACTIVE | INFORMATION SCHEMA | NULL | GPL | | INNODB_BUFFER_PAGE_LRU | ACTIVE | INFORMATION SCHEMA | NULL | GPL | | INNODB_BUFFER_POOL_STATS | ACTIVE | INFORMATION SCHEMA | NULL | GPL | | INNODB_METRICS | ACTIVE | INFORMATION SCHEMA | NULL | GPL | | INNODB_FT_DEFAULT_STOPWORD | ACTIVE | INFORMATION SCHEMA | NULL | GPL | | INNODB_FT_INSERTED | ACTIVE | INFORMATION SCHEMA | NULL | GPL | | INNODB_FT_DELETED | ACTIVE | INFORMATION SCHEMA | NULL | GPL | | INNODB_FT_BEING_DELETED | ACTIVE | INFORMATION SCHEMA | NULL | GPL | | INNODB_FT_CONFIG | ACTIVE | INFORMATION SCHEMA | NULL | GPL | | INNODB_FT_INDEX_CACHE | ACTIVE | INFORMATION SCHEMA | NULL | GPL | | INNODB_FT_INDEX_TABLE | ACTIVE | INFORMATION SCHEMA | NULL | GPL | | INNODB_SYS_TABLES | ACTIVE | INFORMATION SCHEMA | NULL | GPL | | INNODB_SYS_TABLESTATS | ACTIVE | INFORMATION SCHEMA | NULL | GPL | | INNODB_SYS_INDEXES | ACTIVE | INFORMATION SCHEMA | NULL | GPL | | INNODB_SYS_COLUMNS | ACTIVE | INFORMATION SCHEMA | NULL | GPL | | INNODB_SYS_FIELDS | ACTIVE | INFORMATION SCHEMA | NULL | GPL | | INNODB_SYS_FOREIGN | ACTIVE | INFORMATION SCHEMA | NULL | GPL | | INNODB_SYS_FOREIGN_COLS | ACTIVE | INFORMATION SCHEMA | NULL | GPL | | SPHINX | ACTIVE | STORAGE ENGINE | NULL | GPL | | ARCHIVE | ACTIVE | STORAGE ENGINE | NULL | GPL | | BLACKHOLE | ACTIVE | STORAGE ENGINE | NULL | GPL | | FEEDBACK | DISABLED | INFORMATION SCHEMA | NULL | GPL | | partition | ACTIVE | STORAGE ENGINE | NULL | GPL | | pam | ACTIVE | AUTHENTICATION | auth_pam.so | GPL | +----------------------------+----------+--------------------+-------------+---------+ ``` ``` SELECT LOAD_OPTION FROM INFORMATION_SCHEMA.PLUGINS WHERE PLUGIN_NAME LIKE 'tokudb'; Empty set ``` The equivalent [SELECT](../select/index) query would be: ``` SELECT PLUGIN_NAME, PLUGIN_STATUS, PLUGIN_TYPE, PLUGIN_LIBRARY, PLUGIN_LICENSE FROM INFORMATION_SCHEMA.PLUGINS; ``` Other [SELECT](../select/index) queries can be used to see additional information. For example: ``` SELECT PLUGIN_NAME, PLUGIN_DESCRIPTION, PLUGIN_MATURITY, PLUGIN_AUTH_VERSION FROM INFORMATION_SCHEMA.PLUGINS WHERE PLUGIN_TYPE='STORAGE ENGINE' ORDER BY PLUGIN_MATURITY \G *************************** 1. row *************************** PLUGIN_NAME: FEDERATED PLUGIN_DESCRIPTION: FederatedX pluggable storage engine PLUGIN_MATURITY: Beta PLUGIN_AUTH_VERSION: 2.1 *************************** 2. row *************************** PLUGIN_NAME: Aria PLUGIN_DESCRIPTION: Crash-safe tables with MyISAM heritage PLUGIN_MATURITY: Gamma PLUGIN_AUTH_VERSION: 1.5 *************************** 3. row *************************** PLUGIN_NAME: PERFORMANCE_SCHEMA PLUGIN_DESCRIPTION: Performance Schema PLUGIN_MATURITY: Gamma PLUGIN_AUTH_VERSION: 0.1 *************************** 4. row *************************** PLUGIN_NAME: binlog PLUGIN_DESCRIPTION: This is a pseudo storage engine to represent the binlog in a transaction PLUGIN_MATURITY: Stable PLUGIN_AUTH_VERSION: 1.0 *************************** 5. row *************************** PLUGIN_NAME: MEMORY PLUGIN_DESCRIPTION: Hash based, stored in memory, useful for temporary tables PLUGIN_MATURITY: Stable PLUGIN_AUTH_VERSION: 1.0 *************************** 6. row *************************** PLUGIN_NAME: MyISAM PLUGIN_DESCRIPTION: MyISAM storage engine PLUGIN_MATURITY: Stable PLUGIN_AUTH_VERSION: 1.0 *************************** 7. row *************************** PLUGIN_NAME: MRG_MyISAM PLUGIN_DESCRIPTION: Collection of identical MyISAM tables PLUGIN_MATURITY: Stable PLUGIN_AUTH_VERSION: 1.0 *************************** 8. row *************************** PLUGIN_NAME: CSV PLUGIN_DESCRIPTION: CSV storage engine PLUGIN_MATURITY: Stable PLUGIN_AUTH_VERSION: 1.0 *************************** 9. row *************************** PLUGIN_NAME: InnoDB PLUGIN_DESCRIPTION: Supports transactions, row-level locking, and foreign keys PLUGIN_MATURITY: Stable PLUGIN_AUTH_VERSION: 1.2.5 *************************** 10. row *************************** PLUGIN_NAME: BLACKHOLE PLUGIN_DESCRIPTION: /dev/null storage engine (anything you write to it disappears) PLUGIN_MATURITY: Stable PLUGIN_AUTH_VERSION: 1.0 *************************** 11. row *************************** PLUGIN_NAME: ARCHIVE PLUGIN_DESCRIPTION: Archive storage engine PLUGIN_MATURITY: Stable PLUGIN_AUTH_VERSION: 1.0 *************************** 12. row *************************** PLUGIN_NAME: partition PLUGIN_DESCRIPTION: Partition Storage Engine Helper PLUGIN_MATURITY: Stable PLUGIN_AUTH_VERSION: 1.0 ``` Check if a given plugin is available: ``` SELECT LOAD_OPTION FROM INFORMATION_SCHEMA.PLUGINS WHERE PLUGIN_NAME LIKE 'tokudb'; Empty set ``` Show authentication plugins: ``` SELECT PLUGIN_NAME, LOAD_OPTION FROM INFORMATION_SCHEMA.PLUGINS WHERE PLUGIN_TYPE LIKE 'authentication' \G *************************** 1. row *************************** PLUGIN_NAME: mysql_native_password LOAD_OPTION: FORCE *************************** 2. row *************************** PLUGIN_NAME: mysql_old_password LOAD_OPTION: FORCE ``` See Also -------- * [List of Plugins](../list-of-plugins/index) * [Plugin Overview](../plugin-overview/index) * [SHOW PLUGINS](../show-plugins/index) * [INSTALL PLUGIN](../install-plugin/index) * [INSTALL SONAME](../install-soname/index) * [UNINSTALL PLUGIN](../uninstall-plugin/index) * [UNINSTALL SONAME](../uninstall-soname/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb RLIKE RLIKE ===== Syntax ------ ``` expr REGEXP pat, expr RLIKE pat ``` Description ----------- `RLIKE` is a synonym for [REGEXP](../regexp/index). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb 10.3.5-gamma Release Upgrade Tests 10.3.5-gamma Release Upgrade Tests ================================== ### Tested revision 583eb96c2492adb87e88a014b24eb0724fb00257 ### Test date 2018-03-11 12:40:20 ### Summary Known bugs [MDEV-13103](https://jira.mariadb.org/browse/MDEV-13103), [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094). A few upgrades from MySQL and old MariaDB fail because the old versions hang on shutdown ### Details | type | pagesize | OLD version | file format | encrypted | compressed | | NEW version | file format | encrypted | compressed | readonly | result | notes | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | recovery | 16 | 10.3.5 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | recovery | 16 | 10.3.5 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13103](https://jira.mariadb.org/browse/MDEV-13103)(1) | | recovery | 4 | 10.3.5 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | recovery | 4 | 10.3.5 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13103](https://jira.mariadb.org/browse/MDEV-13103)(1) | | recovery | 32 | 10.3.5 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13103](https://jira.mariadb.org/browse/MDEV-13103)(1) | | recovery | 32 | 10.3.5 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | recovery | 64 | 10.3.5 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | recovery | 64 | 10.3.5 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13103](https://jira.mariadb.org/browse/MDEV-13103)(1) | | recovery | 8 | 10.3.5 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | recovery | 8 | 10.3.5 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13103](https://jira.mariadb.org/browse/MDEV-13103)(1) | | recovery | 16 | 10.3.5 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | recovery | 16 | 10.3.5 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | recovery | 4 | 10.3.5 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | recovery | 4 | 10.3.5 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | recovery | 32 | 10.3.5 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | recovery | 32 | 10.3.5 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | recovery | 64 | 10.3.5 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | recovery | 64 | 10.3.5 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | recovery | 8 | 10.3.5 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | recovery | 8 | 10.3.5 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo-recovery | 16 | 10.3.5 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | undo-recovery | 4 | 10.3.5 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | undo-recovery | 32 | 10.3.5 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | undo-recovery | 64 | 10.3.5 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | undo-recovery | 8 | 10.3.5 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | undo-recovery | 16 | 10.3.5 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | undo-recovery | 4 | 10.3.5 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | undo-recovery | 32 | 10.3.5 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | undo-recovery | 64 | 10.3.5 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | undo-recovery | 8 | 10.3.5 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | undo-recovery | 16 | 10.3.5 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | TEST\_FAILURE | | undo-recovery | 4 | 10.3.5 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | TEST\_FAILURE | | undo-recovery | 32 | 10.3.5 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | TEST\_FAILURE | | undo-recovery | 64 | 10.3.5 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | TEST\_FAILURE | | undo-recovery | 8 | 10.3.5 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | TEST\_FAILURE | | undo-recovery | 16 | 10.3.5 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo-recovery | 4 | 10.3.5 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo-recovery | 32 | 10.3.5 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo-recovery | 64 | 10.3.5 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo-recovery | 8 | 10.3.5 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | normal | 16 | 10.3.4 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 16 | 10.3.4 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 4 | 10.3.4 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 4 | 10.3.4 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 32 | 10.3.4 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 32 | 10.3.4 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 64 | 10.3.4 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 64 | 10.3.4 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 8 | 10.3.4 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 8 | 10.3.4 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 16 | 10.3.4 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 16 | 10.3.4 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 4 | 10.3.4 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 4 | 10.3.4 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 32 | 10.3.4 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 32 | 10.3.4 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 64 | 10.3.4 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 64 | 10.3.4 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 8 | 10.3.4 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 8 | 10.3.4 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | crash | 16 | 10.3.4 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | crash | 16 | 10.3.4 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13103](https://jira.mariadb.org/browse/MDEV-13103)(1) | | crash | 4 | 10.3.4 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | crash | 4 | 10.3.4 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13103](https://jira.mariadb.org/browse/MDEV-13103)(1) | | crash | 32 | 10.3.4 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13103](https://jira.mariadb.org/browse/MDEV-13103)(1) | | crash | 32 | 10.3.4 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | crash | 64 | 10.3.4 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | crash | 64 | 10.3.4 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13103](https://jira.mariadb.org/browse/MDEV-13103)(1) | | crash | 8 | 10.3.4 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | crash | 8 | 10.3.4 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13103](https://jira.mariadb.org/browse/MDEV-13103)(1) | | crash | 16 | 10.3.4 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | crash | 16 | 10.3.4 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | crash | 4 | 10.3.4 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | crash | 4 | 10.3.4 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | crash | 32 | 10.3.4 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | crash | 32 | 10.3.4 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | crash | 64 | 10.3.4 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | crash | 64 | 10.3.4 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | crash | 8 | 10.3.4 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | crash | 8 | 10.3.4 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 16 | 10.3.4 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 4 | 10.3.4 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 32 | 10.3.4 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 64 | 10.3.4 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 8 | 10.3.4 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 16 | 10.3.4 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 4 | 10.3.4 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 32 | 10.3.4 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 64 | 10.3.4 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 8 | 10.3.4 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 16 | 10.3.4 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 4 | 10.3.4 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 32 | 10.3.4 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 64 | 10.3.4 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 8 | 10.3.4 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 16 | 10.3.4 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 4 | 10.3.4 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 32 | 10.3.4 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 64 | 10.3.4 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 8 | 10.3.4 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | normal | 16 | 10.2.13 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 16 | 10.2.13 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 4 | 10.2.13 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 4 | 10.2.13 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 32 | 10.2.13 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 32 | 10.2.13 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 64 | 10.2.13 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 64 | 10.2.13 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 8 | 10.2.13 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 8 | 10.2.13 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 16 | 10.2.13 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 16 | 10.2.13 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 4 | 10.2.13 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 4 | 10.2.13 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 32 | 10.2.13 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 32 | 10.2.13 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 64 | 10.2.13 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 64 | 10.2.13 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 8 | 10.2.13 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 8 | 10.2.13 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | crash | 16 | 10.2.13 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | crash | 16 | 10.2.13 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13103](https://jira.mariadb.org/browse/MDEV-13103)(1) | | crash | 4 | 10.2.13 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | crash | 4 | 10.2.13 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13103](https://jira.mariadb.org/browse/MDEV-13103)(1) | | crash | 32 | 10.2.13 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13103](https://jira.mariadb.org/browse/MDEV-13103)(1) | | crash | 32 | 10.2.13 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | crash | 64 | 10.2.13 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | crash | 64 | 10.2.13 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13103](https://jira.mariadb.org/browse/MDEV-13103)(1) | | crash | 8 | 10.2.13 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | crash | 8 | 10.2.13 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13103](https://jira.mariadb.org/browse/MDEV-13103)(1) | | crash | 16 | 10.2.13 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | crash | 16 | 10.2.13 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | crash | 4 | 10.2.13 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | crash | 4 | 10.2.13 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | crash | 32 | 10.2.13 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | crash | 32 | 10.2.13 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | crash | 64 | 10.2.13 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | crash | 64 | 10.2.13 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | crash | 8 | 10.2.13 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | crash | 8 | 10.2.13 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 16 | 10.2.13 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 4 | 10.2.13 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 32 | 10.2.13 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 64 | 10.2.13 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 8 | 10.2.13 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 16 | 10.2.13 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 4 | 10.2.13 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 32 | 10.2.13 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 64 | 10.2.13 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 8 | 10.2.13 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 16 | 10.2.13 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 4 | 10.2.13 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 32 | 10.2.13 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 64 | 10.2.13 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 8 | 10.2.13 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 16 | 10.2.13 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 4 | 10.2.13 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 32 | 10.2.13 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 64 | 10.2.13 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 8 | 10.2.13 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | normal | 16 | 10.2.6 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 16 | 10.2.6 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 4 | 10.2.6 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 4 | 10.2.6 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 32 | 10.2.6 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 32 | 10.2.6 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 64 | 10.2.6 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 64 | 10.2.6 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 8 | 10.2.6 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 8 | 10.2.6 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 16 | 10.2.6 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 16 | 10.2.6 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 4 | 10.2.6 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 4 | 10.2.6 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 32 | 10.2.6 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 32 | 10.2.6 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 64 | 10.2.6 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 64 | 10.2.6 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 8 | 10.2.6 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 8 | 10.2.6 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | crash | 16 | 10.2.6 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | crash | 16 | 10.2.6 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13103](https://jira.mariadb.org/browse/MDEV-13103)(1) | | crash | 4 | 10.2.6 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | crash | 4 | 10.2.6 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13103](https://jira.mariadb.org/browse/MDEV-13103)(1) | | crash | 32 | 10.2.6 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13103](https://jira.mariadb.org/browse/MDEV-13103)(1) | | crash | 32 | 10.2.6 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | crash | 64 | 10.2.6 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | crash | 64 | 10.2.6 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13103](https://jira.mariadb.org/browse/MDEV-13103)(1) | | crash | 8 | 10.2.6 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | crash | 8 | 10.2.6 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13103](https://jira.mariadb.org/browse/MDEV-13103)(1) | | crash | 16 | 10.2.6 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | crash | 16 | 10.2.6 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | crash | 4 | 10.2.6 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | crash | 4 | 10.2.6 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | crash | 32 | 10.2.6 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | crash | 32 | 10.2.6 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | crash | 64 | 10.2.6 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | crash | 64 | 10.2.6 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | crash | 8 | 10.2.6 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | crash | 8 | 10.2.6 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 16 | 10.2.6 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 4 | 10.2.6 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 32 | 10.2.6 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 64 | 10.2.6 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 8 | 10.2.6 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 16 | 10.2.6 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 4 | 10.2.6 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 32 | 10.2.6 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 64 | 10.2.6 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 8 | 10.2.6 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 16 | 10.2.6 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 4 | 10.2.6 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 32 | 10.2.6 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 64 | 10.2.6 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 8 | 10.2.6 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 16 | 10.2.6 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 4 | 10.2.6 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 32 | 10.2.6 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 64 | 10.2.6 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 8 | 10.2.6 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | normal | 16 | 10.1.31 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | normal | 16 | 10.1.31 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | OK | | | normal | 4 | 10.1.31 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | normal | 4 | 10.1.31 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | OK | | | normal | 32 | 10.1.31 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | OK | | | normal | 32 | 10.1.31 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | normal | 64 | 10.1.31 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | normal | 64 | 10.1.31 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | OK | | | normal | 8 | 10.1.31 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | normal | 8 | 10.1.31 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | OK | | | normal | 16 | 10.1.31 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | normal | 16 | 10.1.31 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | normal | 4 | 10.1.31 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | normal | 4 | 10.1.31 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | normal | 32 | 10.1.31 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | normal | 32 | 10.1.31 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | normal | 64 | 10.1.31 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | normal | 64 | 10.1.31 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | normal | 8 | 10.1.31 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | normal | 8 | 10.1.31 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 16 | 10.1.31 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 4 | 10.1.31 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 32 | 10.1.31 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 64 | 10.1.31 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 8 | 10.1.31 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 16 | 10.1.31 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 4 | 10.1.31 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 32 | 10.1.31 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 64 | 10.1.31 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 8 | 10.1.31 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 16 | 10.1.31 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 4 | 10.1.31 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 32 | 10.1.31 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 64 | 10.1.31 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 8 | 10.1.31 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 16 | 10.1.31 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 4 | 10.1.31 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 32 | 10.1.31 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 64 | 10.1.31 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 8 | 10.1.31 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | normal | 16 | 10.1.13 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | normal | 16 | 10.1.13 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | OK | | | normal | 4 | 10.1.13 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | normal | 4 | 10.1.13 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | OK | | | normal | 32 | 10.1.13 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | OK | | | normal | 32 | 10.1.13 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | normal | 64 | 10.1.13 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | normal | 64 | 10.1.13 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | OK | | | normal | 8 | 10.1.13 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | normal | 8 | 10.1.13 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | OK | | | normal | 16 | 10.1.10 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | normal | 16 | 10.1.10 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | normal | 4 | 10.1.10 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | normal | 4 | 10.1.10 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | normal | 32 | 10.1.10 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | normal | 32 | 10.1.10 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | normal | 64 | 10.1.10 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | normal | 64 | 10.1.10 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | normal | 8 | 10.1.10 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | normal | 8 | 10.1.10 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 16 | 10.1.22 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 4 | 10.1.22 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 32 | 10.1.22 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 64 | 10.1.22 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 8 | 10.1.22 (inbuilt) | Barracuda | on | - | => | 10.3.5 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 16 | 10.1.22 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 4 | 10.1.22 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 32 | 10.1.22 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 64 | 10.1.22 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 8 | 10.1.22 (inbuilt) | Barracuda | - | - | => | 10.3.5 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 16 | 10.1.22 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 4 | 10.1.22 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 32 | 10.1.22 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 64 | 10.1.22 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 8 | 10.1.22 (inbuilt) | Barracuda | on | zlib | => | 10.3.5 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 16 | 10.1.22 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 4 | 10.1.22 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 32 | 10.1.22 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 64 | 10.1.22 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 8 | 10.1.22 (inbuilt) | Barracuda | - | zlib | => | 10.3.5 (inbuilt) | Barracuda | - | zlib | - | OK | | | normal | 4 | 10.0.34 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | - | - | - | OK | | | normal | 8 | 10.0.34 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | - | - | - | OK | | | normal | 16 | 10.0.34 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | - | - | - | OK | | | normal | 16 | 10.0.34 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | on | - | - | OK | | | normal | 4 | 10.0.34 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | on | - | - | OK | | | normal | 8 | 10.0.34 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | on | - | - | OK | | | undo | 16 | 10.0.34 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | on | - | - | OK | | | undo | 4 | 10.0.34 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | on | - | - | OK | | | undo | 8 | 10.0.34 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | on | - | - | OK | | | undo | 16 | 10.0.34 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | - | - | - | OK | | | undo | 4 | 10.0.34 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | - | - | - | OK | | | undo | 8 | 10.0.34 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | - | - | - | OK | | | normal | 4 | 10.0.14 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | - | - | - | OK | | | normal | 8 | 10.0.14 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | - | - | - | OK | | | normal | 16 | 10.0.14 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | - | - | - | OK | | | normal | 16 | 10.0.14 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | on | - | - | OK | | | normal | 4 | 10.0.14 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | on | - | - | OK | | | normal | 8 | 10.0.14 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | on | - | - | OK | | | undo | 16 | 10.0.18 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | on | - | - | OK | | | undo | 4 | 10.0.18 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | on | - | - | OK | | | undo | 8 | 10.0.18 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | on | - | - | OK | | | undo | 16 | 10.0.18 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | - | - | - | **FAIL** | TEST\_FAILURE | | undo | 4 | 10.0.18 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | - | - | - | **FAIL** | TEST\_FAILURE | | undo | 8 | 10.0.18 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | - | - | - | **FAIL** | TEST\_FAILURE | | normal | 64 | 5.7.21 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | - | - | - | OK | | | normal | 8 | 5.7.21 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | - | - | - | OK | | | normal | 16 | 5.7.21 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | - | - | - | OK | | | normal | 32 | 5.7.21 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | - | - | - | OK | | | normal | 4 | 5.7.21 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | - | - | - | OK | | | normal | 4 | 5.7.21 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | on | - | - | OK | | | normal | 8 | 5.7.21 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | on | - | - | OK | | | normal | 16 | 5.7.21 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | on | - | - | OK | | | normal | 64 | 5.7.21 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | on | - | - | OK | | | normal | 32 | 5.7.21 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | on | - | - | OK | | | undo | 16 | 5.7.21 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | on | - | - | OK | | | undo | 4 | 5.7.21 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | on | - | - | OK | | | undo | 32 | 5.7.21 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | on | - | - | OK | | | undo | 64 | 5.7.21 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | on | - | - | OK | | | undo | 8 | 5.7.21 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | on | - | - | OK | | | undo | 16 | 5.7.21 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | - | - | - | OK | | | undo | 4 | 5.7.21 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | - | - | - | OK | | | undo | 32 | 5.7.21 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | - | - | - | OK | | | undo | 64 | 5.7.21 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | - | - | - | OK | | | undo | 8 | 5.7.21 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | - | - | - | OK | | | normal | 4 | 5.6.39 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | - | - | - | OK | | | normal | 8 | 5.6.39 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | - | - | - | OK | | | normal | 16 | 5.6.39 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | - | - | - | OK | | | normal | 16 | 5.6.39 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | on | - | - | OK | | | normal | 4 | 5.6.39 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | on | - | - | OK | | | normal | 8 | 5.6.39 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | on | - | - | OK | | | undo | 16 | 5.6.39 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | on | - | - | OK | | | undo | 4 | 5.6.39 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | on | - | - | **FAIL** | TEST\_FAILURE | | undo | 8 | 5.6.39 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | on | - | - | OK | | | undo | 16 | 5.6.39 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | - | - | - | **FAIL** | TEST\_FAILURE | | undo | 4 | 5.6.39 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | - | - | - | OK | | | undo | 8 | 5.6.39 (inbuilt) | | - | - | => | 10.3.5 (inbuilt) | | - | - | - | OK | | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb Replication and Binary Log Status Variables Replication and Binary Log Status Variables =========================================== The terms *master* and *slave* have historically been used in replication, but the terms terms *primary* and *replica* are now preferred. The old terms are used still used in parts of the documentation, and in MariaDB commands, although [MariaDB 10.5](../what-is-mariadb-105/index) has begun the process of renaming. The documentation process is ongoing. See [MDEV-18777](https://jira.mariadb.org/browse/MDEV-18777) to follow progress on this effort. The following status variables are useful in [binary logging](../binary-log/index) and [replication](../replication/index). See [Server Status Variables](../server-status-variables/index) for a complete list of status variables that can be viewed with [SHOW STATUS](../show-status/index). See also the [Full list of MariaDB options, system and status variables](../full-list-of-mariadb-options-system-and-status-variables/index). #### `Binlog_bytes_written` * **Description:** The number of bytes written to the [binary log](../binary-log/index). * **Scope:** Global * **Data Type:** `numeric` --- #### `Binlog_cache_disk_use` * **Description:** Number of transactions which used a temporary disk cache because they could not fit in the regular [binary log](../binary-log/index) cache, being larger than [binlog\_cache\_size](../server-system-variables/index#binlog_cache_size). The global value can be flushed by `[FLUSH STATUS](../flush/index)`. * **Scope:** Global * **Data Type:** `numeric` --- #### `Binlog_cache_use` * **Description:** Number of transaction which used the regular [binary log](../binary-log/index) cache, being smaller than [binlog\_cache\_size](../server-system-variables/index#binlog_cache_size). The global value can be flushed by `[FLUSH STATUS](../flush/index)`. * **Scope:** Global * **Data Type:** `numeric` --- #### `Binlog_commits` * **Description:** Total number of transactions committed to the binary log. * **Scope:** Global * **Data Type:** `numeric` --- #### `Binlog_group_commit_trigger_count` * **Description:** Total number of group commits triggered because of the number of binary log commits in the group reached the limit set by the variable [binlog\_commit\_wait\_count](../replication-and-binary-log-server-system-variables/index#binlog_commit_wait_count). See [Group commit for the binary log](../group-commit-for-the-binary-log/index). * **Scope:** Global * **Data Type:** `numeric` * **Introduced:** [MariaDB 10.1.5](https://mariadb.com/kb/en/mariadb-1015-release-notes/), [MariaDB 10.0.18](https://mariadb.com/kb/en/mariadb-10018-release-notes/) --- #### `Binlog_group_commit_trigger_lock_wait` * **Description:** Total number of group commits triggered because a binary log commit was being delayed because of a lock wait where the lock was held by a prior binary log commit. When this happens the later binary log commit is placed in the next group commit. See [Group commit for the binary log](../group-commit-for-the-binary-log/index). * **Scope:** Global * **Data Type:** `numeric` * **Introduced:** [MariaDB 10.1.5](https://mariadb.com/kb/en/mariadb-1015-release-notes/), [MariaDB 10.0.18](https://mariadb.com/kb/en/mariadb-10018-release-notes/) --- #### `Binlog_group_commit_trigger_timeout` * **Description:** Total number of group commits triggered because of the time since the first binary log commit reached the limit set by the variable [binlog\_commit\_wait\_usec](../replication-and-binary-log-server-system-variables/index#binlog_commit_wait_usec). See [Group commit for the binary log](../group-commit-for-the-binary-log/index). * **Scope:** Global * **Data Type:** `numeric` * **Introduced:** [MariaDB 10.1.5](https://mariadb.com/kb/en/mariadb-1015-release-notes/), [MariaDB 10.0.18](https://mariadb.com/kb/en/mariadb-10018-release-notes/) --- #### `Binlog_group_commits` * **Description:** Total number of group commits done to the binary log. See [Group commit for the binary log](../group-commit-for-the-binary-log/index). * **Scope:** Global * **Data Type:** `numeric` --- #### `Binlog_snapshot_file` * **Description:** The binary log file. Unlike [SHOW MASTER STATUS](../show-master-status/index), can be queried in a transactionally consistent way, irrespective of which other transactions have been committed since the snapshot was taken. See [Enhancements for START TRANSACTION WITH CONSISTENT SNAPSHOT](../enhancements-for-start-transaction-with-consistent-snapshot/index). * **Scope:** Global * **Data Type:** `string` --- #### `Binlog_snapshot_position` * **Description:** The binary log position. Unlike [SHOW MASTER STATUS](../show-master-status/index), can be queried in a transactionally consistent way, irrespective of which other transactions have been committed since the snapshot was taken. See [Enhancements for START TRANSACTION WITH CONSISTENT SNAPSHOT](../enhancements-for-start-transaction-with-consistent-snapshot/index). * **Scope:** Global * **Data Type:** `numeric` --- #### `Binlog_stmt_cache_disk_use` * **Description:** Number of non-transaction statements which used a temporary disk cache because they could not fit in the regular [binary log](../binary-log/index) cache, being larger than [binlog\_stmt\_cache\_size](../server-system-variables/index#binlog_stmt_cache_size). The global value can be flushed by `[FLUSH STATUS](../flush/index)`. * **Scope:** Global * **Data Type:** `numeric` --- #### `Binlog_stmt_cache_use` * **Description:** Number of non-transaction statement which used the regular [binary log](../binary-log/index) cache, being smaller than [binlog\_stmt\_cache\_size](../server-system-variables/index#binlog_stmt_cache_size). The global value can be flushed by `[FLUSH STATUS](../flush/index)`. * **Scope:** Global * **Data Type:** `numeric` --- #### `Com_change_master` * **Description:** Number of [CHANGE MASTER TO](../change-master-to/index) statements executed. * **Scope:** Global, Session * **Data Type:** `numeric` --- #### `Com_show_binlog_status` * **Description:** * **Scope:** Global, Session * **Data Type:** `numeric` * **Introduced:** [MariaDB 10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/) --- #### `Com_show_master_status` * **Description:** Number of [SHOW MASTER STATUS](../show-master-status/index) commands executed. * **Scope:** Global, Session * **Data Type:** `numeric` * **Removed:** [MariaDB 10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/) --- #### `Com_show_new_master` * **Description:** * **Scope:** Global, Session * **Data Type:** `numeric` * **Removed:** `[MariaDB 5.5](../what-is-mariadb-55/index)` --- #### `Com_show_slave_hosts` * **Description:** Number of [SHOW SLAVE HOSTS](../show-slave-hosts/index) commands executed. * **Scope:** Global, Session * **Data Type:** `numeric` --- #### `Com_show_slave_status` * **Description:** Number of [SHOW SLAVE STATUS](../show-slave-status/index) commands executed. * **Scope:** Global, Session * **Data Type:** `numeric` --- #### `Com_slave_start` * **Description:** Number of [START SLAVE](../start-slave/index) commands executed. Removed in [MariaDB 10.0](../what-is-mariadb-100/index), see [Com\_start\_slave](#com_start_slave). * **Scope:** Global, Session * **Data Type:** `numeric` * **Removed:** `[MariaDB 10.0](../what-is-mariadb-100/index)` --- #### `Com_slave_stop` * **Description:** Number of [STOP SLAVE](../stop-slave/index) commands executed. Removed in [MariaDB 10.0](../what-is-mariadb-100/index), see [Com\_stop\_slave](#com_stop_slave). * **Scope:** Global, Session * **Data Type:** `numeric` * **Removed:** `[MariaDB 10.0](../what-is-mariadb-100/index)` --- #### `Com_start_all_slaves` * **Description:** Number of [START ALL SLAVES](../start-slave/index) commands executed. * **Scope:** Global, Session * **Data Type:** `numeric` * **Introduced:** [MariaDB 10.0.0](https://mariadb.com/kb/en/mariadb-1000-release-notes/) --- #### `Com_start_slave` * **Description:** Number of [START SLAVE](../start-slave/index) commands executed. Replaces the old [Com\_slave\_start](#com_slave_start). * **Scope:** Global, Session * **Data Type:** `numeric` * **Introduced:** [MariaDB 10.0.0](https://mariadb.com/kb/en/mariadb-1000-release-notes/) --- #### `Com_stop_all_slaves` * **Description:** Number of [STOP ALL SLAVES](../stop-slave/index) commands executed. * **Scope:** Global, Session * **Data Type:** `numeric` * **Introduced:** [MariaDB 10.0.0](https://mariadb.com/kb/en/mariadb-1000-release-notes/) --- #### `Com_stop_slave` * **Description:** Number of [STOP SLAVE](../stop-slave/index) commands executed. Replaces the old [Com\_slave\_stop](#com_slave_stop). * **Scope:** Global, Session * **Data Type:** `numeric` * **Introduced:** [MariaDB 10.0.0](https://mariadb.com/kb/en/mariadb-1000-release-notes/) --- #### `Master_gtid_wait_count` * **Description:** Number of times MASTER\_GTID\_WAIT called. * **Scope:** Global, Session * **Data Type:** `numeric` * **Introduced:** [MariaDB 10.1.4](https://mariadb.com/kb/en/mariadb-1014-release-notes/) --- #### `Master_gtid_wait_time` * **Description:** Total number of time spent in MASTER\_GTID\_WAIT. * **Scope:** Global, Session * **Data Type:** `numeric` * **Introduced:** [MariaDB 10.1.4](https://mariadb.com/kb/en/mariadb-1014-release-notes/) --- #### `Master_gtid_wait_timeouts` * **Description:** Number of timeouts occurring in MASTER\_GTID\_WAIT. * **Scope:** Global, Session * **Data Type:** `numeric` * **Introduced:** [MariaDB 10.1.4](https://mariadb.com/kb/en/mariadb-1014-release-notes/) --- #### `Rpl_status` * **Description:** For showing the status of fail-safe replication. Removed in MySQL 5.6, still present in [MariaDB 10.0](../what-is-mariadb-100/index). --- #### `Rpl_transactions_multi_engine` * **Description:** Number of replicated transactions that involved changes in multiple (transactional) storage engines, before considering the update of `mysql.gtid_slave_pos`. These are transactions that were already cross-engine, independent of the GTID position update introduced by replication. The global value can be flushed by `[FLUSH STATUS](../flush/index)`. * **Scope:** Global * **Data Type:** `numeric` * **Introduced:** [MariaDB 10.3.1](https://mariadb.com/kb/en/mariadb-1031-release-notes/) --- #### `Slave_connections` * **Description:** Number of REGISTER\_SLAVE attempts. In practice the number of times slaves has tried to connect to the master. * **Scope:** Global * **Data Type:** `numeric` * **Introduced:** [MariaDB 10.1.11](https://mariadb.com/kb/en/mariadb-10111-release-notes/) --- #### `Slave_heartbeat_period` * **Description:** Time in seconds that a heartbeat packet is requested from the master by a slave. * **Scope:** Global * **Data Type:** `numeric` --- #### `Slave_open_temp_tables` * **Description:** Number of temporary tables the slave has open. * **Scope:** Global * **Data Type:** `numeric` --- #### `Slave_received_heartbeats` * **Description:** Number of heartbeats the slave has received from the master. * **Scope:** Global * **Data Type:** `numeric` --- #### `Slave_retried_transactions` * **Description:** Number of times the slave has retried transactions since the server started. The global value can be flushed by `[FLUSH STATUS](../flush/index)`. * **Scope:** Global * **Data Type:** `numeric` --- #### `Slave_running` * **Description:** Whether the slave is running (both I/O and SQL threads running) or not. * **Scope:** Global * **Data Type:** `numeric` --- #### `Slave_skipped_errors` * **Description:** The number of times a slave has skipped errors defined by [slave-skip-errors](../replication-and-binary-log-server-system-variables/index#slave_skip_errors). * **Scope:** Global * **Data Type:** `numeric` * **Introduced:** [MariaDB 10.0.18](https://mariadb.com/kb/en/mariadb-10018-release-notes/) --- #### `Slaves_connected` * **Description:** Number of slaves connected. * **Scope:** Global * **Data Type:** `numeric` * **Introduced:** [MariaDB 10.1.11](https://mariadb.com/kb/en/mariadb-10111-release-notes/) --- #### `Slaves_running` * **Description:** Number of slave SQL threads running. * **Scope:** Global * **Data Type:** `numeric` * **Introduced:** [MariaDB 10.1.11](https://mariadb.com/kb/en/mariadb-10111-release-notes/) --- #### `Transactions_gtid_foreign_engine` * **Description:** Number of replicated transactions where the update of the `gtid_slave_pos` table had to choose a storage engine that did not otherwise participate in the transaction. This can indicate that setting [gtid\_pos\_auto\_engines](../global-transaction-id/index#gtid_pos_auto_engines) might be useful. The global value can be flushed by `[FLUSH STATUS](../flush/index)`. * **Scope:** Global * **Data Type:** `numeric` * **Introduced:** [MariaDB 10.3.1](https://mariadb.com/kb/en/mariadb-1031-release-notes/) --- #### `Transactions_multi_engine` * **Description:** Number of transactions that changed data in multiple (transactional) storage engines. If this is significantly larger than [Rpl\_transactions\_multi\_engine](#rpl_transactions_multi_engine), it indicates that setting <gtid_pos_auto_engines> could reduce the need for cross-engine transactions. The global value can be flushed by `[FLUSH STATUS](../flush/index)`. * **Scope:** Global * **Data Type:** `numeric` * **Introduced:** [MariaDB 10.3.1](https://mariadb.com/kb/en/mariadb-1031-release-notes/) --- Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Joins Joins ====== Articles about joins in MariaDB. | Title | Description | | --- | --- | | [Joining Tables with JOIN Clauses](../joining-tables-with-join-clauses/index) | An introductory tutorial on using the JOIN clause. | | [More Advanced Joins](../more-advanced-joins/index) | A more advanced tutorial on JOINs. | | [JOIN Syntax](../join-syntax/index) | Description MariaDB supports the following JOIN syntaxes for the table\_refe... | | [Comma vs JOIN](../comma-vs-join/index) | A query to grab the list of phone numbers for clients who ordered in the la... | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Scalar Subqueries Scalar Subqueries ================= A scalar subquery is a [subquery](../subqueries/index) that returns a single value. This is the simplest form of a subquery, and can be used in most places a literal or single column value is valid. The data type, length and [character set and collation](../data-types-character-sets-and-collations/index) are all taken from the result returned by the subquery. The result of a subquery can always be NULL, that is, no result returned. Even if the original value is defined as NOT NULL, this is disregarded. A subquery cannot be used where only a literal is expected, for example [LOAD DATA INFILE](../load-data-infile/index) expects a literal string containing the file name, and LIMIT requires a literal integer. Examples -------- ``` CREATE TABLE sq1 (num TINYINT); CREATE TABLE sq2 (num TINYINT); INSERT INTO sq1 VALUES (1); INSERT INTO sq2 VALUES (10* (SELECT num FROM sq1)); SELECT * FROM sq2; +------+ | num | +------+ | 10 | +------+ ``` Inserting a second row means the subquery is no longer a scalar, and this particular query is not valid: ``` INSERT INTO sq1 VALUES (2); INSERT INTO sq2 VALUES (10* (SELECT num FROM sq1)); ERROR 1242 (21000): Subquery returns more than 1 row ``` No rows in the subquery, so the scalar is NULL: ``` INSERT INTO sq2 VALUES (10* (SELECT num FROM sq3 WHERE num='3')); SELECT * FROM sq2; +------+ | num | +------+ | 10 | | NULL | +------+ ``` A more traditional scalar subquery, as part of a WHERE clause: ``` SELECT * FROM sq1 WHERE num = (SELECT MAX(num)/10 FROM sq2); +------+ | num | +------+ | 1 | +------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb MariaDB Error Codes MariaDB Error Codes =================== MariaDB shares error codes with MySQL, as well as adding a number of new error codes specific to MariaDB. An example of an error code is as follows: ``` SELECT * FROM x; ERROR 1046 (3D000): No database selected ``` There are three pieces of information returned in an error: * A numeric error code, in this case `1046`. Error codes from 1900 and up are specific to MariaDB, while error codes from 1000 to 1800 are shared by MySQL and MariaDB. * An [SQLSTATE](../sqlstate/index) value, consisting of five characters, in this case `3D000`. These codes are standard to ODBC and ANSI SQL. When MariaDB cannot allocate a standard SQLSTATE code, a generic `HY000`, or general error, is used. * A string describing the error, in this case `No database selected`. New error codes are being continually being added as new features are added. For a definitive list, see the file `sql/share/errmsg-utf8.txt`, as well as `include/mysqld_error.h` in the build directory, generated by the `comp_err` tool. Also, the [perror](../perror/index) tool can be used to get the error message which is associated with a given error code. Shared MariaDB/MySQL error codes -------------------------------- | Error Code | SQLSTATE | Error | Description | | --- | --- | --- | --- | | 1000 | HY000 | ER\_HASHCHK | hashchk | | 1001 | HY000 | ER\_NISAMCHK | isamchk | | 1002 | HY000 | ER\_NO | NO | | 1003 | HY000 | ER\_YES | YES | | 1004 | HY000 | ER\_CANT\_CREATE\_FILE | Can't create file '%s' (errno: %d) | | 1005 | HY000 | ER\_CANT\_CREATE\_TABLE | Can't create table '%s' (errno: %d) | | 1006 | HY000 | ER\_CANT\_CREATE\_DB | Can't create database '%s' (errno: %d | | 1007 | HY000 | ER\_DB\_CREATE\_EXISTS | Can't create database '%s'; database exists | | 1008 | HY000 | ER\_DB\_DROP\_EXISTS | Can't drop database '%s'; database doesn't exist | | 1009 | HY000 | ER\_DB\_DROP\_DELETE | Error dropping database (can't delete '%s', errno: %d) | | 1010 | HY000 | ER\_DB\_DROP\_RMDIR | Error dropping database (can't rmdir '%s', errno: %d) | | 1011 | HY000 | ER\_CANT\_DELETE\_FILE | Error on delete of '%s' (errno: %d) | | 1012 | HY000 | ER\_CANT\_FIND\_SYSTEM\_REC | Can't read record in system table | | 1013 | HY000 | ER\_CANT\_GET\_STAT | Can't get status of '%s' (errno: %d) | | 1014 | HY000 | ER\_CANT\_GET\_WD | Can't get working directory (errno: %d) | | 1015 | HY000 | ER\_CANT\_LOCK | Can't lock file (errno: %d) | | 1016 | HY000 | ER\_CANT\_OPEN\_FILE | Can't open file: '%s' (errno: %d) | | 1017 | HY000 | ER\_FILE\_NOT\_FOUND | Can't find file: '%s' (errno: %d) | | 1018 | HY000 | ER\_CANT\_READ\_DIR | Can't read dir of '%s' (errno: %d) | | 1019 | HY000 | ER\_CANT\_SET\_WD | Can't change dir to '%s' (errno: %d) | | 1020 | HY000 | ER\_CHECKREAD | Record has changed since last read in table '%s' | | 1021 | HY000 | ER\_DISK\_FULL | Disk full (%s); waiting for someone to free some space... | | 1022 | 23000 | ER\_DUP\_KEY | Can't write; duplicate key in table '%s' | | 1023 | HY000 | ER\_ERROR\_ON\_CLOSE | Error on close of '%s' (errno: %d) | | 1024 | HY000 | ER\_ERROR\_ON\_READ | Error reading file '%s' (errno: %d) | | 1025 | HY000 | ER\_ERROR\_ON\_RENAME | Error on rename of '%s' to '%s' (errno: %d) | | 1026 | HY000 | ER\_ERROR\_ON\_WRITE | Error writing file '%s' (errno: %d) | | 1027 | HY000 | ER\_FILE\_USED | '%s' is locked against change | | 1028 | HY000 | ER\_FILSORT\_ABORT | Sort aborted | | 1029 | HY000 | ER\_FORM\_NOT\_FOUND | View '%s' doesn't exist for '%s' | | 1030 | HY000 | ER\_GET\_ERRN | Got error %d from storage engine | | 1031 | HY000 | ER\_ILLEGAL\_HA | Table storage engine for '%s' doesn't have this option | | 1032 | HY000 | ER\_KEY\_NOT\_FOUND | Can't find record in '%s' | | 1033 | HY000 | ER\_NOT\_FORM\_FILE | Incorrect information in file: '%s' | | 1034 | HY000 | ER\_NOT\_KEYFILE | Incorrect key file for table '%s'; try to repair it | | 1035 | HY000 | ER\_OLD\_KEYFILE | Old key file for table '%s'; repair it! | | 1036 | HY000 | ER\_OPEN\_AS\_READONLY | Table '%s' is read only | | 1037 | HY001 | ER\_OUTOFMEMORY | Out of memory; restart server and try again (needed %d bytes) | | 1038 | HY001 | ER\_OUT\_OF\_SORTMEMORY | Out of sort memory, consider increasing server sort buffer size | | 1039 | HY000 | ER\_UNEXPECTED\_EOF | Unexpected EOF found when reading file '%s' (Errno: %d) | | 1040 | 08004 | ER\_CON\_COUNT\_ERROR | Too many connections | | 1041 | HY000 | ER\_OUT\_OF\_RESOURCES | Out of memory; check if mysqld or some other process uses all available memory; if not, you may have to use 'ulimit' to allow mysqld to use more memory or you can add more swap space | | 1042 | 08S01 | ER\_BAD\_HOST\_ERROR | Can't get hostname for your address | | 1043 | 08S01 | ER\_HANDSHAKE\_ERROR | Bad handshake | | 1044 | 42000 | ER\_DBACCESS\_DENIED\_ERROR | Access denied for user '%s'@'%s' to database '%s' | | 1045 | 28000 | ER\_ACCESS\_DENIED\_ERROR | Access denied for user '%s'@'%s' (using password: %s) | | 1046 | 3D000 | ER\_NO\_DB\_ERROR | No database selected | | 1047 | 08S01 | ER\_UNKNOWN\_COM\_ERROR | Unknown command | | 1048 | 23000 | ER\_BAD\_NULL\_ERROR | Column '%s' cannot be null | | 1049 | 42000 | ER\_BAD\_DB\_ERROR | Unknown database '%s' | | 1050 | 42S01 | ER\_TABLE\_EXISTS\_ERROR | Table '%s' already exists | | 1051 | 42S02 | ER\_BAD\_TABLE\_ERROR | Unknown table '%s' | | 1052 | 23000 | ER\_NON\_UNIQ\_ERROR | Column '%s' in %s is ambiguous | | 1053 | 08S01 | ER\_SERVER\_SHUTDOWN | Server shutdown in progress | | 1054 | 42S22 | ER\_BAD\_FIELD\_ERROR | Unknown column '%s' in '%s' | | 1055 | 42000 | ER\_WRONG\_FIELD\_WITH\_GROUP | '%s' isn't in GROUP BY | | 1056 | 42000 | ER\_WRONG\_GROUP\_FIELD | Can't group on '%s' | | 1057 | 42000 | ER\_WRONG\_SUM\_SELECT | Statement has sum functions and columns in same statement | | 1058 | 21S01 | ER\_WRONG\_VALUE\_COUNT | Column count doesn't match value count | | 1059 | 42000 | ER\_TOO\_LONG\_IDENT | Identifier name '%s' is too long | | 1060 | 42S21 | ER\_DUP\_FIELDNAME | Duplicate column name '%s' | | 1061 | 42000 | ER\_DUP\_KEYNAME | Duplicate key name '%s' | | 1062 | 23000 | ER\_DUP\_ENTRY | Duplicate entry '%s' for key %d | | 1063 | 42000 | ER\_WRONG\_FIELD\_SPEC | Incorrect column specifier for column '%s' | | 1064 | 42000 | ER\_PARSE\_ERROR | %s near '%s' at line %d | | 1065 | 42000 | ER\_EMPTY\_QUERY | Query was empty | | 1066 | 42000 | ER\_NONUNIQ\_TABLE | Not unique table/alias: '%s' | | 1067 | 42000 | ER\_INVALID\_DEFAULT | Invalid default value for '%s' | | 1068 | 42000 | ER\_MULTIPLE\_PRI\_KEY | Multiple primary key defined | | 1069 | 42000 | ER\_TOO\_MANY\_KEYS | Too many keys specified; max %d keys allowed | | 1070 | 42000 | ER\_TOO\_MANY\_KEY\_PARTS | Too many key parts specified; max %d parts allowed | | 1071 | 42000 | ER\_TOO\_LONG\_KEY | Specified key was too long; max key length is %d bytes | | 1072 | 42000 | ER\_KEY\_COLUMN\_DOES\_NOT\_EXITS | Key column '%s' doesn't exist in table | | 1073 | 42000 | ER\_BLOB\_USED\_AS\_KEY | BLOB column '%s' can't be used in key specification with the used table type | | 1074 | 42000 | ER\_TOO\_BIG\_FIELDLENGTH | Column length too big for column '%s' (max = %lu); use BLOB or TEXT instead | | 1075 | 42000 | ER\_WRONG\_AUTO\_KEY | Incorrect table definition; there can be only one auto column and it must be defined as a key | | 1076 | HY000 | ER\_READY | %s: ready for connections. Version: '%s' socket: '%s' port: %d | | 1077 | HY000 | ER\_NORMAL\_SHUTDOWN | %s: Normal shutdown | | 1078 | HY000 | ER\_GOT\_SIGNAL | %s: Got signal %d. Aborting! | | 1079 | HY000 | ER\_SHUTDOWN\_COMPLETE | %s: Shutdown complete | | 1080 | 08S01 | ER\_FORCING\_CLOSE | %s: Forcing close of thread %ld user: '%s' | | 1081 | 08S01 | ER\_IPSOCK\_ERROR | Can't create IP socket | | 1082 | 42S12 | ER\_NO\_SUCH\_INDEX | Table '%s' has no index like the one used in CREATE INDEX; recreate the table | | 1083 | 42000 | ER\_WRONG\_FIELD\_TERMINATORS | Field separator argument is not what is expected; check the manual | | 1084 | 42000 | ER\_BLOBS\_AND\_NO\_TERMINATED | You can't use fixed rowlength with BLOBs; please use 'fields terminated by' | | 1085 | HY000 | ER\_TEXTFILE\_NOT\_READABLE | The file '%s' must be in the database directory or be readable by all | | 1086 | HY000 | ER\_FILE\_EXISTS\_ERROR | File '%s' already exists | | 1087 | HY000 | ER\_LOAD\_INF | Records: %ld Deleted: %ld Skipped: %ld Warnings: %ld | | 1088 | HY000 | ER\_ALTER\_INF | Records: %ld Duplicates: %ld | | 1089 | HY000 | ER\_WRONG\_SUB\_KEY | Incorrect prefix key; the used key part isn't a string, the used length is longer than the key part, or the storage engine doesn't support unique prefix keys | | 1090 | 42000 | ER\_CANT\_REMOVE\_ALL\_FIELDS | You can't delete all columns with ALTER TABLE; use DROP TABLE instead | | 1091 | 42000 | ER\_CANT\_DROP\_FIELD\_OR\_KEY | Can't DROP '%s'; check that column/key exists | | 1092 | HY000 | ER\_INSERT\_INF | Records: %ld Duplicates: %ld Warnings: %ld | | 1093 | HY000 | ER\_UPDATE\_TABLE\_USED | You can't specify target table '%s' for update in FROM clause | | 1094 | HY000 | ER\_NO\_SUCH\_THREAD | Unknown thread id: %lu | | 1095 | HY000 | ER\_KILL\_DENIED\_ERROR | You are not owner of thread %lu | | 1096 | HY000 | ER\_NO\_TABLES\_USED | No tables used | | 1097 | HY000 | ER\_TOO\_BIG\_SET | Too many strings for column %s and SET | | 1098 | HY000 | ER\_NO\_UNIQUE\_LOGFILE | Can't generate a unique log-filename %s.(1-999) | | 1099 | HY000 | ER\_TABLE\_NOT\_LOCKED\_FOR\_WRITE | Table '%s' was locked with a READ lock and can't be updated | | Error Code | SQLSTATE | Error | Description | | --- | --- | --- | --- | | 1100 | HY000 | ER\_TABLE\_NOT\_LOCKED | Table '%s' was not locked with LOCK TABLES | | 1101 | | ER\_UNUSED\_17 | You should never see it | | 1102 | 42000 | ER\_WRONG\_DB\_NAME | Incorrect database name '%s' | | 1103 | 42000 | ER\_WRONG\_TABLE\_NAME | Incorrect table name '%s' | | 1104 | 42000 | ER\_TOO\_BIG\_SELECT | The SELECT would examine more than MAX\_JOIN\_SIZE rows; check your WHERE and use SET SQL\_BIG\_SELECTS=1 or SET MAX\_JOIN\_SIZE=# if the SELECT is okay | | 1105 | HY000 | ER\_UNKNOWN\_ERROR | Unknown error | | 1106 | 42000 | ER\_UNKNOWN\_PROCEDURE | Unknown procedure '%s' | | 1107 | 42000 | ER\_WRONG\_PARAMCOUNT\_TO\_PROCEDURE | Incorrect parameter count to procedure '%s' | | 1108 | HY000 | ER\_WRONG\_PARAMETERS\_TO\_PROCEDURE | Incorrect parameters to procedure '%s' | | 1109 | 42S02 | ER\_UNKNOWN\_TABLE | Unknown table '%s' in %s | | 1110 | 42000 | ER\_FIELD\_SPECIFIED\_TWICE | Column '%s' specified twice | | 1111 | HY000 | ER\_INVALID\_GROUP\_FUNC\_USE | Invalid use of group function | | 1112 | 42000 | ER\_UNSUPPORTED\_EXTENSION | Table '%s' uses an extension that doesn't exist in this MariaDB version | | 1113 | 42000 | ER\_TABLE\_MUST\_HAVE\_COLUMNS | A table must have at least 1 column | | 1114 | HY000 | ER\_RECORD\_FILE\_FULL | The table '%s' is full | | 1115 | 42000 | ER\_UNKNOWN\_CHARACTER\_SET | Unknown character set: '%s' | | 1116 | HY000 | ER\_TOO\_MANY\_TABLES | Too many tables; MariaDB can only use %d tables in a join | | 1117 | HY000 | ER\_TOO\_MANY\_FIELDS | Too many columns | | 1118 | 42000 | ER\_TOO\_BIG\_ROWSIZE | Row size too large. The maximum row size for the used table type, not counting BLOBs, is %ld. You have to change some columns to TEXT or BLOBs | | 1119 | HY000 | ER\_STACK\_OVERRUN | Thread stack overrun: Used: %ld of a %ld stack. Use 'mysqld --thread\_stack=#' to specify a bigger stack if needed | | 1120 | 42000 | ER\_WRONG\_OUTER\_JOIN | Cross dependency found in OUTER JOIN; examine your ON conditions | | 1121 | 42000 | ER\_NULL\_COLUMN\_IN\_INDEX | Table handler doesn't support NULL in given index. Please change column '%s' to be NOT NULL or use another handler | | 1122 | HY000 | ER\_CANT\_FIND\_UDF | Can't load function '%s' | | 1123 | HY000 | ER\_CANT\_INITIALIZE\_UDF | Can't initialize function '%s'; %s | | 1124 | HY000 | ER\_UDF\_NO\_PATHS | No paths allowed for shared library | | 1125 | HY000 | ER\_UDF\_EXISTS | Function '%s' already exists | | 1126 | HY000 | ER\_CANT\_OPEN\_LIBRARY | Can't open shared library '%s' (Errno: %d %s) | | 1127 | HY000 | ER\_CANT\_FIND\_DL\_ENTRY | Can't find symbol '%s' in library | | 1128 | HY000 | ER\_FUNCTION\_NOT\_DEFINED | Function '%s' is not defined | | 1129 | HY000 | ER\_HOST\_IS\_BLOCKED | Host '%s' is blocked because of many connection errors; unblock with 'mysqladmin flush-hosts' | | 1130 | HY000 | ER\_HOST\_NOT\_PRIVILEGED | Host '%s' is not allowed to connect to this MariaDB server | | 1131 | 42000 | ER\_PASSWORD\_ANONYMOUS\_USER | You are using MariaDB as an anonymous user and anonymous users are not allowed to change passwords | | 1132 | 42000 | ER\_PASSWORD\_NOT\_ALLOWED | You must have privileges to update tables in the mysql database to be able to change passwords for others | | 1133 | 42000 | ER\_PASSWORD\_NO\_MATCH | Can't find any matching row in the user table | | 1134 | HY000 | ER\_UPDATE\_INF | Rows matched: %ld Changed: %ld Warnings: %ld | | 1135 | HY000 | ER\_CANT\_CREATE\_THREAD | Can't create a new thread (Errno %d); if you are not out of available memory, you can consult the manual for a possible OS-dependent bug | | 1136 | 21S01 | ER\_WRONG\_VALUE\_COUNT\_ON\_ROW | Column count doesn't match value count at row %ld | | 1137 | HY000 | ER\_CANT\_REOPEN\_TABLE | Can't reopen table: '%s' | | 1138 | 22004 | ER\_INVALID\_USE\_OF\_NULL | Invalid use of NULL value | | 1139 | 42000 | ER\_REGEXP\_ERROR | Got error '%s' from regexp | | 1140 | 42000 | ER\_MIX\_OF\_GROUP\_FUNC\_AND\_FIELDS | Mixing of GROUP columns (MIN(),MAX(),COUNT(),...) with no GROUP columns is illegal if there is no GROUP BY clause | | 1141 | 42000 | ER\_NONEXISTING\_GRANT | There is no such grant defined for user '%s' on host '%s' | | 1142 | 42000 | ER\_TABLEACCESS\_DENIED\_ERROR | %s command denied to user '%s'@'%s' for table '%s' | | 1143 | 42000 | ER\_COLUMNACCESS\_DENIED\_ERROR | %s command denied to user '%s'@'%s' for column '%s' in table '%s' | | 1144 | 42000 | ER\_ILLEGAL\_GRANT\_FOR\_TABLE | Illegal GRANT/REVOKE command; please consult the manual to see which privileges can be used | | 1145 | 42000 | ER\_GRANT\_WRONG\_HOST\_OR\_USER | The host or user argument to GRANT is too long | | 1146 | 42S02 | ER\_NO\_SUCH\_TABLE | Table '%s.%s' doesn't exist | | 1147 | 42000 | ER\_NONEXISTING\_TABLE\_GRANT | There is no such grant defined for user '%s' on host '%s' on table '%s' | | 1148 | 42000 | ER\_NOT\_ALLOWED\_COMMAND | The used command is not allowed with this MariaDB version | | 1149 | 42000 | ER\_SYNTAX\_ERROR | You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use | | 1150 | HY000 | ER\_DELAYED\_CANT\_CHANGE\_LOCK | Delayed insert thread couldn't get requested lock for table %s | | 1151 | HY000 | ER\_TOO\_MANY\_DELAYED\_THREADS | Too many delayed threads in use | | 1152 | 08S01 | ER\_ABORTING\_CONNECTION | Aborted connection %ld to db: '%s' user: '%s' (%s) | | 1153 | 08S01 | ER\_NET\_PACKET\_TOO\_LARGE | Got a packet bigger than 'max\_allowed\_packet' bytes | | 1154 | 08S01 | ER\_NET\_READ\_ERROR\_FROM\_PIPE | Got a read error from the connection pipe | | 1155 | 08S01 | ER\_NET\_FCNTL\_ERROR | Got an error from fcntl() | | 1156 | 08S01 | ER\_NET\_PACKETS\_OUT\_OF\_ORDER | Got packets out of order | | 1157 | 08S01 | ER\_NET\_UNCOMPRESS\_ERROR | Couldn't uncompress communication packet | | 1158 | 08S01 | ER\_NET\_READ\_ERROR | Got an error reading communication packets | | 1159 | 08S01 | ER\_NET\_READ\_INTERRUPTED | Got timeout reading communication packets | | 1160 | 08S01 | ER\_NET\_ERROR\_ON\_WRITE | Got an error writing communication packets | | 1161 | 08S01 | ER\_NET\_WRITE\_INTERRUPTED | Got timeout writing communication packets | | 1162 | 42000 | ER\_TOO\_LONG\_STRING | Result string is longer than 'max\_allowed\_packet' bytes | | 1163 | 42000 | ER\_TABLE\_CANT\_HANDLE\_BLOB | The used table type doesn't support BLOB/TEXT columns | | 1164 | 42000 | ER\_TABLE\_CANT\_HANDLE\_AUTO\_INCREMENT | The used table type doesn't support AUTO\_INCREMENT columns | | 1165 | HY000 | ER\_DELAYED\_INSERT\_TABLE\_LOCKED | INSERT DELAYED can't be used with table '%s' because it is locked with LOCK TABLES | | 1166 | 42000 | ER\_WRONG\_COLUMN\_NAME | Incorrect column name '%s' | | 1167 | 42000 | ER\_WRONG\_KEY\_COLUMN | The used storage engine can't index column '%s' | | 1168 | HY000 | ER\_WRONG\_MRG\_TABLE | Unable to open underlying table which is differently defined or of non-MyISAM type or doesn't exist | | 1169 | 23000 | ER\_DUP\_UNIQUE | Can't write, because of unique constraint, to table '%s' | | 1170 | 42000 | ER\_BLOB\_KEY\_WITHOUT\_LENGTH | BLOB/TEXT column '%s' used in key specification without a key length | | 1171 | 42000 | ER\_PRIMARY\_CANT\_HAVE\_NULL | All parts of a PRIMARY KEY must be NOT NULL; if you need NULL in a key, use UNIQUE instead | | 1172 | 42000 | ER\_TOO\_MANY\_ROWS | Result consisted of more than one row | | 1173 | 42000 | ER\_REQUIRES\_PRIMARY\_KEY | This table type requires a primary key | | 1174 | HY000 | ER\_NO\_RAID\_COMPILED | This version of MariaDB is not compiled with RAID support | | 1175 | HY000 | ER\_UPDATE\_WITHOUT\_KEY\_IN\_SAFE\_MODE | You are using safe update mode and you tried to update a table without a WHERE that uses a KEY column | | 1176 | 42000 | ER\_KEY\_DOES\_NOT\_EXITS | Key '%s' doesn't exist in table '%s' | | 1177 | 42000 | ER\_CHECK\_NO\_SUCH\_TABLE | Can't open table | | 1178 | 42000 | ER\_CHECK\_NOT\_IMPLEMENTED | The storage engine for the table doesn't support %s | | 1179 | 25000 | ER\_CANT\_DO\_THIS\_DURING\_AN\_TRANSACTION | You are not allowed to execute this command in a transaction | | 1180 | HY000 | ER\_ERROR\_DURING\_COMMIT | Got error %d during COMMIT | | 1181 | HY000 | ER\_ERROR\_DURING\_ROLLBACK | Got error %d during ROLLBACK | | 1182 | HY000 | ER\_ERROR\_DURING\_FLUSH\_LOGS | Got error %d during FLUSH\_LOGS | | 1183 | HY000 | ER\_ERROR\_DURING\_CHECKPOINT | Got error %d during CHECKPOINT | | 1184 | 08S01 | ER\_NEW\_ABORTING\_CONNECTION | Aborted connection %ld to db: '%s' user: '%s' host: '%s' (%s) | | 1185 | | ER\_UNUSED\_10 | You should never see it | | 1186 | HY000 | ER\_FLUSH\_MASTER\_BINLOG\_CLOSED | Binlog closed, cannot RESET MASTER | | 1187 | HY000 | ER\_INDEX\_REBUILD | Failed rebuilding the index of dumped table '%s' | | 1188 | HY000 | ER\_MASTER | Error from master: '%s' | | 1189 | 08S01 | ER\_MASTER\_NET\_READ | Net error reading from master | | 1190 | 08S01 | ER\_MASTER\_NET\_WRITE | Net error writing to master | | 1191 | HY000 | ER\_FT\_MATCHING\_KEY\_NOT\_FOUND | Can't find FULLTEXT index matching the column list | | 1192 | HY000 | ER\_LOCK\_OR\_ACTIVE\_TRANSACTION | Can't execute the given command because you have active locked tables or an active transaction | | 1193 | HY000 | ER\_UNKNOWN\_SYSTEM\_VARIABLE | Unknown system variable '%s' | | 1194 | HY000 | ER\_CRASHED\_ON\_USAGE | Table '%s' is marked as crashed and should be repaired | | 1195 | HY000 | ER\_CRASHED\_ON\_REPAIR | Table '%s' is marked as crashed and last (automatic?) repair failed | | 1196 | HY000 | ER\_WARNING\_NOT\_COMPLETE\_ROLLBACK | Some non-transactional changed tables couldn't be rolled back | | 1197 | HY000 | ER\_TRANS\_CACHE\_FULL | Multi-statement transaction required more than 'max\_binlog\_cache\_size' bytes of storage; increase this mysqld variable and try again | | 1198 | HY000 | ER\_SLAVE\_MUST\_STOP | This operation cannot be performed with a running slave; run STOP SLAVE first | | 1199 | HY000 | ER\_SLAVE\_NOT\_RUNNING | This operation requires a running slave; configure slave and do START SLAVE | | Error Code | SQLSTATE | Error | Description | | --- | --- | --- | --- | | 1200 | HY000 | ER\_BAD\_SLAVE | The server is not configured as slave; fix in config file or with CHANGE MASTER TO | | 1201 | HY000 | ER\_MASTER\_INFO | Could not initialize master info structure; more error messages can be found in the MariaDB error log | | 1202 | HY000 | ER\_SLAVE\_THREAD | Could not create slave thread; check system resources | | 1203 | 42000 | ER\_TOO\_MANY\_USER\_CONNECTIONS | User %s already has more than 'max\_user\_connections' active connections | | 1204 | HY000 | ER\_SET\_CONSTANTS\_ONLY | You may only use constant expressions with SET | | 1205 | HY000 | ER\_LOCK\_WAIT\_TIMEOUT | Lock wait timeout exceeded; try restarting transaction | | 1206 | HY000 | ER\_LOCK\_TABLE\_FULL | The total number of locks exceeds the lock table size | | 1207 | 25000 | ER\_READ\_ONLY\_TRANSACTION | Update locks cannot be acquired during a READ UNCOMMITTED transaction | | 1208 | HY000 | ER\_DROP\_DB\_WITH\_READ\_LOCK | DROP DATABASE not allowed while thread is holding global read lock | | 1209 | HY000 | ER\_CREATE\_DB\_WITH\_READ\_LOCK | CREATE DATABASE not allowed while thread is holding global read lock | | 1210 | HY000 | ER\_WRONG\_ARGUMENTS | Incorrect arguments to %s | | 1211 | 42000 | ER\_NO\_PERMISSION\_TO\_CREATE\_USER | '%s'@'%s' is not allowed to create new users | | 1212 | HY000 | ER\_UNION\_TABLES\_IN\_DIFFERENT\_DIR | Incorrect table definition; all MERGE tables must be in the same database | | 1213 | 40001 | ER\_LOCK\_DEADLOCK | Deadlock found when trying to get lock; try restarting transaction | | 1214 | HY000 | ER\_TABLE\_CANT\_HANDLE\_FT | The used table type doesn't support FULLTEXT indexes | | 1215 | HY000 | ER\_CANNOT\_ADD\_FOREIGN | Cannot add foreign key constraint | | 1216 | 23000 | ER\_NO\_REFERENCED\_ROW | Cannot add or update a child row: a foreign key constraint fails | | 1217 | 23000 | ER\_ROW\_IS\_REFERENCED | Cannot delete or update a parent row: a foreign key constraint fails | | 1218 | 08S01 | ER\_CONNECT\_TO\_MASTER | Error connecting to master: %s | | 1219 | HY000 | ER\_QUERY\_ON\_MASTER | Error running query on master: %s | | 1220 | HY000 | ER\_ERROR\_WHEN\_EXECUTING\_COMMAND | Error when executing command %s: %s | | 1221 | HY000 | ER\_WRONG\_USAGE | Incorrect usage of %s and %s | | 1222 | 21000 | ER\_WRONG\_NUMBER\_OF\_COLUMNS\_IN\_SELECT | The used SELECT statements have a different number of columns | | 1223 | HY000 | ER\_CANT\_UPDATE\_WITH\_READLOCK | Can't execute the query because you have a conflicting read lock | | 1224 | HY000 | ER\_MIXING\_NOT\_ALLOWED | Mixing of transactional and non-transactional tables is disabled | | 1225 | HY000 | ER\_DUP\_ARGUMENT | Option '%s' used twice in statement | | 1226 | 42000 | ER\_USER\_LIMIT\_REACHED | User '%s' has exceeded the '%s' resource (current value: %ld) | | 1227 | 42000 | ER\_SPECIFIC\_ACCESS\_DENIED\_ERROR | Access denied; you need (at least one of) the %s privilege(s) for this operation | | 1228 | HY000 | ER\_LOCAL\_VARIABLE | Variable '%s' is a SESSION variable and can't be used with SET GLOBAL | | 1229 | HY000 | ER\_GLOBAL\_VARIABLE | Variable '%s' is a GLOBAL variable and should be set with SET GLOBAL | | 1230 | 42000 | ER\_NO\_DEFAULT | Variable '%s' doesn't have a default value | | 1231 | 42000 | ER\_WRONG\_VALUE\_FOR\_VAR | Variable '%s' can't be set to the value of '%s' | | 1232 | 42000 | ER\_WRONG\_TYPE\_FOR\_VAR | Incorrect argument type to variable '%s' | | 1233 | HY000 | ER\_VAR\_CANT\_BE\_READ | Variable '%s' can only be set, not read | | 1234 | 42000 | ER\_CANT\_USE\_OPTION\_HERE | Incorrect usage/placement of '%s' | | 1235 | 42000 | ER\_NOT\_SUPPORTED\_YET | This version of MariaDB doesn't yet support '%s' | | 1236 | HY000 | ER\_MASTER\_FATAL\_ERROR\_READING\_BINLOG | Got fatal error %d from master when reading data from binary log: '%s' | | 1237 | HY000 | ER\_SLAVE\_IGNORED\_TABLE | Slave SQL thread ignored the query because of replicate-\*-table rules | | 1238 | HY000 | ER\_INCORRECT\_GLOBAL\_LOCAL\_VAR | Variable '%s' is a %s variable | | 1239 | 42000 | ER\_WRONG\_FK\_DEF | Incorrect foreign key definition for '%s': %s | | 1240 | HY000 | ER\_KEY\_REF\_DO\_NOT\_MATCH\_TABLE\_REF | Key reference and table reference don't match | | 1241 | 21000 | ER\_OPERAND\_COLUMNS | Operand should contain %d column(s) | | 1242 | 21000 | ER\_SUBQUERY\_NO\_1\_ROW | Subquery returns more than 1 row | | 1243 | HY000 | ER\_UNKNOWN\_STMT\_HANDLER | Unknown prepared statement handler (%.\*s) given to %s | | 1244 | HY000 | ER\_CORRUPT\_HELP\_DB | Help database is corrupt or does not exist | | 1245 | HY000 | ER\_CYCLIC\_REFERENCE | Cyclic reference on subqueries | | 1246 | HY000 | ER\_AUTO\_CONVERT | Converting column '%s' from %s to %s | | 1247 | 42S22 | ER\_ILLEGAL\_REFERENCE | Reference '%s' not supported (%s) | | 1248 | 42000 | ER\_DERIVED\_MUST\_HAVE\_ALIAS | Every derived table must have its own alias | | 1249 | 01000 | ER\_SELECT\_REDUCED | Select %u was reduced during optimization | | 1250 | 42000 | ER\_TABLENAME\_NOT\_ALLOWED\_HERE | Table '%s' from one of the SELECTs cannot be used in %s | | 1251 | 08004 | ER\_NOT\_SUPPORTED\_AUTH\_MODE | Client does not support authentication protocol requested by server; consider upgrading MariaDB client | | 1252 | 42000 | ER\_SPATIAL\_CANT\_HAVE\_NULL | All parts of a SPATIAL index must be NOT NULL | | 1253 | 42000 | ER\_COLLATION\_CHARSET\_MISMATCH | COLLATION '%s' is not valid for CHARACTER SET '%s' | | 1254 | HY000 | ER\_SLAVE\_WAS\_RUNNING | Slave is already running | | 1255 | HY000 | ER\_SLAVE\_WAS\_NOT\_RUNNING | Slave already has been stopped | | 1256 | HY000 | ER\_TOO\_BIG\_FOR\_UNCOMPRESS | Uncompressed data size too large; the maximum size is %d (probably, length of uncompressed data was corrupted) | | 1257 | HY000 | ER\_ZLIB\_Z\_MEM\_ERROR | ZLIB: Not enough memory | | 1258 | HY000 | ER\_ZLIB\_Z\_BUF\_ERROR | ZLIB: Not enough room in the output buffer (probably, length of uncompressed data was corrupted) | | 1259 | HY000 | ER\_ZLIB\_Z\_DATA\_ERROR | ZLIB: Input data corrupted | | 1260 | HY000 | ER\_CUT\_VALUE\_GROUP\_CONCAT | Row %u was cut by GROUP\_CONCAT() | | 1261 | 01000 | ER\_WARN\_TOO\_FEW\_RECORDS | Row %ld doesn't contain data for all columns | | 1262 | 01000 | ER\_WARN\_TOO\_MANY\_RECORDS | Row %ld was truncated; it contained more data than there were input columns | | 1263 | 22004 | ER\_WARN\_NULL\_TO\_NOTNULL | Column set to default value; NULL supplied to NOT NULL column '%s' at row %ld | | 1264 | 22003 | ER\_WARN\_DATA\_OUT\_OF\_RANGE | Out of range value for column '%s' at row %ld | | 1265 | 01000 | WARN\_DATA\_TRUNCATED | Data truncated for column '%s' at row %ld | | 1266 | HY000 | ER\_WARN\_USING\_OTHER\_HANDLER | Using storage engine %s for table '%s' | | 1267 | HY000 | ER\_CANT\_AGGREGATE\_2COLLATIONS | Illegal mix of collations (%s,%s) and (%s,%s) for operation '%s' | | 1268 | HY000 | ER\_DROP\_USER | Cannot drop one or more of the requested users | | 1269 | HY000 | ER\_REVOKE\_GRANTS | Can't revoke all privileges for one or more of the requested users | | 1270 | HY000 | ER\_CANT\_AGGREGATE\_3COLLATIONS | Illegal mix of collations (%s,%s), (%s,%s), (%s,%s) for operation '%s' | | 1271 | HY000 | ER\_CANT\_AGGREGATE\_NCOLLATIONS | Illegal mix of collations for operation '%s' | | 1272 | HY000 | ER\_VARIABLE\_IS\_NOT\_STRUCT | Variable '%s' is not a variable component (can't be used as XXXX.variable\_name) | | 1273 | HY000 | ER\_UNKNOWN\_COLLATION | Unknown collation: '%s' | | 1274 | HY000 | ER\_SLAVE\_IGNORED\_SSL\_PARAMS | SSL parameters in CHANGE MASTER are ignored because this MariaDB slave was compiled without SSL support; they can be used later if MariaDB slave with SSL is started | | 1275 | HY000 | ER\_SERVER\_IS\_IN\_SECURE\_AUTH\_MODE | Server is running in --secure-auth mode, but '%s'@'%s' has a password in the old format; please change the password to the new format | | 1276 | HY000 | ER\_WARN\_FIELD\_RESOLVED | Field or reference '%s%s%s%s%s' of SELECT #%d was resolved in SELECT #%d | | 1277 | HY000 | ER\_BAD\_SLAVE\_UNTIL\_COND | Incorrect parameter or combination of parameters for START SLAVE UNTIL | | 1278 | HY000 | ER\_MISSING\_SKIP\_SLAVE | It is recommended to use --skip-slave-start when doing step-by-step replication with START SLAVE UNTIL; otherwise, you will get problems if you get an unexpected slave's mysqld restart | | 1279 | HY000 | ER\_UNTIL\_COND\_IGNORED | SQL thread is not to be started so UNTIL options are ignored | | 1280 | 42000 | ER\_WRONG\_NAME\_FOR\_INDEX | Incorrect index name '%s' | | 1281 | 42000 | ER\_WRONG\_NAME\_FOR\_CATALOG | Incorrect catalog name '%s' | | 1282 | HY000 | ER\_WARN\_QC\_RESIZE | Query cache failed to set size %lu; new query cache size is %lu | | 1283 | HY000 | ER\_BAD\_FT\_COLUMN | Column '%s' cannot be part of FULLTEXT index | | 1284 | HY000 | ER\_UNKNOWN\_KEY\_CACHE | Unknown key cache '%s' | | 1285 | HY000 | ER\_WARN\_HOSTNAME\_WONT\_WORK | MariaDB is started in --skip-name-resolve mode; you must restart it without this switch for this grant to work | | 1286 | 42000 | ER\_UNKNOWN\_STORAGE\_ENGINE | Unknown storage engine '%s' | | 1287 | HY000 | ER\_WARN\_DEPRECATED\_SYNTAX | '%s' is deprecated and will be removed in a future release. Please use %s instead | | 1288 | HY000 | ER\_NON\_UPDATABLE\_TABLE | The target table %s of the %s is not updatable | | 1289 | HY000 | ER\_FEATURE\_DISABLED | The '%s' feature is disabled; you need MariaDB built with '%s' to have it working | | 1290 | HY000 | ER\_OPTION\_PREVENTS\_STATEMENT | The MariaDB server is running with the %s option so it cannot execute this statement | | 1291 | HY000 | ER\_DUPLICATED\_VALUE\_IN\_TYPE | Column '%s' has duplicated value '%s' in %s | | 1292 | 22007 | ER\_TRUNCATED\_WRONG\_VALUE | Truncated incorrect %s value: '%s' | | 1293 | HY000 | ER\_TOO\_MUCH\_AUTO\_TIMESTAMP\_COLS | Incorrect table definition; there can be only one TIMESTAMP column with CURRENT\_TIMESTAMP in DEFAULT or ON UPDATE clause | | 1294 | HY000 | ER\_INVALID\_ON\_UPDATE | Invalid ON UPDATE clause for '%s' column | | 1295 | HY000 | ER\_UNSUPPORTED\_PS | This command is not supported in the prepared statement protocol yet | | 1296 | HY000 | ER\_GET\_ERRMSG | Got error %d '%s' from %s | | 1297 | HY000 | ER\_GET\_TEMPORARY\_ERRMSG | Got temporary error %d '%s' from %s | | 1298 | HY000 | ER\_UNKNOWN\_TIME\_ZONE | Unknown or incorrect time zone: '%s' | | 1299 | HY000 | ER\_WARN\_INVALID\_TIMESTAMP | Invalid TIMESTAMP value in column '%s' at row %ld | | Error Code | SQLSTATE | Error | Description | | --- | --- | --- | --- | | 1300 | HY000 | ER\_INVALID\_CHARACTER\_STRING | Invalid %s character string: '%s' | | 1301 | HY000 | ER\_WARN\_ALLOWED\_PACKET\_OVERFLOWED | Result of %s() was larger than max\_allowed\_packet (%ld) - truncated | | 1302 | HY000 | ER\_CONFLICTING\_DECLARATIONS | Conflicting declarations: '%s%s' and '%s%s' | | 1303 | 2F003 | ER\_SP\_NO\_RECURSIVE\_CREATE | Can't create a %s from within another stored routine | | 1304 | 42000 | ER\_SP\_ALREADY\_EXISTS | %s %s already exists | | 1305 | 42000 | ER\_SP\_DOES\_NOT\_EXIST | %s %s does not exist | | 1306 | HY000 | ER\_SP\_DROP\_FAILED | Failed to DROP %s %s | | 1307 | HY000 | ER\_SP\_STORE\_FAILED | Failed to CREATE %s %s | | 1308 | 42000 | ER\_SP\_LILABEL\_MISMATCH | %s with no matching label: %s | | 1309 | 42000 | ER\_SP\_LABEL\_REDEFINE | Redefining label %s | | 1310 | 42000 | ER\_SP\_LABEL\_MISMATCH | End-label %s without match | | 1311 | 01000 | ER\_SP\_UNINIT\_VAR | Referring to uninitialized variable %s | | 1312 | 0A000 | ER\_SP\_BADSELECT | PROCEDURE %s can't return a result set in the given context | | 1313 | 42000 | ER\_SP\_BADRETURN | RETURN is only allowed in a FUNCTION | | 1314 | 0A000 | ER\_SP\_BADSTATEMENT | %s is not allowed in stored procedures | | 1315 | 42000 | ER\_UPDATE\_LOG\_DEPRECATED\_IGNORED | The update log is deprecated and replaced by the binary log; SET SQL\_LOG\_UPDATE has been ignored. This option will be removed in [MariaDB 5.6](../what-is-mariadb-56/index). | | 1316 | 42000 | ER\_UPDATE\_LOG\_DEPRECATED\_TRANSLATED | The update log is deprecated and replaced by the binary log; SET SQL\_LOG\_UPDATE has been translated to SET SQL\_LOG\_BIN. This option will be removed in [MariaDB 5.6](../what-is-mariadb-56/index). | | 1317 | 70100 | ER\_QUERY\_INTERRUPTED | Query execution was interrupted | | 1318 | 42000 | ER\_SP\_WRONG\_NO\_OF\_ARGS | Incorrect number of arguments for %s %s; expected %u, got %u | | 1319 | 42000 | ER\_SP\_COND\_MISMATCH | Undefined CONDITION: %s | | 1320 | 42000 | ER\_SP\_NORETURN | No RETURN found in FUNCTION %s | | 1321 | 2F005 | ER\_SP\_NORETURNEND | FUNCTION %s ended without RETURN | | 1322 | 42000 | ER\_SP\_BAD\_CURSOR\_QUERY | Cursor statement must be a SELECT | | 1323 | 42000 | ER\_SP\_BAD\_CURSOR\_SELECT | Cursor SELECT must not have INTO | | 1324 | 42000 | ER\_SP\_CURSOR\_MISMATCH | Undefined CURSOR: %s | | 1325 | 24000 | ER\_SP\_CURSOR\_ALREADY\_OPEN | Cursor is already open | | 1326 | 24000 | ER\_SP\_CURSOR\_NOT\_OPEN | Cursor is not open | | 1327 | 42000 | ER\_SP\_UNDECLARED\_VAR | Undeclared variable: %s | | 1328 | HY000 | ER\_SP\_WRONG\_NO\_OF\_FETCH\_ARGS | Incorrect number of FETCH variables | | 1329 | 02000 | ER\_SP\_FETCH\_NO\_DATA | No data - zero rows fetched, selected, or processed | | 1330 | 42000 | ER\_SP\_DUP\_PARAM | Duplicate parameter: %s | | 1331 | 42000 | ER\_SP\_DUP\_VAR | Duplicate variable: %s | | 1332 | 42000 | ER\_SP\_DUP\_COND | Duplicate condition: %s | | 1333 | 42000 | ER\_SP\_DUP\_CURS | Duplicate cursor: %s | | 1334 | HY000 | ER\_SP\_CANT\_ALTER | Failed to ALTER %s %s | | 1335 | 0A000 | ER\_SP\_SUBSELECT\_NYI | Subquery value not supported | | 1336 | 0A000 | ER\_STMT\_NOT\_ALLOWED\_IN\_SF\_OR\_TRG | %s is not allowed in stored function or trigger | | 1337 | 42000 | ER\_SP\_VARCOND\_AFTER\_CURSHNDLR | Variable or condition declaration after cursor or handler declaration | | 1338 | 42000 | ER\_SP\_CURSOR\_AFTER\_HANDLER | Cursor declaration after handler declaration | | 1339 | 20000 | ER\_SP\_CASE\_NOT\_FOUND | Case not found for CASE statement | | 1340 | HY000 | ER\_FPARSER\_TOO\_BIG\_FILE | Configuration file '%s' is too big | | 1341 | HY000 | ER\_FPARSER\_BAD\_HEADER | Malformed file type header in file '%s' | | 1342 | HY000 | ER\_FPARSER\_EOF\_IN\_COMMENT | Unexpected end of file while parsing comment '%s' | | 1343 | HY000 | ER\_FPARSER\_ERROR\_IN\_PARAMETER | Error while parsing parameter '%s' (line: '%s') | | 1344 | HY000 | ER\_FPARSER\_EOF\_IN\_UNKNOWN\_PARAMETER | Unexpected end of file while skipping unknown parameter '%s' | | 1345 | HY000 | ER\_VIEW\_NO\_EXPLAIN | EXPLAIN/SHOW can not be issued; lacking privileges for underlying table | | 1346 | HY000 | ER\_FRM\_UNKNOWN\_TYPE | File '%s' has unknown type '%s' in its header | | 1347 | HY000 | ER\_WRONG\_OBJECT | '%s.%s' is not %s | | 1348 | HY000 | ER\_NONUPDATEABLE\_COLUMN | Column '%s' is not updatable | | 1349 | HY000 | ER\_VIEW\_SELECT\_DERIVED | View's SELECT contains a subquery in the FROM clause | | 1350 | HY000 | ER\_VIEW\_SELECT\_CLAUSE | View's SELECT contains a '%s' clause | | 1351 | HY000 | ER\_VIEW\_SELECT\_VARIABLE | View's SELECT contains a variable or parameter | | 1352 | HY000 | ER\_VIEW\_SELECT\_TMPTABLE | View's SELECT refers to a temporary table '%s' | | 1353 | HY000 | ER\_VIEW\_WRONG\_LIST | View's SELECT and view's field list have different column counts | | 1354 | HY000 | ER\_WARN\_VIEW\_MERGE | View merge algorithm can't be used here for now (assumed undefined algorithm) | | 1355 | HY000 | ER\_WARN\_VIEW\_WITHOUT\_KEY | View being updated does not have complete key of underlying table in it | | 1356 | HY000 | ER\_VIEW\_INVALID | View '%s.%s' references invalid table(s) or column(s) or function(s) or definer/invoker of view lack rights to use them | | 1357 | HY000 | ER\_SP\_NO\_DROP\_SP | Can't drop or alter a %s from within another stored routine | | 1358 | HY000 | ER\_SP\_GOTO\_IN\_HNDLR | GOTO is not allowed in a stored procedure handler | | 1359 | HY000 | ER\_TRG\_ALREADY\_EXISTS | Trigger already exists | | 1360 | HY000 | ER\_TRG\_DOES\_NOT\_EXIST | Trigger does not exist | | 1361 | HY000 | ER\_TRG\_ON\_VIEW\_OR\_TEMP\_TABLE | Trigger's '%s' is view or temporary table | | 1362 | HY000 | ER\_TRG\_CANT\_CHANGE\_ROW | Updating of %s row is not allowed in %strigger | | 1363 | HY000 | ER\_TRG\_NO\_SUCH\_ROW\_IN\_TRG | There is no %s row in %s trigger | | 1364 | HY000 | ER\_NO\_DEFAULT\_FOR\_FIELD | Field '%s' doesn't have a default value | | 1365 | 22012 | ER\_DIVISION\_BY\_ZER | Division by 0 | | 1366 | HY000 | ER\_TRUNCATED\_WRONG\_VALUE\_FOR\_FIELD | Incorrect %s value: '%s' for column '%s' at row %ld | | 1367 | 22007 | ER\_ILLEGAL\_VALUE\_FOR\_TYPE | Illegal %s '%s' value found during parsing | | 1368 | HY000 | ER\_VIEW\_NONUPD\_CHECK | CHECK OPTION on non-updatable view '%s.%s' | | 1369 | HY000 | ER\_VIEW\_CHECK\_FAILED | CHECK OPTION failed '%s.%s' | | 1370 | 42000 | ER\_PROCACCESS\_DENIED\_ERROR | %s command denied to user '%s'@'%s' for routine '%s' | | 1371 | HY000 | ER\_RELAY\_LOG\_FAIL | Failed purging old relay logs: %s | | 1372 | HY000 | ER\_PASSWD\_LENGTH | Password hash should be a %d-digit hexadecimal number | | 1373 | HY000 | ER\_UNKNOWN\_TARGET\_BINLOG | Target log not found in binlog index | | 1374 | HY000 | ER\_IO\_ERR\_LOG\_INDEX\_READ | I/O error reading log index file | | 1375 | HY000 | ER\_BINLOG\_PURGE\_PROHIBITED | Server configuration does not permit binlog purge | | 1376 | HY000 | ER\_FSEEK\_FAIL | Failed on fseek() | | 1377 | HY000 | ER\_BINLOG\_PURGE\_FATAL\_ERR | Fatal error during log purge | | 1378 | HY000 | ER\_LOG\_IN\_USE | A purgeable log is in use, will not purge | | 1379 | HY000 | ER\_LOG\_PURGE\_UNKNOWN\_ERR | Unknown error during log purge | | 1380 | HY000 | ER\_RELAY\_LOG\_INIT | Failed initializing relay log position: %s | | 1381 | HY000 | ER\_NO\_BINARY\_LOGGING | You are not using binary logging | | 1382 | HY000 | ER\_RESERVED\_SYNTAX | The '%s' syntax is reserved for purposes internal to the MariaDB server | | 1383 | HY000 | ER\_WSAS\_FAILED | WSAStartup Failed | | 1384 | HY000 | ER\_DIFF\_GROUPS\_PROC | Can't handle procedures with different groups yet | | 1385 | HY000 | ER\_NO\_GROUP\_FOR\_PROC | Select must have a group with this procedure | | 1386 | HY000 | ER\_ORDER\_WITH\_PROC | Can't use ORDER clause with this procedure | | 1387 | HY000 | ER\_LOGGING\_PROHIBIT\_CHANGING\_OF | Binary logging and replication forbid changing the global server %s | | 1388 | HY000 | ER\_NO\_FILE\_MAPPING | Can't map file: %s, errno: %d | | 1389 | HY000 | ER\_WRONG\_MAGIC | Wrong magic in %s | | 1390 | HY000 | ER\_PS\_MANY\_PARAM | Prepared statement contains too many placeholders | | 1391 | HY000 | ER\_KEY\_PART\_0 | Key part '%s' length cannot be 0 | | 1392 | HY000 | ER\_VIEW\_CHECKSUM | View text checksum failed | | 1393 | HY000 | ER\_VIEW\_MULTIUPDATE | Can not modify more than one base table through a join view '%s.%s' | | 1394 | HY000 | ER\_VIEW\_NO\_INSERT\_FIELD\_LIST | Can not insert into join view '%s.%s' without fields list | | 1395 | HY000 | ER\_VIEW\_DELETE\_MERGE\_VIEW | Can not delete from join view '%s.%s' | | 1396 | HY000 | ER\_CANNOT\_USER | Operation %s failed for %s | | 1397 | XAE04 | ER\_XAER\_NOTA | XAER\_NOTA: Unknown XID | | 1398 | XAE05 | ER\_XAER\_INVAL | XAER\_INVAL: Invalid arguments (or unsupported command) | | 1399 | XAE07 | ER\_XAER\_RMFAIL | XAER\_RMFAIL: The command cannot be executed when global transaction is in the %s state | | Error Code | SQLSTATE | Error | Description | | --- | --- | --- | --- | | 1400 | XAE09 | ER\_XAER\_OUTSIDE | XAER\_OUTSIDE: Some work is done outside global transaction | | 1401 | XAE03 | ER\_XAER\_RMERR | XAER\_RMERR: Fatal error occurred in the transaction branch - check your data for consistency | | 1402 | XA100 | ER\_XA\_RBROLLBACK | XA\_RBROLLBACK: Transaction branch was rolled back | | 1403 | 42000 | ER\_NONEXISTING\_PROC\_GRANT | There is no such grant defined for user '%s' on host '%s' on routine '%s' | | 1404 | HY000 | ER\_PROC\_AUTO\_GRANT\_FAIL | Failed to grant EXECUTE and ALTER ROUTINE privileges | | 1405 | HY000 | ER\_PROC\_AUTO\_REVOKE\_FAIL | Failed to revoke all privileges to dropped routine | | 1406 | 22001 | ER\_DATA\_TOO\_LONG | Data too long for column '%s' at row %ld | | 1407 | 42000 | ER\_SP\_BAD\_SQLSTATE | Bad SQLSTATE: '%s' | | 1408 | HY000 | ER\_STARTUP | %s: ready for connections. Version: '%s' socket: '%s' port: %d %s | | 1409 | HY000 | ER\_LOAD\_FROM\_FIXED\_SIZE\_ROWS\_TO\_VAR | Can't load value from file with fixed size rows to variable | | 1410 | 42000 | ER\_CANT\_CREATE\_USER\_WITH\_GRANT | You are not allowed to create a user with GRANT | | 1411 | HY000 | ER\_WRONG\_VALUE\_FOR\_TYPE | Incorrect %s value: '%s' for function %s | | 1412 | HY000 | ER\_TABLE\_DEF\_CHANGED | Table definition has changed, please retry transaction | | 1413 | 42000 | ER\_SP\_DUP\_HANDLER | Duplicate handler declared in the same block | | 1414 | 42000 | ER\_SP\_NOT\_VAR\_ARG | OUT or INOUT argument %d for routine %s is not a variable or NEW pseudo-variable in BEFORE trigger | | 1415 | 0A000 | ER\_SP\_NO\_RETSET | Not allowed to return a result set from a %s | | 1416 | 22003 | ER\_CANT\_CREATE\_GEOMETRY\_OBJECT | Cannot get geometry object from data you send to the GEOMETRY field | | 1417 | HY000 | ER\_FAILED\_ROUTINE\_BREAK\_BINLOG | A routine failed and has neither NO SQL nor READS SQL DATA in its declaration and binary logging is enabled; if non-transactional tables were updated, the binary log will miss their changes | | 1418 | HY000 | ER\_BINLOG\_UNSAFE\_ROUTINE | This function has none of DETERMINISTIC, NO SQL, or READS SQL DATA in its declaration and binary logging is enabled (you \*might\* want to use the less safe log\_bin\_trust\_function\_creators variable) | | 1419 | HY000 | ER\_BINLOG\_CREATE\_ROUTINE\_NEED\_SUPER | You do not have the SUPER privilege and binary logging is enabled (you \*might\* want to use the less safe log\_bin\_trust\_function\_creators variable) | | 1420 | HY000 | ER\_EXEC\_STMT\_WITH\_OPEN\_CURSOR | You can't execute a prepared statement which has an open cursor associated with it. Reset the statement to re-execute it. | | 1421 | HY000 | ER\_STMT\_HAS\_NO\_OPEN\_CURSOR | The statement (%lu) has no open cursor. | | 1422 | HY000 | ER\_COMMIT\_NOT\_ALLOWED\_IN\_SF\_OR\_TRG | Explicit or implicit commit is not allowed in stored function or trigger. | | 1423 | HY000 | ER\_NO\_DEFAULT\_FOR\_VIEW\_FIELD | Field of view '%s.%s' underlying table doesn't have a default value | | 1424 | HY000 | ER\_SP\_NO\_RECURSION | Recursive stored functions and triggers are not allowed. | | 1425 | 42000 | ER\_TOO\_BIG\_SCALE | Too big scale %d specified for column '%s'. Maximum is %lu. | | 1426 | 42000 | ER\_TOO\_BIG\_PRECISION | Too big precision %d specified for column '%s'. Maximum is %lu. | | 1427 | 42000 | ER\_M\_BIGGER\_THAN\_D | For float(M,D, double(M,D or decimal(M,D, M must be >= D (column '%s'). | | 1428 | HY000 | ER\_WRONG\_LOCK\_OF\_SYSTEM\_TABLE | You can't combine write-locking of system tables with other tables or lock types | | 1429 | HY000 | ER\_CONNECT\_TO\_FOREIGN\_DATA\_SOURCE | Unable to connect to foreign data source: %s | | 1430 | HY000 | ER\_QUERY\_ON\_FOREIGN\_DATA\_SOURCE | There was a problem processing the query on the foreign data source. Data source error: %s | | 1431 | HY000 | ER\_FOREIGN\_DATA\_SOURCE\_DOESNT\_EXIST | The foreign data source you are trying to reference does not exist. Data source error: %s | | 1432 | HY000 | ER\_FOREIGN\_DATA\_STRING\_INVALID\_CANT\_CREATE | Can't create federated table. The data source connection string '%s' is not in the correct format | | 1433 | HY000 | ER\_FOREIGN\_DATA\_STRING\_INVALID | The data source connection string '%s' is not in the correct format | | 1434 | HY000 | ER\_CANT\_CREATE\_FEDERATED\_TABLE | Can't create federated table. Foreign data src error: %s | | 1435 | HY000 | ER\_TRG\_IN\_WRONG\_SCHEMA | Trigger in wrong schema | | 1436 | HY000 | ER\_STACK\_OVERRUN\_NEED\_MORE | Thread stack overrun: %ld bytes used of a %ld byte stack, and %ld bytes needed. Use 'mysqld --thread\_stack=#' to specify a bigger stack. | | 1437 | 42000 | ER\_TOO\_LONG\_BODY | Routine body for '%s' is too long | | 1438 | HY000 | ER\_WARN\_CANT\_DROP\_DEFAULT\_KEYCACHE | Cannot drop default keycache | | 1439 | 42000 | ER\_TOO\_BIG\_DISPLAYWIDTH | Display width out of range for column '%s' (max = %lu) | | 1440 | XAE08 | ER\_XAER\_DUPID | XAER\_DUPID: The XID already exists | | 1441 | 22008 | ER\_DATETIME\_FUNCTION\_OVERFLOW | Datetime function: %s field overflow | | 1442 | HY000 | ER\_CANT\_UPDATE\_USED\_TABLE\_IN\_SF\_OR\_TRG | Can't update table '%s' in stored function/trigger because it is already used by statement which invoked this stored function/trigger. | | 1443 | HY000 | ER\_VIEW\_PREVENT\_UPDATE | The definition of table '%s' prevents operation %s on table '%s'. | | 1444 | HY000 | ER\_PS\_NO\_RECURSION | The prepared statement contains a stored routine call that refers to that same statement. It's not allowed to execute a prepared statement in such a recursive manner | | 1445 | HY000 | ER\_SP\_CANT\_SET\_AUTOCOMMIT | Not allowed to set autocommit from a stored function or trigger | | 1446 | HY000 | ER\_MALFORMED\_DEFINER | Definer is not fully qualified | | 1447 | HY000 | ER\_VIEW\_FRM\_NO\_USER | View '%s'.'%s' has no definer information (old table format). Current user is used as definer. Please recreate the view! | | 1448 | HY000 | ER\_VIEW\_OTHER\_USER | You need the SUPER privilege for creation view with '%s'@'%s' definer | | 1449 | HY000 | ER\_NO\_SUCH\_USER | The user specified as a definer ('%s'@'%s') does not exist | | 1450 | HY000 | ER\_FORBID\_SCHEMA\_CHANGE | Changing schema from '%s' to '%s' is not allowed. | | 1451 | 23000 | ER\_ROW\_IS\_REFERENCED\_2 | Cannot delete or update a parent row: a foreign key constraint fails (%s) | | 1452 | 23000 | ER\_NO\_REFERENCED\_ROW\_2 | Cannot add or update a child row: a foreign key constraint fails (%s) | | 1453 | 42000 | ER\_SP\_BAD\_VAR\_SHADOW | Variable '%s' must be quoted with `...`, or renamed | | 1454 | HY000 | ER\_TRG\_NO\_DEFINER | No definer attribute for trigger '%s'.'%s'. The trigger will be activated under the authorization of the invoker, which may have insufficient privileges. Please recreate the trigger. | | 1455 | HY000 | ER\_OLD\_FILE\_FORMAT | '%s' has an old format, you should re-create the '%s' object(s) | | 1456 | HY000 | ER\_SP\_RECURSION\_LIMIT | Recursive limit %d (as set by the max\_sp\_recursion\_depth variable) was exceeded for routine %s | | 1457 | HY000 | ER\_SP\_PROC\_TABLE\_CORRUPT | Failed to load routine %s. The table mysql.proc is missing, corrupt, or contains bad data (internal code %d) | | 1458 | 42000 | ER\_SP\_WRONG\_NAME | Incorrect routine name '%s' | | 1459 | HY000 | ER\_TABLE\_NEEDS\_UPGRADE | Table upgrade required. Please do "REPAIR TABLE `%s`" or dump/reload to fix it! | | 1460 | 42000 | ER\_SP\_NO\_AGGREGATE | AGGREGATE is not supported for stored functions | | 1461 | 42000 | ER\_MAX\_PREPARED\_STMT\_COUNT\_REACHED | Can't create more than max\_prepared\_stmt\_count statements (current value: %lu) | | 1462 | HY000 | ER\_VIEW\_RECURSIVE | `%s`.`%s` contains view recursion | | 1463 | 42000 | ER\_NON\_GROUPING\_FIELD\_USED | Non-grouping field '%s' is used in %s clause | | 1464 | HY000 | ER\_TABLE\_CANT\_HANDLE\_SPKEYS | The used table type doesn't support SPATIAL indexes | | 1465 | HY000 | ER\_NO\_TRIGGERS\_ON\_SYSTEM\_SCHEMA | Triggers can not be created on system tables | | 1466 | HY000 | ER\_REMOVED\_SPACES | Leading spaces are removed from name '%s' | | 1467 | HY000 | ER\_AUTOINC\_READ\_FAILED | Failed to read auto-increment value from storage engine | | 1468 | HY000 | ER\_USERNAME | user name | | 1469 | HY000 | ER\_HOSTNAME | host name | | 1470 | HY000 | ER\_WRONG\_STRING\_LENGTH | String '%s' is too long for %s (should be no longer than %d) | | 1471 | HY000 | ER\_NON\_INSERTABLE\_TABLE | The target table %s of the %s is not insertable-into | | 1472 | HY000 | ER\_ADMIN\_WRONG\_MRG\_TABLE | Table '%s' is differently defined or of non-MyISAM type or doesn't exist | | 1473 | HY000 | ER\_TOO\_HIGH\_LEVEL\_OF\_NESTING\_FOR\_SELECT | Too high level of nesting for select | | 1474 | HY000 | ER\_NAME\_BECOMES\_EMPTY | Name '%s' has become '' | | 1475 | HY000 | ER\_AMBIGUOUS\_FIELD\_TERM | First character of the FIELDS TERMINATED string is ambiguous; please use non-optional and non-empty FIELDS ENCLOSED BY | | 1476 | HY000 | ER\_FOREIGN\_SERVER\_EXISTS | The foreign server, %s, you are trying to create already exists. | | 1477 | HY000 | ER\_FOREIGN\_SERVER\_DOESNT\_EXIST | The foreign server name you are trying to reference does not exist. Data source error: %s | | 1478 | HY000 | ER\_ILLEGAL\_HA\_CREATE\_OPTION | Table storage engine '%s' does not support the create option '%s' | | 1479 | HY000 | ER\_PARTITION\_REQUIRES\_VALUES\_ERROR | Syntax error: %s PARTITIONING requires definition of VALUES %s for each partition | | 1480 | HY000 | ER\_PARTITION\_WRONG\_VALUES\_ERROR | Only %s PARTITIONING can use VALUES %s in partition definition | | 1481 | HY000 | ER\_PARTITION\_MAXVALUE\_ERROR | MAXVALUE can only be used in last partition definition | | 1482 | HY000 | ER\_PARTITION\_SUBPARTITION\_ERROR | Subpartitions can only be hash partitions and by key | | 1483 | HY000 | ER\_PARTITION\_SUBPART\_MIX\_ERROR | Must define subpartitions on all partitions if on one partition | | 1484 | HY000 | ER\_PARTITION\_WRONG\_NO\_PART\_ERROR | Wrong number of partitions defined, mismatch with previous setting | | 1485 | HY000 | ER\_PARTITION\_WRONG\_NO\_SUBPART\_ERROR | Wrong number of subpartitions defined, mismatch with previous setting | | 1486 | HY000 | ER\_CONST\_EXPR\_IN\_PARTITION\_FUNC\_ERROR | Constant/Random expression in (sub)partitioning function is not allowed | | 1486 | HY000 | ER\_WRONG\_EXPR\_IN\_PARTITION\_FUNC\_ERROR | Constant, random or timezone-dependent expressions in (sub)partitioning function are not allowed | | 1487 | HY000 | ER\_NO\_CONST\_EXPR\_IN\_RANGE\_OR\_LIST\_ERROR | Expression in RANGE/LIST VALUES must be constant | | 1488 | HY000 | ER\_FIELD\_NOT\_FOUND\_PART\_ERROR | Field in list of fields for partition function not found in table | | 1489 | HY000 | ER\_LIST\_OF\_FIELDS\_ONLY\_IN\_HASH\_ERROR | List of fields is only allowed in KEY partitions | | 1490 | HY000 | ER\_INCONSISTENT\_PARTITION\_INFO\_ERROR | The partition info in the frm file is not consistent with what can be written into the frm file | | 1491 | HY000 | ER\_PARTITION\_FUNC\_NOT\_ALLOWED\_ERROR | The %s function returns the wrong type | | 1492 | HY000 | ER\_PARTITIONS\_MUST\_BE\_DEFINED\_ERROR | For %s partitions each partition must be defined | | 1493 | HY000 | ER\_RANGE\_NOT\_INCREASING\_ERROR | VALUES LESS THAN value must be strictly increasing for each partition | | 1494 | HY000 | ER\_INCONSISTENT\_TYPE\_OF\_FUNCTIONS\_ERROR | VALUES value must be of same type as partition function | | 1495 | HY000 | ER\_MULTIPLE\_DEF\_CONST\_IN\_LIST\_PART\_ERROR | Multiple definition of same constant in list partitioning | | 1496 | HY000 | ER\_PARTITION\_ENTRY\_ERROR | Partitioning can not be used stand-alone in query | | 1497 | HY000 | ER\_MIX\_HANDLER\_ERROR | The mix of handlers in the partitions is not allowed in this version of MariaDB | | 1498 | HY000 | ER\_PARTITION\_NOT\_DEFINED\_ERROR | For the partitioned engine it is necessary to define all %s | | 1499 | HY000 | ER\_TOO\_MANY\_PARTITIONS\_ERROR | Too many partitions (including subpartitions) were defined | | Error Code | SQLSTATE | Error | Description | | --- | --- | --- | --- | | 1500 | HY000 | ER\_SUBPARTITION\_ERROR | It is only possible to mix RANGE/LIST partitioning with HASH/KEY partitioning for subpartitioning | | 1501 | HY000 | ER\_CANT\_CREATE\_HANDLER\_FILE | Failed to create specific handler file | | 1502 | HY000 | ER\_BLOB\_FIELD\_IN\_PART\_FUNC\_ERROR | A BLOB field is not allowed in partition function | | 1503 | HY000 | ER\_UNIQUE\_KEY\_NEED\_ALL\_FIELDS\_IN\_PF | A %s must include all columns in the table's partitioning function | | 1504 | HY000 | ER\_NO\_PARTS\_ERROR | Number of %s = 0 is not an allowed value | | 1505 | HY000 | ER\_PARTITION\_MGMT\_ON\_NONPARTITIONED | Partition management on a not partitioned table is not possible | | 1506 | HY000 | ER\_FOREIGN\_KEY\_ON\_PARTITIONED | Foreign key clause is not yet supported in conjunction with partitioning | | 1507 | HY000 | ER\_DROP\_PARTITION\_NON\_EXISTENT | Error in list of partitions to %s | | 1508 | HY000 | ER\_DROP\_LAST\_PARTITION | Cannot remove all partitions, use DROP TABLE instead | | 1509 | HY000 | ER\_COALESCE\_ONLY\_ON\_HASH\_PARTITION | COALESCE PARTITION can only be used on HASH/KEY partitions | | 1510 | HY000 | ER\_REORG\_HASH\_ONLY\_ON\_SAME\_N | REORGANIZE PARTITION can only be used to reorganize partitions not to change their numbers | | 1511 | HY000 | ER\_REORG\_NO\_PARAM\_ERROR | REORGANIZE PARTITION without parameters can only be used on auto-partitioned tables using HASH PARTITIONs | | 1512 | HY000 | ER\_ONLY\_ON\_RANGE\_LIST\_PARTITION | %s PARTITION can only be used on RANGE/LIST partitions | | 1513 | HY000 | ER\_ADD\_PARTITION\_SUBPART\_ERROR | Trying to Add partition(s) with wrong number of subpartitions | | 1514 | HY000 | ER\_ADD\_PARTITION\_NO\_NEW\_PARTITION | At least one partition must be added | | 1515 | HY000 | ER\_COALESCE\_PARTITION\_NO\_PARTITION | At least one partition must be coalesced | | 1516 | HY000 | ER\_REORG\_PARTITION\_NOT\_EXIST | More partitions to reorganize than there are partitions | | 1517 | HY000 | ER\_SAME\_NAME\_PARTITION | Duplicate partition name %s | | 1518 | HY000 | ER\_NO\_BINLOG\_ERROR | It is not allowed to shut off binlog on this command | | 1519 | HY000 | ER\_CONSECUTIVE\_REORG\_PARTITIONS | When reorganizing a set of partitions they must be in consecutive order | | 1520 | HY000 | ER\_REORG\_OUTSIDE\_RANGE | Reorganize of range partitions cannot change total ranges except for last partition where it can extend the range | | 1521 | HY000 | ER\_PARTITION\_FUNCTION\_FAILURE | Partition function not supported in this version for this handler | | 1522 | HY000 | ER\_PART\_STATE\_ERROR | Partition state cannot be defined from CREATE/ALTER TABLE | | 1523 | HY000 | ER\_LIMITED\_PART\_RANGE | The %s handler only supports 32 bit integers in VALUES | | 1524 | HY000 | ER\_PLUGIN\_IS\_NOT\_LOADED | Plugin '%s' is not loaded | | 1525 | HY000 | ER\_WRONG\_VALUE | Incorrect %s value: '%s' | | 1526 | HY000 | ER\_NO\_PARTITION\_FOR\_GIVEN\_VALUE | Table has no partition for value %s | | 1527 | HY000 | ER\_FILEGROUP\_OPTION\_ONLY\_ONCE | It is not allowed to specify %s more than once | | 1528 | HY000 | ER\_CREATE\_FILEGROUP\_FAILED | Failed to create %s | | 1529 | HY000 | ER\_DROP\_FILEGROUP\_FAILED | Failed to drop %s | | 1530 | HY000 | ER\_TABLESPACE\_AUTO\_EXTEND\_ERROR | The handler doesn't support autoextend of tablespaces | | 1531 | HY000 | ER\_WRONG\_SIZE\_NUMBER | A size parameter was incorrectly specified, either number or on the form 10M | | 1532 | HY000 | ER\_SIZE\_OVERFLOW\_ERROR | The size number was correct but we don't allow the digit part to be more than 2 billion | | 1533 | HY000 | ER\_ALTER\_FILEGROUP\_FAILED | Failed to alter: %s | | 1534 | HY000 | ER\_BINLOG\_ROW\_LOGGING\_FAILED | Writing one row to the row-based binary log failed | | 1535 | HY000 | ER\_BINLOG\_ROW\_WRONG\_TABLE\_DEF | Table definition on master and slave does not match: %s | | 1536 | HY000 | ER\_BINLOG\_ROW\_RBR\_TO\_SBR | Slave running with --log-slave-updates must use row-based binary logging to be able to replicate row-based binary log events | | 1537 | HY000 | ER\_EVENT\_ALREADY\_EXISTS | Event '%s' already exists | | 1538 | HY000 | ER\_EVENT\_STORE\_FAILED | Failed to store event %s. Error code %d from storage engine. | | 1539 | HY000 | ER\_EVENT\_DOES\_NOT\_EXIST | Unknown event '%s' | | 1540 | HY000 | ER\_EVENT\_CANT\_ALTER | Failed to alter event '%s' | | 1541 | HY000 | ER\_EVENT\_DROP\_FAILED | Failed to drop %s | | 1542 | HY000 | ER\_EVENT\_INTERVAL\_NOT\_POSITIVE\_OR\_TOO\_BIG | INTERVAL is either not positive or too big | | 1543 | HY000 | ER\_EVENT\_ENDS\_BEFORE\_STARTS | ENDS is either invalid or before STARTS | | 1544 | HY000 | ER\_EVENT\_EXEC\_TIME\_IN\_THE\_PAST | Event execution time is in the past. Event has been disabled | | 1545 | HY000 | ER\_EVENT\_OPEN\_TABLE\_FAILED | Failed to open [mysql.event](../mysqlevent-table/index) | | 1546 | HY000 | ER\_EVENT\_NEITHER\_M\_EXPR\_NOR\_M\_AT | No datetime expression provided | | 1547 | HY000 | ER\_COL\_COUNT\_DOESNT\_MATCH\_CORRUPTED | Column count of mysql.%s is wrong. Expected %d, found %d. The table is probably corrupted | | 1548 | HY000 | ER\_CANNOT\_LOAD\_FROM\_TABLE | Cannot load from mysql.%s. The table is probably corrupted | | 1549 | HY000 | ER\_EVENT\_CANNOT\_DELETE | Failed to delete the event from [mysql.event](../mysqlevent-table/index) | | 1550 | HY000 | ER\_EVENT\_COMPILE\_ERROR | Error during compilation of event's body | | 1551 | HY000 | ER\_EVENT\_SAME\_NAME | Same old and new event name | | 1552 | HY000 | ER\_EVENT\_DATA\_TOO\_LONG | Data for column '%s' too long | | 1553 | HY000 | ER\_DROP\_INDEX\_FK | Cannot drop index '%s': needed in a foreign key constraint | | 1554 | HY000 | ER\_WARN\_DEPRECATED\_SYNTAX\_WITH\_VER | The syntax '%s' is deprecated and will be removed in MariaDB %s. Please use %s instead | | 1555 | HY000 | ER\_CANT\_WRITE\_LOCK\_LOG\_TABLE | You can't write-lock a log table. Only read access is possible | | 1556 | HY000 | ER\_CANT\_LOCK\_LOG\_TABLE | You can't use locks with log tables. | | 1557 | 23000 | ER\_FOREIGN\_DUPLICATE\_KEY | Upholding foreign key constraints for table '%s', entry '%s', key %d would lead to a duplicate entry | | 1558 | HY000 | ER\_COL\_COUNT\_DOESNT\_MATCH\_PLEASE\_UPDATE | Column count of mysql.%s is wrong. Expected %d, found %d. Created with MariaDB %d, now running %d. Please use mysql\_upgrade to fix this error. | | 1559 | HY000 | ER\_TEMP\_TABLE\_PREVENTS\_SWITCH\_OUT\_OF\_RBR | Cannot switch out of the row-based binary log format when the session has open temporary tables | | 1560 | HY000 | ER\_STORED\_FUNCTION\_ PREVENTS\_SWITCH\_BINLOG\_FORMAT | Cannot change the binary logging format inside a stored function or trigger | | 1561 | | ER\_UNUSED\_13 | You should never see it | | 1562 | HY000 | ER\_PARTITION\_NO\_TEMPORARY | Cannot create temporary table with partitions | | 1563 | HY000 | ER\_PARTITION\_CONST\_DOMAIN\_ERROR | Partition constant is out of partition function domain | | 1564 | HY000 | ER\_PARTITION\_FUNCTION\_IS\_NOT\_ALLOWED | This partition function is not allowed | | 1565 | HY000 | ER\_DDL\_LOG\_ERROR | Error in DDL log | | 1566 | HY000 | ER\_NULL\_IN\_VALUES\_LESS\_THAN | Not allowed to use NULL value in VALUES LESS THAN | | 1567 | HY000 | ER\_WRONG\_PARTITION\_NAME | Incorrect partition name | | 1568 | 25001 | ER\_CANT\_CHANGE\_TX\_ISOLATION | Transaction isolation level can't be changed while a transaction is in progress | | 1569 | HY000 | ER\_DUP\_ENTRY\_AUTOINCREMENT\_CASE | ALTER TABLE causes auto\_increment resequencing, resulting in duplicate entry '%s' for key '%s' | | 1570 | HY000 | ER\_EVENT\_MODIFY\_QUEUE\_ERROR | Internal scheduler error %d | | 1571 | HY000 | ER\_EVENT\_SET\_VAR\_ERROR | Error during starting/stopping of the scheduler. Error code %u | | 1572 | HY000 | ER\_PARTITION\_MERGE\_ERROR | Engine cannot be used in partitioned tables | | 1573 | HY000 | ER\_CANT\_ACTIVATE\_LOG | Cannot activate '%s' log | | 1574 | HY000 | ER\_RBR\_NOT\_AVAILABLE | The server was not built with row-based replication | | 1575 | HY000 | ER\_BASE64\_DECODE\_ERROR | Decoding of base64 string failed | | 1576 | HY000 | ER\_EVENT\_RECURSION\_FORBIDDEN | Recursion of EVENT DDL statements is forbidden when body is present | | 1577 | HY000 | ER\_EVENTS\_DB\_ERROR | Cannot proceed because system tables used by Event Scheduler were found damaged at server start | | 1578 | HY000 | ER\_ONLY\_INTEGERS\_ALLOWED | Only integers allowed as number here | | 1579 | HY000 | ER\_UNSUPORTED\_LOG\_ENGINE | This storage engine cannot be used for log tables" | | 1580 | HY000 | ER\_BAD\_LOG\_STATEMENT | You cannot '%s' a log table if logging is enabled | | 1581 | HY000 | ER\_CANT\_RENAME\_LOG\_TABLE | Cannot rename '%s'. When logging enabled, rename to/from log table must rename two tables: the log table to an archive table and another table back to '%s' | | 1582 | 42000 | ER\_WRONG\_PARAMCOUNT\_TO\_NATIVE\_FCT | Incorrect parameter count in the call to native function '%s' | | 1583 | 42000 | ER\_WRONG\_PARAMETERS\_TO\_NATIVE\_FCT | Incorrect parameters in the call to native function '%s' | | 1584 | 42000 | ER\_WRONG\_PARAMETERS\_TO\_STORED\_FCT | Incorrect parameters in the call to stored function '%s' | | 1585 | HY000 | ER\_NATIVE\_FCT\_NAME\_COLLISION | This function '%s' has the same name as a native function | | 1586 | 23000 | ER\_DUP\_ENTRY\_WITH\_KEY\_NAME | Duplicate entry '%s' for key '%s' | | 1587 | HY000 | ER\_BINLOG\_PURGE\_EMFILE | Too many files opened, please execute the command again | | 1588 | HY000 | ER\_EVENT\_CANNOT\_CREATE\_IN\_THE\_PAST | Event execution time is in the past and ON COMPLETION NOT PRESERVE is set. The event was dropped immediately after creation. | | 1589 | HY000 | ER\_EVENT\_CANNOT\_ALTER\_IN\_THE\_PAST | Event execution time is in the past and ON COMPLETION NOT PRESERVE is set. The event was dropped immediately after creation. | | 1590 | HY000 | ER\_SLAVE\_INCIDENT | The incident %s occured on the master. Message: %s | | 1591 | HY000 | ER\_NO\_PARTITION\_FOR\_GIVEN\_VALUE\_SILENT | Table has no partition for some existing values | | 1592 | HY000 | ER\_BINLOG\_UNSAFE\_STATEMENT | Unsafe statement written to the binary log using statement format since BINLOG\_FORMAT = STATEMENT. %s | | 1593 | HY000 | ER\_SLAVE\_FATAL\_ERROR | Fatal error: %s | | 1594 | HY000 | ER\_SLAVE\_RELAY\_LOG\_READ\_FAILURE | Relay log read failure: %s | | 1595 | HY000 | ER\_SLAVE\_RELAY\_LOG\_WRITE\_FAILURE | Relay log write failure: %s | | 1596 | HY000 | ER\_SLAVE\_CREATE\_EVENT\_FAILURE | Failed to create %s | | 1597 | HY000 | ER\_SLAVE\_MASTER\_COM\_FAILURE | Master command %s failed: %s | | 1598 | HY000 | ER\_BINLOG\_LOGGING\_IMPOSSIBLE | Binary logging not possible. Message: %s | | 1599 | HY000 | ER\_VIEW\_NO\_CREATION\_CTX | View `%s`.`%s` has no creation context | | Error Code | SQLSTATE | Error | Description | | --- | --- | --- | --- | | 1600 | HY000 | ER\_VIEW\_INVALID\_CREATION\_CTX | Creation context of view `%s`.`%s' is invalid | | 1601 | HY000 | ER\_SR\_INVALID\_CREATION\_CTX | Creation context of stored routine `%s`.`%s` is invalid | | 1602 | HY000 | ER\_TRG\_CORRUPTED\_FILE | Corrupted TRG file for table `%s`.`%s` | | 1603 | HY000 | ER\_TRG\_NO\_CREATION\_CTX | Triggers for table `%s`.`%s` have no creation context | | 1604 | HY000 | ER\_TRG\_INVALID\_CREATION\_CTX | Trigger creation context of table `%s`.`%s` is invalid | | 1605 | HY000 | ER\_EVENT\_INVALID\_CREATION\_CTX | Creation context of event `%s`.`%s` is invalid | | 1606 | HY000 | ER\_TRG\_CANT\_OPEN\_TABLE | Cannot open table for trigger `%s`.`%s` | | 1607 | HY000 | ER\_CANT\_CREATE\_SROUTINE | Cannot create stored routine `%s`. Check warnings | | 1608 | | ER\_UNUSED\_11 | You should never see it | | 1609 | HY000 | ER\_NO\_FORMAT\_DESCRIPTION\_EVENT \_BEFORE\_BINLOG\_STATEMENT | The BINLOG statement of type `%s` was not preceded by a format description BINLOG statement. | | 1610 | HY000 | ER\_SLAVE\_CORRUPT\_EVENT | Corrupted replication event was detected | | 1611 | HY000 | ER\_LOAD\_DATA\_INVALID\_COLUMN | Invalid column reference (%s) in LOAD DATA | | 1612 | HY000 | ER\_LOG\_PURGE\_NO\_FILE | Being purged log %s was not found | | 1613 | XA106 | ER\_XA\_RBTIMEOUT | XA\_RBTIMEOUT: Transaction branch was rolled back: took too long | | 1614 | XA102 | ER\_XA\_RBDEADLOCK | XA\_RBDEADLOCK: Transaction branch was rolled back: deadlock was detected | | 1615 | HY000 | ER\_NEED\_REPREPARE | Prepared statement needs to be re-prepared | | 1616 | HY000 | ER\_DELAYED\_NOT\_SUPPORTED | DELAYED option not supported for table '%s' | | 1617 | HY000 | WARN\_NO\_MASTER\_INF | The master info structure does not exist | | 1618 | HY000 | WARN\_OPTION\_IGNORED | <%s> option ignored | | 1619 | HY000 | WARN\_PLUGIN\_DELETE\_BUILTIN | Built-in plugins cannot be deleted | | 1620 | HY000 | WARN\_PLUGIN\_BUSY | Plugin is busy and will be uninstalled on shutdown | | 1621 | HY000 | ER\_VARIABLE\_IS\_READONLY | %s variable '%s' is read-only. Use SET %s to assign the value | | 1622 | HY000 | ER\_WARN\_ENGINE\_TRANSACTION\_ROLLBACK | Storage engine %s does not support rollback for this statement. Transaction rolled back and must be restarted | | 1623 | HY000 | ER\_SLAVE\_HEARTBEAT\_FAILURE | Unexpected master's heartbeat data: %s | | 1624 | HY000 | ER\_SLAVE\_HEARTBEAT\_VALUE\_OUT\_OF\_RANGE | The requested value for the heartbeat period is either negative or exceeds the maximum allowed (%s seconds). | | 1625 | | ER\_UNUSED\_14 | You should never see it | | 1626 | HY000 | ER\_CONFLICT\_FN\_PARSE\_ERROR | Error in parsing conflict function. Message: %s | | 1627 | HY000 | ER\_EXCEPTIONS\_WRITE\_ERROR | Write to exceptions table failed. Message: %s" | | 1628 | HY000 | ER\_TOO\_LONG\_TABLE\_COMMENT | Comment for table '%s' is too long (max = %lu) | | 1629 | HY000 | ER\_TOO\_LONG\_FIELD\_COMMENT | Comment for field '%s' is too long (max = %lu) | | 1630 | 42000 | ER\_FUNC\_INEXISTENT\_NAME\_COLLISION | FUNCTION %s does not exist. Check the 'Function Name Parsing and Resolution' section in the Reference Manual | | 1631 | HY000 | ER\_DATABASE\_NAME | Database | | 1632 | HY000 | ER\_TABLE\_NAME | Table | | 1633 | HY000 | ER\_PARTITION\_NAME | Partition | | 1634 | HY000 | ER\_SUBPARTITION\_NAME | Subpartition | | 1635 | HY000 | ER\_TEMPORARY\_NAME | Temporary | | 1636 | HY000 | ER\_RENAMED\_NAME | Renamed | | 1637 | HY000 | ER\_TOO\_MANY\_CONCURRENT\_TRXS | Too many active concurrent transactions | | 1638 | HY000 | WARN\_NON\_ASCII\_SEPARATOR\_NOT\_IMPLEMENTED | Non-ASCII separator arguments are not fully supported | | 1639 | HY000 | ER\_DEBUG\_SYNC\_TIMEOUT | debug sync point wait timed out | | 1640 | HY000 | ER\_DEBUG\_SYNC\_HIT\_LIMIT | debug sync point hit limit reached | | 1641 | 42000 | ER\_DUP\_SIGNAL\_SET | Duplicate condition information item '%s' | | 1642 | 01000 | ER\_SIGNAL\_WARN | Unhandled user-defined warning condition | | 1643 | 02000 | ER\_SIGNAL\_NOT\_FOUND | Unhandled user-defined not found condition | | 1644 | HY000 | ER\_SIGNAL\_EXCEPTION | Unhandled user-defined exception condition | | 1645 | 0K000 | ER\_RESIGNAL\_WITHOUT\_ACTIVE\_HANDLER | RESIGNAL when handler not active | | 1646 | HY000 | ER\_SIGNAL\_BAD\_CONDITION\_TYPE | SIGNAL/RESIGNAL can only use a CONDITION defined with SQLSTATE | | 1647 | HY000 | WARN\_COND\_ITEM\_TRUNCATED | Data truncated for condition item '%s' | | 1648 | HY000 | ER\_COND\_ITEM\_TOO\_LONG | Data too long for condition item '%s' | | 1649 | HY000 | ER\_UNKNOWN\_LOCALE | Unknown locale: '%s' | | 1650 | HY000 | ER\_SLAVE\_IGNORE\_SERVER\_IDS | The requested server id %d clashes with the slave startup option --replicate-same-server-id | | 1651 | HY000 | ER\_QUERY\_CACHE\_DISABLED | Query cache is disabled; restart the server with query\_cache\_type=1 to enable it | | 1652 | HY000 | ER\_SAME\_NAME\_PARTITION\_FIELD | Duplicate partition field name '%s' | | 1653 | HY000 | ER\_PARTITION\_COLUMN\_LIST\_ERROR | Inconsistency in usage of column lists for partitioning | | 1654 | HY000 | ER\_WRONG\_TYPE\_COLUMN\_VALUE\_ERROR | Partition column values of incorrect type | | 1655 | HY000 | ER\_TOO\_MANY\_PARTITION\_FUNC\_FIELDS\_ERROR | Too many fields in '%s' | | 1656 | HY000 | ER\_MAXVALUE\_IN\_VALUES\_IN | Cannot use MAXVALUE as value in VALUES IN | | 1657 | HY000 | ER\_TOO\_MANY\_VALUES\_ERROR | Cannot have more than one value for this type of %s partitioning | | 1658 | HY000 | ER\_ROW\_SINGLE\_PARTITION\_FIELD\_ERROR | Row expressions in VALUES IN only allowed for multi-field column partitioning | | 1659 | HY000 | ER\_FIELD\_TYPE\_NOT\_ALLOWED\_AS\_PARTITION\_FIELD | Field '%s' is of a not allowed type for this type of partitioning | | 1660 | HY000 | ER\_PARTITION\_FIELDS\_TOO\_LONG | The total length of the partitioning fields is too large | | 1661 | HY000 | ER\_BINLOG\_ROW\_ENGINE\_AND\_STMT\_ENGINE | Cannot execute statement: impossible to write to binary log since both row-incapable engines and statement-incapable engines are involved. | | 1662 | HY000 | ER\_BINLOG\_ROW\_MODE\_AND\_STMT\_ENGINE | Cannot execute statement: impossible to write to binary log since BINLOG\_FORMAT = ROW and at least one table uses a storage engine limited to statement-based logging. | | 1663 | HY000 | ER\_BINLOG\_UNSAFE\_AND\_STMT\_ENGINE | Cannot execute statement: impossible to write to binary log since statement is unsafe, storage engine is limited to statement-based logging, and BINLOG\_FORMAT = MIXED. %s | | 1664 | HY000 | ER\_BINLOG\_ROW\_INJECTION\_AND\_STMT\_ENGINE | Cannot execute statement: impossible to write to binary log since statement is in row format and at least one table uses a storage engine limited to statement-based logging. | | 1665 | HY000 | ER\_BINLOG\_STMT\_MODE\_AND\_ROW\_ENGINE | Cannot execute statement: impossible to write to binary log since BINLOG\_FORMAT = STATEMENT and at least one table uses a storage engine limited to row-based logging.%s | | 1666 | HY000 | ER\_BINLOG\_ROW\_INJECTION\_AND\_STMT\_MODE | Cannot execute statement: impossible to write to binary log since statement is in row format and BINLOG\_FORMAT = STATEMENT. | | 1667 | HY000 | ER\_BINLOG\_MULTIPLE\_ENGINES \_AND\_SELF\_LOGGING\_ENGINE | Cannot execute statement: impossible to write to binary log since more than one engine is involved and at least one engine is self-logging. | | 1668 | HY000 | ER\_BINLOG\_UNSAFE\_LIMIT | The statement is unsafe because it uses a LIMIT clause. This is unsafe because the set of rows included cannot be predicted. | | 1669 | HY000 | ER\_BINLOG\_UNSAFE\_INSERT\_DELAYED | The statement is unsafe because it uses INSERT DELAYED. This is unsafe because the times when rows are inserted cannot be predicted. | | 1670 | HY000 | ER\_BINLOG\_UNSAFE\_SYSTEM\_TABLE | The statement is unsafe because it uses the general log, slow query log, or performance\_schema table(s). This is unsafe because system tables may differ on slaves. | | 1671 | HY000 | ER\_BINLOG\_UNSAFE\_AUTOINC\_COLUMNS | Statement is unsafe because it invokes a trigger or a stored function that inserts into an AUTO\_INCREMENT column. Inserted values cannot be logged correctly. | | 1672 | HY000 | ER\_BINLOG\_UNSAFE\_UDF | Statement is unsafe because it uses a UDF which may not return the same value on the slave. | | 1673 | HY000 | ER\_BINLOG\_UNSAFE\_SYSTEM\_VARIABLE | Statement is unsafe because it uses a system variable that may have a different value on the slave. | | 1674 | HY000 | ER\_BINLOG\_UNSAFE\_SYSTEM\_FUNCTION | Statement is unsafe because it uses a system function that may return a different value on the slave. | | 1675 | HY000 | ER\_BINLOG\_UNSAFE\_NONTRANS\_AFTER\_TRANS | Statement is unsafe because it accesses a non-transactional table after accessing a transactional table within the same transaction. | | 1676 | HY000 | ER\_MESSAGE\_AND\_STATEMENT | %s Statement: %s | | 1677 | HY000 | ER\_SLAVE\_CONVERSION\_FAILED | Column %d of table '%s.%s' cannot be converted from type '%s' to type '%s' | | 1678 | HY000 | ER\_SLAVE\_CANT\_CREATE\_CONVERSION | Can't create conversion table for table '%s.%s' | | 1679 | HY000 | ER\_INSIDE\_TRANSACTION \_PREVENTS\_SWITCH\_BINLOG\_FORMAT | Cannot modify @@session.binlog\_format inside a transaction | | 1680 | HY000 | ER\_PATH\_LENGTH | The path specified for %s is too long. | | 1681 | HY000 | ER\_WARN\_DEPRECATED\_SYNTAX\_NO\_REPLACEMENT | '%s' is deprecated and will be removed in a future release. | | 1682 | HY000 | ER\_WRONG\_NATIVE\_TABLE\_STRUCTURE | Native table '%s'.'%s' has the wrong structure | | 1683 | HY000 | ER\_WRONG\_PERFSCHEMA\_USAGE | Invalid performance\_schema usage. | | 1684 | HY000 | ER\_WARN\_I\_S\_SKIPPED\_TABLE | Table '%s'.'%s' was skipped since its definition is being modified by concurrent DDL statement | | 1685 | HY000 | ER\_INSIDE\_TRANSACTION \_PREVENTS\_SWITCH\_BINLOG\_DIRECT | Cannot modify @@session.binlog\_direct\_non\_transactional\_updates inside a transaction | | 1686 | HY000 | ER\_STORED\_FUNCTION\_PREVENTS \_SWITCH\_BINLOG\_DIRECT | Cannot change the binlog direct flag inside a stored function or trigger | | 1687 | 42000 | ER\_SPATIAL\_MUST\_HAVE\_GEOM\_COL | A SPATIAL index may only contain a geometrical type column | | 1688 | HY000 | ER\_TOO\_LONG\_INDEX\_COMMENT | Comment for index '%s' is too long (max = %lu) | | 1689 | HY000 | ER\_LOCK\_ABORTED | Wait on a lock was aborted due to a pending exclusive lock | | 1690 | 22003 | ER\_DATA\_OUT\_OF\_RANGE | %s value is out of range in '%s' | | 1691 | HY000 | ER\_WRONG\_SPVAR\_TYPE\_IN\_LIMIT | A variable of a non-integer based type in LIMIT clause | | 1692 | HY000 | ER\_BINLOG\_UNSAFE\_MULTIPLE\_ENGINES \_AND\_SELF\_LOGGING\_ENGINE | Mixing self-logging and non-self-logging engines in a statement is unsafe. | | 1693 | HY000 | ER\_BINLOG\_UNSAFE\_MIXED\_STATEMENT | Statement accesses nontransactional table as well as transactional or temporary table, and writes to any of them. | | 1694 | HY000 | ER\_INSIDE\_TRANSACTION\_ PREVENTS\_SWITCH\_SQL\_LOG\_BIN | Cannot modify @@session.sql\_log\_bin inside a transaction | | 1695 | HY000 | ER\_STORED\_FUNCTION\_ PREVENTS\_SWITCH\_SQL\_LOG\_BIN | Cannot change the sql\_log\_bin inside a stored function or trigger | | 1696 | HY000 | ER\_FAILED\_READ\_FROM\_PAR\_FILE | Failed to read from the .par file | | 1697 | HY000 | ER\_VALUES\_IS\_NOT\_INT\_TYPE\_ERROR | VALUES value for partition '%s' must have type INT | | 1698 | 28000 | ER\_ACCESS\_DENIED\_NO\_PASSWORD\_ERROR | Access denied for user '%s'@'%s' | | 1699 | HY000 | ER\_SET\_PASSWORD\_AUTH\_PLUGIN | SET PASSWORD has no significance for users authenticating via plugins | | Error Code | SQLSTATE | Error | Description | | --- | --- | --- | --- | | 1700 | HY000 | ER\_GRANT\_PLUGIN\_USER\_EXISTS | GRANT with IDENTIFIED WITH is illegal because the user %-.\*s already exists | | 1701 | 42000 | ER\_TRUNCATE\_ILLEGAL\_FK | Cannot truncate a table referenced in a foreign key constraint (%s) | | 1702 | HY000 | ER\_PLUGIN\_IS\_PERMANENT | Plugin '%s' is force\_plus\_permanent and can not be unloaded | | 1703 | HY000 | ER\_SLAVE\_HEARTBEAT\_VALUE\_OUT\_OF\_RANGE\_MIN | The requested value for the heartbeat period is less than 1 millisecond. The value is reset to 0, meaning that heartbeating will effectively be disabled. | | 1704 | HY000 | ER\_SLAVE\_HEARTBEAT\_VALUE\_OUT\_OF\_RANGE\_MAX | The requested value for the heartbeat period exceeds the value of [slave\_net\_timeout](../replication-and-binary-log-server-system-variables/index#slave_net_timeout) seconds. A sensible value for the period should be less than the timeout. | | 1705 | HY000 | ER\_STMT\_CACHE\_FULL | Multi-row statements required more than 'max\_binlog\_stmt\_cache\_size' bytes of storage; increase this mysqld variable and try again | | 1706 | HY000 | ER\_MULTI\_UPDATE\_KEY\_CONFLICT | Primary key/partition key update is not allowed since the table is updated both as '%s' and '%s'. | | 1707 | HY000 | ER\_TABLE\_NEEDS\_REBUILD | Table rebuild required. Please do "ALTER TABLE `%s` FORCE" or dump/reload to fix it! | | 1708 | HY000 | WARN\_OPTION\_BELOW\_LIMIT | The value of '%s' should be no less than the value of '%s' | | 1709 | HY000 | ER\_INDEX\_COLUMN\_TOO\_LONG | Index column size too large. The maximum column size is %lu bytes. | | 1710 | HY000 | ER\_ERROR\_IN\_TRIGGER\_BODY | Trigger '%s' has an error in its body: '%s' | | 1711 | HY000 | ER\_ERROR\_IN\_UNKNOWN\_TRIGGER\_BODY | Unknown trigger has an error in its body: '%s' | | 1712 | HY000 | ER\_INDEX\_CORRUPT | Index %s is corrupted | | 1713 | HY000 | ER\_UNDO\_RECORD\_TOO\_BIG | [Undo log](../undo-log/index) record is too big. | | 1714 | HY000 | ER\_BINLOG\_UNSAFE\_INSERT\_IGNORE\_SELECT | INSERT IGNORE... SELECT is unsafe because the order in which rows are retrieved by the SELECT determines which (if any) rows are ignored. This order cannot be predicted and may differ on master and the slave. | | 1715 | HY000 | ER\_BINLOG\_UNSAFE\_INSERT\_SELECT\_UPDATE | INSERT... SELECT... ON DUPLICATE KEY UPDATE is unsafe because the order in which rows are retrieved by the SELECT determines which (if any) rows are updated. This order cannot be predicted and may differ on master and the slave. | | 1716 | HY000 | ER\_BINLOG\_UNSAFE\_REPLACE\_SELECT | REPLACE... SELECT is unsafe because the order in which rows are retrieved by the SELECT determines which (if any) rows are replaced. This order cannot be predicted and may differ on master and the slave. | | 1717 | HY000 | ER\_BINLOG\_UNSAFE\_CREATE\_IGNORE\_SELECT | CREATE... IGNORE SELECT is unsafe because the order in which rows are retrieved by the SELECT determines which (if any) rows are ignored. This order cannot be predicted and may differ on master and the slave. | | 1718 | HY000 | ER\_BINLOG\_UNSAFE\_CREATE\_REPLACE\_SELECT | CREATE... REPLACE SELECT is unsafe because the order in which rows are retrieved by the SELECT determines which (if any) rows are replaced. This order cannot be predicted and may differ on master and the slave. | | 1719 | HY000 | ER\_BINLOG\_UNSAFE\_UPDATE\_IGNORE | UPDATE IGNORE is unsafe because the order in which rows are updated determines which (if any) rows are ignored. This order cannot be predicted and may differ on master and the slave. | | 1720 | | ER\_UNUSED\_15 | You should never see it | | 1721 | | ER\_UNUSED\_16 | You should never see it | | 1722 | HY000 | ER\_BINLOG\_UNSAFE\_WRITE\_AUTOINC\_SELECT | Statements writing to a table with an auto-increment column after selecting from another table are unsafe because the order in which rows are retrieved determines what (if any) rows will be written. This order cannot be predicted and may differ on master and the slave. | | 1723 | HY000 | ER\_BINLOG\_UNSAFE\_CREATE\_SELECT\_AUTOINC | CREATE TABLE... SELECT... on a table with an auto-increment column is unsafe because the order in which rows are retrieved by the SELECT determines which (if any) rows are inserted. This order cannot be predicted and may differ on master and the slave. | | 1724 | HY000 | ER\_BINLOG\_UNSAFE\_INSERT\_TWO\_KEYS | INSERT... ON DUPLICATE KEY UPDATE on a table with more than one UNIQUE KEY is unsafe | | 1725 | HY000 | ER\_TABLE\_IN\_FK\_CHECK | Table is being used in foreign key check. | | 1726 | HY000 | ER\_UNSUPPORTED\_ENGINE | Storage engine '%s' does not support system tables. [%s.%s] | | 1727 | HY000 | ER\_BINLOG\_UNSAFE\_AUTOINC\_NOT\_FIRST | INSERT into autoincrement field which is not the first part in the composed primary key is unsafe. | | 1728 | HY000 | ER\_CANNOT\_LOAD\_FROM\_TABLE\_V2 | Cannot load from %s.%s. The table is probably corrupted | | 1729 | HY000 | ER\_MASTER\_DELAY\_VALUE\_OUT\_OF\_RANGE | The requested value %s for the master delay exceeds the maximum %u | | 1730 | HY000 | ER\_ONLY\_FD\_AND\_RBR\_EVENTS\_ALLOWED\_IN\_BINLOG\_STATEMENT | Only Format\_description\_log\_event and row events are allowed in BINLOG statements (but %s was provided | | 1731 | HY000 | ER\_PARTITION\_EXCHANGE\_DIFFERENT\_OPTION | Non matching attribute '%s' between partition and table | | 1732 | HY000 | ER\_PARTITION\_EXCHANGE\_PART\_TABLE | Table to exchange with partition is partitioned: '%s' | | 1733 | HY000 | ER\_PARTITION\_EXCHANGE\_TEMP\_TABLE | Table to exchange with partition is temporary: '%s' | | 1734 | HY000 | ER\_PARTITION\_INSTEAD\_OF\_SUBPARTITION | Subpartitioned table, use subpartition instead of partition | | 1735 | HY000 | ER\_UNKNOWN\_PARTITION | Unknown partition '%s' in table '%s' | | 1736 | HY000 | ER\_TABLES\_DIFFERENT\_METADATA | Tables have different definitions | | 1737 | HY000 | ER\_ROW\_DOES\_NOT\_MATCH\_PARTITION | Found a row that does not match the partition | | 1738 | HY000 | ER\_BINLOG\_CACHE\_SIZE\_GREATER\_THAN\_MAX | Option binlog\_cache\_size (%lu) is greater than max\_binlog\_cache\_size (%lu); setting binlog\_cache\_size equal to max\_binlog\_cache\_size. | | 1739 | HY000 | ER\_WARN\_INDEX\_NOT\_APPLICABLE | Cannot use %s access on index '%s' due to type or collation conversion on field '%s' | | 1740 | HY000 | ER\_PARTITION\_EXCHANGE\_FOREIGN\_KEY | Table to exchange with partition has foreign key references: '%s' | | 1741 | HY000 | ER\_NO\_SUCH\_KEY\_VALUE | Key value '%s' was not found in table '%s.%s' | | 1742 | HY000 | ER\_RPL\_INFO\_DATA\_TOO\_LONG | Data for column '%s' too long | | 1743 | HY000 | ER\_NETWORK\_READ\_EVENT\_CHECKSUM\_FAILURE | Replication event checksum verification failed while reading from network. | | 1744 | HY000 | ER\_BINLOG\_READ\_EVENT\_CHECKSUM\_FAILURE | Replication event checksum verification failed while reading from a log file. | | 1745 | HY000 | ER\_BINLOG\_STMT\_CACHE\_SIZE\_GREATER\_THAN\_MAX | Option binlog\_stmt\_cache\_size (%lu) is greater than max\_binlog\_stmt\_cache\_size (%lu); setting binlog\_stmt\_cache\_size equal to max\_binlog\_stmt\_cache\_size. | | 1746 | HY000 | ER\_CANT\_UPDATE\_TABLE\_IN\_CREATE\_TABLE\_SELECT | Can't update table '%s' while '%s' is being created. | | 1747 | HY000 | ER\_PARTITION\_CLAUSE\_ON\_NONPARTITIONED | PARTITION () clause on non partitioned table | | 1748 | HY000 | ER\_ROW\_DOES\_NOT\_MATCH\_GIVEN\_PARTITION\_SET | Found a row not matching the given partition set | | 1749 | HY000 | ER\_NO\_SUCH\_PARTITION\_UNUSED | partition '%s' doesn't exist | | 1750 | HY000 | ER\_CHANGE\_RPL\_INFO\_REPOSITORY\_FAILURE | Failure while changing the type of replication repository: %s. | | 1751 | HY000 | ER\_WARNING\_NOT\_COMPLETE\_ROLLBACK\_WITH\_CREATED\_TEMP\_TABLE | The creation of some temporary tables could not be rolled back. | | 1752 | HY000 | ER\_WARNING\_NOT\_COMPLETE\_ROLLBACK\_WITH\_DROPPED\_TEMP\_TABLE | Some temporary tables were dropped, but these operations could not be rolled back. | | 1753 | HY000 | ER\_MTS\_FEATURE\_IS\_NOT\_SUPPORTED | %s is not supported in multi-threaded slave mode. %s | | 1754 | HY000 | ER\_MTS\_UPDATED\_DBS\_GREATER\_MAX | The number of modified databases exceeds the maximum %d; the database names will not be included in the replication event metadata. | | 1755 | HY000 | ER\_MTS\_CANT\_PARALLEL | Cannot execute the current event group in the parallel mode. Encountered event %s, relay-log name %s, position %s which prevents execution of this event group in parallel mode. Reason: %s. | | 1756 | HY000 | ER\_MTS\_INCONSISTENT\_DATA | %s | | 1757 | HY000 | ER\_FULLTEXT\_NOT\_SUPPORTED\_WITH\_PARTITIONING | FULLTEXT index is not supported for partitioned tables. | | 1758 | 35000 | ER\_DA\_INVALID\_CONDITION\_NUMBER | Invalid condition number | | 1759 | HY000 | ER\_INSECURE\_PLAIN\_TEXT | Sending passwords in plain text without SSL/TLS is extremely insecure. | | 1760 | HY000 | ER\_INSECURE\_CHANGE\_MASTER | Storing MySQL user name or password information in the master info repository is not secure and is therefore not recommended. Please consider using the USER and PASSWORD connection options for START SLAVE; see the 'START SLAVE Syntax' in the MySQL Manual for more information. | | 1761 | 23000 | ER\_FOREIGN\_DUPLICATE\_KEY\_WITH\_CHILD\_INFO | Foreign key constraint for table '%s', record '%s' would lead to a duplicate entry in table '%s', key '%s' | | 1762 | 23000 | ER\_FOREIGN\_DUPLICATE\_KEY\_WITHOUT\_CHILD\_INFO | Foreign key constraint for table '%s', record '%s' would lead to a duplicate entry in a child table | | 1763 | HY000 | ER\_SQLTHREAD\_WITH\_SECURE\_SLAVE | Setting authentication options is not possible when only the Slave SQL Thread is being started. | | 1764 | HY000 | ER\_TABLE\_HAS\_NO\_FT | The table does not have FULLTEXT index to support this query | | 1765 | HY000 | ER\_VARIABLE\_NOT\_SETTABLE\_IN\_SF\_OR\_TRIGGER | The system variable %s cannot be set in stored functions or triggers. | | 1766 | HY000 | ER\_VARIABLE\_NOT\_SETTABLE\_IN\_TRANSACTION | The system variable %s cannot be set when there is an ongoing transaction. | | 1767 | HY000 | ER\_GTID\_NEXT\_IS\_NOT\_IN\_GTID\_NEXT\_LIST | The system variable @@SESSION.GTID\_NEXT has the value %s, which is not listed in @@SESSION.GTID\_NEXT\_LIST. | | 1768 | HY000 | ER\_CANT\_CHANGE\_GTID\_NEXT\_IN\_TRANSACTION\_WHEN\_GTID\_NEXT\_LIST\_IS\_NULL | The system variable @@SESSION.GTID\_NEXT cannot change inside a transaction. | | 1769 | HY000 | ER\_SET\_STATEMENT\_CANNOT\_INVOKE\_FUNCTION | The statement 'SET %s' cannot invoke a stored function. | | 1770 | HY000 | ER\_GTID\_NEXT\_CANT\_BE\_AUTOMATIC\_IF\_GTID\_NEXT\_LIST\_IS\_NON\_NULL | The system variable @@SESSION.GTID\_NEXT cannot be 'AUTOMATIC' when @@SESSION.GTID\_NEXT\_LIST is non-NULL. | | 1771 | HY000 | ER\_SKIPPING\_LOGGED\_TRANSACTION | Skipping transaction %s because it has already been executed and logged. | | 1772 | HY000 | ER\_MALFORMED\_GTID\_SET\_SPECIFICATION | Malformed GTID set specification '%s'. | | 1773 | HY000 | ER\_MALFORMED\_GTID\_SET\_ENCODING | Malformed GTID set encoding. | | 1774 | HY000 | ER\_MALFORMED\_GTID\_SPECIFICATION | Malformed GTID specification '%s'. | | 1775 | HY000 | ER\_GNO\_EXHAUSTED | Impossible to generate Global Transaction Identifier: the integer component reached the maximal value. Restart the server with a new server\_uuid. | | 1776 | HY000 | ER\_BAD\_SLAVE\_AUTO\_POSITION | Parameters MASTER\_LOG\_FILE, MASTER\_LOG\_POS, RELAY\_LOG\_FILE and RELAY\_LOG\_POS cannot be set when MASTER\_AUTO\_POSITION is active. | | 1777 | HY000 | ER\_AUTO\_POSITION\_REQUIRES\_GTID\_MODE\_ON | CHANGE MASTER TO MASTER\_AUTO\_POSITION = 1 can only be executed when @@GLOBAL.GTID\_MODE = ON. | | 1778 | HY000 | ER\_CANT\_DO\_IMPLICIT\_COMMIT\_IN\_TRX\_WHEN\_GTID\_NEXT\_IS\_SET | Cannot execute statements with implicit commit inside a transaction when @@SESSION.GTID\_NEXT != AUTOMATIC. | | 1779 | HY000 | ER\_GTID\_MODE\_2\_OR\_3\_REQUIRES\_DISABLE\_GTID\_UNSAFE\_STATEMENTS\_ON | GTID\_MODE = ON or GTID\_MODE = UPGRADE\_STEP\_2 requires DISABLE\_GTID\_UNSAFE\_STATEMENTS = 1. | | 1779 | HY000 | ER\_GTID\_MODE\_2\_OR\_3\_REQUIRES\_ENFORCE\_GTID\_CONSISTENCY\_ON | @@GLOBAL.GTID\_MODE = ON or UPGRADE\_STEP\_2 requires @@GLOBAL.ENFORCE\_GTID\_CONSISTENCY = 1. | | 1780 | HY000 | ER\_GTID\_MODE\_REQUIRES\_BINLOG | @@GLOBAL.GTID\_MODE = ON or UPGRADE\_STEP\_1 or UPGRADE\_STEP\_2 requires --log-bin and --log-slave-updates. | | 1781 | HY000 | ER\_CANT\_SET\_GTID\_NEXT\_TO\_GTID\_WHEN\_GTID\_MODE\_IS\_OFF | @@SESSION.GTID\_NEXT cannot be set to UUID:NUMBER when @@GLOBAL.GTID\_MODE = OFF. | | 1782 | HY000 | ER\_CANT\_SET\_GTID\_NEXT\_TO\_ANONYMOUS\_WHEN\_GTID\_MODE\_IS\_ON | @@SESSION.GTID\_NEXT cannot be set to ANONYMOUS when @@GLOBAL.GTID\_MODE = ON. | | 1783 | HY000 | ER\_CANT\_SET\_GTID\_NEXT\_LIST\_TO\_NON\_NULL\_WHEN\_GTID\_MODE\_IS\_OFF | @@SESSION.GTID\_NEXT\_LIST cannot be set to a non-NULL value when @@GLOBAL.GTID\_MODE = OFF. | | 1784 | HY000 | ER\_FOUND\_GTID\_EVENT\_WHEN\_GTID\_MODE\_IS\_OFF | Found a Gtid\_log\_event or Previous\_gtids\_log\_event when @@GLOBAL.GTID\_MODE = OFF. | | 1785 | HY000 | ER\_GTID\_UNSAFE\_NON\_TRANSACTIONAL\_TABLE | When @@GLOBAL.ENFORCE\_GTID\_CONSISTENCY = 1, updates to non-transactional tables can only be done in either autocommitted statements or single-statement transactions, and never in the same statement as updates to transactional tables. | | 1786 | HY000 | ER\_GTID\_UNSAFE\_CREATE\_SELECT | CREATE TABLE ... SELECT is forbidden when @@GLOBAL.ENFORCE\_GTID\_CONSISTENCY = 1. | | 1787 | HY000 | ER\_GTID\_UNSAFE\_CREATE\_DROP\_TEMPORARY\_TABLE\_IN\_TRANSACTION | When @@GLOBAL.ENFORCE\_GTID\_CONSISTENCY = 1, the statements CREATE TEMPORARY TABLE and DROP TEMPORARY TABLE can be executed in a non-transactional context only, and require that AUTOCOMMIT = 1. | | 1788 | HY000 | ER\_GTID\_MODE\_CAN\_ONLY\_CHANGE\_ONE\_STEP\_AT\_A\_TIME | The value of @@GLOBAL.GTID\_MODE can only change one step at a time: OFF <-> UPGRADE\_STEP\_1 <-> UPGRADE\_STEP\_2 <-> ON. Also note that this value must be stepped up or down simultaneously on all servers; see the Manual for instructions. | | 1789 | HY000 | ER\_MASTER\_HAS\_PURGED\_REQUIRED\_GTIDS | The slave is connecting using CHANGE MASTER TO MASTER\_AUTO\_POSITION = 1, but the master has purged binary logs containing GTIDs that the slave requires. | | 1790 | HY000 | ER\_CANT\_SET\_GTID\_NEXT\_WHEN\_OWNING\_GTID | @@SESSION.GTID\_NEXT cannot be changed by a client that owns a GTID. The client owns %s. Ownership is released on COMMIT or ROLLBACK. | | 1791 | HY000 | ER\_UNKNOWN\_EXPLAIN\_FORMAT | Unknown EXPLAIN format name: '%s' | | 1792 | 25006 | ER\_CANT\_EXECUTE\_IN\_READ\_ONLY\_TRANSACTION | Cannot execute statement in a READ ONLY transaction. | | 1793 | HY000 | ER\_TOO\_LONG\_TABLE\_PARTITION\_COMMENT | Comment for table partition '%s' is too long (max = %lu | | 1794 | HY000 | ER\_SLAVE\_CONFIGURATION | Slave is not configured or failed to initialize properly. You must at least set --server-id to enable either a master or a slave. Additional error messages can be found in the MySQL error log. | | 1795 | HY000 | ER\_INNODB\_FT\_LIMIT | InnoDB presently supports one FULLTEXT index creation at a time | | 1796 | HY000 | ER\_INNODB\_NO\_FT\_TEMP\_TABLE | Cannot create FULLTEXT index on temporary InnoDB table | | 1797 | HY000 | ER\_INNODB\_FT\_WRONG\_DOCID\_COLUMN | Column '%s' is of wrong type for an InnoDB FULLTEXT index | | 1798 | HY000 | ER\_INNODB\_FT\_WRONG\_DOCID\_INDEX | Index '%s' is of wrong type for an InnoDB FULLTEXT index | | 1799 | HY000 | ER\_INNODB\_ONLINE\_LOG\_TOO\_BIG | Creating index '%s' required more than 'innodb\_online\_alter\_log\_max\_size' bytes of modification log. Please try again. | | Error Code | SQLSTATE | Error | Description | | --- | --- | --- | --- | | 1800 | HY000 | ER\_UNKNOWN\_ALTER\_ALGORITHM | Unknown ALGORITHM '%s' | | 1801 | HY000 | ER\_UNKNOWN\_ALTER\_LOCK | Unknown LOCK type '%s' | | 1802 | HY000 | ER\_MTS\_CHANGE\_MASTER\_CANT\_RUN\_WITH\_GAPS | CHANGE MASTER cannot be executed when the slave was stopped with an error or killed in MTS mode. Consider using RESET SLAVE or START SLAVE UNTIL. | | 1803 | HY000 | ER\_MTS\_RECOVERY\_FAILURE | Cannot recover after SLAVE errored out in parallel execution mode. Additional error messages can be found in the MySQL error log. | | 1804 | HY000 | ER\_MTS\_RESET\_WORKERS | Cannot clean up worker info tables. Additional error messages can be found in the MySQL error log. | | 1805 | HY000 | ER\_COL\_COUNT\_DOESNT\_MATCH\_CORRUPTED\_V2 | Column count of %s.%s is wrong. Expected %d, found %d. The table is probably corrupted | | 1806 | HY000 | ER\_SLAVE\_SILENT\_RETRY\_TRANSACTION | Slave must silently retry current transaction | | 1807 | HY000 | ER\_DISCARD\_FK\_CHECKS\_RUNNING | There is a foreign key check running on table '%s'. Cannot discard the table. | | 1808 | HY000 | ER\_TABLE\_SCHEMA\_MISMATCH | Schema mismatch (%s | | 1809 | HY000 | ER\_TABLE\_IN\_SYSTEM\_TABLESPACE | Table '%s' in system tablespace | | 1810 | HY000 | ER\_IO\_READ\_ERROR | IO Read error: (%lu, %s) %s | | 1811 | HY000 | ER\_IO\_WRITE\_ERROR | IO Write error: (%lu, %s) %s | | 1812 | HY000 | ER\_TABLESPACE\_MISSING | Tablespace is missing for table '%s' | | 1813 | HY000 | ER\_TABLESPACE\_EXISTS | Tablespace for table '%s' exists. Please DISCARD the tablespace before IMPORT. | | 1814 | HY000 | ER\_TABLESPACE\_DISCARDED | Tablespace has been discarded for table '%s' | | 1815 | HY000 | ER\_INTERNAL\_ERROR | Internal error: %s | | 1816 | HY000 | ER\_INNODB\_IMPORT\_ERROR | ALTER TABLE '%s' IMPORT TABLESPACE failed with error %lu : '%s' | | 1817 | HY000 | ER\_INNODB\_INDEX\_CORRUPT | Index corrupt: %s | | 1818 | HY000 | ER\_INVALID\_YEAR\_COLUMN\_LENGTH | YEAR(%lu) column type is deprecated. Creating YEAR(4) column instead. | | 1819 | HY000 | ER\_NOT\_VALID\_PASSWORD | Your password does not satisfy the current policy requirements | | 1820 | HY000 | ER\_MUST\_CHANGE\_PASSWORD | You must SET PASSWORD before executing this statement | | 1821 | HY000 | ER\_FK\_NO\_INDEX\_CHILD | Failed to add the foreign key constaint. Missing index for constraint '%s' in the foreign table '%s' | | 1822 | HY000 | ER\_FK\_NO\_INDEX\_PARENT | Failed to add the foreign key constaint. Missing index for constraint '%s' in the referenced table '%s' | | 1823 | HY000 | ER\_FK\_FAIL\_ADD\_SYSTEM | Failed to add the foreign key constraint '%s' to system tables | | 1824 | HY000 | ER\_FK\_CANNOT\_OPEN\_PARENT | Failed to open the referenced table '%s' | | 1825 | HY000 | ER\_FK\_INCORRECT\_OPTION | Failed to add the foreign key constraint on table '%s'. Incorrect options in FOREIGN KEY constraint '%s' | | 1826 | HY000 | ER\_FK\_DUP\_NAME | Duplicate foreign key constraint name '%s' | | 1827 | HY000 | ER\_PASSWORD\_FORMAT | The password hash doesn't have the expected format. Check if the correct password algorithm is being used with the PASSWORD() function. | | 1828 | HY000 | ER\_FK\_COLUMN\_CANNOT\_DROP | Cannot drop column '%s': needed in a foreign key constraint '%s' | | 1829 | HY000 | ER\_FK\_COLUMN\_CANNOT\_DROP\_CHILD | Cannot drop column '%s': needed in a foreign key constraint '%s' of table '%s' | | 1830 | HY000 | ER\_FK\_COLUMN\_NOT\_NULL | Column '%s' cannot be NOT NULL: needed in a foreign key constraint '%s' SET NULL | | 1831 | HY000 | ER\_DUP\_INDEX | Duplicate index '%s' defined on the table '%s.%s'. This is deprecated and will be disallowed in a future release. | | 1832 | HY000 | ER\_FK\_COLUMN\_CANNOT\_CHANGE | Cannot change column '%s': used in a foreign key constraint '%s' | | 1833 | HY000 | ER\_FK\_COLUMN\_CANNOT\_CHANGE\_CHILD | Cannot change column '%s': used in a foreign key constraint '%s' of table '%s' | | 1834 | HY000 | ER\_FK\_CANNOT\_DELETE\_PARENT | Cannot delete rows from table which is parent in a foreign key constraint '%s' of table '%s' | | 1835 | HY000 | ER\_MALFORMED\_PACKET | Malformed communication packet. | | 1836 | HY000 | ER\_READ\_ONLY\_MODE | Running in read-only mode | | 1837 | HY000 | ER\_GTID\_NEXT\_TYPE\_UNDEFINED\_GROUP | When @@SESSION.GTID\_NEXT is set to a GTID, you must explicitly set it to a different value after a COMMIT or ROLLBACK. Please check GTID\_NEXT variable manual page for detailed explanation. Current @@SESSION.GTID\_NEXT is '%s'. | | 1838 | HY000 | ER\_VARIABLE\_NOT\_SETTABLE\_IN\_SP | The system variable %s cannot be set in stored procedures. | | 1839 | HY000 | ER\_CANT\_SET\_GTID\_PURGED\_WHEN\_GTID\_MODE\_IS\_OFF | @@GLOBAL.GTID\_PURGED can only be set when @@GLOBAL.GTID\_MODE = ON. | | 1840 | HY000 | ER\_CANT\_SET\_GTID\_PURGED\_WHEN\_GTID\_EXECUTED\_IS\_NOT\_EMPTY | @@GLOBAL.GTID\_PURGED can only be set when @@GLOBAL.GTID\_EXECUTED is empty. | | 1841 | HY000 | ER\_CANT\_SET\_GTID\_PURGED\_WHEN\_OWNED\_GTIDS\_IS\_NOT\_EMPTY | @@GLOBAL.GTID\_PURGED can only be set when there are no ongoing transactions (not even in other clients). | | 1842 | HY000 | ER\_GTID\_PURGED\_WAS\_CHANGED | @@GLOBAL.GTID\_PURGED was changed from '%s' to '%s'. | | 1843 | HY000 | ER\_GTID\_EXECUTED\_WAS\_CHANGED | @@GLOBAL.GTID\_EXECUTED was changed from '%s' to '%s'. | | 1844 | HY000 | ER\_BINLOG\_STMT\_MODE\_AND\_NO\_REPL\_TABLES | Cannot execute statement: impossible to write to binary log since BINLOG\_FORMAT = STATEMENT, and both replicated and non replicated tables are written to. | | 1845 | 0A000 | ER\_ALTER\_OPERATION\_NOT\_SUPPORTED | %s is not supported for this operation. Try %s. | | 1846 | 0A000 | ER\_ALTER\_OPERATION\_NOT\_SUPPORTED\_REASON | %s is not supported. Reason: %s. Try %s. | | 1847 | HY000 | ER\_ALTER\_OPERATION\_NOT\_SUPPORTED\_REASON\_COPY | COPY algorithm requires a lock | | 1848 | HY000 | ER\_ALTER\_OPERATION\_NOT\_SUPPORTED\_REASON\_PARTITION | Partition specific operations do not yet support LOCK/ALGORITHM | | 1849 | HY000 | ER\_ALTER\_OPERATION\_NOT\_SUPPORTED\_REASON\_FK\_RENAME | Columns participating in a foreign key are renamed | | 1850 | HY000 | ER\_ALTER\_OPERATION\_NOT\_SUPPORTED\_REASON\_COLUMN\_TYPE | Cannot change column type INPLACE | | 1851 | HY000 | ER\_ALTER\_OPERATION\_NOT\_SUPPORTED\_REASON\_FK\_CHECK | Adding foreign keys needs foreign\_key\_checks=OFF | | 1852 | HY000 | ER\_ALTER\_OPERATION\_NOT\_SUPPORTED\_REASON\_IGNORE | Creating unique indexes with IGNORE requires COPY algorithm to remove duplicate rows | | 1853 | HY000 | ER\_ALTER\_OPERATION\_NOT\_SUPPORTED\_REASON\_NOPK | Dropping a primary key is not allowed without also adding a new primary key | | 1854 | HY000 | ER\_ALTER\_OPERATION\_NOT\_SUPPORTED\_REASON\_AUTOINC | Adding an auto-increment column requires a lock | | 1855 | HY000 | ER\_ALTER\_OPERATION\_NOT\_SUPPORTED\_REASON\_HIDDEN\_FTS | Cannot replace hidden FTS\_DOC\_ID with a user-visible one | | 1856 | HY000 | ER\_ALTER\_OPERATION\_NOT\_SUPPORTED\_REASON\_CHANGE\_FTS | Cannot drop or rename FTS\_DOC\_ID | | 1857 | HY000 | ER\_ALTER\_OPERATION\_NOT\_SUPPORTED\_REASON\_FTS | Fulltext index creation requires a lock | | 1858 | HY000 | ER\_SQL\_SLAVE\_SKIP\_COUNTER\_NOT\_SETTABLE\_IN\_GTID\_MODE | sql\_slave\_skip\_counter can not be set when the server is running with @@GLOBAL.GTID\_MODE = ON. Instead, for each transaction that you want to skip, generate an empty transaction with the same GTID as the transaction | | 1859 | 23000 | ER\_DUP\_UNKNOWN\_IN\_INDEX | Duplicate entry for key '%s' | | 1860 | HY000 | ER\_IDENT\_CAUSES\_TOO\_LONG\_PATH | Long database name and identifier for object resulted in path length exceeding %d characters. Path: '%s'. | | 1861 | HY000 | ER\_ALTER\_OPERATION\_NOT\_SUPPORTED\_REASON\_NOT\_NULL | cannot silently convert NULL values, as required in this SQL\_MODE | | 1862 | HY000 | ER\_MUST\_CHANGE\_PASSWORD\_LOGIN | Your password has expired. To log in you must change it using a client that supports expired passwords. | | 1863 | HY000 | ER\_ROW\_IN\_WRONG\_PARTITION | Found a row in wrong partition %s | | 1864 | HY000 | ER\_MTS\_EVENT\_BIGGER\_PENDING\_JOBS\_SIZE\_MAX | Cannot schedule event %s, relay-log name %s, position %s to Worker thread because its size %lu exceeds %lu of slave\_pending\_jobs\_size\_max. | | 1865 | HY000 | ER\_INNODB\_NO\_FT\_USES\_PARSER | Cannot CREATE FULLTEXT INDEX WITH PARSER on InnoDB table | | 1866 | HY000 | ER\_BINLOG\_LOGICAL\_CORRUPTION | The binary log file '%s' is logically corrupted: %s | | 1867 | HY000 | ER\_WARN\_PURGE\_LOG\_IN\_USE | file %s was not purged because it was being read by %d thread(s), purged only %d out of %d files. | | 1868 | HY000 | ER\_WARN\_PURGE\_LOG\_IS\_ACTIVE | file %s was not purged because it is the active log file. | | 1869 | HY000 | ER\_AUTO\_INCREMENT\_CONFLICT | Auto-increment value in UPDATE conflicts with internally generated values | | 1870 | HY000 | WARN\_ON\_BLOCKHOLE\_IN\_RBR | Row events are not logged for %s statements that modify BLACKHOLE tables in row format. Table(s): '%s' | | 1871 | HY000 | ER\_SLAVE\_MI\_INIT\_REPOSITORY | Slave failed to initialize master info structure from the repository | | 1872 | HY000 | ER\_SLAVE\_RLI\_INIT\_REPOSITORY | Slave failed to initialize relay log info structure from the repository | | 1873 | 28000 | ER\_ACCESS\_DENIED\_CHANGE\_USER\_ERROR | Access denied trying to change to user '%s'@'%s' (using password: %s). Disconnecting. | | 1874 | HY000 | ER\_INNODB\_READ\_ONLY | InnoDB is in read only mode. | | 1875 | HY000 | ER\_STOP\_SLAVE\_SQL\_THREAD\_TIMEOUT | STOP SLAVE command execution is incomplete: Slave SQL thread got the stop signal, thread is busy, SQL thread will stop once the current task is complete. | | 1876 | HY000 | ER\_STOP\_SLAVE\_IO\_THREAD\_TIMEOUT | STOP SLAVE command execution is incomplete: Slave IO thread got the stop signal, thread is busy, IO thread will stop once the current task is complete. | | 1877 | HY000 | ER\_TABLE\_CORRUPT | Operation cannot be performed. The table '%s.%s' is missing, corrupt or contains bad data. | | 1878 | HY000 | ER\_TEMP\_FILE\_WRITE\_FAILURE | Temporary file write failure. | | 1879 | HY000 | ER\_INNODB\_FT\_AUX\_NOT\_HEX\_ID | Upgrade index name failed, please use create index(alter table) algorithm copy to rebuild index. | | 1880 | | ER\_LAST\_MYSQL\_ERROR\_MESSAGE | " | MariaDB-specific error codes ---------------------------- | Error Code | SQLSTATE | Error | Description | | --- | --- | --- | --- | | 1900 | | ER\_UNUSED\_18 | " | | 1901 | | ER\_GENERATED\_COLUMN\_FUNCTION\_IS\_NOT\_ALLOWED | Function or expression '%s' cannot be used in the %s clause of %`s | | 1902 | | ER\_UNUSED\_19 | " | | 1903 | | ER\_PRIMARY\_KEY\_BASED\_ON\_GENERATED\_COLUMN | Primary key cannot be defined upon a generated column | | 1904 | | ER\_KEY\_BASED\_ON\_GENERATED\_VIRTUAL\_COLUMN | Key/Index cannot be defined on a virtual generated column | | 1905 | | ER\_WRONG\_FK\_OPTION\_FOR\_GENERATED\_COLUMN | Cannot define foreign key with %s clause on a generated column | | 1906 | | ER\_WARNING\_NON\_DEFAULT\_VALUE\_FOR\_GENERATED\_COLUMN | The value specified for generated column '%s' in table '%s' has been ignored | | 1907 | | ER\_UNSUPPORTED\_ACTION\_ON\_GENERATED\_COLUMN | This is not yet supported for generated columns | | 1908 | | ER\_UNUSED\_20 | " | | 1909 | | ER\_UNUSED\_21 | " | | 1910 | | ER\_UNSUPPORTED\_ENGINE\_FOR\_GENERATED\_COLUMNS | %s storage engine does not support generated columns | | 1911 | | ER\_UNKNOWN\_OPTION | Unknown option '%-.64s' | | 1912 | | ER\_BAD\_OPTION\_VALUE | Incorrect value '%-.64s' for option '%-.64s' | | 1913 | | ER\_UNUSED\_6 | You should never see it | | 1914 | | ER\_UNUSED\_7 | You should never see it | | 1915 | | ER\_UNUSED\_8 | You should never see it | | 1916 | | ER\_DATA\_OVERFLOW 22003 | Got overflow when converting '%-.128s' to %-.32s. Value truncated. | | 1917 | | ER\_DATA\_TRUNCATED 22003 | Truncated value '%-.128s' when converting to %-.32s | | 1918 | | ER\_BAD\_DATA 22007 | Encountered illegal value '%-.128s' when converting to %-.32s | | 1919 | | ER\_DYN\_COL\_WRONG\_FORMAT | Encountered illegal format of dynamic column string | | 1920 | | ER\_DYN\_COL\_IMPLEMENTATION\_LIMIT | Dynamic column implementation limit reached | | 1921 | | ER\_DYN\_COL\_DATA 22007 | Illegal value used as argument of dynamic column function | | 1922 | | ER\_DYN\_COL\_WRONG\_CHARSET | Dynamic column contains unknown character set | | 1923 | | ER\_ILLEGAL\_SUBQUERY\_OPTIMIZER\_SWITCHES | At least one of the 'in\_to\_exists' or 'materialization' optimizer\_switch flags must be 'on'. | | 1924 | | ER\_QUERY\_CACHE\_IS\_DISABLED | Query cache is disabled (resize or similar command in progress); repeat this command later | | 1925 | | ER\_QUERY\_CACHE\_IS\_GLOBALY\_DISABLED | Query cache is globally disabled and you can't enable it only for this session | | 1926 | | ER\_VIEW\_ORDERBY\_IGNORED | View '%-.192s'.'%-.192s' ORDER BY clause ignored because there is other ORDER BY clause already. | | 1927 | | ER\_CONNECTION\_KILLED 70100 | Connection was killed | | 1928 | ER\_UNUSED\_11 | You should never see it | | 1929 | | ER\_INSIDE\_TRANSACTION\_PREVENTS\_SWITCH\_SKIP\_REPLICATION | Cannot modify @@session.skip\_replication inside a transaction | | 1930 | | ER\_STORED\_FUNCTION\_PREVENTS\_SWITCH\_SKIP\_REPLICATION | Cannot modify @@session.skip\_replication inside a stored function or trigger | | 1931 | | ER\_QUERY\_EXCEEDED\_ROWS\_EXAMINED\_LIMIT | Query execution was interrupted. The query examined at least %llu rows, which exceeds LIMIT ROWS EXAMINED (%llu). The query result may be incomplete. | | 1932 | | ER\_NO\_SUCH\_TABLE\_IN\_ENGINE 42S02 | Table '%-.192s.%-.192s' doesn't exist in engine | | 1933 | | ER\_TARGET\_NOT\_EXPLAINABLE | Target is not running an EXPLAINable command | | 1934 | | ER\_CONNECTION\_ALREADY\_EXISTS | Connection '%.\*s' conflicts with existing connection '%.\*s' | | 1935 | | ER\_MASTER\_LOG\_PREFIX | Master '%.\*s': | | 1936 | | ER\_CANT\_START\_STOP\_SLAVE | Can't %s SLAVE '%.\*s' | | 1937 | | ER\_SLAVE\_STARTED | SLAVE '%.\*s' started | | 1938 | | ER\_SLAVE\_STOPPED | SLAVE '%.\*s' stopped | | 1939 | | ER\_SQL\_DISCOVER\_ERROR | Engine %s failed to discover table %`-.192s.%`-.192s with '%s' | | 1940 | | ER\_FAILED\_GTID\_STATE\_INIT | Failed initializing replication GTID state | | 1941 | | ER\_INCORRECT\_GTID\_STATE | Could not parse GTID list | | 1942 | | ER\_CANNOT\_UPDATE\_GTID\_STATE | Could not update replication slave gtid state | | 1943 | | ER\_DUPLICATE\_GTID\_DOMAIN | GTID %u-%u-%llu and %u-%u-%llu conflict (duplicate domain id %u) | | 1944 | | ER\_GTID\_OPEN\_TABLE\_FAILED | Failed to open %s.%s | | 1945 | | ER\_GTID\_POSITION\_NOT\_FOUND\_IN\_BINLOG | Connecting slave requested to start from GTID %u-%u-%llu, which is not in the master's binlog | | 1946 | | ER\_CANNOT\_LOAD\_SLAVE\_GTID\_STATE | Failed to load replication slave GTID position from table %s.%s | | 1947 | | ER\_MASTER\_GTID\_POS\_CONFLICTS\_WITH\_BINLOG | Specified GTID %u-%u-%llu conflicts with the binary log which contains a more recent GTID %u-%u-%llu. If MASTER\_GTID\_POS=CURRENT\_POS is used, the binlog position will override the new value of @@gtid\_slave\_pos. | | 1948 | | ER\_MASTER\_GTID\_POS\_MISSING\_DOMAIN | Specified value for @@gtid\_slave\_pos contains no value for replication domain %u. This conflicts with the binary log which contains GTID %u-%u-%llu. If MASTER\_GTID\_POS=CURRENT\_POS is used, the binlog position will override the new value of @@gtid\_slave\_pos. | | 1949 | | ER\_UNTIL\_REQUIRES\_USING\_GTID | START SLAVE UNTIL master\_gtid\_pos requires that slave is using GTID | | 1950 | | ER\_GTID\_STRICT\_OUT\_OF\_ORDER | An attempt was made to binlog GTID %u-%u-%llu which would create an out-of-order sequence number with existing GTID %u-%u-%llu, and gtid strict mode is enabled. | | 1951 | | ER\_GTID\_START\_FROM\_BINLOG\_HOLE | The binlog on the master is missing the GTID %u-%u-%llu requested by the slave (even though a subsequent sequence number does exist), and GTID strict mode is enabled | | 1952 | | ER\_SLAVE\_UNEXPECTED\_MASTER\_SWITCH | Unexpected GTID received from master after reconnect. This normally indicates that the master server was replaced without restarting the slave threads. %s | | 1953 | | ER\_INSIDE\_TRANSACTION\_PREVENTS\_SWITCH\_GTID\_DOMAIN\_ID\_SEQ\_NO | Cannot modify @@session.gtid\_domain\_id or @@session.gtid\_seq\_no inside a transaction | | 1954 | | ER\_STORED\_FUNCTION\_PREVENTS\_SWITCH\_GTID\_DOMAIN\_ID\_SEQ\_NO | Cannot modify @@session.gtid\_domain\_id or @@session.gtid\_seq\_no inside a stored function or trigger | | 1955 | | ER\_GTID\_POSITION\_NOT\_FOUND\_IN\_BINLOG2 | Connecting slave requested to start from GTID %u-%u-%llu, which is not in the master's binlog. Since the master's binlog contains GTIDs with higher sequence numbers, it probably means that the slave has diverged due to executing extra errorneous transactions | | 1956 | | ER\_BINLOG\_MUST\_BE\_EMPTY | This operation is not allowed if any GTID has been logged to the binary log. Run RESET MASTER first to erase the log | | 1957 | | ER\_NO\_SUCH\_QUERY | Unknown query id: %lld | | 1958 | | ER\_BAD\_BASE64\_DATA | Bad base64 data as position %u | | 1959 | | ER\_INVALID\_ROLE | Invalid role specification %`s. | | 1960 | | ER\_INVALID\_CURRENT\_USER | The current user is invalid. | | 1961 | | ER\_CANNOT\_GRANT\_ROLE | Cannot grant role '%s' to: %s. | | 1962 | | ER\_CANNOT\_REVOKE\_ROLE | Cannot revoke role '%s' from: %s. | | 1963 | | ER\_CHANGE\_SLAVE\_PARALLEL\_THREADS\_ACTIVE | Cannot change @@slave\_parallel\_threads while another change is in progress | | 1964 | | ER\_PRIOR\_COMMIT\_FAILED | Commit failed due to failure of an earlier commit on which this one depends | | 1965 | | ER\_IT\_IS\_A\_VIEW | '%-.192s' is a view | | 1966 | | ER\_SLAVE\_SKIP\_NOT\_IN\_GTID | When using GTID, @@sql\_slave\_skip\_counter can not be used. Instead, setting @@gtid\_slave\_pos explicitly can be used to skip to after a given GTID position. | | 1967 | | ER\_TABLE\_DEFINITION\_TOO\_BIG | The definition for table %`s is too big | | 1968 | | ER\_PLUGIN\_INSTALLED | Plugin '%-.192s' already installed | | 1969 | | ER\_STATEMENT\_TIMEOUT | Query execution was interrupted (max\_statement\_time exceeded) | | 1970 | | ER\_SUBQUERIES\_NOT\_SUPPORTED | %s does not support subqueries or stored functions. | | 1971 | | ER\_SET\_STATEMENT\_NOT\_SUPPORTED | The system variable %.200s cannot be set in SET STATEMENT. | | 1972 | | ER\_UNUSED\_9 | You should never see it | | 1973 | | ER\_USER\_CREATE\_EXISTS | Can't create user '%-.64s'@'%-.64s'; it already exists | | 1974 | | ER\_USER\_DROP\_EXISTS | Can't drop user '%-.64s'@'%-.64s'; it doesn't exist | | 1975 | | ER\_ROLE\_CREATE\_EXISTS | Can't create role '%-.64s'; it already exists | | 1976 | | ER\_ROLE\_DROP\_EXISTS | Can't drop role '%-.64s'; it doesn't exist | | 1977 | | ER\_CANNOT\_CONVERT\_CHARACTER | Cannot convert '%s' character 0x%-.64s to '%s' | | 1978 | | ER\_INVALID\_DEFAULT\_VALUE\_FOR\_FIELD | Incorrect default value '%-.128s' for column '%.192s' | | 1979 | | ER\_KILL\_QUERY\_DENIED\_ERROR | You are not owner of query %lu | | 1980 | | ER\_NO\_EIS\_FOR\_FIELD | Engine-independent statistics are not collected for column '%s' | | 1981 | | ER\_WARN\_AGGFUNC\_DEPENDENCE | Aggregate function '%-.192s)' of SELECT #%d belongs to SELECT #%d | | 1982 | | WARN\_INNODB\_PARTITION\_OPTION\_IGNORED | <%-.64s> option ignored for InnoDB partition | | Error Code | SQLSTATE | Error | Description | | --- | --- | --- | --- | | 3000 | | ER\_FILE\_CORRUPT | File %s is corrupted | | 3001 | | ER\_ERROR\_ON\_MASTER | Query partially completed on the master (error on master: %d) and was aborted. There is a chance that your master is inconsistent at this point. If you are sure that your master is ok, run this query manually on the slave and then restart the slave with SET GLOBAL SQL\_SLAVE\_SKIP\_COUNTER=1; START SLAVE;. Query:'%s'" | | 3002 | | ER\_INCONSISTENT\_ERROR | Query caused different errors on master and slave. Error on master: message (format)='%s' error code=%d; Error on slave:actual message='%s', error code=%d. Default database:'%s'. Query:'%s' | | 3003 | | ER\_STORAGE\_ENGINE\_NOT\_LOADED | Storage engine for table '%s'.'%s' is not loaded. | | 3004 | | ER\_GET\_STACKED\_DA\_WITHOUT\_ACTIVE\_HANDLER 0Z002 | GET STACKED DIAGNOSTICS when handler not active | | 3005 | | ER\_WARN\_LEGACY\_SYNTAX\_CONVERTED | %s is no longer supported. The statement was converted to %s. | | 3006 | | ER\_BINLOG\_UNSAFE\_FULLTEXT\_PLUGIN | Statement is unsafe because it uses a fulltext parser plugin which may not return the same value on the slave. | | 3007 | | ER\_CANNOT\_DISCARD\_TEMPORARY\_TABLE | Cannot DISCARD/IMPORT tablespace associated with temporary table | | 3008 | | ER\_FK\_DEPTH\_EXCEEDED | Foreign key cascade delete/update exceeds max depth of %d. | | 3009 | | ER\_COL\_COUNT\_DOESNT\_MATCH\_PLEASE\_UPDATE\_V2 | Column count of %s.%s is wrong. Expected %d, found %d. Created with MariaDB %d, now running %d. Please use mysql\_upgrade to fix this error. | | 3010 | | ER\_WARN\_TRIGGER\_DOESNT\_HAVE\_CREATED | Trigger %s.%s.%s does not have CREATED attribute. | | 3011 | | ER\_REFERENCED\_TRG\_DOES\_NOT\_EXIST\_MYSQL | Referenced trigger '%s' for the given action time and event type does not exist. | | 3012 | | ER\_EXPLAIN\_NOT\_SUPPORTED | EXPLAIN FOR CONNECTION command is supported only for SELECT/UPDATE/INSERT/DELETE/REPLACE | | 3013 | | ER\_INVALID\_FIELD\_SIZE | Invalid size for column '%-.192s'. | | 3014 | | ER\_MISSING\_HA\_CREATE\_OPTION | Table storage engine '%-.64s' found required create option missing | | 3015 | | ER\_ENGINE\_OUT\_OF\_MEMORY | Out of memory in storage engine '%-.64s'. | | 3016 | | ER\_PASSWORD\_EXPIRE\_ANONYMOUS\_USER | The password for anonymous user cannot be expired. | | 3017 | | ER\_SLAVE\_SQL\_THREAD\_MUST\_STOP | This operation cannot be performed with a running slave sql thread; run STOP SLAVE SQL\_THREAD first | | 3018 | | ER\_NO\_FT\_MATERIALIZED\_SUBQUERY | Cannot create FULLTEXT index on materialized subquery | | 3019 | | ER\_INNODB\_UNDO\_LOG\_FULL | Undo Log error: %s | | 3020 | | ER\_INVALID\_ARGUMENT\_FOR\_LOGARITHM | Invalid argument for logarithm | | 3021 | | ER\_SLAVE\_CHANNEL\_IO\_THREAD\_MUST\_STOP | This operation cannot be performed with a running slave io thread; run STOP SLAVE IO\_THREAD FOR CHANNEL '%s' first. | | 3022 | | ER\_WARN\_OPEN\_TEMP\_TABLES\_MUST\_BE\_ZERO | This operation may not be safe when the slave has temporary tables. The tables will be kept open until the server restarts or until the tables are deleted by any replicated DROP statement. Suggest to wait until slave\_open\_temp\_tables = 0. | | 3023 | | ER\_WARN\_ONLY\_MASTER\_LOG\_FILE\_NO\_POS | CHANGE MASTER TO with a MASTER\_LOG\_FILE clause but no MASTER\_LOG\_POS clause may not be safe. The old position value may not be valid for the new binary log file. | | 3024 | | ER\_QUERY\_TIMEOUT | Query execution was interrupted, maximum statement execution time exceeded | | 3025 | | ER\_NON\_RO\_SELECT\_DISABLE\_TIMER | Select is not a read only statement, disabling timer | | 3026 | | ER\_DUP\_LIST\_ENTRY | Duplicate entry '%-.192s'. | | 3027 | | ER\_SQL\_MODE\_NO\_EFFECT | '%s' mode no longer has any effect. Use STRICT\_ALL\_TABLES or STRICT\_TRANS\_TABLES instead. | | 3028 | | ER\_AGGREGATE\_ORDER\_FOR\_UNION | Expression #%u of ORDER BY contains aggregate function and applies to a UNION | | 3029 | | ER\_AGGREGATE\_ORDER\_NON\_AGG\_QUERY | Expression #%u of ORDER BY contains aggregate function and applies to the result of a non-aggregated query | | 3030 | | ER\_SLAVE\_WORKER\_STOPPED\_PREVIOUS\_THD\_ERROR | Slave worker has stopped after at least one previous worker encountered an error when slave-preserve-commit-order was enabled. To preserve commit order, the last transaction executed by this thread has not been committed. When restarting the slave after fixing any failed threads, you should fix this worker as well. | | 3031 | | ER\_DONT\_SUPPORT\_SLAVE\_PRESERVE\_COMMIT\_ORDER | slave\_preserve\_commit\_order is not supported %s. | | 3032 | | ER\_SERVER\_OFFLINE\_MODE | The server is currently in offline mode | | 3033 | | ER\_GIS\_DIFFERENT\_SRIDS | Binary geometry function %s given two geometries of different srids: %u and %u, which should have been identical. | | 3034 | | ER\_GIS\_UNSUPPORTED\_ARGUMENT | Calling geometry function %s with unsupported types of arguments. | | 3035 | | ER\_GIS\_UNKNOWN\_ERROR | Unknown GIS error occurred in function %s. | | 3036 | | ER\_GIS\_UNKNOWN\_EXCEPTION | Unknown exception caught in GIS function %s. | | 3037 | | ER\_GIS\_INVALID\_DATA | Invalid GIS data provided to function %s. | | 3038 | | ER\_BOOST\_GEOMETRY\_EMPTY\_INPUT\_EXCEPTION | The geometry has no data in function %s. | | 3039 | | ER\_BOOST\_GEOMETRY\_CENTROID\_EXCEPTION | Unable to calculate centroid because geometry is empty in function %s. | | 3040 | | ER\_BOOST\_GEOMETRY\_OVERLAY\_INVALID\_INPUT\_EXCEPTION | Geometry overlay calculation error: geometry data is invalid in function %s. | | 3041 | | ER\_BOOST\_GEOMETRY\_TURN\_INFO\_EXCEPTION | Geometry turn info calculation error: geometry data is invalid in function %s. | | 3042 | | ER\_BOOST\_GEOMETRY\_SELF\_INTERSECTION\_POINT\_EXCEPTION | Analysis procedures of intersection points interrupted unexpectedly in function %s. | | 3043 | | ER\_BOOST\_GEOMETRY\_UNKNOWN\_EXCEPTION | Unknown exception thrown in function %s. | | 3044 | | ER\_STD\_BAD\_ALLOC\_ERROR | Memory allocation error: %-.256s in function %s. | | 3045 | | ER\_STD\_DOMAIN\_ERROR | Domain error: %-.256s in function %s. | | 3046 | | ER\_STD\_LENGTH\_ERROR | Length error: %-.256s in function %s. | | 3047 | | ER\_STD\_INVALID\_ARGUMENT | Invalid argument error: %-.256s in function %s. | | 3048 | | ER\_STD\_OUT\_OF\_RANGE\_ERROR | Out of range error: %-.256s in function %s. | | 3049 | | ER\_STD\_OVERFLOW\_ERROR | Overflow error error: %-.256s in function %s. | | 3050 | | ER\_STD\_RANGE\_ERROR | Range error: %-.256s in function %s. | | 3051 | | ER\_STD\_UNDERFLOW\_ERROR | Underflow error: %-.256s in function %s. | | 3052 | | ER\_STD\_LOGIC\_ERROR | Logic error: %-.256s in function %s. | | 3053 | | ER\_STD\_RUNTIME\_ERROR | Runtime error: %-.256s in function %s. | | 3054 | | ER\_STD\_UNKNOWN\_EXCEPTION | Unknown exception: %-.384s in function %s. | | 3055 | | ER\_GIS\_DATA\_WRONG\_ENDIANESS | Geometry byte string must be little endian. | | 3056 | | ER\_CHANGE\_MASTER\_PASSWORD\_LENGTH | The password provided for the replication user exceeds the maximum length of 32 characters | | 3057 | 42000 | ER\_USER\_LOCK\_WRONG\_NAME | Incorrect user-level lock name '%-.192s'. | | 3058 | | ER\_USER\_LOCK\_DEADLOCK | Deadlock found when trying to get user-level lock; try rolling back transaction/releasing locks and restarting lock acquisition. | | 3059 | | ER\_REPLACE\_INACCESSIBLE\_ROWS | REPLACE cannot be executed as it requires deleting rows that are not in the view | | 3060 | | ER\_ALTER\_OPERATION\_NOT\_SUPPORTED\_REASON\_GIS | Do not support online operation on table with GIS index | | Error Code | SQLSTATE | Error | Description | | --- | --- | --- | --- | | 4000 | 0A000 | ER\_COMMULTI\_BADCONTEXT | COM\_MULTI can't return a result set in the given context | | 4001 | | ER\_BAD\_COMMAND\_IN\_MULTI | Command '%s' is not allowed for COM\_MULTI | | 4002 | | ER\_WITH\_COL\_WRONG\_LIST | WITH column list and SELECT field list have different column counts | | 4003 | | ER\_TOO\_MANY\_DEFINITIONS\_IN\_WITH\_CLAUSE | Too many WITH elements in WITH clause | | 4004 | | ER\_DUP\_QUERY\_NAME | Duplicate query name %`-.64s in WITH clause | | 4005 | | ER\_RECURSIVE\_WITHOUT\_ANCHORS | No anchors for recursive WITH element '%s' | | 4006 | | ER\_UNACCEPTABLE\_MUTUAL\_RECURSION | Unacceptable mutual recursion with anchored table '%s' | | 4007 | | ER\_REF\_TO\_RECURSIVE\_WITH\_TABLE\_IN\_DERIVED | Reference to recursive WITH table '%s' in materialized derived | | 4008 | | ER\_NOT\_STANDARD\_COMPLIANT\_RECURSIVE | Restrictions imposed on recursive definitions are violated for table '%s'"R\_WRONG\_WINDOW\_SPEC\_NAME | | 4009 | | ER\_WRONG\_WINDOW\_SPEC\_NAME | Window specification with name '%s' is not defined | | 4010 | | ER\_DUP\_WINDOW\_NAME | Multiple window specifications with the same name '%s' | | 4011 | | ER\_PARTITION\_LIST\_IN\_REFERENCING\_WINDOW\_SPEC | Window specification referencing another one '%s' cannot contain partition list | | 4012 | | ER\_ORDER\_LIST\_IN\_REFERENCING\_WINDOW\_SPEC | Referenced window specification '%s' already contains order list | | 4013 | | ER\_WINDOW\_FRAME\_IN\_REFERENCED\_WINDOW\_SPEC | Referenced window specification '%s' cannot contain window frame | | 4014 | | ER\_BAD\_COMBINATION\_OF\_WINDOW\_FRAME\_BOUND\_SPECS | Unacceptable combination of window frame bound specifications | | 4015 | | ER\_WRONG\_PLACEMENT\_OF\_WINDOW\_FUNCTION | Window function is allowed only in SELECT list and ORDER BY clause | | 4016 | | ER\_WINDOW\_FUNCTION\_IN\_WINDOW\_SPEC | Window function is not allowed in window specification | | 4017 | | ER\_NOT\_ALLOWED\_WINDOW\_FRAME | Window frame is not allowed with '%s' | | 4018 | | ER\_NO\_ORDER\_LIST\_IN\_WINDOW\_SPEC | No order list in window specification for '%s' | | 4019 | | ER\_RANGE\_FRAME\_NEEDS\_SIMPLE\_ORDERBY | RANGE-type frame requires ORDER BY clause with single sort key | | 4020 | | ER\_WRONG\_TYPE\_FOR\_ROWS\_FRAME | Integer is required for ROWS-type frame | | 4021 | | ER\_WRONG\_TYPE\_FOR\_RANGE\_FRAME | Numeric datatype is required for RANGE-type frame | | 4022 | | ER\_FRAME\_EXCLUSION\_NOT\_SUPPORTED | Frame exclusion is not supported yet | | 4023 | | ER\_WINDOW\_FUNCTION\_DONT\_HAVE\_FRAME | This window function may not have a window frame | | 4024 | | ER\_INVALID\_NTILE\_ARGUMENT | Argument of NTILE must be greater than 0 | | 4025 | 23000 | ER\_CONSTRAINT\_FAILED | CONSTRAINT %`s failed for %`-.192s.%`-.192s | | 4026 | | ER\_EXPRESSION\_IS\_TOO\_BIG | Expression in the %s clause is too big | | 4027 | | ER\_ERROR\_EVALUATING\_EXPRESSION | Got an error evaluating stored expression %s | | 4028 | | ER\_CALCULATING\_DEFAULT\_VALUE | Got an error when calculating default value for %`s | | 4029 | | ER\_EXPRESSION\_REFERS\_TO\_UNINIT\_FIELD | Expression for field %`-.64s is referring to uninitialized field %`s | | 4030 | | ER\_PARTITION\_DEFAULT\_ERROR | Only one DEFAULT partition allowed | | 4031 | | ER\_REFERENCED\_TRG\_DOES\_NOT\_EXIST | Referenced trigger '%s' for the given action time and event type does not exist | | 4032 | | ER\_INVALID\_DEFAULT\_PARAM | Default/ignore value is not supported for such parameter usage | | 4033 | | ER\_BINLOG\_NON\_SUPPORTED\_BULK | Only row based replication supported for bulk operations | | 4034 | | ER\_BINLOG\_UNCOMPRESS\_ERROR | Uncompress the compressed binlog failed | | 4035 | | ER\_JSON\_BAD\_CHR | Broken JSON string in argument %d to function '%s' at position %d | | 4036 | | ER\_JSON\_NOT\_JSON\_CHR | Character disallowed in JSON in argument %d to function '%s' at position %d | | 4037 | | ER\_JSON\_EOS | Unexpected end of JSON text in argument %d to function '%s' | | 4038 | | ER\_JSON\_SYNTAX | Syntax error in JSON text in argument %d to function '%s' at position %d | | 4039 | | ER\_JSON\_ESCAPING | Incorrect escaping in JSON text in argument %d to function '%s' at position %d | | 4040 | | ER\_JSON\_DEPTH | Limit of %d on JSON nested strucures depth is reached in argument %d to function '%s' at position %d | | 4041 | | ER\_JSON\_PATH\_EOS | Unexpected end of JSON path in argument %d to function '%s' | | 4042 | | ER\_JSON\_PATH\_SYNTAX | Syntax error in JSON path in argument %d to function '%s' at position %d | | 4043 | | ER\_JSON\_PATH\_DEPTH | Limit of %d on JSON path depth is reached in argument %d to function '%s' at position %d | | 4044 | | ER\_JSON\_PATH\_NO\_WILDCARD | Wildcards in JSON path not allowed in argument %d to function '%s' | | 4045 | | ER\_JSON\_PATH\_ARRAY | JSON path should end with an array identifier in argument %d to function '%s' | | 4046 | | ER\_JSON\_ONE\_OR\_ALL | Argument 2 to function '%s' must be "one" or "all". | | 4047 | | ER\_UNSUPPORT\_COMPRESSED\_TEMPORARY\_TABLE | CREATE TEMPORARY TABLE is not allowed with ROW\_FORMAT=COMPRESSED or KEY\_BLOCK\_SIZE. | | 4048 | | ER\_GEOJSON\_INCORRECT | Incorrect GeoJSON format specified for st\_geomfromgeojson function. | | 4049 | | ER\_GEOJSON\_TOO\_FEW\_POINTS | Incorrect GeoJSON format - too few points for linestring specified. | | 4050 | | ER\_GEOJSON\_NOT\_CLOSED | Incorrect GeoJSON format - polygon not closed. | | 4051 | | ER\_JSON\_PATH\_EMPTY | Path expression '$' is not allowed in argument %d to function '%s'. | | 4052 | | ER\_SLAVE\_SAME\_ID | A slave with the same server\_uuid/server\_id as this slave has connected to the master | | 4053 | | ER\_FLASHBACK\_NOT\_SUPPORTED | Flashback does not support %s %s | | 4054 | | ER\_KEYS\_OUT\_OF\_ORDER | Keys are out order during bulk load | | 4055 | | ER\_OVERLAPPING\_KEYS | Bulk load rows overlap existing rows | | 4056 | | ER\_REQUIRE\_ROW\_BINLOG\_FORMAT | Can't execute updates on master with binlog\_format != ROW. | | 4057 | | ER\_ISOLATION\_MODE\_NOT\_SUPPORTED | MyRocks supports only READ COMMITTED and REPEATABLE READ isolation levels. Please change from current isolation level %s | | 4058 | | ER\_ON\_DUPLICATE\_DISABLED | When unique checking is disabled in MyRocks, INSERT,UPDATE,LOAD statements with clauses that update or replace the key (i.e. INSERT ON DUPLICATE KEY UPDATE, REPLACE) are not allowed. Query: %s | | 4059 | | ER\_UPDATES\_WITH\_CONSISTENT\_SNAPSHOT | Can't execute updates when you started a transaction with START TRANSACTION WITH CONSISTENT [ROCKSDB] SNAPSHOT. | | 4060 | | ER\_ROLLBACK\_ONLY | This transaction was rolled back and cannot be committed. Only supported operation is to roll it back, so all pending changes will be discarded. Please restart another transaction. | | 4061 | | ER\_ROLLBACK\_TO\_SAVEPOINT | MyRocks currently does not support ROLLBACK TO SAVEPOINT if modifying rows. | | 4062 | | ER\_ISOLATION\_LEVEL\_WITH\_CONSISTENT\_SNAPSHOT | Only REPEATABLE READ isolation level is supported for START TRANSACTION WITH CONSISTENT SNAPSHOT in RocksDB Storage Engine. | | 4063 | | ER\_UNSUPPORTED\_COLLATION | Unsupported collation on string indexed column %s.%s Use binary collation (%s). | | 4064 | | ER\_METADATA\_INCONSISTENCY | Table '%s' does not exist, but metadata information exists inside MyRocks. This is a sign of data inconsistency. Please check if '%s.frm' exists, and try to restore it if it does not exist. | | 4065 | | ER\_CF\_DIFFERENT | Column family ('%s') flag (%d) is different from an existing flag (%d). Assign a new CF flag, or do not change existing CF flag. | | 4066 | | ER\_RDB\_TTL\_DURATION\_FORMAT | TTL duration (%s) in MyRocks must be an unsigned non-null 64-bit integer. | | 4067 | | ER\_RDB\_STATUS\_GENERAL | Status error %d received from RocksDB: %s | | 4068 | | ER\_RDB\_STATUS\_MSG | %s, Status error %d received from RocksDB: %s | | 4069 | | ER\_RDB\_TTL\_UNSUPPORTED | TTL support is currently disabled when table has a hidden PK. | | 4070 | | ER\_RDB\_TTL\_COL\_FORMAT | TTL column (%s) in MyRocks must be an unsigned non-null 64-bit integer, exist inside the table, and have an accompanying ttl duration. | | 4071 | | ER\_PER\_INDEX\_CF\_DEPRECATED | The per-index column family option has been deprecated | | 4072 | | ER\_KEY\_CREATE\_DURING\_ALTER | MyRocks failed creating new key definitions during alter. | | 4073 | | ER\_SK\_POPULATE\_DURING\_ALTER | MyRocks failed populating secondary key during alter. | | 4074 | | ER\_SUM\_FUNC\_WITH\_WINDOW\_FUNC\_AS\_ARG | Window functions can not be used as arguments to group functions. | | 4075 | | ER\_NET\_OK\_PACKET\_TOO\_LARGE | OK packet too large | | 4076 | | ER\_GEOJSON\_EMPTY\_COORDINATES | Incorrect GeoJSON format - empty 'coordinates' array. | | 4077 | | ER\_MYROCKS\_CANT\_NOPAD\_COLLATION | MyRocks doesn't currently support collations with \"No pad\" attribute. | | 4078 | | ER\_ILLEGAL\_PARAMETER\_DATA\_TYPES2\_FOR\_OPERATION | Illegal parameter data types %s and %s for operation '%s' | | 4079 | | ER\_ILLEGAL\_PARAMETER\_DATA\_TYPE\_FOR\_OPERATION | Illegal parameter data type %s for operation '%s' | | 4080 | | ER\_WRONG\_PARAMCOUNT\_TO\_CURSOR | Incorrect parameter count to cursor '%-.192s' | | 4081 | | ER\_UNKNOWN\_STRUCTURED\_VARIABLE | Unknown structured system variable or ROW routine variable '%-.\*s' | | 4082 | | ER\_ROW\_VARIABLE\_DOES\_NOT\_HAVE\_FIELD | Row variable '%-.192s' does not have a field '%-.192s' | | 4083 | | ER\_END\_IDENTIFIER\_DOES\_NOT\_MATCH | END identifier '%-.192s' does not match '%-.192s' | | 4084 | | ER\_SEQUENCE\_RUN\_OUT | Sequence '%-.64s.%-.64s' has run out | | 4085 | | ER\_SEQUENCE\_INVALID\_DATA | Sequence '%-.64s.%-.64s' values are conflicting | | 4086 | | ER\_SEQUENCE\_INVALID\_TABLE\_STRUCTURE | Sequence '%-.64s.%-.64s' table structure is invalid (%s) | | 4087 | | ER\_SEQUENCE\_ACCESS\_ERROR | Sequence '%-.64s.%-.64s' access error | | 4088 | | ER\_SEQUENCE\_BINLOG\_FORMAT | Sequences requires binlog\_format mixed or row | | 4089 | | ER\_NOT\_SEQUENCE | '%-.64s.%-.64s' is not a SEQUENCE | | 4090 | | ER\_NOT\_SEQUENCE2 | '%-.192s' is not a SEQUENCE | | 4091 | | ER\_UNKNOWN\_SEQUENCES | Unknown SEQUENCE: '%-.300s' | | 4092 | | ER\_UNKNOWN\_VIEW | Unknown VIEW: '%-.300s' | | 4093 | | ER\_WRONG\_INSERT\_INTO\_SEQUENCE | Wrong INSERT into a SEQUENCE. One can only do single table INSERT into a sequence object (like with mysqldump). If you want to change the SEQUENCE, use ALTER SEQUENCE instead. | | 4094 | | ER\_SP\_STACK\_TRACE | At line %u in %s | | 4095 | | ER\_PACKAGE\_ROUTINE\_IN\_SPEC\_NOT\_DEFINED\_IN\_BODY | Subroutine '%-.192s' is declared in the package specification but is not defined in the package body | | 4096 | | ER\_PACKAGE\_ROUTINE\_FORWARD\_DECLARATION\_NOT\_DEFINED | Subroutine '%-.192s' has a forward declaration but is not defined | | 4097 | | ER\_COMPRESSED\_COLUMN\_USED\_AS\_KEY | Compressed column '%-.192s' can't be used in key specification | | 4098 | | ER\_UNKNOWN\_COMPRESSION\_METHOD | Unknown compression method: %s | | 4099 | | ER\_WRONG\_NUMBER\_OF\_VALUES\_IN\_TVC | The used table value constructor has a different number of values | | 4100 | | ER\_FIELD\_REFERENCE\_IN\_TVC | Field reference '%-.192s' can't be used in table value constructor | | 4101 | | ER\_WRONG\_TYPE\_FOR\_PERCENTILE\_FUNC | Numeric datatype is required for %s function | | 4102 | | ER\_ARGUMENT\_NOT\_CONSTANT | Argument to the %s function is not a constant for a partition | | 4103 | | ER\_ARGUMENT\_OUT\_OF\_RANGE | Argument to the %s function does not belong to the range [0,1] | | 4104 | | ER\_WRONG\_TYPE\_OF\_ARGUMENT | %s function only accepts arguments that can be converted to numerical types | | 4105 | | ER\_NOT\_AGGREGATE\_FUNCTION | Aggregate specific instruction (FETCH GROUP NEXT ROW) used in a wrong context | | 4106 | | ER\_INVALID\_AGGREGATE\_FUNCTION | Aggregate specific instruction(FETCH GROUP NEXT ROW) missing from the aggregate function | | 4107 | | ER\_INVALID\_VALUE\_TO\_LIMIT | Limit only accepts integer values | | 4108 | | ER\_INVISIBLE\_NOT\_NULL\_WITHOUT\_DEFAULT | Invisible column %`s must have a default value | | 4109 | | ER\_UPDATE\_INFO\_WITH\_SYSTEM\_VERSIONING | Rows matched: %ld Changed: %ld Inserted: %ld Warnings: %ld | | 4110 | | ER\_VERS\_FIELD\_WRONG\_TYPE | %`s must be of type %s for system-versioned table %`s | | 4111 | | ER\_VERS\_ENGINE\_UNSUPPORTED | Transaction-precise system versioning for %`s is not supported | | 4112 | | ER\_UNUSED\_23 | You should never see it | | 4113 | | ER\_PARTITION\_WRONG\_TYPE | Wrong partitioning type, expected type: %`s | | 4114 | | WARN\_VERS\_PART\_FULL | Versioned table %`s.%`s: last HISTORY partition (%`s) is out of %s, need more HISTORY partitions | | 4115 | | WARN\_VERS\_PARAMETERS | Maybe missing parameters: %s | | 4116 | | ER\_VERS\_DROP\_PARTITION\_INTERVAL | Can only drop oldest partitions when rotating by INTERVAL | | 4117 | | ER\_UNUSED\_25 | You should never see it | | 4118 | | WARN\_VERS\_PART\_NON\_HISTORICAL | Partition %`s contains non-historical data | | 4119 | | ER\_VERS\_ALTER\_NOT\_ALLOWED | Not allowed for system-versioned %`s.%`s. Change @@system\_versioning\_alter\_history to proceed with ALTER. | | 4120 | | ER\_VERS\_ALTER\_ENGINE\_PROHIBITED | Not allowed for system-versioned %`s.%`s. Change to/from native system versioning engine is not supported. | | 4121 | | ER\_VERS\_RANGE\_PROHIBITED | SYSTEM\_TIME range selector is not allowed | | 4122 | | ER\_CONFLICTING\_FOR\_SYSTEM\_TIME | Conflicting FOR SYSTEM\_TIME clauses in WITH RECURSIVE | | 4123 | | ER\_VERS\_TABLE\_MUST\_HAVE\_COLUMNS | Table %`s must have at least one versioned column | | 4124 | | ER\_VERS\_NOT\_VERSIONED | Table %`s is not system-versioned | | 4125 | | ER\_MISSING | Wrong parameters for %`s: missing '%s' | | 4126 | | ER\_VERS\_PERIOD\_COLUMNS | PERIOD FOR SYSTEM\_TIME must use columns %`s and %`s | | 4127 | | ER\_PART\_WRONG\_VALUE | Wrong parameters for partitioned %`s: wrong value for '%s' | | 4128 | | ER\_VERS\_WRONG\_PARTS | Wrong partitions for %`s: must have at least one HISTORY and exactly one last CURRENT | | 4129 | | ER\_VERS\_NO\_TRX\_ID | TRX\_ID %llu not found in `mysql.transaction\_registry` | | 4130 | | ER\_VERS\_ALTER\_SYSTEM\_FIELD | Can not change system versioning field %`s | | 4131 | | ER\_DROP\_VERSIONING\_SYSTEM\_TIME\_PARTITION | Can not DROP SYSTEM VERSIONING for table %`s partitioned BY SYSTEM\_TIME | | 4132 | | ER\_VERS\_DB\_NOT\_SUPPORTED | System-versioned tables in the %`s database are not supported | | 4133 | | ER\_VERS\_TRT\_IS\_DISABLED | Transaction registry is disabled | | 4134 | | ER\_VERS\_DUPLICATE\_ROW\_START\_END | Duplicate ROW %s column %`s | | 4135 | | ER\_VERS\_ALREADY\_VERSIONED | Table %`s is already system-versioned | | 4136 | | ER\_UNUSED\_24 | You should never see it | | 4137 | | ER\_VERS\_NOT\_SUPPORTED | System-versioned tables do not support %s | | 4138 | | ER\_VERS\_TRX\_PART\_HISTORIC\_ROW\_NOT\_SUPPORTED | Transaction-precise system-versioned tables do not support partitioning by ROW START or ROW END | | 4139 | | ER\_INDEX\_FILE\_FULL | The index file for table '%-.192s' is full | | 4140 | | ER\_UPDATED\_COLUMN\_ONLY\_ONCE | The column %`s.%`s cannot be changed more than once in a single UPDATE statement | | 4141 | | ER\_EMPTY\_ROW\_IN\_TVC | Row with no elements is not allowed in table value constructor in this context | | 4142 | | ER\_VERS\_QUERY\_IN\_PARTITION | SYSTEM\_TIME partitions in table %`s does not support historical query | | 4143 | | ER\_KEY\_DOESNT\_SUPPORT | %s index %`s does not support this operation | | 4144 | | ER\_ALTER\_OPERATION\_TABLE\_OPTIONS\_NEED\_REBUILD | Changing table options requires the table to be rebuilt | | 4145 | | ER\_BACKUP\_LOCK\_IS\_ACTIVE | Can't execute the command as you have a BACKUP STAGE active | | 4146 | | ER\_BACKUP\_NOT\_RUNNING | You must start backup with \"BACKUP STAGE START\" | | 4147 | | ER\_BACKUP\_WRONG\_STAGE | Backup stage '%s' is same or before current backup stage '%s' | | 4148 | | ER\_BACKUP\_STAGE\_FAILED | Backup stage '%s' failed | | 4149 | | ER\_BACKUP\_UNKNOWN\_STAGE | Unknown backup stage: '%s'. Stage should be one of START, FLUSH, BLOCK\_DDL, BLOCK\_COMMIT or END | | 4150 | | ER\_USER\_IS\_BLOCKED | User is blocked because of too many credential errors; unblock with 'FLUSH PRIVILEGES' | | 4151 | | ER\_ACCOUNT\_HAS\_BEEN\_LOCKED | Access denied, this account is locked | | 4152 | | ER\_PERIOD\_TEMPORARY\_NOT\_ALLOWED | Application-time period table cannot be temporary | | 4153 | | ER\_PERIOD\_TYPES\_MISMATCH | Fields of PERIOD FOR %`s have different types | | 4154 | | ER\_MORE\_THAN\_ONE\_PERIOD | Cannot specify more than one application-time period | | 4155 | | ER\_PERIOD\_FIELD\_WRONG\_ATTRIBUTES | Period field %`s cannot be %s | | 4156 | | ER\_PERIOD\_NOT\_FOUND | Period %`s is not found in table | | 4157 | | ER\_PERIOD\_COLUMNS\_UPDATED | Column %`s used in period %`s specified in update SET list | | 4158 | | ER\_PERIOD\_CONSTRAINT\_DROP | Can't DROP CONSTRAINT `%s`. Use DROP PERIOD `%s` for this | | 4159 | 42000 S1009 | ER\_TOO\_LONG\_KEYPART | Specified key part was too long; max key part length is %u bytes | | 4160 | | ER\_TOO\_LONG\_DATABASE\_COMMENT | Comment for database '%-.64s' is too long (max = %u) | | 4161 | | ER\_UNKNOWN\_DATA\_TYPE | Unknown data type: '%-.64s' | | 4162 | | ER\_UNKNOWN\_OPERATOR | Operator does not exists: '%-.128s' | | 4163 | | ER\_WARN\_HISTORY\_ROW\_START\_TIME | Table `%s.%s` history row start '%s' is later than row end '%s' | | 4164 | | ER\_PART\_STARTS\_BEYOND\_INTERVAL | %`s: STARTS is later than query time, first history partition may exceed INTERVAL value | | 4165 | | ER\_GALERA\_REPLICATION\_NOT\_SUPPORTED | DDL-statement is forbidden as table storage engine does not support Galera replication | | 4166 | HY000 | ER\_LOAD\_INFILE\_CAPABILITY\_DISABLED | The used command is not allowed because the MariaDB server or client has disabled the local infile capability | | 4167 | | ER\_NO\_SECURE\_TRANSPORTS\_CONFIGURED | No secure transports are configured, unable to set --require\_secure\_transport=ON | | 4168 | | ER\_SLAVE\_IGNORED\_SHARED\_TABLE | Slave SQL thread ignored the '%s' because table is shared | | 4169 | | ER\_NO\_AUTOINCREMENT\_WITH\_UNIQUE | AUTO\_INCREMENT column %`s cannot be used in the UNIQUE index %`s | | 4170 | | ER\_KEY\_CONTAINS\_PERIOD\_FIELDS | Key %`s cannot explicitly include column %`s | | 4171 | | ER\_KEY\_CANT\_HAVE\_WITHOUT\_OVERLAPS | Key %`s cannot have WITHOUT OVERLAPS | | 4172 | | ER\_NOT\_ALLOWED\_IN\_THIS\_CONTEXT | '%-.128s' is not allowed in this context | | 4173 | | ER\_DATA\_WAS\_COMMITED\_UNDER\_ROLLBACK | Engine %s does not support rollback. Changes where commited during rollback call | | 4174 | | ER\_PK\_INDEX\_CANT\_BE\_IGNORED | A primary key cannot be marked as IGNORE | | 4175 | | ER\_BINLOG\_UNSAFE\_SKIP\_LOCKED | SKIP LOCKED makes this statement unsafe | | 4176 | | ER\_JSON\_TABLE\_ERROR\_ON\_FIELD | Field '%s' can't be set for JSON\_TABLE '%s'. | | 4177 | | ER\_JSON\_TABLE\_ALIAS\_REQUIRED | Every table function must have an alias. | | 4178 | | ER\_JSON\_TABLE\_SCALAR\_EXPECTED | Can't store an array or an object in the scalar column '%s' of JSON\_TABLE '%s'. | | 4179 | | ER\_JSON\_TABLE\_MULTIPLE\_MATCHES | Can't store multiple matches of the path in the column '%s' of JSON\_TABLE '%s'. | | 4180 | | ER\_WITH\_TIES\_NEEDS\_ORDER | FETCH ... WITH TIES requires ORDER BY clause to be present | | 4181 | | ER\_REMOVED\_ORPHAN\_TRIGGER | Dropped orphan trigger '%-.64s', originally created for table: '%-.192s' | | 4182 | | ER\_STORAGE\_ENGINE\_DISABLED | Storage engine %s is disabled | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb Plans Plans ====== MariaDB Development Plans | Title | Description | | --- | --- | | [MariaDB Roadmap](../mariadb-roadmap/index) | Describes the MariaDB roadmap and how it is determined. | | [Plans for MariaDB 10.11](../plans-for-mariadb-1011/index) | Roadmap for MariaDB 10.11. | | [Plans for MariaDB 10.10](../plans-for-mariadb-1010/index) | Roadmap for MariaDB 10.10. | | [Plans for MariaDB 10.9](../plans-for-mariadb-109/index) | Roadmap for MariaDB 10.9. | | [Old Plans](../old-plans/index) | Inactive plans for older and current versions of MariaDB | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Programming & Customizing MariaDB Programming & Customizing MariaDB ================================== Ways to add simple code to SQL statements, or create your own functions or stored procedures. | Title | Description | | --- | --- | | [Programmatic & Compound Statements](../programmatic-compound-statements/index) | Compound SQL statements for stored routines and in general. | | [Stored Routines](../stored-routines/index) | Stored procedures and functions. | | [Triggers & Events](../triggers-events/index) | Creating triggers and scheduled events within MariaDB. | | [Views](../views/index) | Stored queries for generating a virtual table. | | [User-Defined Functions](../user-defined-functions/index) | Extending MariaDB with custom functions. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb SHOW TRIGGERS SHOW TRIGGERS ============= Syntax ------ ``` SHOW TRIGGERS [FROM db_name] [LIKE 'pattern' | WHERE expr] ``` Description ----------- `SHOW TRIGGERS` lists the triggers currently defined for tables in a database (the default database unless a `FROM` clause is given). This statement requires the `[TRIGGER](../show-privileges/index)` privilege (prior to MySQL 5.1.22, it required the `SUPER` privilege). The `LIKE` clause, if present on its own, indicates which table names to match and causes the statement to display triggers for those tables. The `WHERE` and `LIKE` clauses can be given to select rows using more general conditions, as discussed in [Extended SHOW](../extended-show/index). Similar information is stored in the `[information\_schema.TRIGGERS](../information-schema-triggers-table/index)` table. **MariaDB starting with [10.2.3](https://mariadb.com/kb/en/mariadb-1023-release-notes/)**If there are multiple triggers for the same action, then the triggers are shown in action order. Examples -------- For the trigger defined at [Trigger Overview](../trigger-overview/index): ``` SHOW triggers Like 'animals' \G *************************** 1. row *************************** Trigger: the_mooses_are_loose Event: INSERT Table: animals Statement: BEGIN IF NEW.name = 'Moose' THEN UPDATE animal_count SET animal_count.animals = animal_count.animals+100; ELSE UPDATE animal_count SET animal_count.animals = animal_count.animals+1; END IF; END Timing: AFTER Created: 2016-09-29 13:53:34.35 sql_mode: Definer: root@localhost character_set_client: utf8 collation_connection: utf8_general_ci Database Collation: latin1_swedish_ci ``` Listing all triggers associated with a certain table: ``` SHOW TRIGGERS FROM test WHERE `Table` = 'user' \G *************************** 1. row *************************** Trigger: user_ai Event: INSERT Table: user Statement: BEGIN END Timing: AFTER Created: 2016-09-29 13:53:34.35 sql_mode: Definer: root@% character_set_client: utf8 collation_connection: utf8_general_ci Database Collation: latin1_swedish_ci ``` ``` SHOW triggers WHERE Event Like 'Insert' \G *************************** 1. row *************************** Trigger: the_mooses_are_loose Event: INSERT Table: animals Statement: BEGIN IF NEW.name = 'Moose' THEN UPDATE animal_count SET animal_count.animals = animal_count.animals+100; ELSE UPDATE animal_count SET animal_count.animals = animal_count.animals+1; END IF; END Timing: AFTER Created: 2016-09-29 13:53:34.35 sql_mode: Definer: root@localhost character_set_client: utf8 collation_connection: utf8_general_ci Database Collation: latin1_swedish_ci ``` * `character_set_client` is the session value of the `[character\_set\_client](../server-system-variables/index#character_set_client)` system variable when the trigger was created. * `collation_connection` is the session value of the `[collation\_connection](../server-system-variables/index#collation_connection)` system variable when the trigger was created. * `Database Collation` is the collation of the database with which the trigger is associated. These columns were added in MariaDB/MySQL 5.1.21. Old triggers created before MySQL 5.7 and [MariaDB 10.2.3](https://mariadb.com/kb/en/mariadb-1023-release-notes/) has NULL in the `Created` column. See also -------- * [Trigger Overview](../trigger-overview/index) * `[CREATE TRIGGER](../create-trigger/index)` * `[DROP TRIGGER](../drop-trigger/index)` * `[information\_schema.TRIGGERS](../information-schema-triggers-table/index)` table * `[SHOW CREATE TRIGGER](../show-create-trigger/index)` * [Trigger Limitations](../trigger-limitations/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb sysbench v0.5 - Single Five Minute Runs on perro sysbench v0.5 - Single Five Minute Runs on perro ================================================ MariDB/MySQL sysbench benchmark comparison in % Each test was run for 5 minutes. ``` Number of threads 1 4 8 16 32 64 128 sysbench test delete 103.72 101.84 106.56 102.80 94.19 86.23 65.13 insert 102.01 95.04 97.44 89.00 82.42 81.82 85.63 oltp_complex_ro 104.21 104.98 105.30 102.67 102.69 102.95 101.10 oltp_complex_rw 105.08 104.34 103.60 102.90 100.76 98.41 89.94 oltp_simple 100.66 100.44 102.82 104.23 103.08 100.55 95.90 select 102.93 101.56 103.70 104.18 102.25 100.65 97.33 update_index 101.74 92.33 101.69 93.09 76.45 73.67 72.88 update_non_index 101.58 98.13 98.91 92.32 84.00 76.75 74.19 (MariaDB q/s / MySQL q/s * 100) ``` Benchmark was run on perro: Linux openSUSE 11.1 (x86\_64), single socket dual-core Intel 3.2GHz. with 1MB L2 cache, 2GB RAM, data\_dir on 2 disk software RAID 0 MariaDB and MySQL were compiled with ``` BUILD/compile-amd64-max ``` MariaDB revision was: ``` revno: 2821 committer: Sergei Golubchik <[email protected]> branch nick: maria-5.1 timestamp: Tue 2010-02-23 13:04:58 +0100 message: fix for a possible DoS in the my_net_skip_rest() ``` MySQL revision was: ``` revno: 3360 [merge] author: [email protected] committer: MySQL Build Team <[email protected]> branch nick: mysql-5.1 timestamp: Wed 2010-02-17 18:48:40 +0100 message: Merge from mysql-5.1.44-release ``` sysbench was run with these parameters: ``` --oltp-table-size=2000000 \ --max-time=300 \ --max-requests=0 \ --mysql-table-engine=InnoDB \ --mysql-user=root \ --mysql-engine-trx=yes ``` and this variable part of parameters ``` --num-threads=$THREADS --test=${TEST_DIR}/${SYSBENCH_TEST} ``` Configuration used for MariDB and MySQL: ``` --no-defaults \ --skip-grant-tables \ --language=./sql/share/english \ --datadir=$DATA_DIR \ --tmpdir=$TEMP_DIR \ --socket=$MY_SOCKET \ --table_open_cache=512 \ --thread_cache=512 \ --query_cache_size=0 \ --query_cache_type=0 \ --innodb_data_home_dir=$DATA_DIR \ --innodb_data_file_path=ibdata1:128M:autoextend \ --innodb_log_group_home_dir=$DATA_DIR \ --innodb_buffer_pool_size=1024M \ --innodb_additional_mem_pool_size=32M \ --innodb_log_file_size=256M \ --innodb_log_buffer_size=16M \ --innodb_flush_log_at_trx_commit=1 \ --innodb_lock_wait_timeout=50 \ --innodb_doublewrite=0 \ --innodb_flush_method=O_DIRECT \ --innodb_thread_concurrency=0 \ --innodb_max_dirty_pages_pct=80" ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Binlog Event Checksum Interoperability Binlog Event Checksum Interoperability ====================================== The terms *master* and *slave* have historically been used in replication, but the terms terms *primary* and *replica* are now preferred. The old terms are used still used in parts of the documentation, and in MariaDB commands, although [MariaDB 10.5](../what-is-mariadb-105/index) has begun the process of renaming. The documentation process is ongoing. See [MDEV-18777](https://jira.mariadb.org/browse/MDEV-18777) to follow progress on this effort. The introduction of [checksums on binlog events](../binlog-event-checksums/index) changes the format that events are stored in [binary log](../binary-log/index) files and sent over the network to slaves. This raises the question on what happens when replicating between different versions of the server, where one server is a newer version that has the binlog checksum feature implemented, while the other server is an older version that does not know about binlog checksums. When checksums are disabled on the master (or the master has the old version with no checksums implemented), there is no problem. In this case the binlog format is backwards compatible, and replication works fine. When the master is a newer version with checksums enabled in the binlog, but the slave is an old version that does not understand checksums, replication will fail. The master will disconnect the slave with an error, and also log a warning in its own error log. This prevents sending events to the slave that it will be unable to interpret correctly, but means that binlog checksums can not be used with older slaves. (With the recommended upgrade path, where slaves are upgraded before masters, this is not a problem of course). Replicating from a new MySQL master with checksums enabled to a new MariaDB which also understands checksums works, and the MariaDB slave will verify checksums on replicated events. There is however a problem when a newer MySQL slave replicates against a newer MariaDB master with checksums enabled. The slave server looks at the master server version to know whether events include checksums or not, and MySQL has not yet been updated to learn that MariaDB does this already from version 5.3.0 (as of the time of writing, MySQL 5.6.2). Thus, if MariaDB at least version 5.3.0 but less that 5.6.1 is used as a master with binlog checksums enabled, a MySQL slave will interpret the received events incorrectly as it does not realise the last part of the events is the checksum. So replication will fail with an error about corrupt events or even silent corruption of replicated data in unlucky cases. This requires changes to the MySQL server to fix. Here is a summary table of the status of replication between different combination of master and slave servers and checksum enabled/disabled: * **OLD:** MySQL <5.6.1 or MariaDB < 5.3.0 with no checksum capabilities * **NEW-MARIA:** MariaDB >= 5.3.0 with checksum capabilities * **NEW-MYSQL:** MySQL >= 5.6.1 with checksum capabilities | Master mysqlbinlog | Slave / enabled? | Checksums | Status | | --- | --- | --- | --- | | OLD | OLD | - | Ok | | OLD | NEW-MARIA | - | Ok | | OLD | MYSQL | - | Ok | | NEW-MARIA | OLD | No | Ok | | NEW-MARIA | OLD | Yes | Master will refuse with error | | NEW-MARIA | NEW-MARIA | Yes/No | Ok | | NEW-MARIA | NEW-MYSQL | No | Ok | | NEW-MARIA | NEW-MYSQL | Yes | Fail. Requires changes in MySQL, otherwise it will not realise MariaDB < 5.6.1 does checksums and will be confused. | | NEW-MYSQL | OLD | No | Ok | | NEW-MYSQL | OLD | Yes | Master will refuse with error | | NEW-MYSQL | NEW-MARIA | Yes/No | Ok | | NEW-MYSQL | NEW-MYSQL | Yes/No | Ok | Checksums and `mysqlbinlog` --------------------------- When using the `[mysqlbinlog](../mysqlbinlog/index)` client program, there are similar issues. A version of `mysqlbinlog` which understands checksums can read binlog files from either old or new servers, with or without checksums enabled. An old version of `mysqlbinlog` can read binlog files produced by a new server version **if** checksums were disabled when the log was produced. Old versions of `mysqlbinlog` reading a new binlog file containing checksums will be confused, and output will be garbled, with the added checksums being interpreted as extra garbage at the end of query strings and similar entries. No error will be reported in this case, just wrong output. A version of `mysqlbinlog` from MySQL >= 5.6.1 will have similar problems as a slave until this is fixed in MySQL. When reading a binlog file with checksums produced by MariaDB >= 5.3.0 but < 5.6.1, it will not realise that checksums are included, and will produce garbled output just like an old version of `mysqlbinlog`. The MariaDB version of `mysqlbinlog` can read binlog files produced by either MySQL or MariaDB just fine. See Also -------- * [Binlog Event Checksums](../binlog-event-checksums/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb DBT-3 Queries DBT-3 Queries ============= Q1 -- See [MDEV-4309](https://jira.mariadb.org/browse/MDEV-4309) (just speeding up temptable-based GROUP BY execution). Optimizer seems to make a good choice here. ``` select l_returnflag, l_linestatus, sum(l_quantity) as sum_qty, sum(l_extendedprice) as sum_base_price, sum(l_extendedprice * (1 - l_discount)) as sum_disc_price, sum(l_extendedprice * (1 - l_discount) * (1 + l_tax)) as sum_charge, avg(l_quantity) as avg_qty, avg(l_extendedprice) as avg_price, avg(l_discount) as avg_disc, count(*) as count_order from lineitem where l_shipdate <= date_sub('1998-12-01', interval 63 day) group by l_returnflag, l_linestatus order by l_returnflag, l_linestatus ``` Q4 -- See [MDEV-6015](https://jira.mariadb.org/browse/MDEV-6015). Applicable optimizations: * subquery cache brings no benefit because subquery refers to outer\_table.pk, which is different for each row * EXISTS-to-IN is applicable + After that, BKA brings slight speedup Comments on query plan choice * It seems, we're using the best possible query plan here. ``` select o_orderpriority, count(*) as order_count from orders where o_orderdate >= '1995-06-06' and o_orderdate < date_add('1995-06-06', interval 3 month) and exists ( select * from lineitem where l_orderkey = o_orderkey and l_commitdate < l_receiptdate ) group by o_orderpriority order by o_orderpriority; ``` . Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb IS_IPV4_COMPAT IS\_IPV4\_COMPAT ================ Syntax ------ ``` IS_IPV4_COMPAT(expr) ``` Description ----------- Returns 1 if a given numeric binary string IPv6 address, such as returned by [INET6\_ATON()](../inet6_aton/index), is IPv4-compatible, otherwise returns 0. **MariaDB starting with [10.5.0](https://mariadb.com/kb/en/mariadb-1050-release-notes/)**From [MariaDB 10.5.0](https://mariadb.com/kb/en/mariadb-1050-release-notes/), when the argument is not [INET6](../inet6/index), automatic implicit [CAST](../cast/index) to INET6 is applied. As a consequence, `IS_IPV4_COMPAT` now understands arguments in both text representation and binary(16) representation. Before [MariaDB 10.5.0](https://mariadb.com/kb/en/mariadb-1050-release-notes/), the function understood only binary(16) representation. Examples -------- ``` SELECT IS_IPV4_COMPAT(INET6_ATON('::10.0.1.1')); +------------------------------------------+ | IS_IPV4_COMPAT(INET6_ATON('::10.0.1.1')) | +------------------------------------------+ | 1 | +------------------------------------------+ SELECT IS_IPV4_COMPAT(INET6_ATON('::48f3::d432:1431:ba23:846f')); +-----------------------------------------------------------+ | IS_IPV4_COMPAT(INET6_ATON('::48f3::d432:1431:ba23:846f')) | +-----------------------------------------------------------+ | 0 | +-----------------------------------------------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb TINYBLOB TINYBLOB ======== Syntax ------ ``` TINYBLOB ``` Description ----------- A [BLOB](../blob/index) column with a maximum length of 255 (28 - 1) bytes. Each TINYBLOB value is stored using a one-byte length prefix that indicates the number of bytes in the value. See Also -------- * [BLOB](../blob/index) * [BLOB and TEXT Data Types](../blob-and-text-data-types/index) * [Data Type Storage Requirements](../data-type-storage-requirements/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Benchmarking Aria Benchmarking Aria ================= We have not yet had time to benchmark [Aria](../aria/index) properly. Here follows some things that have been discussed on the [maria-discuss](http://launchpad.net/~maria-discuss) email list. Aria used for internal temporary tables --------------------------------------- By default Aria (instead of MyISAM) is used for the internal temporary tables when MEMORY tables overflows to disk or MEMORY tables can't be used (for example when you are using temporary results with BLOB's). In most cases Aria should give you better performance than using MyISAM, but this is not always the case. ``` CREATE TABLE `t1` (`id` int(11) DEFAULT NULL, `tea` text) ENGINE=MyISAM DEFAULT CHARSET=latin1; insert t1 select rand()*2e8, repeat(rand(), rand()*64) from t1; ``` Repeat the last row until you get 2097152 rows. The queries tested ``` Q1: SELECT id, tea from t1 group by left(id,1) order by null; Q2: SELECT id, count(*), tea from t1 group by left(id,1) order by null; Q3: SELECT id, tea from t1 group by left(id,2) order by null; Q4: SELECT id, count(*), tea from t1 group by left(id,2) order by null; Q5: SELECT id, tea from t1 group by id % 100 order by null; Q6: SELECT id, count(*), tea from t1 group by id % 100 order by null; ``` Results (times in seconds, lower is better): | Test | Aria 8K page size | Aria 2K page size | MyISAM | | --- | --- | --- | --- | | Q1 | 3.08 | 2.41 | 2.17 | | Q2 | 6.24 | 5.21 | 12.89 | | Q3 | 4.87 | 4.05 | 4.04 | | Q4 | 8.20 | 7.04 | 15.14 | | Q5 | 7.10 | 6.37 | 6.28 | | Q6 | 10.38 | 9.09 | 17.00 | The good news is that for common group by queries that is using summary functions there is a close to 50 % speedup of using Aria for internal temporary tables. Note that queries Q1,Q3 and Q5 are not typical queries as there is no sum functions involved. In this case rows are just written to the tmp tables and there is no updates. As soon as there are summary functions and updates the new row format in Aria gives a close to 50 % speedup. The above table also shows how the page size (determined by the [aria\_block\_size](../aria-system-variables/index#aria_block_size) system variable) affects the performance. The reason for the difference is that there is more data to move back/from the page cache for inserting of keys. (When reading data we are normally not copying pages). The bigger page size however allows longer keys and fewer index levels so for bigger data sets the different should be smaller. It's possible to in the future optimize Aria to not copy pages from the page cache also for index writes and then this difference should disappear. The default page size for Aria is 8K. If you want to run MariaDB with MyISAM for temporary tables, don't use the configure option '--with-aria-tmp-tables' when building MariaDB. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb CHECK VIEW CHECK VIEW ========== Syntax ------ ``` CHECK VIEW view_name ``` Description ----------- The `CHECK VIEW` statement was introduced in [MariaDB 10.0.18](https://mariadb.com/kb/en/mariadb-10018-release-notes/) to assist with fixing [MDEV-6916](https://jira.mariadb.org/browse/MDEV-6916), an issue introduced in [MariaDB 5.2](../what-is-mariadb-52/index) where the view algorithms were swapped. It checks whether the view algorithm is correct. It is run as part of [mysql\_upgrade](../mysql_upgrade/index), and should not normally be required in regular use. See Also -------- * [REPAIR VIEW](../repair-view/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb MyRocks and Data Compression MyRocks and Data Compression ============================ MyRocks supports several compression algorithms. Supported Compression Algorithms -------------------------------- Supported compression algorithms can be checked like so: ``` show variables like 'rocksdb%compress%'; +-------------------------------------+------------------------------------+ | Variable_name | Value | +-------------------------------------+------------------------------------+ | rocksdb_supported_compression_types | Snappy,Zlib,LZ4,LZ4HC,ZSTDNotFinal | +-------------------------------------+------------------------------------+ ``` Another way to make the check is to look into `#rocksdb/LOG` file in the data directory. It should have lines like: ``` 2019/04/12-14:08:23.869919 7f839188b540 Compression algorithms supported: 2019/04/12-14:08:23.869920 7f839188b540 kZSTDNotFinalCompression supported: 1 2019/04/12-14:08:23.869922 7f839188b540 kZSTD supported: 1 2019/04/12-14:08:23.869923 7f839188b540 kXpressCompression supported: 0 2019/04/12-14:08:23.869924 7f839188b540 kLZ4HCCompression supported: 1 2019/04/12-14:08:23.869924 7f839188b540 kLZ4Compression supported: 1 2019/04/12-14:08:23.869925 7f839188b540 kBZip2Compression supported: 0 2019/04/12-14:08:23.869926 7f839188b540 kZlibCompression supported: 1 2019/04/12-14:08:23.869927 7f839188b540 kSnappyCompression supported: 1 ``` Compression Settings -------------------- Compression is set on a per-Column Family basis. See [MyRocks Column Families](../myrocks-column-families/index). ### Checking Compression Settings To check current compression settings for a column family one can use a query like so: ``` select * from information_schema.rocksdb_cf_options where option_type like '%ompression%' and cf_name='default'; ``` The output will be like: ``` +---------+-----------------------------------------+---------------------------+ | CF_NAME | OPTION_TYPE | VALUE | +---------+-----------------------------------------+---------------------------+ | default | COMPRESSION_TYPE | kSnappyCompression | | default | COMPRESSION_PER_LEVEL | NUL | | default | COMPRESSION_OPTS | -14:32767:0 | | default | BOTTOMMOST_COMPRESSION | kDisableCompressionOption | | default | TABLE_FACTORY::VERIFY_COMPRESSION | 0 | | default | TABLE_FACTORY::ENABLE_INDEX_COMPRESSION | 1 | +---------+-----------------------------------------+---------------------------+ ``` Current column family settings will be used for the new SST files. ### Modifying Compression Settings Compression settings are not dynamic parameters, one cannot change them by setting [rocksdb\_update\_cf\_options](../myrocks-system-variables/index#rocksdb_update_cf_options). The procedure to change compression settings is as follows: * Edit `my.cnf` to set [rocksdb\_override\_cf\_options](../myrocks-system-variables/index#rocksdb_override_cf_options). Example: ``` rocksdb-override-cf-options='cf1={compression=kZSTD;bottommost_compression=kZSTD;}' ``` * Restart the server. The data will not be re-compressed immediately. However, all new SST files will use the new compression settings, so as data gets inserted/updated the column family will gradually start using the new option. ### Caveat: Syntax Errors Please note that `rocksdb-override-cf-options` syntax is quite strict. Any typos will result in the parse error, and MyRocks plugin will not be loaded. Depending on your configuration, the server may still start. If it does start, you can use this command to check if the plugin is loaded: ``` select * from information_schema.plugins where plugin_name='ROCKSDB' ``` (note that you need the "ROCKSDB" plugin. Other auxiliary plugins like "ROCKSDB\_TRX" might still get loaded). Another way is to detect the error is check the error log. When option parsing fails, it will contain messages like so: ``` 2019-04-16 11:07:57 140283675678016 [Warning] Invalid cf config for cf1 in override options (options: cf1={compression=kLZ4Compression;bottommost_compression=kZSTDCompression;}) 2019-04-16 11:07:57 140283675678016 [ERROR] RocksDB: Failed to initialize CF options map. 2019-04-16 11:07:57 140283675678016 [ERROR] Plugin 'ROCKSDB' init function returned error. 2019-04-16 11:07:57 140283675678016 [ERROR] Plugin 'ROCKSDB' registration as a STORAGE ENGINE failed. ``` Checking How the Data is Compressed ----------------------------------- A query to check what compression is used in the SST files that store the data for a given table (test.t1): ``` select SP.sst_name, SP.compression_algo from information_schema.rocksdb_sst_props SP, information_schema.rocksdb_ddl D, information_schema.rocksdb_index_file_map IFM where D.table_schema='test' and D.table_name='t1' and D.index_number= IFM.index_number and IFM.sst_name=SP.sst_name; ``` Example output: ``` +------------+------------------+ | sst_name | compression_algo | +------------+------------------+ | 000028.sst | Snappy | | 000028.sst | Snappy | | 000026.sst | Snappy | | 000026.sst | Snappy | +------------+------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Compressing Events to Reduce Size of the Binary Log Compressing Events to Reduce Size of the Binary Log =================================================== **MariaDB starting with [10.2.3](https://mariadb.com/kb/en/mariadb-1023-release-notes/)**Starting from [MariaDB 10.2.3](https://mariadb.com/kb/en/mariadb-1023-release-notes/), selected events in the [binary log](../binary-log/index) can be optionally compressed, to save space in the binary log on disk and in network transfers. The events that can be compressed are the events that normally can be of a significant size: Query events (for DDL and DML in [statement-based](../binary-log-formats/index#statement-based) [replication](../standard-replication/index)), and row events (for DML in [row-based](../binary-log-formats/index#row-based) [replication](../standard-replication/index)). Compression is fully transparent. Events are compressed on the primary before being written into the binary log, and are uncompressed by the I/O thread on the replica before being written into the relay log. The [mysqlbinlog](../mysqlbinlog/index) command will likewise uncompress events for its output. Currently, the zlib compression algorithm is used to compress events. Compression will have the most impact when events are of a non-negligible size, as each event is compressed individually. For example, batch INSERT statements that insert many rows or large values, or row-based events that touch a number of rows in one query. The [log\_bin\_compress](../replication-and-binary-log-server-system-variables/index#log_bin_compress) option is used to enable compression of events. Only events with data (query text or row data) above a certain size are compressed; the limit is set with the [log\_bin\_compress\_min\_len](../replication-and-binary-log-server-system-variables/index#log_bin_compress_min_len) option. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb NULL Values NULL Values =========== NULL represents an unknown value. It is *not* an empty string (by default), or a zero value. These are all valid values, and are not NULLs. When a table is [created](../create-table/index) or the format [altered](../alter-table/index), columns can be specified as accepting NULL values, or not accepting them, with the `NULL` and `NOT NULL` clauses respectively. For example, a customer table could contain dates of birth. For some customers, this information is unknown, so the value could be NULL. The same system could allocate a customer ID for each customer record, and in this case a NULL value would not be permitted. ``` CREATE TABLE customer ( id INT NOT NULL, date_of_birth DATE NULL ... ) ``` [User-defined variables](../user-defined-variables/index) are NULL until a value is explicitly assigned. [Stored routines](../stored-programs-and-views/index) parameters and [local variables](../declare-variable/index) can always be set to NULL. If no DEFAULT value is specified for a local variable, its initial value will be NULL. If no value is assigned to an OUT parameter in a stored procedure, NULL is assigned at the end of the procedure. Syntax ------ The case of `NULL` is not relevant. `\N` (uppercase) is an alias for `NULL`. The `[IS](../is/index)` operator accepts `UNKNOWN` as an alias for `NULL`, which is meant for [boolean contexts](../sql-language-structure-boolean-literals/index). Comparison Operators -------------------- NULL values cannot be used with most [comparison operators](../comparison-operators/index). For example, [=](../equal/index), [>](../greater-than/index), [>=](../greater-than-or-equal/index), [<=](../less-than-or-equal/index), [<](../less-than/index), or [!=](../not-equal/index) cannot be used, as any comparison with a NULL always returns a NULL value, never true (1) or false (0). ``` SELECT NULL = NULL; +-------------+ | NULL = NULL | +-------------+ | NULL | +-------------+ SELECT 99 = NULL; +-----------+ | 99 = NULL | +-----------+ | NULL | +-----------+ ``` To overcome this, certain operators are specifically designed for use with NULL values. To cater for testing equality between two values that may contain NULLs, there's [<=>](../null-safe-equal/index), NULL-safe equal. ``` SELECT 99 <=> NULL, NULL <=> NULL; +-------------+---------------+ | 99 <=> NULL | NULL <=> NULL | +-------------+---------------+ | 0 | 1 | +-------------+---------------+ ``` Other operators for working with NULLs include [IS NULL](../is-null/index) and [IS NOT NULL](../is-not-null/index), [ISNULL](../isnull/index) (for testing an expression) and [COALESCE](../coalesce/index) (for returning the first non-NULL parameter). Ordering -------- When you order by a field that may contain NULL values, any NULLs are considered to have the lowest value. So ordering in DESC order will see the NULLs appearing last. To force NULLs to be regarded as highest values, one can add another column which has a higher value when the main field is NULL. Example: ``` SELECT col1 FROM tab ORDER BY ISNULL(col1), col1; ``` Descending order, with NULLs first: ``` SELECT col1 FROM tab ORDER BY IF(col1 IS NULL, 0, 1), col1 DESC; ``` All NULL values are also regarded as equivalent for the purposes of the DISTINCT and GROUP BY clauses. Functions --------- In most cases, functions will return NULL if any of the parameters are NULL. There are also functions specifically for handling NULLs. These include [IFNULL()](../ifnull/index), [NULLIF()](../nullif/index) and [COALESCE()](../coalesce/index). ``` SELECT IFNULL(1,0); +-------------+ | IFNULL(1,0) | +-------------+ | 1 | +-------------+ SELECT IFNULL(NULL,10); +-----------------+ | IFNULL(NULL,10) | +-----------------+ | 10 | +-----------------+ SELECT COALESCE(NULL,NULL,1); +-----------------------+ | COALESCE(NULL,NULL,1) | +-----------------------+ | 1 | +-----------------------+ ``` Aggregate functions, such as [SUM](../sum/index) and [AVG](../avg/index) ignore NULLs. ``` CREATE TABLE t(x INT); INSERT INTO t VALUES (1),(9),(NULL); SELECT SUM(x) FROM t; +--------+ | SUM(x) | +--------+ | 10 | +--------+ SELECT AVG(x) FROM t; +--------+ | AVG(x) | +--------+ | 5.0000 | +--------+ ``` The one exception is [COUNT(\*)](../count/index), which counts rows, and doesn't look at whether a value is NULL or not. Compare for example, COUNT(x), which ignores the NULL, and COUNT(\*), which counts it: ``` SELECT COUNT(x) FROM t; +----------+ | COUNT(x) | +----------+ | 2 | +----------+ SELECT COUNT(*) FROM t; +----------+ | COUNT(*) | +----------+ | 3 | +----------+ ``` AUTO\_INCREMENT, TIMESTAMP and Virtual Columns ---------------------------------------------- MariaDB handles NULL values in a special way if the field is an [AUTO\_INCREMENT](../auto_increment/index), a [TIMESTAMP](../timestamp/index) or a [virtual column](../virtual-columns/index). Inserting a NULL value into a numeric AUTO\_INCREMENT column will result in the next number in the auto increment sequence being inserted instead. This technique is frequently used with AUTO\_INCREMENT fields, which are left to take care of themselves. ``` CREATE TABLE t2(id INT PRIMARY KEY AUTO_INCREMENT, letter CHAR(1)); INSERT INTO t2(letter) VALUES ('a'),('b'); SELECT * FROM t2; +----+--------+ | id | letter | +----+--------+ | 1 | a | | 2 | b | +----+--------+ ``` Similarly, if a NULL value is assigned to a TIMESTAMP field, the current date and time is assigned instead. ``` CREATE TABLE t3 (x INT, ts TIMESTAMP); INSERT INTO t3(x) VALUES (1),(2); ``` After a pause, ``` INSERT INTO t3(x) VALUES (3); SELECT* FROM t3; +------+---------------------+ | x | ts | +------+---------------------+ | 1 | 2013-09-05 10:14:18 | | 2 | 2013-09-05 10:14:18 | | 3 | 2013-09-05 10:14:29 | +------+---------------------+ ``` If a `NULL` is assigned to a `VIRTUAL` or `PERSISTENT` column, the default value is assigned instead. ``` CREATE TABLE virt (c INT, v INT AS (c+10) PERSISTENT) ENGINE=InnoDB; INSERT INTO virt VALUES (1, NULL); SELECT c, v FROM virt; +------+------+ | c | v | +------+------+ | 1 | 11 | +------+------+ ``` In all these special cases, `NULL` is equivalent to the `DEFAULT` keyword. Inserting --------- If a NULL value is single-row inserted into a column declared as NOT NULL, an error will be returned. However, if the [SQL mode](../sql_mode/index) is not [strict](../sql-mode/index#strict-mode) (default until [MariaDB 10.2.3](https://mariadb.com/kb/en/mariadb-1023-release-notes/)), if a NULL value is multi-row inserted into a column declared as NOT NULL, the implicit default for the column type will be inserted (and NOT the default value in the table definition). The implicit defaults are an empty string for string types, and the zero value for numeric, date and time types. Since [MariaDB 10.2.4](https://mariadb.com/kb/en/mariadb-1024-release-notes/), by default both cases will result in an error. ### Examples ``` CREATE TABLE nulltest ( a INT(11), x VARCHAR(10) NOT NULL DEFAULT 'a', y INT(11) NOT NULL DEFAULT 23 ); ``` Single-row insert: ``` INSERT INTO nulltest (a,x,y) VALUES (1,NULL,NULL); ERROR 1048 (23000): Column 'x' cannot be null ``` Multi-row insert with [SQL mode](../sql_mode/index) not [strict](../sql-mode/index#strict-mode) (default until [MariaDB 10.2.3](https://mariadb.com/kb/en/mariadb-1023-release-notes/)): ``` show variables like 'sql_mode%'; +---------------+--------------------------------------------+ | Variable_name | Value | +---------------+--------------------------------------------+ | sql_mode | NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION | +---------------+--------------------------------------------+ INSERT INTO nulltest (a,x,y) VALUES (1,NULL,NULL),(2,NULL,NULL); Query OK, 2 rows affected, 4 warnings (0.08 sec) Records: 2 Duplicates: 0 Warnings: 4 ``` The specified defaults have not been used; rather, the implicit column type defaults have been inserted ``` SELECT * FROM nulltest; +------+---+---+ | a | x | y | +------+---+---+ | 1 | | 0 | | 2 | | 0 | +------+---+---+ ``` Primary Keys and UNIQUE Indexes ------------------------------- UNIQUE indexes can contain multiple NULL values. Primary keys are never nullable. **MariaDB starting with [10.3](../what-is-mariadb-103/index)**Oracle Compatibility -------------------- In [Oracle mode](../sql_modeoracle-from-mariadb-103/index#null-handling), NULL can be used as a statement: ``` IF a=10 THEN NULL; ELSE NULL; END IF ``` In [Oracle mode](../sql_modeoracle-from-mariadb-103/index#null-handling), [CONCAT](../concat/index) and the [Logical OR operator ||](../or/index) ignore [NULL](null). When setting [sql\_mode=EMPTY\_STRING\_IS\_NULL](../sql-mode/index), empty strings and NULLs are the same thing. For example: ``` SET sql_mode=EMPTY_STRING_IS_NULL; SELECT '' IS NULL; -- returns TRUE INSERT INTO t1 VALUES (''); -- inserts NULL ``` See Also -------- * [Primary Keys with Nullable Columns](../primary-keys-with-nullable-columns/index) * [IS NULL operator](../is-null/index) * [IS NOT NULL operator](../is-not-null/index) * [ISNULL function](../isnull/index) * [COALESCE function](../coalesce/index) * [IFNULL function](../ifnull/index) * [NULLIF function](../nullif/index) * [CONNECT data types](../connect-data-types/index#null-handling) * [Oracle mode from MariaDB 10.3](../sql_modeoracle-from-mariadb-103/index#null-handling) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Buildbot Setup for Virtual Machines - Centos 5 amd64 Buildbot Setup for Virtual Machines - Centos 5 amd64 ==================================================== Base install ------------ ``` cd /kvm wget http://ftp.klid.dk/ftp/centos/5.3/isos/x86_64/CentOS-5.3-x86_64-bin-DVD.iso qemu-img create -f qcow2 vms/vm-centos5-amd64-serial.qcow2 8G kvm -m 2047 -hda /kvm/vms/vm-centos5-amd64-serial.qcow2 -cdrom CentOS-5.3-x86_64-bin-DVD.iso -redir 'tcp:2237::22' -boot d -smp 2 -cpu qemu64 -net nic,model=virtio -net user ``` Serial port and account setup ----------------------------- ``` kvm -m 2047 -hda /kvm/vms/vm-centos5-amd64-serial.qcow2 -cdrom CentOS-5.3-i386-bin-DVD.iso -redir 'tcp:2237::22' -boot c -smp 2 -cpu qemu64 -net nic,model=virtio -net user -nographic ``` Add to /boot/grub/menu.lst: ``` serial --unit=0 --speed=115200 --word=8 --parity=no --stop=1 terminal --timeout=3 serial console ``` also add in menu.lst to kernel line (after removing `quiet splash'): ``` console=tty0 console=ttyS0,115200n8 ``` Run these commands: ``` cat >>/etc/inittab <<END # Serial console. S0:2345:respawn:/sbin/agetty -h -L ttyS0 19200 vt100 END ``` ``` useradd buildbot # Password is disabled by default in Centos5. usermod -a -G wheel buildbot visudo # Uncomment the line "%wheel ALL=(ALL) NOPASSWD: ALL" # Comment out this line: # Defaults requiretty # Put in public ssh key for own account and host buildbot account. # Note that Centos5 seems to require .ssh/authorized_keys chmod go-rwx. su - buildbot mkdir .ssh chmod go-rwx .ssh cat >.ssh/authorized_keys chmod go-rwx .ssh/authorized_keys ``` Image for rpm build ------------------- ``` qemu-img create -b vm-centos5-amd64-serial.qcow2 -f qcow2 vm-centos5-amd64-build.qcow2 kvm -m 2047 -hda /kvm/vms/vm-centos5-amd64-build.qcow2 -cdrom /kvm/CentOS-5.3-x86_64-bin-DVD.iso -redir 'tcp:2237::22' -boot c -smp 2 -cpu qemu64 -net nic,model=virtio -net user -nographic ``` Install compilers etc: ``` sudo yum groupinstall "Development Tools" sudo yum install gperf readline-devel ncurses-devel libaio-devel openssl-devel zlib-devel perl perl\(DBI\) ``` Download 5.0 rpm for shared-compat: ``` sudo mkdir -p /srv/shared/yum/CentOS/5/x86_64/RPMS/ cd /srv/shared/yum/CentOS/5/x86_64/RPMS/ sudo wget http://mirror.ourdelta.org/yum/CentOS/5/x86_64/RPMS/MySQL-OurDelta-shared-5.0.87.d10-65.el5.x86_64.rpm ``` Image for install/test ---------------------- ``` qemu-img create -b vm-centos5-amd64-serial.qcow2 -f qcow2 vm-centos5-amd64-install.qcow2 kvm -m 2047 -hda /kvm/vms/vm-centos5-amd64-install.qcow2 -cdrom /kvm/CentOS-5.3-x86_64-bin-DVD.iso -redir 'tcp:2237::22' -boot c -smp 2 -cpu qemu64 -net nic,model=virtio -net user -nographic ``` Install extra dependencies: ``` sudo yum install perl perl\(DBI\) ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb Assignment Operators Assignment Operators ===================== Operators for assigning a value | Title | Description | | --- | --- | | [Assignment Operator (:=)](../assignment-operator/index) | Assignment operator for assigning a value. | | [Assignment Operator (=)](../assignment-operators-assignment-operator/index) | The equal sign as an assignment operator. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb PERCENT_RANK PERCENT\_RANK ============= **MariaDB starting with [10.2](../what-is-mariadb-102/index)**The PERCENT\_RANK() function was first introduced with [window functions](../window-functions/index) in [MariaDB 10.2.0](https://mariadb.com/kb/en/mariadb-1020-release-notes/). Syntax ------ ``` PERCENT_RANK() OVER ( [ PARTITION BY partition_expression ] [ ORDER BY order_list ] ) ``` Description ----------- PERCENT\_RANK() is a [window function](../window-functions/index) that returns the relative percent rank of a given row. The following formula is used to calculate the percent rank: ``` (rank - 1) / (number of rows in the window or partition - 1) ``` Examples -------- ``` create table t1 ( pk int primary key, a int, b int ); insert into t1 values ( 1 , 0, 10), ( 2 , 0, 10), ( 3 , 1, 10), ( 4 , 1, 10), ( 8 , 2, 10), ( 5 , 2, 20), ( 6 , 2, 20), ( 7 , 2, 20), ( 9 , 4, 20), (10 , 4, 20); select pk, a, b, rank() over (order by a) as rank, percent_rank() over (order by a) as pct_rank, cume_dist() over (order by a) as cume_dist from t1; +----+------+------+------+--------------+--------------+ | pk | a | b | rank | pct_rank | cume_dist | +----+------+------+------+--------------+--------------+ | 1 | 0 | 10 | 1 | 0.0000000000 | 0.2000000000 | | 2 | 0 | 10 | 1 | 0.0000000000 | 0.2000000000 | | 3 | 1 | 10 | 3 | 0.2222222222 | 0.4000000000 | | 4 | 1 | 10 | 3 | 0.2222222222 | 0.4000000000 | | 5 | 2 | 20 | 5 | 0.4444444444 | 0.8000000000 | | 6 | 2 | 20 | 5 | 0.4444444444 | 0.8000000000 | | 7 | 2 | 20 | 5 | 0.4444444444 | 0.8000000000 | | 8 | 2 | 10 | 5 | 0.4444444444 | 0.8000000000 | | 9 | 4 | 20 | 9 | 0.8888888889 | 1.0000000000 | | 10 | 4 | 20 | 9 | 0.8888888889 | 1.0000000000 | +----+------+------+------+--------------+--------------+ select pk, a, b, percent_rank() over (order by pk) as pct_rank, cume_dist() over (order by pk) as cume_dist from t1 order by pk; +----+------+------+--------------+--------------+ | pk | a | b | pct_rank | cume_dist | +----+------+------+--------------+--------------+ | 1 | 0 | 10 | 0.0000000000 | 0.1000000000 | | 2 | 0 | 10 | 0.1111111111 | 0.2000000000 | | 3 | 1 | 10 | 0.2222222222 | 0.3000000000 | | 4 | 1 | 10 | 0.3333333333 | 0.4000000000 | | 5 | 2 | 20 | 0.4444444444 | 0.5000000000 | | 6 | 2 | 20 | 0.5555555556 | 0.6000000000 | | 7 | 2 | 20 | 0.6666666667 | 0.7000000000 | | 8 | 2 | 10 | 0.7777777778 | 0.8000000000 | | 9 | 4 | 20 | 0.8888888889 | 0.9000000000 | | 10 | 4 | 20 | 1.0000000000 | 1.0000000000 | +----+------+------+--------------+--------------+ select pk, a, b, percent_rank() over (partition by a order by a) as pct_rank, cume_dist() over (partition by a order by a) as cume_dist from t1; +----+------+------+--------------+--------------+ | pk | a | b | pct_rank | cume_dist | +----+------+------+--------------+--------------+ | 1 | 0 | 10 | 0.0000000000 | 1.0000000000 | | 2 | 0 | 10 | 0.0000000000 | 1.0000000000 | | 3 | 1 | 10 | 0.0000000000 | 1.0000000000 | | 4 | 1 | 10 | 0.0000000000 | 1.0000000000 | | 5 | 2 | 20 | 0.0000000000 | 1.0000000000 | | 6 | 2 | 20 | 0.0000000000 | 1.0000000000 | | 7 | 2 | 20 | 0.0000000000 | 1.0000000000 | | 8 | 2 | 10 | 0.0000000000 | 1.0000000000 | | 9 | 4 | 20 | 0.0000000000 | 1.0000000000 | | 10 | 4 | 20 | 0.0000000000 | 1.0000000000 | +----+------+------+--------------+--------------+ ``` See Also -------- * [CUME\_DIST()](../cume_dist/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Point Properties Point Properties ================= Point properties | Title | Description | | --- | --- | | [ST\_X](../st_x/index) | X-coordinate value for a point. | | [ST\_Y](../st_y/index) | Y-coordinate for a point. | | [X](../point-properties-x/index) | Synonym for ST\_X. | | [Y](../point-properties-y/index) | Synonym for ST\_Y. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Using CONNECT - Virtual and Special Columns Using CONNECT - Virtual and Special Columns =========================================== CONNECT supports MariaDB [virtual and persistent columns](../virtual-columns/index). It is also possible to declare a column as being a CONNECT special column. Let us see on an example how this can be done. The boys table we have seen previously can be recreated as: ``` create table boys ( linenum int(6) not null default 0 special=rowid, name char(12) not null, city char(12) not null, birth date not null date_format='DD/MM/YYYY', hired date not null date_format='DD/MM/YYYY' flag=36, agehired int(3) as (floor(datediff(hired,birth)/365.25)) virtual, fn char(100) not null default '' special=FILEID) engine=CONNECT table_type=FIX file_name='boys.txt' mapped=YES lrecl=47; ``` We have defined two CONNECT special columns. You can give them any name; it is the field SPECIAL option that specifies the special column functional name. **Note:** the default values specified for the special columns do not mean anything. They are specified just to prevent getting warning messages when inserting new rows. For the definition of the *agehired* virtual column, no CONNECT options can be specified as it has no offset or length, not being stored in the file. The command: ``` select * from boys where city = 'boston'; ``` will return: | linenum | name | city | birth | hired | agehired | fn | | --- | --- | --- | --- | --- | --- | --- | | 1 | John | Boston | 1986-01-25 | 2010-06-02 | 24 | d:\mariadb\sql\data\boys.txt | | 2 | Henry | Boston | 1987-06-07 | 2008-04-01 | 20 | d:\mariadb\sql\data\boys.txt | | 6 | Bill | Boston | 1986-09-11 | 2008-02-10 | 21 | d:\mariadb\sql\data\boys.txt | Existing special columns are listed in the following table: | Special Name | Type | Description of the column value | | --- | --- | --- | | ROWID | Integer | The row ordinal number in the table. This is not quite equivalent to a virtual column with an auto increment of 1 because rows are renumbered when deleting rows. | | ROWNUM | Integer | The row ordinal number in the file. This is different from ROWID for multiple tables, TBL/XCOL/OCCUR/PIVOT tables, XML tables with a multiple column, and for DBF tables where ROWNUM includes soft deleted rows. | | FILEID FDISK FPATH FNAME FTYPE | String | FILEID returns the full name of the file this row belongs to. Useful in particular for multiple tables represented by several files. The other special columns can be used to retrieve only one part of the full name. | | TABID | String | The name of the table this row belongs to. Useful for TBL tables. | | PARTID | String | The name of the partition this row belongs to. Specific to partitioned tables. | | SERVID | String | The name of the federated server or server host used by a MYSQL table. “ODBC” for an ODBC table, "JDBC" for a JDBC table and “Current” for all other tables. | **Note:** CONNECT does not currently support auto incremented columns. However, a `ROWID` special column will do the job of a column auto incremented by 1. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Basic SQL Debugging Basic SQL Debugging =================== Designing Queries ----------------- Following a few conventions makes finding errors in queries a lot easier, especially when you ask for help from people who might know SQL, but know nothing about your particular schema. A query easy to read is a query easy to debug. Use whitespace to group clauses within the query. Choose good table and field aliases to add clarity, not confusion. Choose the syntax that supports the query's meaning. ### Using Whitespace A query hard to read is a query hard to debug. White space is free. New lines and indentation make queries easy to read, particularly when constructing a query inside a scripting language, where variables are interspersed throughout the query. There is a syntax error in the following. How fast can you find it? ``` SELECT u.id, u.name, alliance.ally FROM users u JOIN alliance ON (u.id=alliance.userId) JOIN team ON (alliance.teamId=team.teamId WHERE team.teamName='Legionnaires' AND u.online=1 AND ((u.subscription='paid' AND u.paymentStatus='current') OR u.subscription='free') ORDER BY u.name; ``` Here's the same query, with correct use of whitespace. Can you find the error faster? ``` SELECT u.id , u.name , alliance.ally FROM users u JOIN alliance ON (u.id = alliance.userId) JOIN team ON (alliance.teamId = team.teamId WHERE team.teamName = 'Legionnaires' AND u.online = 1 AND ( (u.subscription = 'paid' AND u.paymentStatus = 'current') OR u.subscription = 'free' ) ORDER BY u.name; ``` Even if you don't know SQL, you might still have caught the missing ')' following team.teamId. The exact formatting style you use isn't so important. You might like commas in the select list to follow expressions, rather than precede them. You might indent with tabs or with spaces. Adherence to some particular form is not important. Legibility is the only goal. ### Table and Field Aliases Aliases allow you to rename tables and fields for use within a query. This can be handy when the original names are very long, and is required for self joins and certain subqueries. However, poorly chosen aliases can make a query harder to debug, rather than easier. Aliases should reflect the original table name, not an arbitrary string. Bad: ``` SELECT * FROM financial_reportQ_1 AS a JOIN sales_renderings AS b ON (a.salesGroup = b.groupId) JOIN sales_agents AS c ON (b.groupId = c.group) WHERE b.totalSales > 10000 AND c.id != a.clientId ``` As the list of joined tables and the WHERE clause grow, it becomes necessary to repeatedly look back to the top of the query to see to which table any given alias refers. Better: ``` SELECT * FROM financial_report_Q_1 AS frq1 JOIN sales_renderings AS sr ON (frq1.salesGroup = sr.groupId) JOIN sales_agents AS sa ON (sr.groupId = sa.group) WHERE sr.totalSales > 10000 AND sa.id != frq1.clientId ``` Each alias is just a little longer, but the table initials give enough clues that anyone familiar with the database only need see the full table name once, and can generally remember which table goes with which alias while reading the rest of the query. ### Placing JOIN conditions The manual warns against using the JOIN condition (that is, the ON clause) for restricting rows. Some queries, particularly those using implicit joins, take the opposite extreme - all join conditions are moved to the WHERE clause. In consequence, the table relationships are mixed with the business logic. Bad: ``` SELECT * FROM family, relationships WHERE family.personId = relationships.personId AND relationships.relation = 'father' ``` Without digging through the WHERE clause, it is impossible to say what links the two tables. Better: ``` SELECT * FROM family JOIN relationships ON (family.personId = relationships.personId) WHERE relationships.relation = 'father' ``` The relation between the tables is immediately obvious. The WHERE clause is left to limit rows in the result set. Compliance with such a restriction negates the use of the comma operator to join tables. It is a small price to pay. Queries should be written using the explicit JOIN keyword anyway, and the two should never be mixed (unless you like rewriting all your queries every time a new version changes operator precedence). Finding Syntax Errors --------------------- Syntax errors are among the easiest problems to solve. MariaDB provides an error message showing the exact point where the parser became confused. Check the query, including a few words before the phrase shown in the error message. Most syntax and parsing errors are obvious after a second look, but some are more elusive, especially when the error text seems empty, points to a valid keyword, or seems to error on syntax that appears exactly correct. ### Interpreting the Empty Error Most syntax errors are easy to interpret. The error generally details the exact source of the trouble. A careful look at the query, with the error message in mind, often reveals an obvious mistake, such as mispelled field names, a missing 'AND', or an extra closing parenthesis. Sometimes the error is a little less helpful. A frequent, less-than-helpful message: ``` ERROR 1064: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near ' ' at line 1 ``` The empty ' ' can be disheartening. Clearly there is an error, but where? A good place to look is at the end of the query. The ' ' suggests that the parser reached the end of the statement while still expecting some syntax token to appear. Check for missing closers, such as ' and ): ``` SELECT * FROM someTable WHERE field = 'value ``` Look for incomplete clauses, often indicated by an exposed comma: ``` SELECT * FROM someTable WHERE field = 1 GROUP BY id, ``` ### Checking for keywords MariaDB allows table and field names and aliases that are also [reserved words](../reserved-words/index). To prevent ambiguity, such names must be enclosed in backticks (`): ``` SELECT * FROM actionTable WHERE `DELETE` = 1; ``` If the syntax error is shown near one of your identifiers, check if it appears on the [reserved word list](../reserved-words/index). A text editor with color highlighting for SQL syntax helps to find these errors. When you enter a field name, and it shows up in the same color as the SELECT keyword, you know something is amiss. Some common culprits: * **DESC** is a common abbreviation for "description" fields. It means "descending" in a MariaDB **ORDER** clause. * **DATE**, **TIME**, and **TIMESTAMP** are all common field names. They are also field types. * **ORDER** appears in sales applications. MariaDB uses it to specify sorting for results. Some keywords are so common that MariaDB makes a special allowance to use them unquoted. My advice: don't. If it's a keyword, quote it. ### Version specific syntax As MariaDB adds new features, the syntax must change to support them. Most of the time, old syntax will work in newer versions of MariaDB. One notable exception is the change in precedence of the comma operator relative to the JOIN keyword in version 5.0. A query that used to work, such as ``` SELECT * FROM a, b JOIN c ON a.x = c.x; ``` will now fail. More common, however, is an attempt to use new syntax in an old version. Web hosting companies are notoriously slow to upgrade MariaDB, and you may find yourself using a version several years out of date. The result can be very frustrating when a query that executes flawlessly on your own workstation, running a recent installation, fails completely in your production environment. This query fails in any version of MySQL prior to 4.1, when subqueries were added to the server: ``` SELECT * FROM someTable WHERE someId IN (SELECT id FROM someLookupTable); ``` This query fails in some early versions of MySQL, because the JOIN syntax did not originally allow an ON clause: ``` SELECT * FROM tableA JOIN tableB ON tableA.x = tableB.y; ``` Always check the installed version of MariaDB, and read the section of the manual relevant for that version. The manual usually indicates exactly when particular syntax became available for use. *The initial version of this article was copied, with permission, from <http://hashmysql.org/wiki/Basic_Debugging> on 2012-10-05.* Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb BINLOG BINLOG ====== Syntax ------ ``` BINLOG 'str' ``` Description ----------- `BINLOG` is an internal-use statement. It is generated by the [mariadb-binlog/mysqlbinlog](../mysqlbinlog/index) program as the printable representation of certain events in [binary log](../binary-log/index) files. The `'str'` value is a base 64-encoded string the that server decodes to determine the data change indicated by the corresponding event. This statement requires the [SUPER](../grant/index#super) privilege (<= [MariaDB 10.5.1](https://mariadb.com/kb/en/mariadb-1051-release-notes/)) or the[BINLOG REPLAY](../grant/index#binlog-replay) privilege (>= [MariaDB 10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/)). See also -------- * [MariaDB replication](../high-availability-performance-tuning-mariadb-replication/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Performance Schema objects_summary_global_by_type Table Performance Schema objects\_summary\_global\_by\_type Table =========================================================== It aggregates object wait events, and contains the following columns: | Column | Description | | --- | --- | | `OBJECT_TYPE` | Groups records together with `OBJECT_SCHEMA` and `OBJECT_NAME`. | | `OBJECT_SCHEMA` | Groups records together with `OBJECT_TYPE` and `OBJECT_NAME`. | | `OBJECT_NAME` | Groups records together with `OBJECT_SCHEMA` and `OBJECT_TYPE`. | | `COUNT_STAR` | Number of summarized events | | `SUM_TIMER_WAIT` | Total wait time of the summarized events that are timed. | | `MIN_TIMER_WAIT` | Minimum wait time of the summarized events that are timed. | | `AVG_TIMER_WAIT` | Average wait time of the summarized events that are timed. | | `MAX_TIMER_WAIT` | Maximum wait time of the summarized events that are timed. | You can [TRUNCATE](../truncate-table/index) the table, which will reset all counters to zero. Example ------- ``` SELECT * FROM objects_summary_global_by_type\G ... *************************** 101. row *************************** OBJECT_TYPE: TABLE OBJECT_SCHEMA: test OBJECT_NAME: v COUNT_STAR: 0 SUM_TIMER_WAIT: 0 MIN_TIMER_WAIT: 0 AVG_TIMER_WAIT: 0 MAX_TIMER_WAIT: 0 *************************** 102. row *************************** OBJECT_TYPE: TABLE OBJECT_SCHEMA: test OBJECT_NAME: xx2 COUNT_STAR: 2 SUM_TIMER_WAIT: 1621920 MIN_TIMER_WAIT: 481344 AVG_TIMER_WAIT: 810960 MAX_TIMER_WAIT: 1140576 ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb Data Manipulation Data Manipulation ================== SQL commands for querying and manipulating data, such as SELECT, UPDATE, DELETE etc. | Title | Description | | --- | --- | | [Selecting Data](../selecting-data/index) | Documentation on the SELECT statement and related clauses. | | [Inserting & Loading Data](../inserting-loading-data/index) | Documentation on the INSERT statement and related clauses. | | [Changing & Deleting Data](../changing-deleting-data/index) | Documentation on the UPDATE, REPLACE, and DELETE Statements. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb SHOW CREATE PROCEDURE SHOW CREATE PROCEDURE ===================== Syntax ------ ``` SHOW CREATE PROCEDURE proc_name ``` Description ----------- This statement is a MariaDB extension. It returns the exact string that can be used to re-create the named [stored procedure](../stored-procedures/index), as well as the `[SQL\_MODE](../sql-mode/index)` that was used when the trigger has been created and the character set used by the connection.. A similar statement, `[SHOW CREATE FUNCTION](../show-create-function/index)`, displays information about [stored functions](../stored-functions/index). Both statements require that you are the owner of the routine or have the `[SELECT](../grant/index)` privilege on the `[mysql.proc](../mysqlproc-table/index)` table. When neither is true, the statements display `NULL` for the `Create Procedure` or `Create Function` field. **Warning** Users with `SELECT` privileges on `[mysql.proc](../mysqlproc-table/index)` or `USAGE` privileges on `*.*` can view the text of routines, even when they do not have privileges for the function or procedure itself. The output of these statements is unreliably affected by the `[sql\_quote\_show\_create](../server-system-variables/index#sql_quote_show_create)` server system variable - see <http://bugs.mysql.com/bug.php?id=12719> Examples -------- Here's a comparison of the `SHOW CREATE PROCEDURE` and `[SHOW CREATE FUNCTION](../show-create-function/index)` statements. ``` SHOW CREATE PROCEDURE test.simpleproc\G *************************** 1. row *************************** Procedure: simpleproc sql_mode: Create Procedure: CREATE PROCEDURE `simpleproc`(OUT param1 INT) BEGIN SELECT COUNT(*) INTO param1 FROM t; END character_set_client: latin1 collation_connection: latin1_swedish_ci Database Collation: latin1_swedish_ci SHOW CREATE FUNCTION test.hello\G *************************** 1. row *************************** Function: hello sql_mode: Create Function: CREATE FUNCTION `hello`(s CHAR(20)) RETURNS CHAR(50) RETURN CONCAT('Hello, ',s,'!') character_set_client: latin1 collation_connection: latin1_swedish_ci Database Collation: latin1_swedish_ci ``` When the user issuing the statement does not have privileges on the routine, attempting to `[CALL](../call/index)` the procedure raises Error 1370. ``` CALL test.prc1(); Error 1370 (42000): execute command denieed to user 'test_user'@'localhost' for routine 'test'.'prc1' ``` If the user neither has privilege to the routine nor the `[SELECT](../grant/index)` privilege on `[mysql.proc](../mysqlproc-table/index)` table, it raises Error 1305, informing them that the procedure does not exist. ``` SHOW CREATE TABLES test.prc1\G Error 1305 (42000): PROCEDURE prc1 does not exist ``` See Also -------- * [Stored Procedure Overview](../stored-procedure-overview/index) * [CREATE PROCEDURE](../create-procedure/index) * [ALTER PROCEDURE](../alter-procedure/index) * [DROP PROCEDURE](../drop-procedure/index) * [SHOW PROCEDURE STATUS](../show-procedure-status/index) * [Stored Routine Privileges](../stored-routine-privileges/index) * [Information Schema ROUTINES Table](../information-schema-routines-table/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Delayed Insert Connection Thread States Delayed Insert Connection Thread States ======================================= This article documents thread states that are related to the connection thread that processes [INSERT DELAYED](../insert-delayed/index) statements. These correspond to the `STATE` values listed by the [SHOW PROCESSLIST](../show-processlist/index) statement or in the [Information Schema PROCESSLIST Table](../information-schema-processlist-table/index) as well as the `PROCESSLIST_STATE` value listed in the [Performance Schema threads Table](../performance-schema-threads-table/index). | Value | Description | | --- | --- | | allocating local table | Preparing to allocate rows to the delayed-insert handler thread. Follows from the `got handler lock` state. | | Creating delayed handler | Creating a handler for the delayed-inserts. | | got handler lock | Lock to access the delayed-insert handler thread has been received. Follows from the `waiting for handler lock` state and before the `allocating local table` state. | | got old table | The initialization phase is over. Follows from the `waiting for handler open` state. | | storing row into queue | Adding new row to the list of rows to be inserted by the delayed-insert handler thread. | | waiting for delay\_list | Initializing (trying to find the delayed-insert handler thread). | | waiting for handler insert | Waiting for new inserts, as all inserts have been processed. | | waiting for handler lock | Waiting for delayed insert-handler lock to access the delayed-insert handler thread. | | waiting for handler open | Waiting for the delayed-insert handler thread to initialize. Follows from the `Creating delayed handler` state and before the `got old table` state. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Non-semi-join Subquery Optimizations Non-semi-join Subquery Optimizations ==================================== Certain kinds of IN-subqueries cannot be flattened into [semi-joins](../semi-join-subquery-optimizations/index). These subqueries can be both correlated or non-correlated. In order to provide consistent performance in all cases, MariaDB provides several alternative strategies for these types of subqueries. Whenever several strategies are possible, the optimizer chooses the optimal one based on cost estimates. The two primary non-semi-join strategies are materialization (also called outside-in materialization), and in-to-exists transformation. Materialization is applicable only for non-correlated subqueries, while in-to-exist can be used both for correlated and non-correlated subqueries. Applicability ------------- An IN subquery cannot be flattened into a semi-join in the following cases. The examples below use the *World* database from the MariaDB regression test suite. ### Subquery in a disjunction (OR) The subquery is located directly or indirectly under an OR operation in the WHERE clause of the outer query. Query pattern: ``` SELECT ... FROM ... WHERE (expr1, ..., exprN) [NOT] IN (SELECT ... ) OR expr; ``` Example: ``` SELECT Name FROM Country WHERE (Code IN (select Country from City where City.Population > 100000) OR Name LIKE 'L%') AND surfacearea > 1000000; ``` ### Negated subquery predicate (NOT IN) The subquery predicate itself is negated. Query pattern: ``` SELECT ... FROM ... WHERE ... (expr1, ..., exprN) NOT IN (SELECT ... ) ...; ``` Example: ``` SELECT Country.Name FROM Country, CountryLanguage WHERE Code NOT IN (SELECT Country FROM CountryLanguage WHERE Language = 'English') AND CountryLanguage.Language = 'French' AND Code = Country; ``` ### Subquery in the SELECT or HAVING clause The subquery is located in the SELECT or HAVING clauses of the outer query. Query pattern: ``` SELECT field1, ..., (SELECT ...) WHERE ...; SELECT ... WHERE ... HAVING (SELECT ...); ``` Example: ``` select Name, City.id in (select capital from Country where capital is not null) as is_capital from City where City.population > 10000000; ``` ### Subquery with a UNION The subquery itself is a UNION, while the IN predicate may be anywhere in the query where IN is allowed. Query pattern: ``` ... [NOT] IN (SELECT ... UNION SELECT ...) ``` Example: ``` SELECT * from City where (Name, 91) IN (SELECT Name, round(Population/1000) FROM City WHERE Country = "IND" AND Population > 2500000 UNION SELECT Name, round(Population/1000) FROM City WHERE Country = "IND" AND Population < 100000); ``` Materialization for non-correlated IN-subqueries ------------------------------------------------ ### Materialization basics The basic idea of subquery materialization is to execute the subquery and store its result in an internal temporary table indexed on all its columns. Naturally, this is possible only when the subquery is non-correlated. The IN predicate tests whether its left operand is present in the subquery result. Therefore it is not necessary to store duplicate subquery result rows in the temporary table. Storing only unique subquery rows provides two benefits - the size of the temporary table is smaller, and the index on all its columns can be unique. If the size of the temporary table is less than the tmp\_table\_size system variable, the table is a hash-indexed in-memory HEAP table. In the rare cases when the subquery result exceeds this limit, the temporary table is stored on disk in an ARIA or MyISAM B-tree indexed table (ARIA is the default). Subquery materialization happens on demand during the first execution of the IN predicate. Once the subquery is materialized, the IN predicate is evaluated very efficiently by index lookups of the outer expression into the unique index of the materialized temporary table. If there is a match, IN is TRUE, otherwise IN is FALSE. ### NULL-aware efficient execution An IN predicate may produce a NULL result if there is a NULL value in either of its arguments. Depending on its location in a query, a NULL predicate value is equivalent to FALSE. These are the cases when substituting NULL with FALSE would reject exactly the same result rows. A NULL result of IN is indistinguishable from a FALSE if the IN predicate is: * not negated, * not a function argument, * inside a WHERE or ON clause. In all these cases the evaluation of IN is performed as described in the previous paragraph via index lookups into the materialized subquery. In all remaining cases when NULL cannot be substituted with FALSE, it is not possible to use index lookups. This is not a limitation in the server, but a consequence of the NULL semantics in the ANSI SQL standard. Suppose an IN predicate is evaluated as ``` NULL IN (select not_null_col from t1) ``` , that is, the left operand of IN is a NULL value, and there are no NULLs in the subquery. In this case the value of IN is neither FALSE, nor TRUE. Instead it is NULL. If we were to perform an index lookup with the NULL as a key, such a value would not be found in not\_null\_col, and the IN predicate would incorrectly produce a FALSE. In general, an NULL value on either side of an IN acts as a "wildcard" that matches any value, and if a match exists, the result of IN is NULL. Consider the following example: If the left argument of IN is the row: `(7, NULL, 9)`, and the result of the right subquery operand of IN is the table: ``` (7, 8, 10) (6, NULL, NULL) (7, 11, 9) ``` The the IN predicate matches the row `(7, 11, 9)`, and the result of IN is NULL. Matches where the differing values on either side of the IN arguments are matched by a NULL in the other IN argument, are called *partial matches*. In order to efficiently compute the result of an IN predicate in the presence of NULLs, MariaDB implements two special algorithms for [partial matching, described here in detail](http://askmonty.org/worklog/Server-Sprint/?tid=68). * Rowid-merge partial matching This technique is used when the number of rows in the subquery result is above a certain limit. The technique creates special indexes on some of the columns of the temporary table, and merges them by alternative scanning of each index thus performing an operation similar to set-intersection. * Table scan partial matching This algorithm is used for very small tables when the overhead of the rowid-merge algorithm is not justifiable. Then the server simply scans the materialized subquery, and checks for partial matches. Since this strategy doesn't need any in-memory buffers, it is also used when there is not enough memory to hold the indexes of the rowid-merge strategy. ### Limitations In principle the subquery materialization strategy is universal, however, due to some technical limitations in the MariaDB server, there are few cases when the server cannot apply this optimization. * BLOB fields Either the left operand of an IN predicate refers to a BLOB field, or the subquery selects one or more BLOBs. * Incomparable fields TODO In the above cases, the server reverts to the [IN-TO-EXISTS](index#the-in-to-exists-transformation) transformation. The IN-TO-EXISTS transformation ------------------------------- This optimization is the only subquery execution strategy that existed in older versions of MariaDB and MySQL prior to [MariaDB 5.3](../what-is-mariadb-53/index). We have made various changes and fixed a number of bugs in this code as well, but in essence it remains the same. Performance discussion ---------------------- ### Example speedup over MySQL 5.x and [MariaDB 5.1](../what-is-mariadb-51/index)/5.2 Depending on the query and data, either of the two strategies described here may result in orders of magnitude better/worse plan than the other strategy. Older versions of MariaDB and any current MySQL version (including MySQL 5.5, and MySQL 5.6 DMR as of July 2011) implement only the IN-TO-EXISTS transformation. As illustrated below, this strategy is inferior in many common cases to subquery materialization. Consider the following query over the data of the DBT3 benchmark scale 10. Find customers with top balance in their nations: ``` SELECT * FROM part WHERE p_partkey IN (SELECT l_partkey FROM lineitem WHERE l_shipdate between '1997-01-01' and '1997-02-01') ORDER BY p_retailprice DESC LIMIT 10; ``` The times to run this query is as follows: * Execution time in [MariaDB 5.2](../what-is-mariadb-52/index)/MySQL 5.x (any MySQL): **> 1 h** The query takes more than one hour (we didn't wait longer), which makes it impractical to use subqueries in such cases. The EXPLAIN below shows that the subquery was transformed into a correlated one, which indicates an IN-TO-EXISTS transformation. ``` +--+------------------+--------+--------------+-------------------+----+------+---------------------------+ |id|select_type |table |type |key |ref |rows |Extra | +--+------------------+--------+--------------+-------------------+----+------+---------------------------+ | 1|PRIMARY |part |ALL |NULL |NULL|199755|Using where; Using filesort| | 2|DEPENDENT SUBQUERY|lineitem|index_subquery|i_l_suppkey_partkey|func| 14|Using where | +--+------------------+--------+--------------+-------------------+----+------+---------------------------+ ``` * Execution time in [MariaDB 5.3](../what-is-mariadb-53/index): **43 sec** In [MariaDB 5.3](../what-is-mariadb-53/index) it takes less than a minute to run the same query. The EXPLAIN shows that the subquery remains uncorrelated, which is an indication that it is being executed via subquery materialization. ``` +--+------------+-----------+------+------------------+----+------+-------------------------------+ |id|select_type |table |type |key |ref |rows |Extra | +--+------------+-----------+------+------------------+----+------+-------------------------------+ | 1|PRIMARY |part |ALL |NULL |NULL|199755|Using temporary; Using filesort| | 1|PRIMARY |<subquery2>|eq_ref|distinct_key |func| 1| | | 2|MATERIALIZED|lineitem |range |l_shipdate_partkey|NULL|160060|Using where; Using index | +--+------------+-----------+------+------------------+----+------+-------------------------------+ ``` The speedup here is practically infinite, because both MySQL and older MariaDB versions cannot complete the query in any reasonable time. In order to show the benefits of partial matching we extended the *customer* table from the DBT3 benchmark with two extra columns: * c\_pref\_nationkey - preferred nation to buy from, * c\_pref\_brand - preferred brand. Both columns are prefixed with the percent NULL values in the column, that is, c\_pref\_nationkey\_05 contains 5% NULL values. Consider the query "Find all customers that didn't buy from a preferred country, and from a preferred brand withing some date ranges": ``` SELECT count(*) FROM customer WHERE (c_custkey, c_pref_nationkey_05, c_pref_brand_05) NOT IN (SELECT o_custkey, s_nationkey, p_brand FROM orders, supplier, part, lineitem WHERE l_orderkey = o_orderkey and l_suppkey = s_suppkey and l_partkey = p_partkey and p_retailprice < 1200 and l_shipdate >= '1996-04-01' and l_shipdate < '1996-04-05' and o_orderdate >= '1996-04-01' and o_orderdate < '1996-04-05'); ``` * Execution time in [MariaDB 5.2](../what-is-mariadb-52/index)/MySQL 5.x (any MySQL): **40 sec** * Execution time in [MariaDB 5.3](../what-is-mariadb-53/index): **2 sec** The speedup for this query is 20 times. ### Performance guidelines TODO Optimizer control ----------------- In certain cases it may be necessary to override the choice of the optimizer. Typically this is needed for benchmarking or testing purposes, or to mimic the behavior of an older version of the server, or if the optimizer made a poor choice. All the above strategies can be controlled via the following switches in [optimizer\_switch](../server-system-variables/index#optimizer_switch) system variable. * materialization=on/off In some very special cases, even if materialization was forced, the optimizer may still revert to the IN-TO-EXISTS strategy if materialization is not applicable. In the cases when materialization requres partial matching (because of the presense of NULL values), there are two subordinate switches that control the two partial matching strategies: + partial\_match\_rowid\_merge=on/off This switch controls the Rowid-merge strategy. In addition to this switch, the system variable [rowid\_merge\_buff\_size](../server-system-variables/index#rowid_merge_buff_size) controls the maximum memory available to the Rowid-merge strategy. + partial\_match\_table\_scan=on/off Controls the alternative partial match strategy that performs matching via a table scan. * in\_to\_exists=on/off This switch controls the IN-TO-EXISTS transformation. * tmp\_table\_size and max\_heap\_table\_size system variables The *tmp\_table\_size* system variable sets the upper limit for internal MEMORY temporary tables. If an internal temporary table exceeds this size, it is converted automatically into a Aria or MyISAM table on disk with a B-tree index. Notice however, that a MEMORY table cannot be larger than *max\_heap\_table\_size*. The two main optimizer switches - *materialization* and *in\_to\_exists* cannot be simultaneously off. If both are set to off, the server will issue an error. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb SHOW ENGINE SHOW ENGINE =========== Syntax ------ ``` SHOW ENGINE engine_name {STATUS | MUTEX} ``` Description ----------- `SHOW ENGINE` displays operational information about a storage engine. The following statements currently are supported: ``` SHOW ENGINE INNODB STATUS SHOW ENGINE INNODB MUTEX SHOW ENGINE PERFORMANCE_SCHEMA STATUS SHOW ENGINE ROCKSDB STATUS ``` If the [Sphinx Storage Engine](../sphinxse/index) is installed, the following is also supported: ``` SHOW ENGINE SPHINX STATUS ``` See `[SHOW ENGINE SPHINX STATUS](../about-sphinxse/index#show-engine-sphinx-status)`. Older (and now removed) synonyms were `SHOW INNODB STATUS` for `SHOW ENGINE INNODB STATUS` and `SHOW MUTEX STATUS` for `SHOW ENGINE INNODB MUTEX`. ### SHOW ENGINE INNODB STATUS `SHOW ENGINE INNODB STATUS` displays extensive information from the standard InnoDB Monitor about the state of the InnoDB storage engine. See `[SHOW ENGINE INNODB STATUS](../show-engine-innodb-status/index)` for more. ### SHOW ENGINE INNODB MUTEX `SHOW ENGINE INNODB MUTEX` displays InnoDB mutex statistics. The statement displays the following output fields: * **Type:** Always InnoDB. * **Name:** The source file where the mutex is implemented, and the line number in the file where the mutex is created. The line number is dependent on the MariaDB version. * **Status:** This field displays the following values if `UNIV_DEBUG` was defined at compilation time (for example, in include/univ.h in the InnoDB part of the source tree). Only the `os_waits` value is displayed if `UNIV_DEBUG` was not defined. Without `UNIV_DEBUG`, the information on which the output is based is insufficient to distinguish regular mutexes and mutexes that protect rw-locks (which allow multiple readers or a single writer). Consequently, the output may appear to contain multiple rows for the same mutex. + **count** indicates how many times the mutex was requested. + **spin\_waits** indicates how many times the spinlock had to run. + **spin\_rounds** indicates the number of spinlock rounds. (spin\_rounds divided by spin\_waits provides the average round count.) + **os\_waits** indicates the number of operating system waits. This occurs when the spinlock did not work (the mutex was not locked during the spinlock and it was necessary to yield to the operating system and wait). + **os\_yields** indicates the number of times a the thread trying to lock a mutex gave up its timeslice and yielded to the operating system (on the presumption that allowing other threads to run will free the mutex so that it can be locked). + **os\_wait\_times** indicates the amount of time (in ms) spent in operating system waits, if the timed\_mutexes system variable is 1 (ON). If timed\_mutexes is 0 (OFF), timing is disabled, so os\_wait\_times is 0. timed\_mutexes is off by default. Information from this statement can be used to diagnose system problems. For example, large values of spin\_waits and spin\_rounds may indicate scalability problems. The `[information\_schema](../information-schema/index).[INNODB\_MUTEXES](../information-schema-innodb_mutexes-table/index)` table provides similar information. ### SHOW ENGINE PERFORMANCE\_SCHEMA STATUS This statement shows how much memory is used for `[performance\_schema](../performance-schema/index)` tables and internal buffers. The output contains the following fields: * **Type:** Always `performance_schema`. * **Name:** The name of a table, the name of an internal buffer, or the `performance_schema` word, followed by a dot and an attribute. Internal buffers names are enclosed by parenthesis. `performance_schema` means that the attribute refers to the whole database (it is a total). * **Status:** The value for the attribute. The following attributes are shown, in this order, for all tables: * **row\_size:** The memory used for an individual record. This value will never change. * **row\_count:** The number of rows in the table or buffer. For some tables, this value depends on a server system variable. * **memory:** For tables and `performance_schema`, this is the result of `row_size` \* `row_count`. For internal buffers, the attributes are: * **count** * **size** ### SHOW ENGINE ROCKSDB STATUS See also [MyRocks Performance Troubleshooting](../myrocks-performance-troubleshooting/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb ST_GeomFromWKB ST\_GeomFromWKB =============== Syntax ------ ``` ST_GeomFromWKB(wkb[,srid]) ST_GeometryFromWKB(wkb[,srid]) GeomFromWKB(wkb[,srid]) GeometryFromWKB(wkb[,srid]) ``` Description ----------- Constructs a geometry value of any type using its [WKB](../well-known-binary-wkb-format/index) representation and SRID. `ST_GeomFromWKB()`, `ST_GeometryFromWKB()`, `GeomFromWKB()` and `GeometryFromWKB()` are synonyms. Examples -------- ``` SET @g = ST_AsBinary(ST_LineFromText('LINESTRING(0 4, 4 6)')); SELECT ST_AsText(ST_GeomFromWKB(@g)); +-------------------------------+ | ST_AsText(ST_GeomFromWKB(@g)) | +-------------------------------+ | LINESTRING(0 4,4 6) | +-------------------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb xtrabackup-v2 SST Method xtrabackup-v2 SST Method ======================== In [MariaDB 10.1](../what-is-mariadb-101/index) and later, [Mariabackup](../mariabackup/index) is the recommended backup method to use instead of Percona XtraBackup. In [MariaDB 10.3](../what-is-mariadb-103/index), Percona XtraBackup is **not supported**. See [Percona XtraBackup Overview: Compatibility with MariaDB](../percona-xtrabackup-overview/index#compatibility-with-mariadb) for more information. In [MariaDB 10.2](../what-is-mariadb-102/index) and [MariaDB 10.1](../what-is-mariadb-101/index), Percona XtraBackup is only **partially supported**. See [Percona XtraBackup Overview: Compatibility with MariaDB](../percona-xtrabackup-overview/index#compatibility-with-mariadb) for more information. The `xtrabackup-v2` SST method uses the [Percona XtraBackup](../backup-restore-and-import-clients-percona-xtrabackup/index) utility for performing SSTs. It is one of the methods that does not block the donor node. Note that if you use the `xtrabackup-v2` SST method, then you also need to have [socat](#socat-dependency) installed on the server. This is needed to stream the backup from the donor node to the joiner node. Since [Percona XtraBackup](../backup-restore-and-import-clients-percona-xtrabackup/index) is a third party product, it may require additional installation and additional configuration. Please refer to [Percona's xtrabackup SST documentation](http://www.percona.com/doc/percona-xtradb-cluster/5.5/manual/xtrabackup_sst.html) for information from the vendor. Choosing Percona XtraBackup for SSTs ------------------------------------ To use the `xtrabackup-v2` SST method, you must set the `[wsrep\_sst\_method=xtrabackup-v2](../galera-cluster-system-variables/index#wsrep_sst_method)` on both the donor and joiner node. It can be changed dynamically with `[SET GLOBAL](../set/index#global-session)` on the node that you intend to be a SST donor. For example: ``` SET GLOBAL wsrep_sst_method='xtrabackup-v2'; ``` It can be set in a server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index) prior to starting up a node: ``` [mariadb] ... wsrep_sst_method = xtrabackup-v2 ``` For an SST to work properly, the donor and joiner node must use the same SST method. Therefore, it is recommended to set `[wsrep\_sst\_method](../galera-cluster-system-variables/index#wsrep_sst_method)` to the same value on all nodes, since any node will usually be a donor or joiner node at some point. Authentication and Privileges ----------------------------- To use the `xtrabackup-v2` SST method, [Percona XtraBackup](../backup-restore-and-import-clients-percona-xtrabackup/index) needs to be able to authenticate locally on the donor node, so that it can create a backup to stream to the joiner. You can tell the donor node what username and password to use by setting the `[wsrep\_sst\_auth](../galera-cluster-system-variables/index#wsrep_sst_auth)` system variable. It can be changed dynamically with `[SET GLOBAL](../set/index#global-session)` on the node that you intend to be a SST donor. For example: ``` SET GLOBAL wsrep_sst_auth = 'xtrabackup:mypassword'; ``` It can also be set in a server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index) prior to starting up a node: ``` [mariadb] ... wsrep_sst_auth = xtrabackup:mypassword ``` Some [authentication plugins](../authentication-plugins/index) do not require a password. For example, the `[unix\_socket](../authentication-plugin-unix-socket/index)` and `[gssapi](../authentication-plugin-gssapi/index)` authentication plugins do not require a password. If you are using a user account that does not require a password in order to log in, then you can just leave the password component of `[wsrep\_sst\_auth](../galera-cluster-system-variables/index#wsrep_sst_auth)` empty. For example: ``` [mariadb] ... wsrep_sst_auth = xtrabackup: ``` The user account that performs the backup for the SST needs to have [the same privileges as Percona XtraBackup](../percona-xtrabackup-overview/index#authentication-and-privileges), which are the `RELOAD` , `PROCESS`, `LOCK TABLES` and `REPLICATION CLIENT` [global privileges](../grant/index#global-privileges). To be safe, you should ensure that these privileges are set on each node in your cluster. [Percona XtraBackup](../backup-restore-and-import-clients-percona-xtrabackup/index) connects locally on the donor node to perform the backup, so the following user should be sufficient: ``` CREATE USER 'xtrabackup'@'localhost' IDENTIFIED BY 'mypassword'; GRANT RELOAD, PROCESS, LOCK TABLES, REPLICATION CLIENT ON *.* TO 'xtrabackup'@'localhost'; ``` ### Passwordless Authentication - Unix Socket It is possible to use the `[unix\_socket](../authentication-plugin-unix-socket/index)` authentication plugin for the user account that performs SSTs. This would provide the benefit of not needing to configure a plain-text password in `[wsrep\_sst\_auth](../galera-cluster-system-variables/index#wsrep_sst_auth)`. The user account would have to have the same name as the operating system user account that is running the `mysqld` process. On many systems, this is the user account configured as the `[user](../mysqld-options/index#-user)` option, and it tends to default to `mysql`. For example, if the `[unix\_socket](../authentication-plugin-unix-socket/index)` authentication plugin is already installed, then you could execute the following to create the user account: ``` CREATE USER 'mysql'@'localhost' IDENTIFIED VIA unix_socket; GRANT RELOAD, PROCESS, LOCK TABLES, REPLICATION CLIENT ON *.* TO 'mysql'@'localhost'; ``` And then to configure `[wsrep\_sst\_auth](../galera-cluster-system-variables/index#wsrep_sst_auth)`, you could set the following in a server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index) prior to starting up a node: ``` [mariadb] ... wsrep_sst_auth = mysql: ``` ### Passwordless Authentication - GSSAPI It is possible to use the `[gssapi](../authentication-plugin-gssapi/index)` authentication plugin for the user account that performs SSTs. This would provide the benefit of not needing to configure a plain-text password in `[wsrep\_sst\_auth](../galera-cluster-system-variables/index#wsrep_sst_auth)`. The following steps would need to be done beforehand: * You need a KDC running [MIT Kerberos](http://web.mit.edu/Kerberos/krb5-1.12/doc/index.html) or [Microsoft Active Directory](https://docs.microsoft.com/en-us/windows-server/identity/ad-ds/get-started/virtual-dc/active-directory-domain-services-overview). * You will need to [create a keytab file](../authentication-plugin-gssapi/index#creating-a-keytab-file-on-a-unix-server) for the MariaDB server. * You will need to [install the package](../authentication-plugin-gssapi/index#installing-the-plugins-package) containing the `[gssapi](../authentication-plugin-gssapi/index)` authentication plugin. * You will need to [install the plugin](../authentication-plugin-gssapi/index#installing-the-plugin) in MariaDB, so that the `[gssapi](../authentication-plugin-gssapi/index)` authentication plugin is available to use. * You will need to [configure the plugin](../authentication-plugin-gssapi/index#configuring-the-plugin). * You will need to [create a user account](../authentication-plugin-gssapi/index#creating-users) that authenticates with the `[gssapi](../authentication-plugin-gssapi/index)` authentication plugin, so that the user account can be used for SSTs. This user account will need to correspond with a user account that exists on the backend KDC. For example, you could execute the following to create the user account in MariaDB: ``` CREATE USER 'xtrabackup'@'localhost' IDENTIFIED VIA gssapi; GRANT RELOAD, PROCESS, LOCK TABLES, REPLICATION CLIENT ON *.* TO 'xtrabackup'@'localhost'; ``` And then to configure `[wsrep\_sst\_auth](../galera-cluster-system-variables/index#wsrep_sst_auth)`, you could set the following in a server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index) prior to starting up a node: ``` [mariadb] ... wsrep_sst_auth = xtrabackup: ``` Choosing a Donor Node --------------------- When Percona XtraBackup is used to create the backup for the SST on the donor node, XtraBackup briefly requires a system-wide lock at the end of the backup. This is done with `[FLUSH TABLES WITH READ LOCK](../flush/index)`. If a specific node in your cluster is acting as the *primary* node by receiving all of the application's write traffic, then this node should not usually be used as the donor node, because the system-wide lock could interfere with the application. In this case, you can define one or more preferred donor nodes by setting the `[wsrep\_sst\_donor](../galera-cluster-system-variables/index#wsrep_sst_donor)` system variable. For example, let's say that we have a 5-node cluster with the nodes `node1`, `node2`, `node3`, `node4`, and `node5`, and let's say that `node1` is acting as the *primary* node.The preferred donor nodes for `node2` could be configured by setting the following in a server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index) prior to starting up a node: ``` [mariadb] ... wsrep_sst_donor=node3,node4,node5, ``` The trailing comma tells the server to allow any other node as donor when the preferred donors are not available. Therefore, if `node1` is the only node left in the cluster, the trailing comma allows it to be used as the donor node. Socat Dependency ---------------- During the SST process, the donor node uses [socat](http://www.dest-unreach.org/socat/doc/socat.html) to stream the backup to the joiner node. Then the joiner node prepares the backup before restoring it. The socat utility must be installed on both the donor node and the joiner node in order for this to work. Otherwise, the MariaDB error log will contain an error like: ``` WSREP_SST: [ERROR] socat not found in path: /usr/sbin:/sbin:/usr//bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin (20180122 14:55:32.993) ``` ### Installing Socat on RHEL/CentOS On RHEL/CentOS, `socat` can be installed from the [Extra Packages for Enterprise Linux (EPEL)](https://fedoraproject.org/wiki/EPEL) repository. TLS --- This SST method supports three different TLS methods. The specific method can be selected by setting the `encrypt` option in the `[sst]` section of the MariaDB configuration file. The options are: * TLS using OpenSSL encryption built into `socat` (`encrypt=2`) * TLS using OpenSSL encryption with Galera-compatible certificates and keys (`encrypt=3`) * TLS using OpenSSL encryption with MariaDB-compatible certificates and keys (`encrypt=4`) Note that `encrypt=1` refers to a TLS encryption method that has been deprecated and removed. ### TLS Using OpenSSL Encryption Built into Socat To generate keys compatible with this encryption method, you can follow [these directions](http://www.dest-unreach.org/socat/doc/socat-openssltunnel.html). For example: * First, generate the keys and certificates: ``` FILENAME=sst openssl genrsa -out $FILENAME.key 1024 openssl req -new -key $FILENAME.key -x509 -days 3653 -out $FILENAME.crt cat $FILENAME.key $FILENAME.crt >$FILENAME.pem chmod 600 $FILENAME.key $FILENAME.pem ``` * On some systems, you may also have to add dhparams to the certificate: ``` openssl dhparam -out dhparams.pem 2048 cat dhparams.pem >> sst.pem ``` * Then, copy the certificate and keys to all nodes in the cluster. * Then, configure the following on all nodes in the cluster: ``` [sst] encrypt=2 tca=/etc/my.cnf.d/certificates/sst.crt tcert=/etc/my.cnf.d/certificates/sst.pem ``` But replace the paths with whatever is relevant on your system. This should allow your SSTs to be encrypted. ### TLS Using OpenSSL Encryption with Galera-compatible Certificates and Keys To generate keys compatible with this encryption method, you can follow [these directions](https://galeracluster.com/library/documentation/ssl-sst.html#ssl-xtrabackup). For example: * First, generate the keys and certificates: ``` # CA openssl genrsa 2048 > ca-key.pem openssl req -new -x509 -nodes -days 365000 \ -key ca-key.pem -out ca-cert.pem # server1 openssl req -newkey rsa:2048 -days 365000 \ -nodes -keyout server1-key.pem -out server1-req.pem openssl rsa -in server1-key.pem -out server1-key.pem openssl x509 -req -in server1-req.pem -days 365000 \ -CA ca-cert.pem -CAkey ca-key.pem -set_serial 01 \ -out server1-cert.pem ``` * Then, copy the certificate and keys to all nodes in the cluster. * Then, configure the following on all nodes in the cluster: ``` [sst] encrypt=3 tkey=/etc/my.cnf.d/certificates/server1-key.pem tcert=/etc/my.cnf.d/certificates/server1-cert.pem ``` But replace the paths with whatever is relevant on your system. This should allow your SSTs to be encrypted. ### TLS Using OpenSSL Encryption with MariaDB-compatible Certificates and Keys To generate keys compatible with this encryption method, you can follow [these directions](../certificate-creation-with-openssl/index). For example: * First, generate the keys and certificates: ``` # CA openssl genrsa 2048 > ca-key.pem openssl req -new -x509 -nodes -days 365000 \ -key ca-key.pem -out ca-cert.pem # server1 openssl req -newkey rsa:2048 -days 365000 \ -nodes -keyout server1-key.pem -out server1-req.pem openssl rsa -in server1-key.pem -out server1-key.pem openssl x509 -req -in server1-req.pem -days 365000 \ -CA ca-cert.pem -CAkey ca-key.pem -set_serial 01 \ -out server1-cert.pem ``` * Then, copy the certificate and keys to all nodes in the cluster. * Then, configure the following on all nodes in the cluster: ``` [sst] encrypt=4 ssl-ca=/etc/my.cnf.d/certificates/ca-cert.pem ssl-cert=/etc/my.cnf.d/certificates/server1-cert.pem ssl-key=/etc/my.cnf.d/certificates/server1-key.pem ``` But replace the paths with whatever is relevant on your system. This should allow your SSTs to be encrypted. Logs ---- The `xtrabackup-v2` SST method has its own logging outside of the MariaDB Server logging. ### Logging to SST Logs By default, on the donor node, it logs to `innobackup.backup.log`. This log file is located in the `[datadir](../server-system-variables/index#datadir)`. By default, on the joiner node, it logs to `innobackup.prepare.log` and `innobackup.move.log`. These log files are located in the `.sst` directory, which is a hidden directory inside the `[datadir](../server-system-variables/index#datadir)`. These log files are overwritten by each subsequent SST, so if an SST fails, it is best to copy them somewhere safe before starting another SST, so that the log files can be analyzed. See [MDEV-17973](https://jira.mariadb.org/browse/MDEV-17973) about that. ### Logging to Syslog You can redirect the SST logs to the syslog instead by setting the following in the `[sst]` [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index): ``` [sst] sst-syslog=1 ``` You can also redirect the SST logs to the syslog by setting the following in the `[mysqld_safe]` [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index): ``` [mysqld_safe] syslog ``` Performing SSTs with IPv6 Addresses ----------------------------------- If you are performing Percona XtraBackup SSTs with IPv6 addresses, then the `socat` utility needs to be passed the `pf=ip6` option. This can be done by setting the `sockopt` option in the `[sst]` [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index). For example: ``` [sst] sockopt=",pf=ip6" ``` See [MDEV-18797](https://jira.mariadb.org/browse/MDEV-18797) for more information. Manual SST with Percona XtraBackup ---------------------------------- In some cases, if Galera Cluster's automatic SSTs repeatedly fail, then it can be helpful to perform a "manual SST". See the following page on how to do that: * [Manual SST of Galera Cluster node with Percona XtraBackup](../manual-sst-of-galera-cluster-node-with-percona-xtrabackup/index) See Also -------- * [Percona XtraBackup SST Configuration](https://www.percona.com/doc/percona-xtradb-cluster/5.7/manual/xtrabackup_sst.html) * [Encrypting PXC Traffic: ENCRYPTING SST TRAFFIC](https://www.percona.com/doc/percona-xtradb-cluster/5.7/security/encrypt-traffic.html#encrypt-sst) * [XTRABACKUP PARAMETERS](https://galeracluster.com/library/documentation/xtrabackup-options.html) * [SSL FOR STATE SNAPSHOT TRANSFERS: ENABLING SSL FOR XTRABACKUP](https://galeracluster.com/library/documentation/ssl-sst.html#ssl-xtrabackup) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb TIME_TO_SEC TIME\_TO\_SEC ============= Syntax ------ ``` TIME_TO_SEC(time) ``` Description ----------- Returns the time argument, converted to seconds. The value returned by `TIME_TO_SEC` is of type `[DOUBLE](../double/index)`. Before [MariaDB 5.3](../what-is-mariadb-53/index) (and MySQL 5.6), the type was `[INT](../int/index)`. The returned value preserves microseconds of the argument. See also [Microseconds in MariaDB](../microseconds-in-mariadb/index). Examples -------- ``` SELECT TIME_TO_SEC('22:23:00'); +-------------------------+ | TIME_TO_SEC('22:23:00') | +-------------------------+ | 80580 | +-------------------------+ ``` ``` SELECT TIME_TO_SEC('00:39:38'); +-------------------------+ | TIME_TO_SEC('00:39:38') | +-------------------------+ | 2378 | +-------------------------+ ``` ``` SELECT TIME_TO_SEC('09:12:55.2355'); +------------------------------+ | TIME_TO_SEC('09:12:55.2355') | +------------------------------+ | 33175.2355 | +------------------------------+ 1 row in set (0.000 sec) ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Running Triggers on the Replica for Row-based Events Running Triggers on the Replica for Row-based Events ==================================================== The terms *master* and *slave* have historically been used in replication, but the terms terms *primary* and *replica* are now preferred. The old terms are used still used in parts of the documentation, and in MariaDB commands, although [MariaDB 10.5](../what-is-mariadb-105/index) has begun the process of renaming. The documentation process is ongoing. See [MDEV-18777](https://jira.mariadb.org/browse/MDEV-18777) to follow progress on this effort. MariaDB can force the replica thread to run [triggers](../triggers/index) for row-based binlog events. The setting is controlled by the [slave\_run\_triggers\_for\_rbr](../replication-and-binary-log-server-system-variables/index#slave_run_triggers_for_rbr) global variable. It can be also specified as a command-line option or in my.cnf. Possible values are: | Value | Meaning | | --- | --- | | NO (Default) | Don't invoke triggers for row-based events | | YES | Invoke triggers for row-based events, don't log their effect into the binary log | | LOGGING | Invoke triggers for row-based events, and log their effect into the binary log | | ENFORCE | From [MariaDB 10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/) only. Triggers will always be run on the replica, even if there are triggers on the master. ENFORCE implies LOGGING. | **Note that if you just want to use triggers together with replication, you most likely don't need this option.** Read below for details. When to Use slave\_run\_triggers\_for\_rbr ------------------------------------------ ### Background Normally, MariaDB's replication system can replicate trigger actions automatically. * When one uses statement-based replication, the binary log contains SQL statements. Replica server(s) execute the SQL statements. Triggers are run on the master and on each replica, independently. * When one uses row-based replication, the binary log contains row changes. It will have both the changes made by the statement itself, and the changes made by the triggers that were invoked by the statement. Replica server(s) do not need to run triggers for row changes they are applying. ### Target Usecase One may want to have a setup where a replica has triggers that are not present on the master (Suppose the replica needs to update summary tables or perform some other ETL-like process). If one uses statement-based replication, they can just create the required triggers on the replica. The replica will run the statements from the binary log, which will cause the triggers to be invoked. However, there are cases where you have to use row-based replication. It could be because the master runs non-deterministic statements, or the master could be a node in a Galera cluster. In that case, you would want row-based events to invoke triggers on the replica. This is what the `slave_run_triggers_for_rbr` option is for. Setting the option to `YES` will cause the SQL replica thread to invoke triggers for row-based events; setting it to `LOGGING` will also cause the changes made by the triggers to be written into the binary log. The following triggers are invoked: * Update\_row\_event runs an UPDATE trigger * Delete\_row\_event runs a DELETE trigger * Write\_row\_event runs an INSERT trigger. Additionally it runs a DELETE trigger if there was a conflicting row that had to be deleted. Preventing Multiple Trigger Invocations --------------------------------------- There is a basic protection against triggers being invoked both on the master and replica. If the master modifies a table that has triggers, it will produce row-based binlog events with the "triggers were invoked for this event" flag. The replica will not invoke any triggers for flagged events. See Also -------- * Task in Jira, [MDEV-5095](https://jira.mariadb.org/browse/MDEV-5095). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb mysql.spider_tables Table mysql.spider\_tables Table ========================== The `mysql.spider_tables` table is installed by the [Spider storage engine](../spider/index). **MariaDB starting with [10.4](../what-is-mariadb-104/index)**In [MariaDB 10.4](../what-is-mariadb-104/index) and later, this table uses the [Aria](../aria/index) storage engine. **MariaDB until [10.3](../what-is-mariadb-103/index)**In [MariaDB 10.3](../what-is-mariadb-103/index) and before, this table uses the [MyISAM](../myisam-storage-engine/index) storage engine. It contains the following fields: | Field | Type | Null | Key | Default | Description | | --- | --- | --- | --- | --- | --- | | db\_name | char(64) | NO | PRI | | | | table\_name | char(199) | NO | PRI | | | | link\_id | int(11) | NO | PRI | 0 | | | priority | bigint(20) | NO | MUL | 0 | | | server | char(64) | YES | | NULL | | | scheme | char(64) | YES | | NULL | | | host | char(64) | YES | | NULL | | | port | char(5) | YES | | NULL | | | socket | text | YES | | NULL | | | username | char(64) | YES | | NULL | | | password | char(64) | YES | | NULL | | | ssl\_ca | text | YES | | NULL | | | ssl\_capath | text | YES | | NULL | | | ssl\_cert | text | YES | | NULL | | | ssl\_cipher | char(64) | YES | | NULL | | | ssl\_key | text | YES | | NULL | | | ssl\_verify\_server\_cert | tinyint(4) | NO | | 0 | | | monitoring\_binlog\_pos\_at\_failing | tinyint(4) | NO | | 0 | | | default\_file | text | YES | | NULL | | | default\_group | char(64) | YES | | NULL | | | dsn | char(64) | YES | | NULL | | | filedsn | text | YES | | NULL | | | driver | char(64) | YES | | NULL | | | tgt\_db\_name | char(64) | YES | | NULL | | | tgt\_table\_name | char(64) | YES | | NULL | | | link\_status | tinyint(4) | NO | | 1 | | | block\_status | tinyint(4) | NO | | 0 | | | static\_link\_id | char(64) | YES | | NULL | | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb SHOW CREATE PACKAGE SHOW CREATE PACKAGE =================== **MariaDB starting with [10.3.5](https://mariadb.com/kb/en/mariadb-1035-release-notes/)**Oracle-style packages were introduced in [MariaDB 10.3.5](https://mariadb.com/kb/en/mariadb-1035-release-notes/). Syntax ------ ``` SHOW CREATE PACKAGE [ db_name . ] package_name ``` Description ----------- The `SHOW CREATE PACKAGE` statement can be used when [Oracle SQL\_MODE](../sql_modeoracle-from-mariadb-103/index) is set. Shows the `CREATE` statement that creates the given package specification. Examples -------- ``` SHOW CREATE PACKAGE employee_tools\G *************************** 1. row *************************** Package: employee_tools sql_mode: PIPES_AS_CONCAT,ANSI_QUOTES,IGNORE_SPACE,ORACLE,NO_KEY_OPTIONS,NO_TABLE_OPTIONS,NO_FIELD_OPTIONS,NO_AUTO_CREATE_USER Create Package: CREATE DEFINER="root"@"localhost" PACKAGE "employee_tools" AS FUNCTION getSalary(eid INT) RETURN DECIMAL(10,2); PROCEDURE raiseSalary(eid INT, amount DECIMAL(10,2)); PROCEDURE raiseSalaryStd(eid INT); PROCEDURE hire(ename TEXT, esalary DECIMAL(10,2)); END character_set_client: utf8 collation_connection: utf8_general_ci Database Collation: latin1_swedish_ci ``` See Also -------- * [CREATE PACKAGE](../create-package/index) * [DROP PACKAGE](../drop-package/index) * [CREATE PACKAGE BODY](../create-package-body/index) * [SHOW CREATE PACKAGE BODY](../show-create-package-body/index) * [DROP PACKAGE BODY](../drop-package-body/index) * [Oracle SQL\_MODE](../sql_modeoracle-from-mariadb-103/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Benchmark Builds Benchmark Builds ================ When you build for benchmarks, it's important to use consistent compile time settings across different versions and even products (i.e. when comparing MySQL and MariaDB). MariaDB and MySQL are now built using *cmake*. This makes it hard to fine tune settings because when you chose a predefined build configuration (recommended: *RelWithDebInfo*) then other settings like *CFLAGS* are overwritten by those from the *CMakefile*. There are more pain points with cmake: * cmake uses a different install layout than autotools builds * the OQGraph engine is included by default, but fails often due to mismatching boost libraries * make install tries to create directories in system locations (/etc/my.cnf.d etc.) which fails as ordinary user * CMakefiles for different products sometimes use different CFLAGS So here is my build script that fixes all those things. ``` #!/bin/bash INSTDIR=${1:?usage: $0 install-dir} CFLAGS="-O3 -g -fno-omit-frame-pointer -fno-strict-aliasing -DNDEBUG -DDBUG_OFF" CXXFLAGS="$CFLAGS -felide-constructors" CMAKE_LAYOUT_OPTS="-DINSTALL_LAYOUT=RPM -DINSTALL_SCRIPTDIR=bin \ -DINSTALL_MYSQLDATADIR=var -DINSTALL_SBINDIR=libexec \ -DINSTALL_SUPPORTFILESDIR=share -DINSTALL_SYSCONFDIR=etc \ -DINSTALL_SYSCONF2DIR=etc/my.cnf.d -DCMAKE_INSTALL_PREFIX=$INSTDIR \ -DMYSQL_DATADIR=$INSTDIR/var" CMAKE_FEATURE_OPTS="-DWITH_READLINE=1 -DWITHOUT_OQGRAPH_STORAGE_ENGINE=1" CMAKE_BUILD_OPTS="-DCMAKE_BUILD_TYPE=RelWithDebInfo" cmake .. $CMAKE_BUILD_OPTS $CMAKE_LAYOUT_OPTS $CMAKE_FEATURE_OPTS \ -DCMAKE_C_FLAGS_RELWITHDEBINFO="$CFLAGS" \ -DCMAKE_CXX_FLAGS_RELWITHDEBINFO="$CXXFLAGS" make && make install ``` The script shall be run from a subdir of a source tree. i.e. ``` tar xfz mariadb-10.0.7.tar.gz cd mariadb-10.0.7 mkdir build cd build #... run the build script above ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb MariaDB ColumnStore software upgrade 1.1.6 GA to 1.1.7 GA MariaDB ColumnStore software upgrade 1.1.6 GA to 1.1.7 GA ========================================================= MariaDB ColumnStore software upgrade 1.1.6 GA to 1.1.7 GA --------------------------------------------------------- Additional Dependency Packages exist for 1.1.7, so make sure you install those based on the "Preparing for ColumnStore Installation" Guide. Note: Columnstore.xml modifications you manually made are not automatically carried forward on an upgrade. These modifications will need to be incorporated back into .XML once the upgrade has occurred. The previous configuration file will be saved as /usr/local/mariadb/columnstore/etc/Columnstore.xml.rpmsave. If you have specified a root database password (which is good practice), then you must configure a .my.cnf file with user credentials for the upgrade process to use. Create a .my.cnf file in the user home directory with 600 file permissions with the following content (updating PASSWORD as appropriate): ``` [mysqladmin] user = root password = PASSWORD ``` ### Additional Library Install: Jemalloc **Note**: This release introduces a dependency on the jemalloc os library to resolve some memory management issues that can lead to memory leaks. On each ColumnStore you must install jemalloc: For CentOS: ``` yum install epel-release yum install jemalloc ``` For Ubuntu and Debian: ``` apt-get install libjemalloc1 ``` For SLES: ``` zypper addrepo https://download.opensuse.org/repositories/network:cluster/SLE_12_SP3/network:cluster.repo zypper refresh zypper install jemalloc ``` ### Choosing the type of upgrade As noted on the Preparing guide, you can installing MariaDB ColumnStore with the use of soft-links. If you have the softlinks be setup at the Data Directory Levels, like mariadb/columnstore/data and mariadb/columnstore/dataX, then your upgrade will happen without any issues. In the case where you have a softlink at the top directory, like /usr/local/mariadb, you will need to upgrade using the binary package. If you updating using the rpm package and tool, this softlink will be deleted when you perform the upgrade process and the upgrade will fail. #### Root User Installs #### Upgrading MariaDB ColumnStore using RPMs tar package Upgrade MariaDB ColumnStore as user root on the server designated as PM1: **Download the package mariadb-columnstore-1.1.7-1-centos#.x86\_64.rpm.tar.gz to the PM1 server where you are installing MariaDB ColumnStore.** Shutdown the MariaDB ColumnStore system: ``` # mcsadmin shutdownsystem y ``` * Unpack the tarball, which will generate a set of RPMs that will reside in the /root/ directory. ``` # tar -zxf mariadb-columnstore-1.1.7-1-centos#.x86_64.rpm.tar.gz ``` * Upgrade the RPMs. The MariaDB ColumnStore software will be installed in /usr/local/. ``` # rpm -e --nodeps $(rpm -qa | grep '^mariadb-columnstore') # rpm -ivh mariadb-columnstore-*1.1.7*rpm ``` * Run postConfigure using the upgrade option, which will utilize the configuration from the Columnstore.xml.rpmsave ``` # /usr/local/mariadb/columnstore/bin/postConfigure -u ``` For RPM Upgrade, the previous configuration file will be saved as: /usr/local/mariadb/columnstore/etc/Columnstore.xml.rpmsave #### Upgrading MariaDB ColumnStore using RPM Package Repositories The system can be upgrade when it was previously installed from the Package Repositories. This will need to be run on each module in the system Additional information can be found in this document on how to setup and install using the 'yum' package repo command: [https://mariadb.com/kb/en/library/installing-mariadb-ax-from-the-package-repositories](../library/installing-mariadb-ax-from-the-package-repositories) Upgrade MariaDB ColumnStore as user root on the server designated as PM1: **Shutdown the MariaDB ColumnStore system:** ``` # mcsadmin shutdownsystem y ``` * Uninstall MariaDB ColumnStore Packages ``` # yum remove mariadb-columnstore* ``` * Install MariaDB ColumnStore Packages ``` # yum --enablerepo=mariadb-columnstore clean metadata # yum install mariadb-columnstore* ``` NOTE: On the non-pm1 module, start the columnstore service ``` # /usr/local/mariadb/columnstore/bin/columnstore start ``` * Run postConfigure using the upgrade and non-distributed options, which will utilize the configuration from the Columnstore.xml.rpmsave ``` # /usr/local/mariadb/columnstore/bin/postConfigure -u -n ``` For RPM Upgrade, the previous configuration file will be saved as: /usr/local/mariadb/columnstore/etc/Columnstore.xml.rpmsave ### Initial download/install of MariaDB ColumnStore binary package Upgrade MariaDB ColumnStore as user root on the server designated as PM1: * Download the package into the /usr/local directory -mariadb-columnstore-1.1.7-1.x86\_64.bin.tar.gz (Binary 64-BIT)to the server where you are installing MariaDB ColumnStore. * Shutdown the MariaDB ColumnStore system: ``` # mcsadmin shutdownsystem y ``` * Run pre-uninstall script ``` # /usr/local/mariadb/columnstore/bin/pre-uninstall ``` * Unpack the tarball, in the /usr/local/ directory. ``` # tar -zxvf mariadb-columnstore-1.1.7-1.x86_64.bin.tar.gz ``` * Run post-install scripts ``` # /usr/local/mariadb/columnstore/bin/post-install ``` * Run postConfigure using the upgrade option, which will utilize the configuration from the Columnstore.xml,rpmsave ``` # /usr/local/mariadb/columnstore/bin/postConfigure -u ``` ### Upgrading MariaDB ColumnStore using the DEB package A DEB upgrade would be done on a system that supports DEBs like Debian or Ubuntu systems. Upgrade MariaDB ColumnStore as user root on the server designated as PM1: * Download the package into the /root directory mariadb-columnstore-1.1.7-1.amd64.deb.tar.gz (DEB 64-BIT) to the server where you are installing MariaDB ColumnStore. * Shutdown the MariaDB ColumnStore system: ``` # mcsadmin shutdownsystem y ``` * Unpack the tarball, which will generate DEBs. ``` # tar -zxf mariadb-columnstore-1.1.7-1.amd64.deb.tar.gz ``` * Remove and install all MariaDB ColumnStore debs ``` # cd /root/ # dpkg -r $(dpkg --list | grep 'mariadb-columnstore' | awk '{print $2}') # dpkg --install mariadb-columnstore-*1.1.7-1*deb ``` * Run postConfigure using the upgrade option, which will utilize the configuration from the Columnstore.xml,rpmsave ``` # /usr/local/mariadb/columnstore/bin/postConfigure -u ``` #### Upgrading MariaDB ColumnStore using DEB Package Repositories The system can be upgrade when it was previously installed from the Package Repositories. This will need to be run on each module in the system Additional information can be found in this document on how to setup and install using the 'apt-get' package repo command: [https://mariadb.com/kb/en/library/installing-mariadb-ax-from-the-package-repositories](../library/installing-mariadb-ax-from-the-package-repositories) Upgrade MariaDB ColumnStore as user root on the server designated as PM1: **Shutdown the MariaDB ColumnStore system:** ``` # mcsadmin shutdownsystem y ``` * Uninstall MariaDB ColumnStore Packages ``` # apt-get remove mariadb-columnstore* ``` * Install MariaDB ColumnStore Packages ``` # apt-get update # sudo apt-get install mariadb-columnstore* ``` NOTE: On the non-pm1 module, start the columnstore service ``` # /usr/local/mariadb/columnstore/bin/columnstore start ``` * Run postConfigure using the upgrade and non-distributed options, which will utilize the configuration from the Columnstore.xml.rpmsave ``` # /usr/local/mariadb/columnstore/bin/postConfigure -u -n ``` For RPM Upgrade, the previous configuration file will be saved as: /usr/local/mariadb/columnstore/etc/Columnstore.xml.rpmsave #### Non-Root User Installs ### Initial download/install of MariaDB ColumnStore binary package Upgrade MariaDB ColumnStore as user root on the server designated as PM1: * Download the package into the /home/'non-root-user" directory mariadb-columnstore-1.1.7-1.x86\_64.bin.tar.gz (Binary 64-BIT)to the server where you are installing MariaDB ColumnStore. * Shutdown the MariaDB ColumnStore system: ``` # mcsadmin shutdownsystem y ``` * Run pre-uninstall script ``` # $HOME/mariadb/columnstore/bin/pre-uninstall --installdir=/home/guest/mariadb/columnstore ``` * Unpack the tarball, which will generate the $HOME/ directory. ``` # tar -zxvf mariadb-columnstore-1.1.7-1.x86_64.bin.tar.gz ``` * Run post-install scripts ``` # $HOME/mariadb/columnstore/bin/post-install --installdir=/home/guest/mariadb/columnstore ``` * Run postConfigure using the upgrade option, which will utilize the configuration from the Columnstore.xml,rpmsave ``` # $HOME/mariadb/columnstore/bin/postConfigure -u -i /home/guest/mariadb/columnstore ``` ### Running the mysql\_upgrade script As part of the upgrade process, the user is required to run the mysql\_upgrade script on all of the following nodes. * User Modules on a system configured with separate User and Performance Modules * Performance Modules on a system configured with separate User and Performance Modules and Local Query Feature is enabled * Performance Modules on a system configured with combined User and Performance Modules mysql\_upgrade should be run once the upgrade has been completed. This is an example of how it run on a root user install: ``` /usr/local/mariadb/columnstore/mysql/bin/mysql_upgrade --defaults-file=/usr/local/mariadb/columnstore/mysql/my.cnf --force ``` This is an example of how it run on a non-root user install, assuming ColumnStore is installed under the user's home directory: ``` $HOME/mariadb/columnstore/mysql/bin/mysql_upgrade --defaults-file=$HOME/mariadb/columnstore/mysql/my.cnf --force ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb Information Schema INNODB_SYS_TABLESTATS Table Information Schema INNODB\_SYS\_TABLESTATS Table ================================================ The [Information Schema](../information_schema/index) `INNODB_SYS_TABLESTATS` table contains InnoDB status information. It can be used for developing new performance-related extensions, or high-level performance monitoring. The `PROCESS` [privilege](../grant/index) is required to view the table. Note that the MySQL InnoDB and Percona XtraDB versions of the tables differ (see [XtraDB and InnoDB](../xtradb-and-innodb/index)). It contains the following columns: | Column | Description | | --- | --- | | `TABLE_ID` | Table ID, matching the [INNODB\_SYS\_TABLES.TABLE\_ID](../information-schema-innodb_sys_tables-table/index) value. | | `SCHEMA` | Database name (XtraDB only). | | `NAME` | Table name, matching the [INNODB\_SYS\_TABLES.NAME](../information-schema-innodb_sys_tables-table/index) value. | | `STATS_INITIALIZED` | `Initialized` if statistics have already been collected, otherwise `Uninitialized`. | | `NUM_ROWS` | Estimated number of rows currently in the table. Updated after each statement modifying the data, but uncommited transactions mean it may not be accurate. | | `CLUST_INDEX_SIZE` | Number of pages on disk storing the clustered index, holding InnoDB table data in primary key order, or `NULL` if not statistics yet collected. | | `OTHER_INDEX_SIZE` | Number of pages on disk storing secondary indexes for the table, or `NULL` if not statistics yet collected. | | `MODIFIED_COUNTER` | Number of rows modified by statements modifying data. | | `AUTOINC` | [Auto\_increment](../auto_increment/index) value. | | `REF_COUNT` | Countdown to zero, when table metadata can be removed from the table cache. (InnoDB only) | | `MYSQL_HANDLES_OPENED` | (XtraDB only). | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb DBT3 Benchmark Results InnoDB DBT3 Benchmark Results InnoDB ============================= Introduction ------------ This page shows the results for benchmarking the following configuration: * [MariaDB 5.3.1](https://mariadb.com/kb/en/mariadb-531-release-notes/) Beta + XtraDB with all optimizations (optimizater\_switch) set to `ON` * [MariaDB 5.3.1](https://mariadb.com/kb/en/mariadb-531-release-notes/) Beta + XtraDB with Igor's suggested optimizations * MySQL 5.5.13 + InnoDB * MySQL 5.6.2 + InnoDB The test is performed using the automation script under `/mariadb-tools/dbt3_benchmark`. Details about this automation script could be found in [DBT3 automation scripts](../dbt3-automation-scripts/index) Hardware -------- The tests were performed on pitbull.askmonty.org. It has the following parameters: * **CPU:** Two socket X hexacore Intel Xeon X5660 = 12 CPUs with hyperthreading on: 24 virtual CPUs * **Memory:** 23GB * **Logical disk:** HDD 500.1 GB as software RAID1 + device size with M = 1000\*1000: 500107 MBytes (500 GB) + cache/buffer size = 16384 KBytes + Nominal Media Rotation Rate: 7200 * **Operating System:** Ubuntu 10.10 (x86\_64) Scale factor 10 --------------- This test is performed with the following parameters: * **Scale factor:** 10 * **Query timeout:** 600 sec. * **Cluster size:** 3 * **Total DB size on disk:** about 24GB ### Steps to reproduce Follow the instructions in [DBT3 automation scripts](../dbt3-automation-scripts/index) to prepare the environment for the test. Before you run the test, reassure that the settings into the test configuration files match your prepared environment. For more details on the test configuration, please, refer to the [test configuration parameters](../dbt3-automation-scripts/index#test-configuration). For that test you should set the SCALE\_FACTOR parameter to 10 for the following files before the test: * mariadb\_innodb\_igor\_s1.pm * mariadb\_innodb\_s1.pm * mysql\_5\_5\_15\_innodb\_s1.pm * mysql\_5\_6\_2\_innodb\_s1.pm **NOTE:** In future versions the scale factor will be passed in as an input parameter to `launcher.pl` instead of being test configuration parameter. After the environment is prepared, the following command should be executed in the shell: ``` perl launcher.pl --test={PROJECT_HOME}/mariadb-tools/dbt3_benchmark/tests/mariadb_myisam_s1.pm \ --test={PROJECT_HOME}/mariadb-tools/dbt3_benchmark/tests/mysql_5_5_15_myisam_s1.pm \ --test={PROJECT_HOME}/mariadb-tools/dbt3_benchmark/tests/mysql_5_6_2_myisam_s1.pm --results-output-dir=path/to/results/output/dir ``` ### Results Here is the graphics of the results: ![innodb-test-scale-10-timeout-600](https://mariadb.com/kb/en/dbt3-benchmark-results-innodb/+image/innodb-test-scale-10-timeout-600 "innodb-test-scale-10-timeout-600") **NOTE:** Queries that are cut off by the graphics have timed out the period of 600 seconds for that test. Here are the actual results: | Configuration | 1.sql | 2.sql | 3.sql | 4.sql | 5.sql | 6.sql | 7.sql | 8.sql | 9.sql | 10.sql | 11.sql | 12.sql | 13.sql | 14.sql | 15.sql | 16.sql | 17.sql | 18.sql | 19.sql | 20.sql | 21.sql | 22.sql | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | [MariaDB 5.3.1](https://mariadb.com/kb/en/mariadb-531-release-notes/) + XtraDB with all optimizations to ON | 165 | n/a | 424.333 | n/a | n/a | 114.333 | n/a | n/a | n/a | n/a | 536 | 173 | n/a | n/a | n/a | 52 | 452 | n/a | n/a | n/a | n/a | 8 | | [MariaDB 5.3.1](https://mariadb.com/kb/en/mariadb-531-release-notes/) + XtraDB with Igor's suggestions for optimization | 163.667 | n/a | n/a | n/a | n/a | 114 | n/a | n/a | n/a | n/a | 538 | 280.667 | n/a | 257 | n/a | 60 | 456 | n/a | n/a | n/a | n/a | 8 | | MySQL 5.5.15 + InnoDB | 104 | n/a | n/a | n/a | n/a | 103 | n/a | n/a | n/a | n/a | 534.667 | 177 | n/a | n/a | n/a | n/a | 476 | n/a | n/a | n/a | n/a | 6 | | MySQL 5.6.2 + InnoDB | 103 | n/a | n/a | n/a | n/a | 104 | n/a | n/a | n/a | n/a | 531 | 168 | n/a | n/a | n/a | 55 | 460.667 | n/a | n/a | n/a | n/a | 6 | The archived folder with all the results and details for that benchmark can be downloaded from: <http://askmonty.org/wiki/Image:Res_myisam_timeout_120_s10_2011-09-15_190613.zip> From the graphics we can see that for the first query MySQL has performed better than MariaDB with about 37%. For the third query on the other hand MariaDB with all optimizations set to ON is the only one query that returned results before the timeout exceeded. This means that it has at least 30% better performance. Also there is some option that could optimize Igor's set of settings even more for that query. For the particular numbers, the same test should be performed with longer timeouts. For query #6 it turns out that both MySQL 5.5.15 and 5.6.2 are faster than MariaDB with about 10%. For query #12 Igor's settings could be readjusted, so that the query execution time could fall with 38%. Igor's settings turned out to be the only one that could finish query #14 before the timeout exceeded. From query #16 we can see that MySQL have made a great performance improvement from version 5.5.15 to 5.6.2 to make the query finish at least ten times faster. For all the other queries the results are either statistically the same, or the queries have timed out for all configurations and the test should be repeated with longer timeout limit. Summary ------- Most of the queries have timed out for the given period of 10 minutes per query and until a new test with longer timeout is performed, no correct comparison summary could be made. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb ColumnStore Rename Table ColumnStore Rename Table ======================== The RENAME TABLE statement renames one or more ColumnStore tables. images here Notes: * You cannot currently use RENAME TABLE to move a table from one database to another. * See the ALTER TABLE syntax for an alternate to RENAME table. The following statement renames the *orders* table: ``` RENAME TABLE orders TO customer_order; ``` The following statement renames both the *orders* table and *customer* table: ``` RENAME TABLE orders TO customer_orders,customer TO customers; ``` You may also use RENAME TABLE to swap tables. This example swaps the *customer* and *vendor* tables (assuming the *temp\_table* does not already exist): ``` RENAME TABLE customer TO temp_table, vendor TO customer,temp_table to vendor; ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb FOR FOR === **MariaDB starting with [10.3](../what-is-mariadb-103/index)**FOR loops were introduced in [MariaDB 10.3](../what-is-mariadb-103/index). Syntax ------ Integer range FOR loop: ``` [begin_label:] FOR var_name IN [ REVERSE ] lower_bound .. upper_bound DO statement_list END FOR [ end_label ] ``` Explicit cursor FOR loop ``` [begin_label:] FOR record_name IN cursor_name [ ( cursor_actual_parameter_list)] DO statement_list END FOR [ end_label ] ``` Explicit cursor FOR loop ([Oracle mode](../sql_modeoracle/index)) ``` [begin_label:] FOR record_name IN cursor_name [ ( cursor_actual_parameter_list)] LOOP statement_list END LOOP [ end_label ] ``` Implicit cursor FOR loop ``` [begin_label:] FOR record_name IN ( select_statement ) DO statement_list END FOR [ end_label ] ``` Description ----------- FOR loops allow code to be executed a fixed number of times. In an integer range FOR loop, MariaDB will compare the lower bound and upper bound values, and assign the lower bound value to a counter. If REVERSE is not specified, and the upper bound value is greater than or equal to the counter, the counter will be incremented and the statement will continue, after which the loop is entered again. If the upper bound value is greater than the counter, the loop will be exited. If REVERSE is specified, the counter is decremented, and the upper bound value needs to be less than or equal for the loop to continue. Examples -------- Intger range FOR loop: ``` CREATE TABLE t1 (a INT); DELIMITER // FOR i IN 1..3 DO INSERT INTO t1 VALUES (i); END FOR; // DELIMITER ; SELECT * FROM t1; +------+ | a | +------+ | 1 | | 2 | | 3 | +------+ ``` REVERSE integer range FOR loop: ``` CREATE OR REPLACE TABLE t1 (a INT); DELIMITER // FOR i IN REVERSE 4..12 DO INSERT INTO t1 VALUES (i); END FOR; // Query OK, 9 rows affected (0.422 sec) DELIMITER ; SELECT * FROM t1; +------+ | a | +------+ | 12 | | 11 | | 10 | | 9 | | 8 | | 7 | | 6 | | 5 | | 4 | +------+ ``` Explicit cursor in [Oracle mode](../sql_modeoracle/index): ``` SET sql_mode=ORACLE; CREATE OR REPLACE TABLE t1 (a INT, b VARCHAR(32)); INSERT INTO t1 VALUES (10,'b0'); INSERT INTO t1 VALUES (11,'b1'); INSERT INTO t1 VALUES (12,'b2'); DELIMITER // CREATE OR REPLACE PROCEDURE p1(pa INT) AS CURSOR cur(va INT) IS SELECT a, b FROM t1 WHERE a=va; BEGIN FOR rec IN cur(pa) LOOP SELECT rec.a, rec.b; END LOOP; END; // DELIMITER ; CALL p1(10); +-------+-------+ | rec.a | rec.b | +-------+-------+ | 10 | b0 | +-------+-------+ CALL p1(11); +-------+-------+ | rec.a | rec.b | +-------+-------+ | 11 | b1 | +-------+-------+ CALL p1(12); +-------+-------+ | rec.a | rec.b | +-------+-------+ | 12 | b2 | +-------+-------+ CALL p1(13); Query OK, 0 rows affected (0.000 sec) ``` See Also -------- * [LOOP](../loop/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb System Variables Added in MariaDB 10.6 System Variables Added in MariaDB 10.6 ====================================== This is a list of [system variables](../server-system-variables/index) that have been added in the [MariaDB 10.6](../what-is-mariadb-106/index) series. The list does not include variables that are not part of the default release. | Variable | Added | | --- | --- | | [binlog\_expire\_logs\_seconds](../replication-and-binary-log-system-variables/index#binlog_expire_logs_seconds) | [MariaDB 10.6.0](https://mariadb.com/kb/en/mariadb-1060-release-notes/) | | [innodb\_deadlock\_report](../innodb-system-variables/index#innodb_deadlock_report) | [MariaDB 10.6.0](https://mariadb.com/kb/en/mariadb-1060-release-notes/) | | [innodb\_read\_only\_compressed](../innodb-system-variables/index#innodb_read_only_compressed) | [MariaDB 10.6.0](https://mariadb.com/kb/en/mariadb-1060-release-notes/) | | [wsrep\_mode](../galera-cluster-system-variables/index#wsrep_mode) | [MariaDB 10.6.0](https://mariadb.com/kb/en/mariadb-1060-release-notes/) | See Also -------- * [Status Variables Added in MariaDB 10.6](../status-variables-added-in-mariadb-106/index) * [System Variables Added in MariaDB 10.5](../system-variables-added-in-mariadb-104/index) * [System Variables Added in MariaDB 10.4](../system-variables-added-in-mariadb-103/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Encrypting Binary Logs Encrypting Binary Logs ====================== MariaDB Server can encrypt the server's [binary logs](../binary-log/index) and [relay logs](../relay-log/index). This ensures that your binary logs are only accessible through MariaDB. Basic Configuration ------------------- Since [MariaDB 10.1.7](https://mariadb.com/kb/en/mariadb-1017-release-notes/), MariaDB can also encrypt [binary logs](../binary-log/index) (including [relay logs](../relay-log/index)). Encryption of binary logs is configured by the `[encrypt\_binlog](../replication-and-binary-log-system-variables/index#encrypt_binlog)` system variable. Users of data-at-rest encryption will also need to have a [key management and encryption plugin](../encryption-key-management/index) configured. Some examples are [File Key Management Plugin](../file-key-management-encryption-plugin/index) and [AWS Key Management Plugin](../aws-key-management-encryption-plugin/index). ``` [mariadb] ... # File Key Management plugin_load_add = file_key_management file_key_management_filename = /etc/mysql/encryption/keyfile.enc file_key_management_filekey = FILE:/etc/mysql/encryption/keyfile.key file_key_management_encryption_algorithm = AES_CTR # Binary Log Encryption encrypt_binlog=ON ``` Encryption Keys --------------- [Key management and encryption plugins](../encryption-key-management/index) support [using multiple encryption keys](../encryption-key-management/index#using-multiple-encryption-keys). Each encryption key can be defined with a different 32-bit integer as a key identifier. MariaDB uses the encryption key with ID 1 to encrypt [binary logs](../binary-log/index). ### Key Rotation Some [key management and encryption plugins](../encryption-key-management/index) allow you to automatically rotate and version your encryption keys. If a plugin support key rotation, and if it rotates the encryption keys, then InnoDB's [background encryption threads](../innodb-background-encryption-threads/index) can re-encrypt InnoDB pages that use the old key version with the new key version. However, the binary log does **not** have a similar mechanism, which means that existing binary logs remain encrypted with the older key version, but new binary logs will be encrypted with the new key version. For more information, see [MDEV-20098](https://jira.mariadb.org/browse/MDEV-20098). In order for key rotation to work, both the backend key management service (KMS) and the corresponding [key management and encryption plugin](../encryption-key-management/index) have to support key rotation. See [Encryption Key Management: Support for Key Rotation in Encryption Plugins](../encryption-key-management/index#support-for-key-rotation-in-encryption-plugins) to determine which plugins currently support key rotation. Enabling Encryption ------------------- Encryption of binary logs can be enabled by doing the following process. * First, stop the server. * Then, set `[encrypt\_binlog=ON](../replication-and-binary-log-system-variables/index#encrypt_binlog)` in the MariaDB configuration file. * Then, start the server. From that point forward, any new [binary logs](../binary-log/index) will be encrypted. To delete old unencrypted [binary logs](../binary-log/index), you can use [RESET MASTER](../reset-master/index) or [PURGE BINARY LOGS](../sql-commands-purge-logs/index). Disabling Encryption -------------------- Encryption of [binary logs](../binary-log/index) can be disabled by doing the following process. * First, stop the server. * Then, set `[encrypt\_binlog=OFF](../replication-and-binary-log-system-variables/index#encrypt_binlog)` in the MariaDB configuration file. * Then, start the server. From that point forward, any new [binary logs](../binary-log/index) will be unencrypted. If you would like the server to continue to have access to old encrypted [binary logs](../binary-log/index), then make sure to keep your [key management and encryption plugin](../encryption-key-management/index) loaded. Understanding Binlog Encryption ------------------------------- When starting with binary log encryption, MariaDB Server logs a `Format_descriptor_log_event` and a `START_ENCRYPTION_EVENT`, then encrypts all subsequent events for the binary log. Each event's header and footer are created and processed to produce encrypted blocks. These encrypted blocks are produced before transactions are committed and before the events are flushed to the binary log. As such, they exist in an encrypted state in memory buffers and in the `IO_CACHE` files for user connections. ### Effects of Data-at-Rest Encryption on Replication When using encrypted binary logs with [replication](../replication/index), it is completely supported to have different encryption keys on the master and slave. The master decrypts encrypted binary log events as it reads them from disk, and before its [binary log dump thread](../replication-threads/index#binary-log-dump-thread) sends them to the slave, so the slave actually receives the unencrypted binary log events. If you want to ensure that binary log events are encrypted as they are transmitted between the master and slave, then you will have to use [TLS with the replication connection](../replication-with-secure-connections/index). ### Effects of Data-at-Rest Encryption on mysqlbinlog [mysqlbinlog](../mysqlbinlog/index) does not currently have the ability to decrypt encrypted [binary logs](../binary-log/index) on its own (see [MDEV-8813](https://jira.mariadb.org/browse/MDEV-8813) about that). In order to use mysqlbinlog with encrypted [binary logs](../binary-log/index), you have to use the [--read-from-remote-server](../mysqlbinlog-options/index) command-line option, so that the server can decrypt the [binary logs](../binary-log/index) for mysqlbinlog. Note, using `--read-from-remote-server` option on versions of the `mysqlbinlog` utility that do not have the [MDEV-20574](https://jira.mariadb.org/browse/MDEV-20574) fix, can corrupt binlog positions when the binary log is encrypted. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb Spider Use Cases Spider Use Cases ================ Introduction ============ This article will cover simple working examples for some standard use cases for Spider. The example will be illustrated using a sales opportunities table to be consistent throughout. In some cases the actual examples will be contrived but are used to illustrate the varying syntax options. Basic setup =========== Have 3 or more servers available and Install MariaDB on each of these servers: * **spider** server which will act as the front end server hosting the spider storage engine. * **backend1** which will act as a backed server storing data * **backend2** which will act as a second backend server storing data Follow the instructions [here](../spider-storage-engine-overview/index#installing) to enable the Spider storage engine on the spider server: ``` mysql -u root -p < /usr/share/mysql/install_spider.sql ``` Enable use of non root connections ---------------------------------- When using the [General Query Log](../general-query-log/index), non-root users may encounter issues when querying Spider tables. Explicitly setting the `[spider\_internal\_sql\_log\_off](../spider-server-system-variables/index#spider_internal_sql_log_off)` system variable causes the Spider node to execute `SET sql_log_off` statements on the data nodes to enable or disable the General Query Log. When this is done, queries issued by users without the `SUPER` privilege raise an error. To avoid this, don't explicitly set the `[spider\_internal\_sql\_log\_off](../spider-server-system-variables/index#spider_internal_sql_log_off)` system variable. Create accounts for spider to connect with on backend servers ------------------------------------------------------------- Spider needs a remote connection to the backend server to actually perform the remote query. So this should be setup on each backend server. In this case 172.21.21.2 is the ip address of the spider node limiting access to just that server. ``` backend1> mysql grant all on test.* to spider@'172.21.21.2' identified by 'spider'; backend2> mysql grant all on test.* to spider@'172.21.21.2' identified by 'spider'; ``` Now verify that these connections can be used from the spider node (here 172.21.21.3 = backend1 and 172.21.21.4 = backend2): ``` spider> mysql -u spider -p -h 172.21.21.3 test spider> mysql -u spider -p -h 172.21.21.4 test ``` Create table on backend servers ------------------------------- The table definition should be created in the test database on both backend1 and backend2 servers: ``` create table opportunities ( id int, accountName varchar(20), name varchar(128), owner varchar(7), amount decimal(10,2), closeDate date, stageName varchar(11), primary key (id), key (accountName) ) engine=InnoDB; ``` Create server entries on spider server -------------------------------------- While the connection information can also be specified inline in the comment, it is cleaner to define a server object representing each remote backend server connection: ``` create server backend1 foreign data wrapper mysql options (host '172.21.21.3', database 'test', user 'spider', password 'spider', port 3306); create server backend2 foreign data wrapper mysql options (host '172.21.21.4', database 'test', user 'spider', password 'spider', port 3306); ``` ### Unable to Connect Errors Bear in mind, if you ever need to remove, recreate or otherwise modify the server definition for any reason, you need to also execute a `FLUSH TABLES` statement. Otherwise, Spider continues to use the old server definition, which can result in queries raising the error ``` Error 1429: Unable to connect to foreign data source ``` If you encounter this error when querying Spider tables, issue a `FLUSH TABLES` statement to update the server definitions. ``` FLUSH TABLES; ``` Use case 1: remote table ======================== In this case, a spider table is created to allow remote access to the opportunities table hosted on backend1. This then allows for queries and remote dml into the backend1 server from the spider server: ``` create table opportunities ( id int, accountName varchar(20), name varchar(128), owner varchar(7), amount decimal(10,2), closeDate date, stageName varchar(11), primary key (id), key (accountName) ) engine=spider comment='wrapper "mysql", srv "backend1" , table "opportunities"'; ``` Use case 2: sharding by hash ============================ In this case a spider table is created to distribute data across backend1 and backend2 by hashing the id column. Since the id column is an incrementing numeric value the hashing will ensure even distribution across the 2 nodes. ``` create table opportunities ( id int, accountName varchar(20), name varchar(128), owner varchar(7), amount decimal(10,2), closeDate date, stageName varchar(11), primary key (id), key (accountName) ) engine=spider COMMENT='wrapper "mysql", table "opportunities"' PARTITION BY HASH (id) ( PARTITION pt1 COMMENT = 'srv "backend1"', PARTITION pt2 COMMENT = 'srv "backend2"' ) ; ``` Use case 3: sharding by range ============================= In this case a spider table is created to distribute data across backend1 and backend2 based on the first letter of the accountName field. All accountNames that start with the letter L and prior will be stored in backend1 and all other values stored in backend2. Note that the accountName column must be added to the primary key which is a requirement of MariaDB partitioning: ``` create table opportunities ( id int, accountName varchar(20), name varchar(128), owner varchar(7), amount decimal(10,2), closeDate date, stageName varchar(11), primary key (id, accountName), key(accountName) ) engine=spider COMMENT='wrapper "mysql", table "opportunities"' PARTITION BY range columns (accountName) ( PARTITION pt1 values less than ('M') COMMENT = 'srv "backend1"', PARTITION pt2 values less than (maxvalue) COMMENT = 'srv "backend2"' ) ; ``` Use case 4: sharding by list ============================ In this case a spider table is created to distribute data across backend1 and backend2 based on specific values in the owner field. Bill, Bob, and Chris will be stored in backend1 and Maria and Olivier stored in backend2. Note that the owner column must be added to the primary key which is a requirement of MariaDB partitioning: ``` create table opportunities ( id int, accountName varchar(20), name varchar(128), owner varchar(7), amount decimal(10,2), closeDate date, stageName varchar(11), primary key (id, owner), key(accountName) ) engine=spider COMMENT='wrapper "mysql", table "opportunities"' PARTITION BY list columns (owner) ( PARTITION pt1 values in ('Bill', 'Bob', 'Chris') COMMENT = 'srv "backend1"', PARTITION pt2 values in ('Maria', 'Olivier') COMMENT = 'srv "backend2"' ) ; ``` With [MariaDB 10.2](../what-is-mariadb-102/index) the following partition clause can be used to specify a default partition for all other values, however this must be a distinct partition / shard: ``` PARTITION partition_name DEFAULT ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb ST_INTERSECTS ST\_INTERSECTS ============== Syntax ------ ``` ST_INTERSECTS(g1,g2) ``` Description ----------- Returns `1` or `0` to indicate whether geometry *`g1`* spatially intersects geometry *`g2`*. ST\_INTERSECTS() uses object shapes, while [INTERSECTS()](../intersects/index), based on the original MySQL implementation, uses object bounding rectangles. ST\_INTERSECTS() tests the opposite relationship to [ST\_DISJOINT()](../st_disjoint/index). Examples -------- ``` SET @g1 = ST_GEOMFROMTEXT('POINT(0 0)'); SET @g2 = ST_GEOMFROMTEXT('LINESTRING(0 0, 0 2)'); SELECT ST_INTERSECTS(@g1,@g2); +------------------------+ | ST_INTERSECTS(@g1,@g2) | +------------------------+ | 1 | +------------------------+ ``` ``` SET @g2 = ST_GEOMFROMTEXT('LINESTRING(2 0, 0 2)'); SELECT ST_INTERSECTS(@g1,@g2); +------------------------+ | ST_INTERSECTS(@g1,@g2) | +------------------------+ | 0 | +------------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb MyISAM Log MyISAM Log ========== The MyISAM log records all changes to [MyISAM](../myisam/index) tables. It is not enabled by default. To enable it, start the server with the [--log-isam](../mysqld-options/index#-log-isam) option, for example: ``` --log-isam=myisam.log ``` The *isam* instead of *myisam* above is not a typo - it's a legacy from when the predecessor to the MyISAM format, called ISAM. The option can be used without specifying a filename, in which case the default, *myisam.log* is used. To process the contents of the log file, use the [myisamlog](../myisamlog/index) utility. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Configuring ColumnStore Cross-Engine Joins Configuring ColumnStore Cross-Engine Joins ========================================== MariaDB ColumnStore allows columnstore tables to be joined with non-columnstore tables (e.g. [MyISAM](../myisam/index) tables) within a query. The non-columnstore table may be on the MariaDB ColumnStore system OR on an external server that supports MariaDB client connections. To enable this process, the <CrossEngineSupport> section in Columnstore.xml is configured with connection information. The following is an example entry in the Columnstore.XML configuration file to gain access to joined tables Single Server MariaDB ColumnStore install. The Host needs to be either 127.0.0.1 or 'localhost': ``` <CrossEngineSupport> <Host>127.0.0.1</Host> <Port>3306</Port> <User>mydbuser</User> <Password>pwd</Password> </CrossEngineSupport> ``` For a Multi-Node MariaDB Columnstore Installation, the Host needs to be the IP Address of the User-Module #1 or the Combination User/Performance Module #1. If the MariaDB Client is is running on an external Server, then it would be the IP Address of that server. For version 1.2.0 onwards the additional options in the <CrossEngineSupport> section are supported to add SSL/TLS encryption to the connections: ``` <TLSCA></TLSCA> <TLSClientCert></TLSClientCert> <TLSClientKey></TLSClientKey> ``` This change should be made while the ColumnStore server is down. In a multi node deployment, the change should be made on the PM1 node only as this will be replicated to other instances upon restart. Check here on how to make changes via the command line to Columnstore.xml: [https://mariadb.com/kb/en/mariadb/columnstore-configuration-file-update-and-distribution](../mariadb/columnstore-configuration-file-update-and-distribution) Troubleshooting --------------- **ERROR 1815 (HY000): Internal error: IDB-8001: CrossEngineSupport section in Columnstore.xml is not properly configured** * Confirm that Columnstore.xml was correctly updated on pm1 and the server restarted. **ERROR 1815 (HY000): Internal error: fatal error in drizzle\_con\_connect()(23)(23)** * Confirm that the values specified for CrossEngineSupport in ColumnStore.xml are correct for the login to be used. **ERROR 1815 (HY000): Internal error: fatal error executing query in crossengine client lib(17)(17)** * Confirm that the login used has create temporary tables permission on infinidb\_vtable: ``` grant create temporary tables on infinidb_vtable.* to [email protected]; ``` * Confirm that the login used has grant SELECT on the table referenced in the cross engine join. Verify by attempting to connect from each UM using mcsmysql and query the table you want to reference: ``` mcsmysql -u mydbuser -p -h 127.0.0.1 > use mydb; > select * from innodb_table limit 10; ``` Notes ----- * Cross engine will not work against a MyISAM/Aria table that has 0 or 1 rows in it. This is due to MariaDB's optimizer shortcut for this specific condition. We recommend using InnoDB instead of MyISAM/Aria for this case. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb What is MariaDB Galera Cluster? What is MariaDB Galera Cluster? =============================== The most recent release of [MariaDB 10.5](../what-is-mariadb-105/index) is: **[MariaDB 10.5.17](https://mariadb.com/kb/en/mariadb-10517-release-notes/)** Stable (GA) [DownloadNow](https://mariadb.com/downloads/) *[Alternate download from mariadb.org](https://mariadb.org/download/?tab=mariadb&release=10.5.17&product=mariadb)* About ----- MariaDB Galera Cluster is a [virtually synchronous](../about-galera-replication/index) multi-primary cluster for MariaDB. It is available on Linux only, and only supports the [InnoDB](../innodb/index) storage engine (although there is experimental support for [MyISAM](../myisam/index) and, from [MariaDB 10.6](../what-is-mariadb-106/index), [Aria](../aria/index). See the [wsrep\_replicate\_myisam](../galera-cluster-system-variables/index#wsrep_replicate_myisam) system variable, or, from [MariaDB 10.6](../what-is-mariadb-106/index), the [wsrep\_mode](../galera-cluster-system-variables/index#wsrep_mode) system variable). Features -------- * [Virtually synchronous replication](../about-galera-replication/index) * Active-active multi-primary topology * Read and write to any cluster node * Automatic membership control, failed nodes drop from the cluster * Automatic node joining * True parallel replication, on row level * Direct client connections, native MariaDB look & feel Benefits -------- The above features yield several benefits for a DBMS clustering solution, including: * No replica lag * No lost transactions * Read scalability * Smaller client latencies The [Getting Started with MariaDB Galera Cluster](../getting-started-with-mariadb-galera-cluster/index) page has instructions on how to get up and running with MariaDB Galera Cluster. A great resource for Galera users is [Codership on Google Groups](https://groups.google.com/forum/?fromgroups#!forum/codership-team) (*`codership-team` `'at'` `googlegroups` `(dot)` `com`*) - If you use Galera it is recommended you subscribe. Galera Versions --------------- MariaDB Galera Cluster is powered by: * MariaDB Server. * The [Galera wsrep provider library](https://github.com/codership/galera/). The functionality of MariaDB Galera Cluster can be obtained by installing the standard MariaDB Server packages and the [Galera wsrep provider library](https://github.com/codership/galera/) package. The following [Galera](../galera/index) version corresponds to each MariaDB Server version: * In [MariaDB 10.4](../what-is-mariadb-104/index) and later, MariaDB Galera Cluster uses [Galera](../galera/index) 4. This means that the wsrep API version is 26 and the [Galera wsrep provider library](https://github.com/codership/galera/) is version 4.X. * In [MariaDB 10.3](../what-is-mariadb-103/index) and before, MariaDB Galera Cluster uses [Galera](../galera/index) 3. This means that the wsrep API is version 25 and the [Galera wsrep provider library](https://github.com/codership/galera/) is version 3.X. See [Deciphering Galera Version Numbers](https://galeracluster.com/library/documentation/versioning-information.html/) for more information about how to interpret these version numbers. ### Galera 4 Versions The following table lists each version of the [Galera](../galera/index) 4 wsrep provider, and it lists which version of MariaDB each one was first released in. If you would like to install [Galera](../galera/index) 4 using [yum](../yum/index), [apt](../installing-mariadb-deb-files/index#installing-mariadb-with-apt), or [zypper](../installing-mariadb-with-zypper/index), then the package is called `galera-4`. | Galera Version | Released in MariaDB Version | | --- | --- | | **26.4.11** | [MariaDB 10.8.1](https://mariadb.com/kb/en/mariadb-1081-release-notes/), [MariaDB 10.7.2](https://mariadb.com/kb/en/mariadb-1072-release-notes/), [MariaDB 10.6.6](https://mariadb.com/kb/en/mariadb-1066-release-notes/), [MariaDB 10.5.14](https://mariadb.com/kb/en/mariadb-10514-release-notes/), [MariaDB 10.4.22](https://mariadb.com/kb/en/mariadb-10422-release-notes/) | | **26.4.9** | [MariaDB 10.6.4](https://mariadb.com/kb/en/mariadb-1064-release-notes/), [MariaDB 10.5.12](https://mariadb.com/kb/en/mariadb-10512-release-notes/), [MariaDB 10.4.21](https://mariadb.com/kb/en/mariadb-10421-release-notes/) | | **26.4.8** | [MariaDB 10.6.1](https://mariadb.com/kb/en/mariadb-1061-release-notes/), [MariaDB 10.5.10](https://mariadb.com/kb/en/mariadb-10510-release-notes/), [MariaDB 10.4.19](https://mariadb.com/kb/en/mariadb-10419-release-notes/) | | **26.4.7** | [MariaDB 10.5.9](https://mariadb.com/kb/en/mariadb-1059-release-notes/), [MariaDB 10.4.18](https://mariadb.com/kb/en/mariadb-10418-release-notes/) | | **26.4.6** | [MariaDB 10.5.7](https://mariadb.com/kb/en/mariadb-1057-release-notes/), [MariaDB 10.4.16](https://mariadb.com/kb/en/mariadb-10416-release-notes/) | | **26.4.5** | [MariaDB 10.5.4](https://mariadb.com/kb/en/mariadb-1054-release-notes/), [MariaDB 10.4.14](https://mariadb.com/kb/en/mariadb-10414-release-notes/) | | **26.4.4** | [MariaDB 10.5.1](https://mariadb.com/kb/en/mariadb-1051-release-notes/), [MariaDB 10.4.13](https://mariadb.com/kb/en/mariadb-10413-release-notes/) | | **26.4.3** | [MariaDB 10.5.0](https://mariadb.com/kb/en/mariadb-1050-release-notes/), [MariaDB 10.4.9](https://mariadb.com/kb/en/mariadb-1049-release-notes/) | | **26.4.2** | [MariaDB 10.4.4](https://mariadb.com/kb/en/mariadb-1044-release-notes/) | | **26.4.1** | [MariaDB 10.4.3](https://mariadb.com/kb/en/mariadb-1043-release-notes/) | | **26.4.0** | [MariaDB 10.4.2](https://mariadb.com/kb/en/mariadb-1042-release-notes/) | ### Galera 3 Versions The following table lists each version of the [Galera](../galera/index) 3 wsrep provider, and it lists which version of MariaDB each one was first released in. If you would like to install [Galera](../galera/index) 3 using [yum](../yum/index), [apt](../installing-mariadb-deb-files/index#installing-mariadb-with-apt), or [zypper](../installing-mariadb-with-zypper/index), then the package is called `galera`. | Galera Version | Released in MariaDB Version | | --- | --- | | **25.3.35** | [MariaDB 10.3.33](https://mariadb.com/kb/en/mariadb-10333-release-notes/), [MariaDB 10.2.42](https://mariadb.com/kb/en/mariadb-10242-release-notes/) | | **25.3.34** | [MariaDB 10.3.31](https://mariadb.com/kb/en/mariadb-10331-release-notes/), [MariaDB 10.2.40](https://mariadb.com/kb/en/mariadb-10240-release-notes/) | | **25.3.33** | [MariaDB 10.3.29](https://mariadb.com/kb/en/mariadb-10329-release-notes/), [MariaDB 10.2.38](https://mariadb.com/kb/en/mariadb-10238-release-notes/) | | **25.3.32** | [MariaDB 10.3.28](https://mariadb.com/kb/en/mariadb-10328-release-notes/), [MariaDB 10.2.37](https://mariadb.com/kb/en/mariadb-10237-release-notes/) | | **25.3.31** | [MariaDB 10.3.26](https://mariadb.com/kb/en/mariadb-10326-release-notes/), [MariaDB 10.2.35](https://mariadb.com/kb/en/mariadb-10235-release-notes/), [MariaDB 10.1.48](https://mariadb.com/kb/en/mariadb-10148-release-notes/) | | **25.3.30** | [MariaDB 10.3.25](https://mariadb.com/kb/en/mariadb-10325-release-notes/), [MariaDB 10.2.34](https://mariadb.com/kb/en/mariadb-10234-release-notes/), [MariaDB 10.1.47](https://mariadb.com/kb/en/mariadb-10147-release-notes/) | | **25.3.29** | [MariaDB 10.3.23](https://mariadb.com/kb/en/mariadb-10323-release-notes/), [MariaDB 10.2.32](https://mariadb.com/kb/en/mariadb-10232-release-notes/), [MariaDB 10.1.45](https://mariadb.com/kb/en/mariadb-10145-release-notes/) | | **25.3.28** | [MariaDB 10.3.19](https://mariadb.com/kb/en/mariadb-10319-release-notes/), [MariaDB 10.2.28](https://mariadb.com/kb/en/mariadb-10228-release-notes/), [MariaDB 10.1.42](https://mariadb.com/kb/en/mariadb-10142-release-notes/) | | **25.3.27** | [MariaDB 10.3.18](https://mariadb.com/kb/en/mariadb-10318-release-notes/), [MariaDB 10.2.27](https://mariadb.com/kb/en/mariadb-10227-release-notes/) | | **25.3.26** | [MariaDB 10.3.14](https://mariadb.com/kb/en/mariadb-10314-release-notes/), [MariaDB 10.2.23](https://mariadb.com/kb/en/mariadb-10223-release-notes/), [MariaDB 10.1.39](https://mariadb.com/kb/en/mariadb-10139-release-notes/) | | **25.3.25** | [MariaDB 10.3.12](https://mariadb.com/kb/en/mariadb-10312-release-notes/), [MariaDB 10.2.20](https://mariadb.com/kb/en/mariadb-10220-release-notes/), [MariaDB 10.1.38](https://mariadb.com/kb/en/mariadb-10138-release-notes/), [MariaDB Galera Cluster 10.0.38](https://mariadb.com/kb/en/mariadb-galera-cluster-10038-release-notes/), [MariaDB Galera Cluster 5.5.63](https://mariadb.com/kb/en/mariadb-galera-cluster-5563-release-notes/) | | **25.3.24** | [MariaDB 10.4.0](https://mariadb.com/kb/en/mariadb-1040-release-notes/), [MariaDB 10.3.10](https://mariadb.com/kb/en/mariadb-10310-release-notes/), [MariaDB 10.2.18](https://mariadb.com/kb/en/mariadb-10218-release-notes/), [MariaDB 10.1.37](https://mariadb.com/kb/en/mariadb-10137-release-notes/), [MariaDB Galera Cluster 10.0.37](https://mariadb.com/kb/en/mariadb-galera-cluster-10037-release-notes/), [MariaDB Galera Cluster 5.5.62](https://mariadb.com/kb/en/mariadb-galera-cluster-5562-release-notes/) | | **25.3.23** | [MariaDB 10.3.5](https://mariadb.com/kb/en/mariadb-1035-release-notes/), [MariaDB 10.2.13](https://mariadb.com/kb/en/mariadb-10213-release-notes/), [MariaDB 10.1.32](https://mariadb.com/kb/en/mariadb-10132-release-notes/), [MariaDB Galera Cluster 10.0.35](https://mariadb.com/kb/en/mariadb-galera-cluster-10035-release-notes/), [MariaDB Galera Cluster 5.5.60](https://mariadb.com/kb/en/mariadb-galera-cluster-5560-release-notes/) | | **25.3.22** | [MariaDB 10.3.3](https://mariadb.com/kb/en/mariadb-1033-release-notes/), [MariaDB 10.2.11](https://mariadb.com/kb/en/mariadb-10211-release-notes/), [MariaDB 10.1.29](https://mariadb.com/kb/en/mariadb-10129-release-notes/), [MariaDB Galera Cluster 10.0.33](https://mariadb.com/kb/en/mariadb-galera-cluster-10033-release-notes/), [MariaDB Galera Cluster 5.5.59](https://mariadb.com/kb/en/mariadb-galera-cluster-5559-release-notes/) | | **25.3.21** | N/A | | **25.3.20** | [MariaDB 10.3.1](https://mariadb.com/kb/en/mariadb-1031-release-notes/), [MariaDB 10.2.6](https://mariadb.com/kb/en/mariadb-1026-release-notes/), [MariaDB 10.1.23](https://mariadb.com/kb/en/mariadb-10123-release-notes/), [MariaDB Galera Cluster 10.0.31](https://mariadb.com/kb/en/mariadb-galera-cluster-10031-release-notes/), [MariaDB Galera Cluster 5.5.56](https://mariadb.com/kb/en/mariadb-galera-cluster-5556-release-notes/) | | **25.3.19** | [MariaDB 10.3.0](https://mariadb.com/kb/en/mariadb-1030-release-notes/), [MariaDB 10.2.3](https://mariadb.com/kb/en/mariadb-1023-release-notes/), [MariaDB 10.1.20](https://mariadb.com/kb/en/mariadb-10120-release-notes/), [MariaDB Galera Cluster 10.0.29](https://mariadb.com/kb/en/mariadb-galera-cluster-10029-release-notes/), [MariaDB Galera Cluster 5.5.54](https://mariadb.com/kb/en/mariadb-galera-cluster-5554-release-notes/) | | **25.3.18** | [MariaDB 10.2.2](https://mariadb.com/kb/en/mariadb-1022-release-notes/), [MariaDB 10.1.18](https://mariadb.com/kb/en/mariadb-10118-release-notes/), [MariaDB Galera Cluster 10.0.28](https://mariadb.com/kb/en/mariadb-galera-cluster-10028-release-notes/), [MariaDB Galera Cluster 5.5.53](https://mariadb.com/kb/en/mariadb-galera-cluster-5553-release-notes/) | | **25.3.17** | [MariaDB 10.1.17](https://mariadb.com/kb/en/mariadb-10117-release-notes/), [MariaDB Galera Cluster 10.0.27](https://mariadb.com/kb/en/mariadb-galera-cluster-10027-release-notes/), [MariaDB Galera Cluster 5.5.51](https://mariadb.com/kb/en/mariadb-galera-cluster-5551-release-notes/) | | **25.3.16** | N/A | | **25.3.15** | [MariaDB 10.2.0](https://mariadb.com/kb/en/mariadb-1020-release-notes/), [MariaDB 10.1.13](https://mariadb.com/kb/en/mariadb-10113-release-notes/), [MariaDB Galera Cluster 10.0.25](https://mariadb.com/kb/en/mariadb-galera-cluster-10025-release-notes/), [MariaDB Galera Cluster 5.5.49](https://mariadb.com/kb/en/mariadb-galera-cluster-5549-release-notes/) | | **25.3.14** | [MariaDB 10.1.12](https://mariadb.com/kb/en/mariadb-10112-release-notes/), [MariaDB Galera Cluster 10.0.24](https://mariadb.com/kb/en/mariadb-galera-cluster-10024-release-notes/), [MariaDB Galera Cluster 5.5.48](https://mariadb.com/kb/en/mariadb-galera-cluster-5548-release-notes/) | | **25.3.12** | [MariaDB 10.1.11](https://mariadb.com/kb/en/mariadb-10111-release-notes/) | | **25.3.11** | N/A | | **25.3.10** | N/A | | **25.3.9** | [MariaDB 10.1.3](https://mariadb.com/kb/en/mariadb-1013-release-notes/), [MariaDB Galera Cluster 10.0.17](https://mariadb.com/kb/en/mariadb-galera-cluster-10017-release-notes/), [MariaDB Galera Cluster 5.5.42](https://mariadb.com/kb/en/mariadb-galera-cluster-5542-release-notes/) | | **25.3.8** | N/A | | **25.3.7** | N/A | | **25.3.6** | N/A | | **25.3.5** | [MariaDB 10.1.1](https://mariadb.com/kb/en/mariadb-1011-release-notes/), [MariaDB Galera Cluster 10.0.10](https://mariadb.com/kb/en/mariadb-galera-cluster-10010-release-notes/), [MariaDB Galera Cluster 5.5.37](https://mariadb.com/kb/en/mariadb-galera-cluster-5537-release-notes/) | | **25.3.4** | N/A | | **25.3.3** | N/A | | **25.3.2** | [MariaDB Galera Cluster 10.0.7](https://mariadb.com/kb/en/mariadb-galera-cluster-1007-release-notes/), [MariaDB Galera Cluster 5.5.35](https://mariadb.com/kb/en/mariadb-galera-cluster-5535-release-notes/) | See Also -------- * [Codership on Google Groups](https://groups.google.com/forum/?fromgroups#!forum/codership-team) (*`codership-team 'at' googlegroups (dot) com`*) - A great mailing list for Galera users. * [About Galera Replication](../about-galera-replication/index) * [Codership: Using Galera Cluster](http://codership.com/content/using-galera-cluster) * [Galera Use Cases](../galera-use-cases/index) * [Getting Started with MariaDB Galera Cluster](../getting-started-with-mariadb-galera-cluster/index) * [MariaDB Galera Cluster - Known Limitations](../mariadb-galera-cluster-known-limitations/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb ColumnStore Data Ingestion ColumnStore Data Ingestion =========================== ColumnStore provides several mechanisms to ingest data: * [cpimport](../columnstore-bulk-data-loading/index) provides the fastest performance for inserting data and ability to route data to particular PM nodes. **Normally this should be the default choice for loading data** . * [LOAD DATA INFILE](../columnstore-load-data-infile/index) provides another means of bulk inserting data. + By default with autocommit on it will internally stream the data to an instance of the cpimport process. This requires some memory overhead on the UM server so may be less reliable than cpimport for very large imports. + In transactional mode DML inserts are performed which will be significantly slower plus it will consume both binlog transaction files and ColumnStore VersionBuffer files. * DML, i.e. INSERT, UPDATE, and DELETE, provide row level changes. ColumnStore is optimized towards bulk modifications and so these operations are slower than they would be in say InnoDB. + Currently ColumnStore does not support operating as a replication slave target. + Bulk DML operations will in general perform better than multiple individual statements. - [INSERT INTO SELECT](../columnstore-batch-insert-mode/index) with autocommit behaves similarly to LOAD DATE INFILE in that internally it is mapped to cpimport for higher performance. - Bulk update operations based on a join with a small staging table can be relatively fast especially if updating a single column. * Using [ColumnStore Bulk Write SDK](../columnstore-bulk-write-sdk/index) or [ColumnStore Streaming Data Adapters](../columnstore-streaming-data-adapters/index) | Title | Description | | --- | --- | | [ColumnStore Bulk Data Loading](../columnstore-bulk-data-loading/index) | Using high-speed bulk load utility cpimport | | [ColumnStore LOAD DATA INFILE](../columnstore-load-data-infile/index) | Using the LOAD DATA INFILE statement for bulk data loading. | | [ColumnStore Batch Insert Mode](../columnstore-batch-insert-mode/index) | Batch data insert mode with cpimport | | [ColumnStore Bulk Write SDK](../columnstore-bulk-write-sdk/index) | Introduction Starting with MariaDB ColumnStore 1.1 a C++ SDK is available ... | | [ColumnStore remote bulk data import: mcsimport](../columnstore-remote-bulk-data-import-mcsimport/index) | Overview mcsimport is a high-speed bulk load utility that imports data int... | | [ColumnStore Streaming Data Adapters](../columnstore-streaming-data-adapters/index) | The ColumnStore Bulk Data API enables the creation of higher performance a... | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb INET6_NTOA INET6\_NTOA =========== Syntax ------ ``` INET6_NTOA(expr) ``` Description ----------- Given an IPv6 or IPv4 network address as a numeric binary string, returns the address as a nonbinary string in the connection character set. The return string is lowercase, and is platform independent, since it does not use functions specific to the operating system. It has a maximum length of 39 characters. Returns NULL if the argument is not understood. Examples -------- ``` SELECT INET6_NTOA(UNHEX('0A000101')); +-------------------------------+ | INET6_NTOA(UNHEX('0A000101')) | +-------------------------------+ | 10.0.1.1 | +-------------------------------+ SELECT INET6_NTOA(UNHEX('48F3000000000000D4321431BA23846F')); +-------------------------------------------------------+ | INET6_NTOA(UNHEX('48F3000000000000D4321431BA23846F')) | +-------------------------------------------------------+ | 48f3::d432:1431:ba23:846f | +-------------------------------------------------------+ ``` See Also -------- * [INET6\_ATON()](../inet6_aton/index) * [INET\_NTOA()](../inet_ntoa/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb MariaDB on Amazon AWS MariaDB on Amazon AWS ===================== MariaDB is available on Amazon AWS through MariaDB SkySQL, as one of the database options when using Amazon's RDS service, or using a MariaDB AMI on Amazon EC2 from the AWS Marketplace. MariaDB SkySQL -------------- Cloud database service is available through MariaDB SkySQL on Amazon AWS. MariaDB SkySQL delivers MariaDB with enterprise features for mission-critical workloads. Support is provided directly by MariaDB. Refer to [SkySQL Documentation](https://mariadb.com/products/skysql/docs/) for complete details. [Get started](https://mariadb.com/products/skysql/get-started/) to launch a MariaDB database on AWS in minutes. Amazon RDS ---------- To get started with MariaDB on Amazon's RDS service, click on the RDS link in the Database section of the [AWS console](https://console.aws.amazon.com/console/home). Next, click on the **Get Started Now** button. Alternatively, you can click on the **Launch DB Instance** button from the [Instances section of the RDS Dashboard](https://console.aws.amazon.com/rds/home#dbinstances:). In either case, you will be brought to the page where you can select the database engine you want to use. Click on the **MariaDB** logo and then click on the **Select** button. You will then move to step 2 where you choose whether or not you want to use your MariaDB instance for production or non-production usage. Amazon has links on this page to documentation on the various options. After selecting the choice you want you will move to step 3 where you specify the details for your database, including setting up an admin user in the database. You will then move to step 4 where you can configure advanced settings, including security settings, various options, backup settings, maintenance defaults, and so on. Refer to [Amazon's RDS documentation](https://aws.amazon.com/documentation/rds/) for complete documentation on all the various settings and for information on connecting to and using your RDS MariaDB instances. AMI on EC2 ---------- MariaDB AMIs (Amazon Machine Images) are available in the AWS Marketplace. These AMIs, kept up-to-date with the most recently released versions of MariaDB, are a great way to try out the newest MariaDB versions before they make it to RDS and/or to use MariaDB in a more traditional server environment. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Installing MariaDB ColumnStore 5 Installing MariaDB ColumnStore 5 ================================ MariaDB Enterprise ColumnStore 5 is included with MariaDB Enterprise Server 10.5, and MariaDB ColumnStore 5 is included with MariaDB Community Server 10.5. MariaDB Enterprise ColumnStore 5 -------------------------------- * [Deploy ColumnStore Object Storage Topology with MariaDB Enterprise Server 10.5](https://mariadb.com/docs/deploy/topologies/columnstore-object-storage/enterprise-server-10-5/) * [Deploy ColumnStore Shared Local Storage Topology with MariaDB Enterprise Server 10.5](https://mariadb.com/docs/deploy/topologies/columnstore-shared-local-storage/enterprise-server-10-5/) * [Deploy Single-Node Enterprise ColumnStore 5 with Local Storage](https://mariadb.com/docs/deploy/topologies/single-node/enterprise-columnstore-es10-5-local/) * [Deploy Single-Node Enterprise ColumnStore 5 with Object Storage](https://mariadb.com/docs/deploy/topologies/single-node/enterprise-columnstore-es10-5-object/) MariaDB ColumnStore 5 --------------------- * [Deploy MariaDB ColumnStore 5.5 with MariaDB Community Server 10.5](https://mariadb.com/docs/deploy/topologies/single-node/community-columnstore-cs10-5/) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb SQL Server Features Implemented Differently in MariaDB SQL Server Features Implemented Differently in MariaDB ====================================================== Modern DBMSs implement several advanced features. While an SQL standard exists, the complete feature list is different for every database system. Sometimes different features allow achieving the same purpose, but with a different logic and different limitations. This is something to take into account when planning a migration. Some features are implemented by different DBMSs, with a similar logic and similar syntax. But there could be important differences that users should be aware of. This page has a list of SQL Server features that MariaDB implements in a different way, and SQL Server features for which MariaDB has an alternative feature. Minor differences are not taken into account here. The list is not exhaustive. SQL --- * The list of supported [data types](../data-types/index) is different. * There are relevant [differences in transaction isolation levels](../mariadb-transactions-and-isolation-levels-for-sql-server-users/index#isolation-levels-and-locks). * `SNAPSHOT` isolation level is not supported. Instead, you can use `START TRANSACTION WITH CONSISTENT SNAPSHOT` to acquire a snapshot at the beginning of the transaction. This is compatible with all isolation levels. See [How Isolation Levels are Implemented in MariaDB](../mariadb-transactions-and-isolation-levels-for-sql-server-users/index#how-isolation-levels-are-implemented-in-mariadb). * JSON support is [different](../sql-server-and-mariadb-types-comparison/index#json). Indexes and Performance ----------------------- * Clustered indexes. In MariaDB, the physical order of rows is delegated to the storage engine. InnoDB uses the primary key as a clustered index. * Hash indexes. Only some storage engines support `HASH` indexes. + The [InnoDB](../innodb/index) storage engine has a feature called adaptive hash index, enabled by default. It means that in InnoDB all indexes are created as `BTREE`, and depending on how they are used, InnoDB could convert them from BTree to hash indexes, or the other way around. This happens in the background. + The [MEMORY](../memory-storage-engine/index) storage engine uses hash indexes by default, if we don't specify the `BTREE` keyword. + See [Storage Engine Index Types](../storage-engine-index-types/index) for more information. * Query store. MariaDB allows query performance analysis using the [slow log](../slow-query-log/index) and [performance\_schema](../performance-schema/index). Some open source or commercial 3rd party tools read that information to produce statistics and make it easy to identify slow queries. Tables ------ * Computed columns are called [generated columns](../generated-columns/index) in MariaDB and are created with a different syntax. See also [Implementation Differences Compared to Microsoft SQL Server](../generated-columns/index#implementation-differences-compared-to-microsoft-sql-server). * [Temporal tables](../temporal-data-tables/index) use a different (more standard) syntax on MariaDB. In MariaDB, the history is stored in the same table as current data (but optionally in different partitions). MariaDB supports both [SYSTEM\_TIME](../temporal-data-tables/index#creating-a-system-versioned-table) and [APPLICATION\_TIME](../temporal-data-tables/index#application-time-periods). * Hidden columns are [Invisible columns](../invisible-columns/index) in MariaDB. * [Temporary tables](../create-table/index#create-temporary-table) are implemented and used differently. High Availability ----------------- * `NOT FOR REPLICATION` + MariaDB supports [replication filters](../replication-filters/index) to exclude some tables or databases from replication + It is possible to keep a table empty in a slave (or in the master) by using the [BLACKHOLE storage engine](../blackhole/index). + The master can have columns that are not present in a slave (the other way around is also supported). Before using this feature, carefully read the [Replication When the Master and Slave Have Different Table Definitions](../replication-when-the-master-and-slave-have-different-table-definitions/index#different-number-or-order-of-columns) page. + With MariaDB it's possible to [prevent a trigger from running on slaves](../running-triggers-on-the-slave-for-row-based-events/index). + It's possible to run [events](../event-scheduler/index) without replicating them. The same applies to some administrative statements. + MariaDB superusers can run statements without replicating them, by using the [sql\_log\_bin](../set-sql_log_bin/index) system variable. + Constraints and triggers cannot be disabled for replication, but it is possible to drop them on the slaves. + The `IF EXISTS` syntax allows one to easily create a table on the master that already exists (possibly in a different version) on a slave. * pollinginterval option. See [Delayed Replication](../delayed-replication/index). Security -------- * The list of [permissions](../grant/index#privilege-levels) is different. * Security policies. MariaDB allows one to achieve the same results by assigning permissions on views and stored procedures. However, this is not a common practice and it's more complicated than defining security policies. See [Other Uses of Views](../creating-using-views/index#other-uses-of-views). * MariaDB does not support an `OUTPUT` clause. Instead, we can use [DELETE RETURNING](../delete/index) and, since [MariaDB 10.5](../what-is-mariadb-105/index), [INSERT RETURNING](../insertreturning/index) and [REPLACE RETURNING](../replacereturning/index). Other Features -------------- * Linked servers. MariaDB supports storage engines to read from, and write to, remote tables. When using the [CONNECT](../connect/index) engine, those tables could be in different DBMSs, including SQL Server. * Job scheduler: MariaDB uses an [event scheduler](../event-scheduler/index) to schedule events instead. See Also -------- * [SQL Server features not available in MariaDB](../sql-server-features-not-available-in-mariadb/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Information Schema INNODB_LOCKS Table Information Schema INNODB\_LOCKS Table ====================================== The [Information Schema](../information_schema/index) `INNODB_LOCKS` table stores information about locks that InnoDB transactions have requested but not yet acquired, or that are blocking another transaction. It has the following columns: | Column | Description | | --- | --- | | `LOCK_ID` | Lock ID number - the format is not fixed, so do not rely upon the number for information. | | `LOCK_TRX_ID` | Lock's transaction ID. Matches the [INNODB\_TRX.TRX\_ID](../information-schema-innodb_trx-table/index) column. | | `LOCK_MODE` | [Lock mode](../xtradbinnodb-lock-modes/index). One of `S` (shared), `X` (exclusive), `IS` (intention shared), `IX` (intention exclusive row lock), `S_GAP` (shared gap lock), `X_GAP` (exclusive gap lock), `IS_GAP` (intention shared gap lock), `IX_GAP` (intention exclusive gap lock) or `AUTO_INC` ([auto-increment table level lock](../auto_increment-handling-in-xtradbinnodb/index)). | | `LOCK_TYPE` | Whether the lock is `RECORD` (row level) or `TABLE` level. | | `LOCK_TABLE` | Name of the locked table,or table containing locked rows. | | `LOCK_INDEX` | Index name if a `RECORD` `LOCK_TYPE`, or `NULL` if not. | | `LOCK_SPACE` | Tablespace ID if a `RECORD` `LOCK_TYPE`, or `NULL` if not. | | `LOCK_PAGE` | Locked record page number if a `RECORD` `LOCK_TYPE`, or `NULL` if not. | | `LOCK_REC` | Locked record heap number if a `RECORD` `LOCK_TYPE`, or `NULL` if not. | | `LOCK_DATA` | Locked record primary key as an SQL string if a `RECORD` `LOCK_TYPE`, or `NULL` if not. If no primary key exists, the internal InnoDB row\_id number is instead used. To avoid unnecessary IO, also `NULL` if the locked record page is not in the [buffer pool](../xtradbinnodb-buffer-pool/index) | The table is often used in conjunction with the [INNODB\_LOCK\_WAITS](../information-schema-innodb_lock_waits-table/index) and [INNODB\_TRX](../information-schema-innodb_trx-table/index) tables to diagnose problematic locks and transactions Example ------- ``` -- session 1 START TRANSACTION; UPDATE t SET id = 15 WHERE id = 10; -- session 2 DELETE FROM t WHERE id = 10; -- session 1 USE information_schema; SELECT l.*, t.* FROM information_schema.INNODB_LOCKS l JOIN information_schema.INNODB_TRX t ON l.lock_trx_id = t.trx_id WHERE trx_state = 'LOCK WAIT' \G *************************** 1. row *************************** lock_id: 840:40:3:2 lock_trx_id: 840 lock_mode: X lock_type: RECORD lock_table: `test`.`t` lock_index: PRIMARY lock_space: 40 lock_page: 3 lock_rec: 2 lock_data: 10 trx_id: 840 trx_state: LOCK WAIT trx_started: 2019-12-23 18:43:46 trx_requested_lock_id: 840:40:3:2 trx_wait_started: 2019-12-23 18:43:46 trx_weight: 2 trx_mysql_thread_id: 46 trx_query: DELETE FROM t WHERE id = 10 trx_operation_state: starting index read trx_tables_in_use: 1 trx_tables_locked: 1 trx_lock_structs: 2 trx_lock_memory_bytes: 1136 trx_rows_locked: 1 trx_rows_modified: 0 trx_concurrency_tickets: 0 trx_isolation_level: REPEATABLE READ trx_unique_checks: 1 trx_foreign_key_checks: 1 trx_last_foreign_key_error: NULL trx_is_read_only: 0 trx_autocommit_non_locking: 0 ``` . Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb COLUMN_EXISTS COLUMN\_EXISTS ============== Syntax ------ ``` COLUMN_EXISTS(dyncol_blob, column_nr); COLUMN_EXISTS(dyncol_blob, column_name); ``` Description ----------- Checks if a column with name `column_name` exists in `dyncol_blob`. If yes, return `1`, otherwise return `0`. See [dynamic columns](../dynamic-columns/index) for more information. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb MariaDB ColumnStore software upgrade 1.0.8 to 1.0.9 MariaDB ColumnStore software upgrade 1.0.8 to 1.0.9 =================================================== MariaDB ColumnStore software upgrade 1.0.8 to 1.0.9 --------------------------------------------------- Note: Columnstore.xml modifications you manually made are not automatically carried forward on an upgrade. These modifications will need to be incorporated back into .XML once the upgrade has occurred. The previous configuration file will be saved as /usr/local/mariadb/columnstore/etc/Columnstore.xml.rpmsave. If you have specified a root database password (which is good practice), then you must configure a .my.cnf file with user credentials for the upgrade process to use. Create a .my.cnf file in the user home directory with 600 file permissions with the following content (updating PASSWORD as appropriate): ``` [mysqladmin] user = root password = PASSWORD ``` ### Choosing the type of upgrade As noted on the Preparing guide, you can installing MariaDB ColumnStore with the use of soft-links. If you have the softlinks be setup at the Data Directory Levels, like mariadb/columnstore/data and mariadb/columnstore/dataX, then your upgrade will happen without any issues. In the case where you have a softlink at the top directory, like /usr/local/mariadb, you will need to upgrade using the binary package. If you updating using the rpm package and tool, this softlink will be deleted when you perform the upgrade process and the upgrade will fail. #### Root User Installs #### Upgrading MariaDB ColumnStore using RPMs Upgrade MariaDB ColumnStore as user root on the server designated as PM1: **Download the package mariadb-columnstore-1.0.9-1-centos#.x86\_64.rpm.tar.gz to the PM1 server where you are installing MariaDB ColumnStore.** Shutdown the MariaDB ColumnStore system: ``` # mcsadmin shutdownsystem y ``` * Unpack the tarball, which will generate a set of RPMs that will reside in the /root/ directory. `tar -zxf mariadb-columnstore-1.0.9-1-centos#.x86_64.rpm.tar.gz` * Upgrade the RPMs. The MariaDB ColumnStore software will be installed in /usr/local/. ``` rpm -e --nodeps $(rpm -qa | grep '^mariadb-columnstore') rpm -ivh mariadb-columnstore-*1.0.9*rpm ``` * Run postConfigure using the upgrade option, which will utilize the configuration from the Columnstore.xml.rpmsave ``` # /usr/local/mariadb/columnstore/bin/postConfigure -u ``` For RPM Upgrade, the previous configuration file will be saved as: /usr/local/mariadb/columnstore/etc/Columnstore.xml.rpmsave ### Initial download/install of MariaDB ColumnStore binary package Upgrade MariaDB ColumnStore as user root on the server designated as PM1: * Download the package into the /usr/local directory -mariadb-columnstore-1.0.9-1.x86\_64.bin.tar.gz (Binary 64-BIT)to the server where you are installing MariaDB ColumnStore. * Shutdown the MariaDB ColumnStore system: `mcsadmin shutdownsystem y` * Run pre-uninstall script `/usr/local/mariadb/columnstore/bin/pre-uninstall` * Unpack the tarball, in the /usr/local/ directory. `tar -zxvf -mariadb-columnstore-1.0.9-1.x86_64.bin.tar.gz` * Run post-install scripts `/usr/local/mariadb/columnstore/bin/post-install` * Run postConfigure using the upgrade option, which will utilize the configuration from the Columnstore.xml,rpmsave `/usr/local/mariadb/columnstore/bin/postConfigure -u` ### Upgrading MariaDB ColumnStore using the DEB package A DEB upgrade would be done on a system that supports DEBs like Debian or Ubuntu systems. Upgrade MariaDB ColumnStore as user root on the server designated as PM1: * Download the package into the /root directory ``` mariadb-columnstore-1.0.9-1.amd64.deb.tar.gz ``` (DEB 64-BIT) to the server where you are installing MariaDB ColumnStore. * Shutdown the MariaDB ColumnStore system: ``` mcsadmin shutdownsystem y ``` * Unpack the tarball, which will generate DEBs. ``` tar -zxf mariadb-columnstore-1.0.9-1.amd64.deb.tar.gz ``` * Remove, purge and install all MariaDB ColumnStore debs ``` cd /root/ dpkg -r mariadb-columnstore*deb dpkg -P mariadb-columnstore*deb ``` * Run postConfigure using the upgrade option, which will utilize the configuration from the Columnstore.xml,rpmsave ``` /usr/local/mariadb/columnstore/bin/postConfigure -u ``` #### Non-Root User Installs ### Initial download/install of MariaDB ColumnStore binary package Upgrade MariaDB ColumnStore as user root on the server designated as PM1: * Download the package into the /home/'non-root-user" directory mariadb-columnstore-1.0.9-1.x86\_64.bin.tar.gz (Binary 64-BIT)to the server where you are installing MariaDB ColumnStore. * Shutdown the MariaDB ColumnStore system: `mcsadmin shutdownsystem y` * Run pre-uninstall script `$HOME/mariadb/columnstore/bin/pre-uninstall -i /home/guest/mariadb/columnstore` * Unpack the tarball, which will generate the $HOME/ directory. `tar -zxvf -mariadb-columnstore-1.0.9-1.x86_64.bin.tar.gz` * Run post-install scripts 1. $HOME/mariadb/columnstore/bin/post-install -i /home/guest/mariadb/columnstore * Run postConfigure using the upgrade option, which will utilize the configuration from the Columnstore.xml,rpmsave `$HOME/mariadb/columnstore/bin/postConfigure -u -i /home/guest/mariadb/columnstore` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb CONNECT PROXY Table Type CONNECT PROXY Table Type ======================== A `PROXY` table is a table that accesses and reads the data of another table or view. For instance, to create a table based on the boys `FIX` table: ``` create table xboy engine=connect table_type=PROXY tabname=boys; ``` Simply, `PROXY` being the default type when `TABNAME` is specified: ``` create table xboy engine=connect tabname=boys; ``` Because the boys table can be directly used, what can be the use of a proxy table? Well, its main use is to be internally used by other table types such as [TBL](../connect-table-types-tbl-table-type-table-list/index), [XCOL](../connect-table-types-xcol-table-type/index), [OCCUR](../connect-table-types-occur-table-type/index), or [PIVOT](../connect-table-types-pivot-table-type/index). Sure enough, PROXY tables are CONNECT tables, meaning that they can be based on tables of any engines and accessed by table types that need to access CONNECT tables. Proxy on non-CONNECT Tables --------------------------- When the sub-table is a view or not a CONNECT table, CONNECT internally creates a temporary CONNECT table of [MYSQL](../connect-table-types-mysql-table-type-accessing-mysqlmariadb-tables/index) type to access it. This connection uses the same default parameters as for a `MYSQL` table. It is also possible to specify them to the `PROXY` table using in the `PROXY` declaration the same `OPTION_LIST` options as for a `MYSQL` table. Of course, it is simpler and more natural to use directly the MYSQL type in this case. Normally, the default parameters should enable the `PROXY` table to reconnect the server. However, an issue is when the current user was logged using a password. The security protocol prevents CONNECT to retrieve this password and requires it to be given in the `PROXY` table create statement. For instance adding to it: ``` ... option_list='Password=mypass'; ``` However, it is often not advisable to write in clear a password that can be seen by all user able to see the table declaration by show create table, in particular, if the table is used when the current user is root. To avoid this, a specific user should be created on the local host that will be used by proxy tables to retrieve local tables. This user can have minimum grant options, for instance SELECT on desired directories, and needs no password. Supposing ‘proxy’ is such a user, the option list to add will be: ``` ... option_list='user=proxy'; ``` Using a PROXY Table as a View ----------------------------- A `PROXY` table can also be used by itself to modify the way a table is viewed. For instance, a proxy table does not use the indexes of the object table. It is also possible to define its columns with different names or type, to use only some of them or to changes their order. For instance: ``` create table city ( city varchar(11), boy char(12) flag=1, birth date) engine=CONNECT tabname=boys; select * from city; ``` This will display: | city | boy | birth | | --- | --- | --- | | Boston | John | 1986-01-25 | | Boston | Henry | 1987-06-07 | | San Jose | George | 1981-08-10 | | Chicago | Sam | 1979-11-22 | | Dallas | James | 1992-05-13 | | Boston | Bill | 1986-09-11 | Here we did not have to specify column format or offset because data are retrieved from the boys table, not directly from the boys.txt file. The flag option of the *boy* column indicates that it correspond to the first column of the boys table, the *name* column. Avoiding PROXY table loop ------------------------- CONNECT is able to test whether a `PROXY`, or `PROXY`-based, table refers directly or indirectly to itself. If a direct reference can tested at table creation, an indirect reference can only be tested when executing a query on the table. However, this is possible only for local tables. When using remote tables or views, a problem can occur if the remote table or the view refers back to one of the local tables of the chain. The same caution should be used than when using `[FEDERATEDX](../federatedx-storage-engine/index)` tables. **Note:** All `PROXY` or `PROXY`-based tables are read-only in this version. Modifying Operations -------------------- All [INSERT](../insert/index) / [UPDATE](../update/index) / [DELETE](../delete/index) operations can be used with proxy tables. However, the same restrictions applying to the source table also apply to the proxy table. Note: All PROXY and PROXY-based table types are not indexable. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb GeomFromText GeomFromText ============ A synonym for [ST\_GeomFromText](../st_geomfromtext/index). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Perl Compatible Regular Expressions (PCRE) Documentation Perl Compatible Regular Expressions (PCRE) Documentation ======================================================== PCRE Versions ------------- | PCRE Version | Introduced | Maturity | | --- | --- | --- | | [PCRE2](http://www.pcre.org/) 10.34 | [MariaDB 10.5.1](https://mariadb.com/kb/en/mariadb-1051-release-notes/) | Stable | | PCRE 8.43 | [MariaDB 10.1.39](https://mariadb.com/kb/en/mariadb-10139-release-notes/) | Stable | | PCRE 8.42 | [MariaDB 10.2.15](https://mariadb.com/kb/en/mariadb-10215-release-notes/), [MariaDB 10.1.33](https://mariadb.com/kb/en/mariadb-10133-release-notes/), [MariaDB 10.0.35](https://mariadb.com/kb/en/mariadb-10035-release-notes/) | Stable | | PCRE 8.41 | [MariaDB 10.2.8](https://mariadb.com/kb/en/mariadb-1028-release-notes/), [MariaDB 10.1.26](https://mariadb.com/kb/en/mariadb-10126-release-notes/), [MariaDB 10.0.32](https://mariadb.com/kb/en/mariadb-10032-release-notes/) | Stable | | PCRE 8.40 | [MariaDB 10.2.5](https://mariadb.com/kb/en/mariadb-1025-release-notes/), [MariaDB 10.1.22](https://mariadb.com/kb/en/mariadb-10122-release-notes/), [MariaDB 10.0.30](https://mariadb.com/kb/en/mariadb-10030-release-notes/) | Stable | | PCRE 8.39 | [MariaDB 10.1.15](https://mariadb.com/kb/en/mariadb-10115-release-notes/), [MariaDB 10.0.26](https://mariadb.com/kb/en/mariadb-10026-release-notes/) | Stable | | PCRE 8.38 | [MariaDB 10.1.10](https://mariadb.com/kb/en/mariadb-10110-release-notes/), [MariaDB 10.0.23](https://mariadb.com/kb/en/mariadb-10023-release-notes/) | Stable | | PCRE 8.37 | [MariaDB 10.1.5](https://mariadb.com/kb/en/mariadb-1015-release-notes/), [MariaDB 10.0.18](https://mariadb.com/kb/en/mariadb-10018-release-notes/) | Stable | | PCRE 8.36 | [MariaDB 10.1.2](https://mariadb.com/kb/en/mariadb-1012-release-notes/), [MariaDB 10.0.15](https://mariadb.com/kb/en/mariadb-10015-release-notes/) | Stable | | PCRE 8.35 | [MariaDB 10.1.0](https://mariadb.com/kb/en/mariadb-1010-release-notes/), [MariaDB 10.0.12](https://mariadb.com/kb/en/mariadb-10012-release-notes/) | Stable | | PCRE 8.34 | [MariaDB 10.0.8](https://mariadb.com/kb/en/mariadb-1008-release-notes/) | Stable | PCRE Enhancements ----------------- [MariaDB 10.0.5](https://mariadb.com/kb/en/mariadb-1005-release-notes/) switched to the PCRE library, which significantly improved the power of the [REGEXP/RLIKE](../regexp/index) operator. The switch to PCRE added a number of features, including recursive patterns, named capture, look-ahead and look-behind assertions, non-capturing groups, non-greedy quantifiers, Unicode character properties, extended syntax for characters and character classes, multi-line matching, and many other. Additionally, [MariaDB 10.0.5](https://mariadb.com/kb/en/mariadb-1005-release-notes/) introduced three new functions that work with regular expressions: [REGEXP\_REPLACE()](../regexp_replace/index), [REGEXP\_INSTR()](../regexp_instr/index) and [REGEXP\_SUBSTR()](../regexp_substr/index). Also, REGEXP/RLIKE, and the new functions, now work correctly with all multi-byte [character sets](../data-types-character-sets-and-collations/index) supported by MariaDB, including East-Asian character sets (big5, gb2313, gbk, eucjp, eucjpms, cp932, ujis, euckr), and Unicode character sets (utf8, utf8mb4, ucs2, utf16, utf16le, utf32). In earlier versions of MariaDB (and all MySQL versions) REGEXP/RLIKE works correctly only with 8-bit character sets. New Regular Expression Functions -------------------------------- * [REGEXP\_REPLACE(subject, pattern, replace)](../regexp_replace/index) - Replaces all occurrences of a pattern. * [REGEXP\_INSTR(subject, pattern)](../regexp_instr/index) - Position of the first appearance of a regex . * [REGEXP\_SUBSTR(subject,pattern)](../regexp_substr/index) - Returns the matching part of a string. See the individual articles for more details and examples. PCRE Syntax ----------- In most cases PCRE is backward compatible with the old POSIX 1003.2 compliant regexp library (see [Regular Expressions Overview](../regular-expressions-overview/index)), so you won't need to change your applications that use SQL queries with the REGEXP/RLIKE predicate. [MariaDB 10.0.11](https://mariadb.com/kb/en/mariadb-10011-release-notes/) introduced the [default\_regex\_flags](../server-system-variables/index#default_regex_flags) variable to address the remaining compatibilities between PCRE and the old regex library. This section briefly describes the most important extended PCRE features. For more details please refer to the documentation on the [PCRE site](http://www.pcre.org/), or to the documentation which is bundled in the /pcre/doc/html/ directory of a MariaDB sources distribution. The pages pcresyntax.html and pcrepattern.html should be a good start. [Regular-Expressions.Info](http://www.regular-expressions.info/tutorial.html) is another good resource to learn about PCRE and regular expressions generally. ### Special Characters PCRE supports the following escape sequences to match special characters: | Sequence | Description | | --- | --- | | \a | 0x07 (BEL) | | \cx | "control-x", where x is any ASCII character | | \e | 0x1B (escape) | | \f | 0x0C (form feed) | | \n | 0x0A (newline) | | \r | 0x0D (carriage return) | | \t | 0x09 (TAB) | | \ddd | character with octal code ddd | | \xhh | character with hex code hh | | \x{hhh..} | character with hex code hhh.. | Note, the backslash characters (here, and in all examples in the sections below) must be escaped with another backslash, unless you're using the [SQL\_MODE](../sql-mode/index) `NO_BACKSLASH_ESCAPES`. This example tests if a character has hex code 0x61: ``` SELECT 'a' RLIKE '\\x{61}'; -> 1 ``` ### Character Classes PCRE supports the standard POSIX character classes such as `alnum`, `alpha`, `blank`, `cntrl`, `digit`, `graph`, `lower`, `print`, `punct`, `space`, `upper`, `xdigit`, with the following additional classes: | Class | Description | | --- | --- | | ascii | any ASCII character (0x00..0x7F) | | word | any "word" character (a letter, a digit, or an underscore) | This example checks if the string consists of ASCII characters only: ``` SELECT 'abc' RLIKE '^[[:ascii:]]+$'; -> 1 ``` ### Generic Character Types Generic character types complement the POSIX character classes and serve to simplify writing patterns: | Class | Description | | --- | --- | | \d | a decimal digit (same as [:digit:]) | | \D | a character that is not a decimal digit | | \h | a horizontal white space character | | \H | a character that is not a horizontal white space character | | \N | a character that is not a new line | | \R | a newline sequence | | \s | a white space character | | \S | a character that is not a white space character | | \v | a vertical white space character | | \V | a character that is not a vertical white space character | | \w | a "word" character (same as [:word:]) | | \W | a "non-word" character | This example checks if the string consists of "word" characters only: ``` SELECT 'abc' RLIKE '^\\w+$'; -> 1 ``` ### Unicode Character Properties `\p{xx}` is a character with the `xx` property, and `\P{xx}` is a character without the `xx` property. The property names represented by `xx` above are limited to the Unicode script names, the general category properties, and "Any", which matches any character (including newline). Those that are not part of an identified script are lumped together as "Common". #### General Category Properties For \p and \P | Property | Description | | --- | --- | | C | Other | | Cc | Control | | Cf | Format | | Cn | Unassigned | | Co | Private use | | Cs | Surrogate | | L | Letter | | Ll | Lower case letter | | Lm | Modifier letter | | Lo | Other letter | | Lt | Title case letter | | Lu | Upper case letter | | L& | Ll, Lu, or Lt | | M | Mark | | Mc | Spacing mark | | Me | Enclosing mark | | Mn | Non-spacing mark | | N | Number | | Nd | Decimal number | | Nl | Letter number | | No | Other number | | P | Punctuation | | Pc | Connector punctuation | | Pd | Dash punctuation | | Pe | Close punctuation | | Pf | Final punctuation | | Pi | Initial punctuation | | Po | Other punctuation | | Ps | Open punctuation | | S | Symbol | | Sc | Currency symbol | | Sk | Modifier symbol | | Sm | Mathematical symbol | | So | Other symbol | | Z | Separator | | Zl | Line separator | | Zp | Paragraph separator | | Zs | Space separator | This example checks if the string consists only of characters with property N (number): ``` SELECT '1¼①' RLIKE '^\\p{N}+$'; -> 1 ``` #### Special Category Properties For \p and \P | Property | Description | | --- | --- | | Xan | Alphanumeric: union of properties L and N | | Xps | POSIX space: property Z or tab, NL, VT, FF, CR | | Xsp | Perl space: property Z or tab, NL, FF, CR | | Xuc | A character than can be represented by a Universal Character Name | | Xwd | Perl word: property Xan or underscore | The property `Xuc` matches any character that can be represented by a Universal Character Name (in C++ and other programming languages). These include `$`, `@`, ```, and all characters with Unicode code points greater than `U+00A0`, excluding the surrogates `U+D800`..`U+DFFF`. #### Script Names For \p and \P Arabic, Armenian, Avestan, Balinese, Bamum, Batak, Bengali, Bopomofo, Brahmi, Braille, Buginese, Buhid, Canadian\_Aboriginal, Carian, Chakma, Cham, Cherokee, Common, Coptic, Cuneiform, Cypriot, Cyrillic, Deseret, Devanagari, Egyptian\_Hieroglyphs, Ethiopic, Georgian, Glagolitic, Gothic, Greek, Gujarati, Gurmukhi, Han, Hangul, Hanunoo, Hebrew, Hiragana, Imperial\_Aramaic, Inherited, Inscriptional\_Pahlavi, Inscriptional\_Parthian, Javanese, Kaithi, Kannada, Katakana, Kayah\_Li, Kharoshthi, Khmer, Lao, Latin, Lepcha, Limbu, Linear\_B, Lisu, Lycian, Lydian, Malayalam, Mandaic, Meetei\_Mayek, Meroitic\_Cursive, Meroitic\_Hieroglyphs, Miao, Mongolian, Myanmar, New\_Tai\_Lue, Nko, Ogham, Old\_Italic, Old\_Persian, Old\_South\_Arabian, Old\_Turkic, Ol\_Chiki, Oriya, Osmanya, Phags\_Pa, Phoenician, Rejang, Runic, Samaritan, Saurashtra, Sharada, Shavian, Sinhala, Sora\_Sompeng, Sundanese, Syloti\_Nagri, Syriac, Tagalog, Tagbanwa, Tai\_Le, Tai\_Tham, Tai\_Viet, Takri, Tamil, Telugu, Thaana, Thai, Tibetan, Tifinagh, Ugaritic, Vai, Yi. This example checks if the string consists only of Greek characters: ``` SELECT 'ΣΦΩ' RLIKE '^\\p{Greek}+$'; -> 1 ``` ### Extended Unicode Grapheme Sequence The `\X` escape sequence matches a character sequence that makes an "extended grapheme cluster", i.e. a composite character that consists of multiple Unicode code points. One of the examples of a composite character can be a letter followed by non-spacing accent marks. This example demonstrates that `U+0045 LATIN CAPITAL LETTER E` followed by `U+0302 COMBINING CIRCUMFLEX ACCENT` followed by `U+0323 COMBINING DOT BELOW` together form an extended grapheme cluster: ``` SELECT _ucs2 0x004503020323 RLIKE '^\\X$'; -> 1 ``` See the [PCRE documentation](http://www.pcre.org) for the other types of extended grapheme clusters. ### Simple Assertions An assertion specifies a certain condition that must match at a particular point, but without consuming characters from the subject string. In addition to the standard POSIX simple assertions `^` (that matches at the beginning of a line) and `$` (that matches at the end of a line), PCRE supports a number of other assertions: | Assertion | Description | | --- | --- | | \b | matches at a word boundary | | \B | matches when not at a word boundary | | \A | matches at the start of the subject | | \Z | matches at the end of the subject, also matches before a newline at the end of the subject | | \z | matches only at the end of the subject | | \G | matches at the first matching position in the subject | This example cuts a word that consists only of 3 characters from a string: ``` SELECT REGEXP_SUBSTR('---abcd---xyz---', '\\b\\w{3}\\b'); -> xyz ``` Notice that the two `\b` assertions checked the word boundaries but did not get into the matching pattern. The `\b` assertions work well in the beginning and the end of the subject string: ``` SELECT REGEXP_SUBSTR('xyz', '\\b\\w{3}\\b'); -> xyz ``` By default, the `^` and `$` assertions have the same meaning with `\A`, `\Z`, and `\z`. However, the meanings of `^` and `$` can change in multiline mode (see below). By contrast, the meanings of `\A`, `\Z`, and `\z` are always the same; they are independent of the multiline mode. ### Option Setting A number of options that control the default match behavior can be changed within the pattern by a sequence of option letters enclosed between `(?` and `)`. | Option | Description | | --- | --- | | (?i) | case insensitive match | | (?m) | multiline mode | | (?s) | dotall mode (dot matches newline characters) | | (?x) | extended (ignore white space) | | (?U) | ungreedy (lazy) match | | (?J) | allow named subpatterns with duplicate names | | (?X) | extra PCRE functionality (e.g. force error on unknown escaped character) | | (?-...) | unset option(s) | For example, `(?im)` sets case insensitive multiline matching. A hyphen followed by the option letters unset the options. For example, `(?-im)` means case sensitive single line match. A combined setting and unsetting is also possible, e.g. `(?im-sx)`. If an option is set outside of subpattern parentheses, the option applies to the remainder of the pattern that follows the option. If an option is set inside a subpattern, it applies to the part of this subpattern that follows the option. In this example the pattern `(?i)m((?-i)aria)db` matches the words `MariaDB`, `Mariadb`, `mariadb`, but not `MARIADB`: ``` SELECT 'MariaDB' RLIKE '(?i)m((?-i)aria)db'; -> 1 SELECT 'mariaDB' RLIKE '(?i)m((?-i)aria)db'; -> 1 SELECT 'Mariadb' RLIKE '(?i)m((?-i)aria)db'; -> 1 SELECT 'MARIADB' RLIKE '(?i)m((?-i)aria)db'; -> 0 ``` This example demonstrates that the `(?x)` option makes the regexp engine ignore all white spaces in the pattern (other than in a class). ``` SELECT 'ab' RLIKE '(?x)a b'; -> 1 ``` Note, putting spaces into a pattern in combination with the (?x) option can be useful to split different logical parts of a complex pattern, to make it more readable. ### Multiline Matching Multiline matching changes the meaning of `^` and `$` from "the beginning of the subject string" and "the end of the subject string" to "the beginning of any line in the subject string" and "the end of any line in the subject string" respectively. This example checks if the subject string contains two consequent lines that fully consist of digits: ``` SELECT 'abc\n123\n456\nxyz\n' RLIKE '(?m)^\\d+\\R\\d+$'; -> 1 ``` Notice the `(?m)` option in the beginning of the pattern, which switches to the multiline matching mode. ### Newline Conventions PCRE supports five line break conventions: * `CR (\r)` - a single carriage return character * `LF (\n)` - a single linefeed character * `CRLF (\r\n)` - a carriage return followed by a linefeed * any of the previous three * any Unicode newline sequence By default, the newline convention is set to any Unicode newline sequence, which includes: | Sequence | Description | | --- | --- | | LF | (U+000A, carriage return) | | CR | (U+000D, carriage return) | | CRLF | (a carriage return followed by a linefeed) | | VT | (U+000B, vertical tab) | | FF | (U+000C, form feed) | | NEL | (U+0085, next line) | | LS | (U+2028, line separator) | | PS | (U+2029, paragraph separator) | The newline convention can be set by starting a pattern with one of the following sequences: | Sequence | Description | | --- | --- | | (\*CR) | carriage return | | (\*LF) | linefeed | | (\*CRLF) | carriage return followed by linefeed | | (\*ANYCRLF) | any of the previous three | | (\*ANY) | all Unicode newline sequences | The newline conversion affects the `^` and `$` assertions, the interpretation of the dot metacharacter, and the behavior of `\N`. Note, the new line convention does not affect the meaning of `\R`. This example demonstrates that the dot metacharacter matches `\n`, because it is not a newline sequence anymore: ``` SELECT 'a\nb' RLIKE '(*CR)a.b'; -> 1 ``` ### Newline Sequences By default, the escape sequence `\R` matches any Unicode newline sequences. The meaning of `\R` can be set by starting a pattern with one of the following sequences: | Sequence | Description | | --- | --- | | (\*BSR\_ANYCRLF) | any of CR, LF or CRLF | | (\*BSR\_UNICODE) | any Unicode newline sequence | It's possible to include comments inside a pattern. Comments do not participate in the pattern matching. Comments start at the `(?`# sequence and continue up to the next closing parenthesis: ``` SELECT 'ab12' RLIKE 'ab(?#expect digits)12'; -> 1 ``` ### Quoting POSIX uses the backslash to remove a special meaning from a character. PCRE introduces a syntax to remove special meaning from a sequence of characters. The characters inside `\Q` ... `\E` are treated literally, without their special meaning. This example checks if the string matches a dollar sign followed by a parenthesized name (a variable reference in some languages): ``` SELECT '$(abc)' RLIKE '^\\Q$(\\E\\w+\\Q)\\E$'; -> 1 ``` Note that the leftmost dollar sign and the parentheses are used literally, while the rightmost dollar sign is still used to match the end of the string. ### Resetting the Match Start The escape sequence `\K` causes any previously matched characters to be excluded from the final matched sequence. For example, the pattern: `(foo)\Kbar` matches `foobar`, but reports that it has matched `bar`. This feature is similar to a look-behind assertion. However, in this case, the part of the subject before the real match does not have to be of fixed length: ``` SELECT REGEXP_SUBSTR('aaa123', '[a-z]*\\K[0-9]*'); -> 123 ``` ### Non-Capturing Groups The question mark and the colon after the opening parenthesis create a non-capturing group: `(?:...)`. This example removes an optional article from a word, for example for better sorting of the results. ``` SELECT REGEXP_REPLACE('The King','(?:the|an|a)[^a-z]([a-z]+)','\\1'); -> King ``` Note that the articles are listed inside the left parentheses using the alternation operator `|` but they do not produce a captured subpattern, so the word followed by the article is referenced by `' 1'` in the third argument to the function. Using non-capturing groups can be useful to save numbers on the sup-patterns that won't be used in the third argument of [REGEXP\_REPLACE()](../regexp_replace/index), as well as for performance purposes. ### Non-Greedy Quantifiers By default, the repetition quantifiers `?`, `*`, `+` and `{n,m}` are "greedy", that is, they try to match as much as possible. Adding a question mark after a repetition quantifier makes it "non-greedy", so the pattern matches the minimum number of times possible. This example cuts C comments from a line: ``` SELECT REGEXP_REPLACE('/* Comment1 */ i+= 1; /* Comment2 */', '/[*].*?[*]/',''); -> i+= 1; ``` The pattern without the non-greedy flag to the quantifier `/[*].*[*]/` would match the entire string between the leftmost `/*` and the rightmost `*/`. ### Atomic Groups A sequence inside `(?>`...`)` makes an atomic group. Backtracking inside an atomic group is prevented once it has matched; however, backtracking past to the previous items works normally. Consider the pattern `\d+foo` applied to the subject string `123bar`. Once the engine scans `123` and fails on the letter `b`, it would normally backtrack to `2` and try to match again, then fail and backtrack to `1` and try to match and fail again, and finally fail the entire pattern. In case of an atomic group `(?>\d+)foo` with the same subject string `123bar`, the engine gives up immediately after the first failure to match `foo`. An atomic group with a quantifier can match all or nothing. Atomic groups produce faster false results (i.e. in case when a long subject string does not match the pattern), because the regexp engine saves performance on backtracking. However, don't hurry to put everything into atomic groups. This example demonstrates the difference between atomic and non-atomic match: ``` SELECT 'abcc' RLIKE 'a(?>bc|b)c' AS atomic1; -> 1 SELECT 'abc' RLIKE 'a(?>bc|b)c' AS atomic2; -> 0 SELECT 'abcc' RLIKE 'a(bc|b)c' AS non_atomic1; -> 1 SELECT 'abc' RLIKE 'a(bc|b)c' AS non_atomic2; -> 1 ``` The non-atomic pattern matches both `abbc` and `abc`, while the atomic pattern matches `abbc` only. The atomic group `(?>bc|b)` in the above example can be "translated" as "if there is `bc`, then don't try to match as `b`". So `b` can match only if `bc` is not found. Atomic groups are not capturing. To make an atomic group capturing, put it into parentheses: ``` SELECT REGEXP_REPLACE('abcc','a((?>bc|b))c','\\1'); -> bc ``` ### Possessive quantifiers An atomic group which ends with a quantifier can be rewritten using a so called "possessive quantifier" syntax by putting an additional `+` sign following the quantifier. The pattern `(?>\d+)foo` from the previous section's example can be rewritten as `\d++foo`. ### Absolute and Relative Numeric Backreferences Backreferences match the same text as previously matched by a capturing group. Backreferences can be written using: * a backslash followed by a digit * the `\g` escape sequence followed by a positive or negative number * the `\g` escape sequence followed by a positive or negative number enclosed in braces The following backreferences are identical and refer to the first capturing group: * `\1` * `\g1` * `\g{1}` This example demonstrates a pattern that matches "sense and sensibility" and "response and responsibility", but not "sense and responsibility": ``` SELECT 'sense and sensibility' RLIKE '(sens|respons)e and \\1ibility'; -> 1 ``` This example removes doubled words that can unintentionally creep in when you edit a text in a text editor: ``` SELECT REGEXP_REPLACE('using using the the regexp regexp', '\\b(\\w+)\\s+\\1\\b','\\1'); -> using the regexp ``` Note that all double words were removed, in the beginning, in the middle and in the end of the subject string. A negative number in a `\g` sequence means a relative reference. Relative references can be helpful in long patterns, and also in patterns that are created by joining fragments together that contain references within themselves. The sequence `\g{-1}` is a reference to the most recently started capturing subpattern before `\g`. In this example `\g{-1}` is equivalent to `\2`: ``` SELECT 'abc123def123' RLIKE '(abc(123)def)\\g{-1}'; -> 1 SELECT 'abc123def123' RLIKE '(abc(123)def)\\2'; -> 1 ``` ### Named Subpatterns and Backreferences Using numeric backreferences for capturing groups can be hard to track in a complicated regular expression. Also, the numbers can change if an expression is modified. To overcome these difficulties, PCRE supports named subpatterns. A subpattern can be named in one of three ways: `(?<name>`...`)` or `(?'name'`...`)` as in Perl, or `(?P<name>`...`)` as in Python. References to capturing subpatterns from other parts of the pattern, can be made by name as well as by number. Backreferences to a named subpattern can be written using the .NET syntax `\k{name}`, the Perl syntax `\k<name>` or `\k'name'` or `\g{name}`, or the Python syntax `(?P=name)`. This example tests if the string is a correct HTML tag: ``` SELECT '<a href="../">Up</a>' RLIKE '<(?<tag>[a-z][a-z0-9]*)[^>]*>[^<]*</(?P=tag)>'; -> 1 ``` ### Positive and Negative Look-Ahead and Look-Behind Assertions Look-ahead and look-behind assertions serve to specify the context for the searched regular expression pattern. Note that the assertions only check the context, they do not capture anything themselves! This example finds the letter which is not followed by another letter (negative look-ahead): ``` SELECT REGEXP_SUBSTR('ab1','[a-z](?![a-z])'); -> b ``` This example finds the letter which is followed by a digit (positive look-ahead): ``` SELECT REGEXP_SUBSTR('ab1','[a-z](?=[0-9])'); -> b ``` This example finds the letter which does not follow a digit character (negative look-behind): ``` SELECT REGEXP_SUBSTR('1ab','(?<![0-9])[a-z]'); -> b ``` This example finds the letter which follows another letter character (positive look-behind): ``` SELECT REGEXP_SUBSTR('1ab','(?<=[a-z])[a-z]'); -> b ``` Note that look-behind assertions can only be of fixed length; you cannot have repetition operators or alternations with different lengths: ``` SELECT 'aaa' RLIKE '(?<=(a|bc))a'; ERROR 1139 (42000): Got error 'lookbehind assertion is not fixed length at offset 10' from regexp ``` ### Subroutine Reference and Recursive Patterns PCRE supports a special syntax to recourse the entire pattern or its individual subpatterns: | Syntax | Description | | --- | --- | | (?R) | Recourse the entire pattern | | (?n) | call subpattern by absolute number | | (?+n) | call subpattern by relative number | | (?-n) | call subpattern by relative number | | (?&name) | call subpattern by name (Perl) | | (?P>name) | call subpattern by name (Python) | | \g<name> | call subpattern by name (Oniguruma) | | \g'name' | call subpattern by name (Oniguruma) | | \g<n> | call subpattern by absolute number (Oniguruma) | | \g'n' | call subpattern by absolute number (Oniguruma) | | \g<+n> | call subpattern by relative number | | \g<-n> | call subpattern by relative number | | \g'+n' | call subpattern by relative number | | \g'-n' | call subpattern by relative number | This example checks for a correct additive arithmetic expression consisting of numbers, unary plus and minus, binary plus and minus, and parentheses: ``` SELECT '1+2-3+(+(4-1)+(-2)+(+1))' RLIKE '^(([+-]?(\\d+|[(](?1)[)]))(([+-](?1))*))$'; -> 1 ``` The recursion is done using `(?1)` to call for the first parenthesized subpattern, which includes everything except the leading `^` and the trailing `$`. The regular expression in the above example implements the following BNF grammar: 1. `<expression> ::= <term> [(<sign> <term>)...]` 2. `<term> ::= [ <sign> ] <primary>` 3. `<primary> ::= <number> | <left paren> <expression> <right paren>` 4. `<sign> ::= <plus sign> | <minus sign>` ### Defining Subpatterns For Use By Reference Use the `(?(DEFINE)`...`)` syntax to define subpatterns that can be referenced from elsewhere. This example defines a subpattern with the name `letters` that matches one or more letters, which is further reused two times: ``` SELECT 'abc123xyz' RLIKE '^(?(DEFINE)(?<letters>[a-z]+))(?&letters)[0-9]+(?&letters)$'; -> 1 ``` The above example can also be rewritten to define the digit part as a subpattern as well: ``` SELECT 'abc123xyz' RLIKE '^(?(DEFINE)(?<letters>[a-z]+)(?<digits>[0-9]+))(?&letters)(?&digits)(?&letters)$'; -> 1 ``` ### Conditional Subpatterns There are two forms of conditional subpatterns: ``` (?(condition)yes-pattern) (?(condition)yes-pattern|no-pattern) ``` The `yes-pattern` is used if the condition is satisfied, otherwise the `no-pattern` (if any) is used. #### Conditions With Subpattern References If a condition consists of a number, it makes a condition with a subpattern reference. Such a condition is true if a capturing subpattern corresponding to the number has previously matched. This example finds an optionally parenthesized number in a string: ``` SELECT REGEXP_SUBSTR('a(123)b', '([(])?[0-9]+(?(1)[)])'); -> (123) ``` The `([(])?` part makes a capturing subpattern that matches an optional opening parenthesis; the `[0-9]+` part matches a number, and the `(?(1)[)])` part matches a closing parenthesis, but only if the opening parenthesis has been previously found. #### Other Kinds of Conditions The other possible condition kinds are: recursion references and assertions. See the [PCRE documentation](http://www.pcre.org) for details. ### Matching Zero Bytes (0x00) PCRE correctly works with zero bytes in the subject strings: ``` SELECT 'a\0b' RLIKE '^a.b$'; -> 1 ``` Zero bytes, however, are not supported literally in the pattern strings and should be escaped using the `\xhh` or `\x{hh}` syntax: ``` SELECT 'a\0b' RLIKE '^a\\x{00}b$'; -> 1 ``` ### Other PCRE Features PCRE provides other extended features that were not covered in this document, such as duplicate subpattern numbers, backtracking control, breaking utf-8 sequences into individual bytes, setting the match limit, setting the recursion limit, optimization control, recursion conditions, assertion conditions and more types of extended grapheme clusters. Please refer to the [PCRE documentation](http://www.pcre.org) for details. Enhanced regex was implemented as a GSoC 2013 project by Sudheera Palihakkara. ### default\_regex\_flags Examples **MariaDB starting with [10.0.11](https://mariadb.com/kb/en/mariadb-10011-release-notes/)**The [default\_regex\_flags](../server-system-variables/index#default_regex_flags) variable was introduced in **MariaDB** 10.0.11 The [default\_regex\_flags](../server-system-variables/index#default_regex_flags) variable was introduced to address the remaining incompatibilities between PCRE and the old regex library. Here are some examples of its usage: The default behaviour (multiline match is off) ``` SELECT 'a\nb\nc' RLIKE '^b$'; +---------------------------+ | '(?m)a\nb\nc' RLIKE '^b$' | +---------------------------+ | 0 | +---------------------------+ ``` Enabling the multiline option using the PCRE option syntax: ``` SELECT 'a\nb\nc' RLIKE '(?m)^b$'; +---------------------------+ | 'a\nb\nc' RLIKE '(?m)^b$' | +---------------------------+ | 1 | +---------------------------+ ``` Enabling the miltiline option using default\_regex\_flags ``` SET default_regex_flags='MULTILINE'; SELECT 'a\nb\nc' RLIKE '^b$'; +-----------------------+ | 'a\nb\nc' RLIKE '^b$' | +-----------------------+ | 1 | +-----------------------+ ``` ### See Also * [MariaDB upgrades to PCRE-8.34](https://blog.mariadb.org/mariadb-upgrades-to-pcre-8-34/) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb mariadb-fix-extensions mariadb-fix-extensions ====================== **MariaDB starting with [10.4.6](https://mariadb.com/kb/en/mariadb-1046-release-notes/)**From [MariaDB 10.4.6](https://mariadb.com/kb/en/mariadb-1046-release-notes/), `mariadb-fix-extensions` is a symlink to `mysql_fix_extensions`, the tool for converting the extensions for [MyISAM](../myisam/index) (or ISAM) table files to their canonical forms. **MariaDB starting with [10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/)**From [MariaDB 10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/), `mysql_fix_extensions` is the symlink, and `mariadb-fix-extensions` the binary name. See [mysql\_fix\_extensions](../mysql_fix_extensions/index) for details. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb CREATE FUNCTION UDF CREATE FUNCTION UDF =================== Syntax ------ ``` CREATE [OR REPLACE] [AGGREGATE] FUNCTION [IF NOT EXISTS] function_name RETURNS {STRING|INTEGER|REAL|DECIMAL} SONAME shared_library_name ``` Description ----------- A user-defined function (UDF) is a way to extend MariaDB with a new function that works like a native (built-in) MariaDB function such as [ABS()](../abs/index) or [CONCAT()](../concat/index). `function_name` is the name that should be used in SQL statements to invoke the function. To create a function, you must have the [INSERT privilege](../grant/index) for the mysql database. This is necessary because`CREATE FUNCTION` adds a row to the [mysql.func system table](../mysqlfunc-table/index) that records the function's name, type, and shared library name. If you do not have this table, you should run the [mysql\_upgrade](../mysql_upgrade/index) command to create it. UDFs need to be written in C, C++ or another language that uses C calling conventions, MariaDB needs to have been dynamically compiled, and your operating system must support dynamic loading. For an example, see `sql/udf_example.cc` in the source tree. For a collection of existing UDFs see <http://www.mysqludf.org/>. Statements making use of user-defined functions are not [safe for replication](../unsafe-statements-for-replication/index). For creating a stored function as opposed to a user-defined function, see [CREATE FUNCTION](../create-function/index). For valid identifiers to use as function names, see [Identifier Names](../identifier-names/index). #### RETURNS The `RETURNS` clause indicates the type of the function's return value, and can be one of [STRING](string), [INTEGER](../integer/index), [REAL](real) or [DECIMAL](../decimal/index). `DECIMAL` functions currently return string values and should be written like [STRING](../string-data-types/index) functions. #### shared\_library\_name `shared_library_name` is the basename of the shared object file that contains the code that implements the function. The file must be located in the plugin directory. This directory is given by the value of the [plugin\_dir](../server-system-variables/index#plugin_dir) system variable. Note that before MariaDB/MySQL 5.1, the shared object could be located in any directory that was searched by your system's dynamic linker. #### AGGREGATE Aggregate functions are summary functions such as [SUM()](../sum/index) and [AVG()](../avg/index). **MariaDB starting with [10.4](../what-is-mariadb-104/index)**Aggregate UDF functions can be used as [window functions](../window-functions/index). #### OR REPLACE **MariaDB starting with [10.1.3](https://mariadb.com/kb/en/mariadb-1013-release-notes/)**The `OR REPLACE` clause was added in [MariaDB 10.1.3](https://mariadb.com/kb/en/mariadb-1013-release-notes/) If the optional `OR REPLACE` clause is used, it acts as a shortcut for: ``` DROP FUNCTION IF EXISTS function_name; CREATE FUNCTION name ...; ``` #### IF NOT EXISTS **MariaDB starting with [10.1.3](https://mariadb.com/kb/en/mariadb-1013-release-notes/)**The `IF NOT EXISTS` clause was added in [MariaDB 10.1.3](https://mariadb.com/kb/en/mariadb-1013-release-notes/) When the IF NOT EXISTS clause is used, MariaDB will return a warning instead of an error if the specified function already exists. Cannot be used together with OR REPLACE. ### Upgrading a UDF To upgrade the UDF's shared library, first run a [DROP FUNCTION](../drop-function/index) statement, then upgrade the shared library and finally run the CREATE FUNCTION statement. If you upgrade without following this process, you may crash the server. ### Examples ``` CREATE FUNCTION jsoncontains_path RETURNS integer SONAME 'ha_connect.so'; Query OK, 0 rows affected (0.00 sec) ``` OR REPLACE and IF NOT EXISTS: ``` CREATE FUNCTION jsoncontains_path RETURNS integer SONAME 'ha_connect.so'; ERROR 1125 (HY000): Function 'jsoncontains_path' already exists CREATE OR REPLACE FUNCTION jsoncontains_path RETURNS integer SONAME 'ha_connect.so'; Query OK, 0 rows affected (0.00 sec) CREATE FUNCTION IF NOT EXISTS jsoncontains_path RETURNS integer SONAME 'ha_connect.so'; Query OK, 0 rows affected, 1 warning (0.00 sec) SHOW WARNINGS; +-------+------+---------------------------------------------+ | Level | Code | Message | +-------+------+---------------------------------------------+ | Note | 1125 | Function 'jsoncontains_path' already exists | +-------+------+---------------------------------------------+ ``` See Also -------- * [Identifier Names](../identifier-names/index) * [DROP FUNCTION](../drop-function/index) * [CREATE FUNCTION](../create-function/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb MariaDB Galera Cluster Releases MariaDB Galera Cluster Releases ================================ Since [MariaDB 10.1](../what-is-mariadb-101/index), Galera has been a standard part of MariaDB Server. See [MariaDB Server Release Notes](../release-notes/index). | Title | Description | | --- | --- | | [MariaDB Galera 10.0 Changelogs](../mariadb-galera-100-changelogs/index) | Changelogs for MariaDB Galera Cluster 10.0.x releases. | | [MariaDB Galera 10.0 Release Notes](https://mariadb.com/kb/en/mariadb-galera-100-release-notes/) | Release notes for MariaDB Galera Cluster 10.0 releases. | | [MariaDB Galera 5.5 Changelogs](../mariadb-galera-55-changelogs/index) | Changelogs for MariaDB Galera 5.5 releases. | | [MariaDB Galera 5.5 Release Notes](https://mariadb.com/kb/en/mariadb-galera-55-release-notes/) | Release Notes for MariaDB Galera Cluster 5.5 releases. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb ST_Y ST\_Y ===== Syntax ------ ``` ST_Y(p) Y(p) ``` Description ----------- Returns the Y-coordinate value for the point p as a double-precision number. `ST_Y()` and `Y()` are synonyms. Examples -------- ``` SET @pt = 'Point(56.7 53.34)'; SELECT Y(GeomFromText(@pt)); +----------------------+ | Y(GeomFromText(@pt)) | +----------------------+ | 53.34 | +----------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb DUAL DUAL ==== Description ----------- You are allowed to specify `DUAL` as a dummy table name in situations where no tables are referenced, such as the following [SELECT](../select/index) statement: ``` SELECT 1 + 1 FROM DUAL; +-------+ | 1 + 1 | +-------+ | 2 | +-------+ ``` `DUAL` is purely for the convenience of people who require that all `SELECT` statements should have `FROM` and possibly other clauses. MariaDB ignores the clauses. MariaDB does not require `FROM DUAL` if no tables are referenced. FROM DUAL could be used when you only SELECT computed values, but require a WHERE clause, perhaps to test that a script correctly handles empty resultsets: ``` SELECT 1 FROM DUAL WHERE FALSE; Empty set (0.00 sec) ``` See Also -------- * [SELECT](../select/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb WKT WKT ==== The Well-Known Text (WKT) representation of Geometry is designed to exchange geometry data in ASCII form. This section has articles on WKT in MariaDB. | Title | Description | | --- | --- | | [WKT Definition](../wkt-definition/index) | Well-Known Text for exchanging geometry data in ASCII form. | | [AsText](../wkt-astext/index) | Synonym for ST\_AsText. | | [AsWKT](../wkt-aswkt/index) | Synonym for ST\_AsText. | | [GeomCollFromText](../wkt-geomcollfromtext/index) | Synonym for ST\_GeomCollFromText. | | [GeometryCollectionFromText](../geometrycollectionfromtext/index) | Synonym for ST\_GeomCollFromText. | | [GeometryFromText](../geometryfromtext/index) | Synonym for ST\_GeomFromText. | | [GeomFromText](../wkt-geomfromtext/index) | Synonym for ST\_GeomFromText. | | [LineFromText](../wkt-linefromtext/index) | Synonym for ST\_LineFromText. | | [LineStringFromText](../linestringfromtext/index) | Synonym for ST\_LineFromText. | | [MLineFromText](../mlinefromtext/index) | Constructs MULTILINESTRING using its WKT representation and SRID. | | [MPointFromText](../mpointfromtext/index) | Constructs a MULTIPOINT value using its WKT and SRID. | | [MPolyFromText](../mpolyfromtext/index) | Constructs a MULTIPOLYGON value. | | [MultiLineStringFromText](../multilinestringfromtext/index) | Synonym for MLineFromText. | | [MultiPointFromText](../multipointfromtext/index) | Synonym for MPointFromText. | | [MultiPolygonFromText](../multipolygonfromtext/index) | Synonym for MPolyFromText. | | [PointFromText](../wkt-pointfromtext/index) | Synonym for ST\_PointFromText. | | [PolyFromText](../wkt-polyfromtext/index) | Synonym for ST\_PolyFromText. | | [PolygonFromText](../polygonfromtext/index) | Synonym for ST\_PolyFromText. | | [ST\_AsText](../st_astext/index) | Converts a value to its WKT-Definition. | | [ST\_ASWKT](../st_aswkt/index) | Synonym for ST\_ASTEXT(). | | [ST\_GeomCollFromText](../st_geomcollfromtext/index) | Constructs a GEOMETRYCOLLECTION value. | | [ST\_GeometryCollectionFromText](../st_geometrycollectionfromtext/index) | Synonym for ST\_GeomCollFromText. | | [ST\_GeometryFromText](../st_geometryfromtext/index) | Synonym for ST\_GeomFromText. | | [ST\_GeomFromText](../st_geomfromtext/index) | Constructs a geometry value using its WKT and SRID. | | [ST\_LineFromText](../st_linefromtext/index) | Creates a linestring value. | | [ST\_LineStringFromText](../st_linestringfromtext/index) | Synonym for ST\_LineFromText. | | [ST\_PointFromText](../st_pointfromtext/index) | Constructs a POINT value. | | [ST\_PolyFromText](../st_polyfromtext/index) | Constructs a POLYGON value. | | [ST\_PolygonFromText](../st_polygonfromtext/index) | Synonym for ST\_PolyFromText. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb MULTIPOLYGON MULTIPOLYGON ============ Syntax ------ ``` MultiPolygon(poly1,poly2,...) ``` Description ----------- Constructs a [WKB](../wkb/index) MultiPolygon value from a set of WKB [Polygon](../polygon/index) arguments. If any argument is not a WKB Polygon, the return value is `NULL`. Example ------- ``` CREATE TABLE gis_multi_polygon (g MULTIPOLYGON); INSERT INTO gis_multi_polygon VALUES (MultiPolygonFromText('MULTIPOLYGON(((28 26,28 0,84 0,84 42,28 26),(52 18,66 23,73 9,48 6,52 18)), ((59 18,67 18,67 13,59 13,59 18)))')), (MPolyFromText('MULTIPOLYGON(((28 26,28 0,84 0,84 42,28 26),(52 18,66 23,73 9,48 6,52 18)), ((59 18,67 18,67 13,59 13,59 18)))')), (MPolyFromWKB(AsWKB(MultiPolygon(Polygon(LineString( Point(0, 3), Point(3, 3), Point(3, 0), Point(0, 3))))))); ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb FORMAT FORMAT ====== Syntax ------ ``` FORMAT(num, decimal_position[, locale]) ``` Description ----------- Formats the given number for display as a string, adding separators to appropriate position and rounding the results to the given decimal position. For instance, it would format `15233.345` to `15,233.35`. If the given decimal position is `0`, it rounds to return no decimal point or fractional part. You can optionally specify a [locale](../server-locale/index) value to format numbers to the pattern appropriate for the given region. Examples -------- ``` SELECT FORMAT(1234567890.09876543210, 4) AS 'Format'; +--------------------+ | Format | +--------------------+ | 1,234,567,890.0988 | +--------------------+ SELECT FORMAT(1234567.89, 4) AS 'Format'; +----------------+ | Format | +----------------+ | 1,234,567.8900 | +----------------+ SELECT FORMAT(1234567.89, 0) AS 'Format'; +-----------+ | Format | +-----------+ | 1,234,568 | +-----------+ SELECT FORMAT(123456789,2,'rm_CH') AS 'Format'; +----------------+ | Format | +----------------+ | 123'456'789,00 | +----------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb mysql_convert_table_format mysql\_convert\_table\_format ============================= **MariaDB starting with [10.4.6](https://mariadb.com/kb/en/mariadb-1046-release-notes/)**From [MariaDB 10.4.6](https://mariadb.com/kb/en/mariadb-1046-release-notes/), `mariadb-convert-table-format` is a symlink to `mysql_convert_table_format`. **MariaDB starting with [10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/)**From [MariaDB 10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/), `mariadb-convert-table-format` is the name of the tool, with `mysql_convert_table_format` a symlink . Usage ----- ``` mysql_convert_table_format [options] db_name ``` Description ----------- mysql\_convert\_table\_format converts the tables in a database to use a particular storage engine ([MyISAM](../myisam/index) by default). mysql\_convert\_table\_format is written in Perl and requires that the DBI and DBD::mysql Perl modules be installed Invoke mysql\_convert\_table\_format like this: ``` shell> mysql_convert_table_format [options]db_name ``` The `db_name` argument indicates the database containing the tables to be converted. Options ------- `mysql_convert_table_format` supports the options described in the following list: | Option | Description | | --- | --- | | --help | Display a help message and exit. | | --force | Continue even if errors occur. | | --host=host\_name | Connect to the MariaDB server on the given host. | | --password=password | The password to use when connecting to the server. Note that the password value is not optional for this option, unlike for other client programs. Specifying the password on the command-line is generally considered insecure. | | --port=port\_num | The TCP/IP port number to use for the connection. | | --socket=path | For connections to localhost, the Unix socket file to use. | | --type=engine\_name | Specify the storage engine that the tables should be converted to use. The default is [MyISAM](../myisam/index) if this option is not given. | | --user=user\_name | The MariaDB user name to use when connecting to the server. | | --verbose | Verbose mode. Print more information about what the program does. | | --version | Display version information and exit. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Configuring Git to Send Commit Notices Configuring Git to Send Commit Notices ====================================== Commit emails for MariaDB are sent to `[[email protected]](http://lists.askmonty.org/cgi-bin/mailman/listinfo/commits)`. You can find the archive [here](http://lists.askmonty.org/pipermail/commits). To allow others to see what you are working on in your MariaDB tree, you should: 1. [subscribe](http://lists.askmonty.org/cgi-bin/mailman/listinfo/commits) to the email list 2. configure git to send your commits to `[[email protected]](http://lists.askmonty.org/cgi-bin/mailman/listinfo/commits)`. Download the [post-commit git trigger](http://bazaar.launchpad.net/~maria-captains/mariadb-tools/trunk/view/head:/git_template/hooks/post-commit) script. Configure as ``` git config --global hooks.postcommitrecipients "[email protected]" git config --global hooks.postcommitbranches "*" ``` Also you might want to check the [README](http://bazaar.launchpad.net/~maria-captains/mariadb-tools/trunk/view/head:/git_template/README) for the post-commit trigger. The post-commit git trigger uses *sendmail* for sending emails. Some platforms don't have *sendmail* and then you'll need to modify to make use of something that is supported. Also, the post-commit trigger is just one approach. You can also use git-email on at least Debian and Fedora to send commit emails to the MariaDB commits email list. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Information Schema TABLE_STATISTICS Table Information Schema TABLE\_STATISTICS Table ========================================== The [Information Schema](../information_schema/index) `TABLE_STATISTICS` table shows statistics on table usage. This is part of the [User Statistics](../user-statistics/index) feature, which is not enabled by default. It contains the following columns: | Field | Type | Notes | | --- | --- | --- | | `TABLE_SCHEMA` | `varchar(192)` | The schema (database) name. | | `TABLE_NAME` | `varchar(192)` | The table name. | | `ROWS_READ` | `int(21)` | The number of rows read from the table. | | `ROWS_CHANGED` | `int(21)` | The number of rows changed in the table. | | `ROWS_CHANGED_X_INDEXES` | `int(21)` | The number of rows changed in the table, multiplied by the number of indexes changed. | #### Example ``` SELECT * FROM INFORMATION_SCHEMA.TABLE_STATISTICS WHERE TABLE_NAME='user'; +--------------+------------+-----------+--------------+------------------------+ | TABLE_SCHEMA | TABLE_NAME | ROWS_READ | ROWS_CHANGED | ROWS_CHANGED_X_INDEXES | +--------------+------------+-----------+--------------+------------------------+ | mysql | user | 5 | 2 | 2 | +--------------+------------+-----------+--------------+------------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb Performance Schema status_by_account Table Performance Schema status\_by\_account Table ============================================ **MariaDB starting with [10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/)**The `status_by_account` table was added in [MariaDB 10.5.2](https://mariadb.com/kb/en/mariadb-1052-release-notes/). The `status_by_account` table contains status variable information by user/host account. The table does not collect statistics for `Com_xxx` variables. The table contains the following columns: | Column | Description | | --- | --- | | USER | User for which the status variable is reported. | | HOST | Host for which the status variable is reported. | | VARIABLE\_NAME | Status variable name. | | VARIABLE\_VALUE | Aggregated status variable value | If [TRUNCATE TABLE](../truncate-table/index) is run, will aggregate the status from terminated sessions to user and host status, then reset the account status. If [FLUSH STATUS](flush-status) is run, session status from all active sessions are added to the global status variables, the status of all active sessions are reset, and values aggregated from disconnected sessions are reset. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb System Variables Added in MariaDB 10.1 System Variables Added in MariaDB 10.1 ====================================== This is a list of [system variables](../server-system-variables/index) that were added in the [MariaDB 10.1](../what-is-mariadb-101/index) series. The list excludes the following variables, related to storage engines and plugins included in [MariaDB 10.1](../what-is-mariadb-101/index): * [Spider System Variables](../spider-server-system-variables/index) | Variable | Added | | --- | --- | | [aria\_encrypt\_tables](../aria-system-variables/index#aria_encrypt_tables) | [MariaDB 10.1.3](https://mariadb.com/kb/en/mariadb-1013-release-notes/) | | [default\_tmp\_storage\_engine](../server-system-variables/index#default_tmp_storage_engine) | [MariaDB 10.1.0](https://mariadb.com/kb/en/mariadb-1010-release-notes/) | | [encrypt\_binlog](../server-system-variables/index#encrypt_binlog) | [MariaDB 10.1.7](https://mariadb.com/kb/en/mariadb-1017-release-notes/) | | [encrypt\_tmp\_disk\_tables](../server-system-variables/index#encrypt_tmp_disk_tables) | [MariaDB 10.1.3](https://mariadb.com/kb/en/mariadb-1013-release-notes/) | | [encrypt\_tmp\_files](../server-system-variables/index#encrypt_tmp_files) | [MariaDB 10.1.5](https://mariadb.com/kb/en/mariadb-1015-release-notes/) | | [enforce\_storage\_engine](../server-system-variables/index#enforce_storage_engine) | [MariaDB 10.1.4](https://mariadb.com/kb/en/mariadb-1014-release-notes/) | | [explicit\_defaults\_for\_timestamp](../server-system-variables/index#explicit_defaults_for_timestamp) | [MariaDB 10.1.8](https://mariadb.com/kb/en/mariadb-1018-release-notes/) | | [innodb\_background\_scrub\_data\_check\_interval](../xtradbinnodb-server-system-variables/index#innodb_background_scrub_data_check_interval) | [MariaDB 10.1.3](https://mariadb.com/kb/en/mariadb-1013-release-notes/) | | [innodb\_background\_scrub\_data\_compressed](../xtradbinnodb-server-system-variables/index#innodb_background_scrub_data_compressed) | [MariaDB 10.1.3](https://mariadb.com/kb/en/mariadb-1013-release-notes/) | | [innodb\_background\_scrub\_data\_interval](../xtradbinnodb-server-system-variables/index#innodb_background_scrub_data_interval) | [MariaDB 10.1.3](https://mariadb.com/kb/en/mariadb-1013-release-notes/) | | [innodb\_background\_scrub\_data\_uncompressed](../xtradbinnodb-server-system-variables/index#innodb_background_scrub_data_uncompressed) | [MariaDB 10.1.3](https://mariadb.com/kb/en/mariadb-1013-release-notes/) | | [innodb\_buf\_dump\_status\_frequency](../xtradbinnodb-server-system-variables/index#innodb_buf_dump_status_frequency) | [MariaDB 10.1.6](https://mariadb.com/kb/en/mariadb-1016-release-notes/) | | [innodb\_compression\_algorithm](../xtradbinnodb-server-system-variables/index#innodb_compression_algorithm) | [MariaDB 10.1.0](https://mariadb.com/kb/en/mariadb-1010-release-notes/) | | [innodb\_default\_encryption\_key\_id](../xtradbinnodb-server-system-variables/index#innodb_default_page_encryption_key) | [MariaDB 10.1.4](https://mariadb.com/kb/en/mariadb-1014-release-notes/) | | [innodb\_default\_row\_format](../xtradbinnodb-server-system-variables/index#innodb_default_row_format) | [MariaDB 10.1.32](https://mariadb.com/kb/en/mariadb-10132-release-notes/) | | [innodb\_defragment](../xtradbinnodb-server-system-variables/index#innodb_defragment) | [MariaDB 10.1.1](https://mariadb.com/kb/en/mariadb-1011-release-notes/) | | [innodb\_defragment\_fill\_factor](../xtradbinnodb-server-system-variables/index#innodb_defragment_fill_factor) | [MariaDB 10.1.1](https://mariadb.com/kb/en/mariadb-1011-release-notes/) | | [innodb\_defragment\_fill\_factor\_n\_recs](../xtradbinnodb-server-system-variables/index#innodb_defragment_fill_factor_n_recs) | [MariaDB 10.1.1](https://mariadb.com/kb/en/mariadb-1011-release-notes/) | | [innodb\_defragment\_frequency](../xtradbinnodb-server-system-variables/index#innodb_defragment_frequency) | [MariaDB 10.1.1](https://mariadb.com/kb/en/mariadb-1011-release-notes/) | | [innodb\_defragment\_n\_pages](../xtradbinnodb-server-system-variables/index#innodb_defragment_n_pages) | [MariaDB 10.1.1](https://mariadb.com/kb/en/mariadb-1011-release-notes/) | | [innodb\_defragment\_stats\_accuracy](../xtradbinnodb-server-system-variables/index#innodb_defragment_stats_accuracy) | [MariaDB 10.1.1](https://mariadb.com/kb/en/mariadb-1011-release-notes/) | | [innodb\_disallow\_writes](../xtradbinnodb-server-system-variables/index#innodb_disallow_writes) | [MariaDB 10.1.3](https://mariadb.com/kb/en/mariadb-1013-release-notes/) | | [innodb\_encrypt\_log](../xtradbinnodb-server-system-variables/index#innodb_encrypt_log) | [MariaDB 10.1.3](https://mariadb.com/kb/en/mariadb-1013-release-notes/) | | [innodb\_encrypt\_tables](../xtradbinnodb-server-system-variables/index#innodb_encrypt_tables) | [MariaDB 10.1.3](https://mariadb.com/kb/en/mariadb-1013-release-notes/) | | [innodb\_encryption\_rotate\_key\_age](../xtradbinnodb-server-system-variables/index#innodb_encryption_rotate_key_age) | [MariaDB 10.1.3](https://mariadb.com/kb/en/mariadb-1013-release-notes/) | | [innodb\_encryption\_rotation\_iops](../xtradbinnodb-server-system-variables/index#innodb_encryption_rotation_iops) | [MariaDB 10.1.3](https://mariadb.com/kb/en/mariadb-1013-release-notes/) | | [innodb\_encryption\_threads](../xtradbinnodb-server-system-variables/index#innodb_encryption_threads) | [MariaDB 10.1.3](https://mariadb.com/kb/en/mariadb-1013-release-notes/) | | [innodb\_fatal\_semaphore\_wait\_threshold](../xtradbinnodb-server-system-variables/index#innodb_fatal_semaphore_wait_threshold) | [MariaDB 10.1.2](https://mariadb.com/kb/en/mariadb-1012-release-notes/) | | [innodb\_force\_primary\_key](../xtradbinnodb-server-system-variables/index#innodb_force_primary_key) | [MariaDB 10.1.0](https://mariadb.com/kb/en/mariadb-1010-release-notes/) | | [innodb\_idle\_flush\_pct](../xtradbinnodb-server-system-variables/index#innodb_idle_flush_pct) | [MariaDB 10.1.2](https://mariadb.com/kb/en/mariadb-1012-release-notes/) | | [innodb\_immediate\_scrub\_data\_uncompressed](../xtradbinnodb-server-system-variables/index#innodb_immediate_scrub_data_uncompressed) | [MariaDB 10.1.3](https://mariadb.com/kb/en/mariadb-1013-release-notes/) | | [innodb\_instrument\_semaphores](../xtradbinnodb-server-system-variables/index#innodb_instrument_semaphores) | [MariaDB 10.1.3](https://mariadb.com/kb/en/mariadb-1013-release-notes/) | | [innodb\_mtflush\_threads](../xtradbinnodb-server-system-variables/index#innodb_mtflush_threads) | [MariaDB 10.1.0](https://mariadb.com/kb/en/mariadb-1010-release-notes/) | | [innodb\_prefix\_index\_cluster\_optimization](../xtradbinnodb-server-system-variables/index#innodb_prefix_index_cluster_optimization) | [MariaDB 10.1.2](https://mariadb.com/kb/en/mariadb-1012-release-notes/) | | [innodb\_scrub\_log](../xtradbinnodb-server-system-variables/index#innodb_scrub_log) | [MariaDB 10.1.3](https://mariadb.com/kb/en/mariadb-1013-release-notes/) | | [innodb\_scrub\_log\_speed](../xtradbinnodb-server-system-variables/index#innodb_scrub_log_speed) | [MariaDB 10.1.4](https://mariadb.com/kb/en/mariadb-1014-release-notes/) | | [innodb\_use\_mtflush](../xtradbinnodb-server-system-variables/index#innodb_use_mtflush) | [MariaDB 10.1.0](https://mariadb.com/kb/en/mariadb-1010-release-notes/) | | [innodb\_use\_trim](../xtradbinnodb-server-system-variables/index#innodb_use_trim) | [MariaDB 10.1.0](https://mariadb.com/kb/en/mariadb-1010-release-notes/) | | [log\_bin\_basename](../replication-and-binary-log-server-system-variables/index#log_bin_basename) | [MariaDB 10.1.6](https://mariadb.com/kb/en/mariadb-1016-release-notes/) | | [log\_bin\_index](../replication-and-binary-log-server-system-variables/index#log_bin_index) | [MariaDB 10.1.6](https://mariadb.com/kb/en/mariadb-1016-release-notes/) | | [log\_tc\_size](../server-system-variables/index#log_tc_size) | [MariaDB 10.1.3](https://mariadb.com/kb/en/mariadb-1013-release-notes/) | | [max\_digest\_length](../server-system-variables/index#max_digest_length) | [MariaDB 10.1.5](https://mariadb.com/kb/en/mariadb-1015-release-notes/) | | [max\_session\_mem\_used](../server-system-variables/index#max_session_mem_used) | [MariaDB 10.1.21](https://mariadb.com/kb/en/mariadb-10121-release-notes/) | | [max\_statement\_time](../server-system-variables/index#max_statement_time) | [MariaDB 10.1.1](https://mariadb.com/kb/en/mariadb-1011-release-notes/) | | [mysql56\_temporal\_format](../server-system-variables/index#mysql56_temporal_format) | [MariaDB 10.1.2](https://mariadb.com/kb/en/mariadb-1012-release-notes/) | | [relay\_log\_basename](../replication-and-binary-log-server-system-variables/index#relay_log_basename) | [MariaDB 10.1.6](https://mariadb.com/kb/en/mariadb-1016-release-notes/) | | [strict\_password\_validation](../server-system-variables/index#strict_password_validation) | [MariaDB 10.1.2](https://mariadb.com/kb/en/mariadb-1012-release-notes/) | | [skip\_parallel\_replication](../replication-and-binary-log-server-system-variables/index#skip_parallel_replication) | [MariaDB 10.1.3](https://mariadb.com/kb/en/mariadb-1013-release-notes/) | | [slave\_parallel\_mode](../replication-and-binary-log-server-system-variables/index#slave_parallel_mode) | [MariaDB 10.1.3](https://mariadb.com/kb/en/mariadb-1013-release-notes/) | | [slave\_run\_triggers\_for\_rbr](../replication-and-binary-log-server-system-variables/index#slave_run_triggers_for_rbr) | [MariaDB 10.1.1](https://mariadb.com/kb/en/mariadb-1011-release-notes/) | | [version\_ssl\_library](../ssl-system-variables/index#version_ssl_library) | [MariaDB 10.1.3](https://mariadb.com/kb/en/mariadb-1013-release-notes/) | | [wsrep\_certification\_rules](../galera-cluster-system-variables/index#wsrep_certification_rules) | [MariaDB 10.1.38](https://mariadb.com/kb/en/mariadb-10138-release-notes/) | | [wsrep\_dirty\_reads](../galera-cluster-system-variables/index#wsrep_dirty_reads) | [MariaDB 10.1.3](https://mariadb.com/kb/en/mariadb-1013-release-notes/) | See Also -------- * [Status Variables Added in MariaDB 10.1](../status-variables-added-in-mariadb-101/index) * [System Variables Added in MariaDB 10.2](../system-variables-added-in-mariadb-102/index) * [System Variables Added in MariaDB 10.0](../system-variables-added-in-mariadb-100/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb PointN PointN ====== A synonym for [ST\_PointN](../st_pointn/index). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb MariaDB Internals Documentation MariaDB Internals Documentation ================================ Documentation on the internal workings of MariaDB. | Title | Description | | --- | --- | | [Contributing Code](../contributing-code/index) | Guidelines and procedures for contributing code to MariaDB. | | [Writing Plugins for MariaDB](../development-writing-plugins-for-mariadb/index) | Writing plugins for MariaDB. | | [Pluggable Authentication Overview](../pluggable-authentication-overview/index) | The authentication of users is delegated to plugins. | | [Information Schema plugins: SHOW and FLUSH statements](../information-schema-plugins-show-and-flush-statements/index) | Information Schema plugins can support SHOW and FLUSH statements. | | [Using MariaDB with Your Programs (API)](../using-mariadb-with-your-programs-api/index) | Using MariaDB with your programs (API) | | [Storage Engine Development](../storage-engines-storage-engine-development/index) | Storage Engine Development. | | [Merging into MariaDB](../mariadb-internals-documentation-merging-into-mariadb/index) | How to merge various source trees into MariaDB | | [MariaDB Source Code Internals](../mariadb-source-code-internals/index) | Articles about MariaDB source code and related internals. | | [Optimizer Trace](../mariadb-internals-documentation-optimizer-trace/index) | Produces a JSON trace with decision info taken by the optimizer during the optimization phase. | | [Condition Selectivity Computation Internals](../condition-selectivity-computation-internals/index) | How the MariaDB optimizer computes condition selectivities. | | [Encryption Plugin API](../encryption-plugin-api/index) | MariaDB uses plugins to handle key management and encryption of data. | | [Optimizer Debugging With GDB](../optimizer-debugging-with-gdb/index) | Useful things for debugging optimizer code with gdb. | | [Password Validation Plugin API](../password-validation/index) | Allows the creation of password validation plugins to check user passwords as they are set. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Spider Spider ======= The Spider storage engine supports partitioning and [xa transactions](../xa-transactions/index), and allows tables of different MariaDB instances to be handled as if they were on the same instance. ### Versions of Spider in MariaDB From [MariaDB 10.9.2](https://mariadb.com/kb/en/mariadb-1092-release-notes/), the Spider version number matches the server version. | Spider Version | Introduced | Maturity | | --- | --- | --- | | Spider 3.3.15 | [MariaDB 10.5.7](https://mariadb.com/kb/en/mariadb-1057-release-notes/), [MariaDB 10.4.6](https://mariadb.com/kb/en/mariadb-1046-release-notes/) | Stable | | Spider 3.3.15 | [MariaDB 10.5.4](https://mariadb.com/kb/en/mariadb-1054-release-notes/) | Gamma | | Spider 3.3.14 | [MariaDB 10.4.3](https://mariadb.com/kb/en/mariadb-1043-release-notes/), [MariaDB 10.3.13](https://mariadb.com/kb/en/mariadb-10313-release-notes/) | Stable | | Spider 3.3.13 | [MariaDB 10.3.7](https://mariadb.com/kb/en/mariadb-1037-release-notes/) | Stable | | Spider 3.3.13 | [MariaDB 10.3.3](https://mariadb.com/kb/en/mariadb-1033-release-notes/) | Gamma | | Spider 3.2.37 | [MariaDB 10.1.10](https://mariadb.com/kb/en/mariadb-10110-release-notes/), [MariaDB 10.0.23](https://mariadb.com/kb/en/mariadb-10023-release-notes/) | Gamma | | Spider 3.2.21 | [MariaDB 10.1.5](https://mariadb.com/kb/en/mariadb-1015-release-notes/), [MariaDB 10.0.18](https://mariadb.com/kb/en/mariadb-10018-release-notes/) | Gamma | | Spider 3.2.18 | [MariaDB 10.0.17](https://mariadb.com/kb/en/mariadb-10017-release-notes/) | Gamma | | Spider 3.2.11 | [MariaDB 10.0.14](https://mariadb.com/kb/en/mariadb-10014-release-notes/) | Gamma | | Spider 3.2.4 | [MariaDB 10.0.12](https://mariadb.com/kb/en/mariadb-10012-release-notes/) | Gamma | | Spider 3.2 | [MariaDB 10.0.11](https://mariadb.com/kb/en/mariadb-10011-release-notes/) | Gamma | | Spider 3.0 | [MariaDB 10.0.4](https://mariadb.com/kb/en/mariadb-1004-release-notes/) | Beta | Spider Documentation -------------------- See the [spider-2.0-doc](http://bazaar.launchpad.net/~kentokushiba/spiderformysql/spider-2.0-doc/files) repository for complete, older, documentation. [Presentation for new sharding features in Spider 3.3](https://speakerdeck.com/kentoku/new-features-and-enhancements-of-spider-storage-engine-for-sharding). | Title | Description | | --- | --- | | [Spider Storage Engine Overview](../spider-storage-engine-overview/index) | Storage engine with sharding features. | | [Spider Installation](../spider-installation/index) | Setting up Spider. | | [Spider Storage Engine Core Concepts](../spider-storage-engine-core-concepts/index) | Key Spider concepts | | [Spider Use Cases](../spider-use-cases/index) | Basic working examples for Spider | | [Spider Cluster Management](../spider-cluster-management/index) | Spider cluster management. | | [Spider Feature Matrix](../spider-feature-matrix/index) | Matrix of Spider features | | [Spider Server System Variables](../spider-server-system-variables/index) | System variables for the Spider storage engine. | | [Spider Table Parameters](../spider-table-parameters/index) | Spider table parameters available in the CREATE TABLE ... COMMENT clause | | [Spider Status Variables](../spider-status-variables/index) | Spider server status variables. | | [Spider Functions](../spider-functions/index) | User-defined functions available with the Spider storage engine. | | [Spider mysql Database Tables](../spider-mysql-database-tables/index) | System tables related to the Spider storage engine. | | [Information Schema SPIDER\_ALLOC\_MEM Table](../information-schema-spider_alloc_mem-table/index) | Information about Spider's memory usage. | | [Information Schema SPIDER\_WRAPPER\_PROTOCOLS Table](../information-schema-spider_wrapper_protocols-table/index) | Installed along with the Spider storage engine. | | [Spider Differences Between SpiderForMySQL and MariaDB](../spider-differences-between-spiderformysql-and-mariadb/index) | Spider differences between MySQL and MariaDB | | [Spider Case Studies](../spider-case-studies/index) | List of clients using Spider | | [Spider Benchmarks](../spider-benchmarks/index) | Benchmarks for Spider | | [Spider FAQ](../spider-faq/index) | Frequently-asked questions about the Spider storage engine | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb ColumnStore Rollback ColumnStore Rollback ==================== The ROLLBACK statement undoes transactions that have not been permanently saved to the database with the COMMIT statement.You cannot rollback changes to table properties including ALTER, CREATE, or DROP TABLE statements. images here Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb ~ ~ = Syntax ------ ``` ~ ``` Description ----------- Bitwise NOT. Converts the value to 4 bytes binary and inverts all bits. Examples -------- ``` SELECT 3 & ~1; +--------+ | 3 & ~1 | +--------+ | 2 | +--------+ SELECT 5 & ~1; +--------+ | 5 & ~1 | +--------+ | 4 | +--------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb STDDEV STDDEV ====== Syntax ------ ``` STDDEV(expr) ``` Description ----------- Returns the population standard deviation of *`expr`*. This function is provided for compatibility with Oracle. The standard SQL function `[STDDEV\_POP()](../stddev_pop/index)` can be used instead. It is an [aggregate function](../aggregate-functions/index), and so can be used with the [GROUP BY](../group-by/index) clause. From [MariaDB 10.2.2](https://mariadb.com/kb/en/mariadb-1022-release-notes/), STDDEV() can be used as a [window function](../window-functions/index). This function returns `NULL` if there were no matching rows. Examples -------- As an [aggregate function](../aggregate-functions/index): ``` CREATE OR REPLACE TABLE stats (category VARCHAR(2), x INT); INSERT INTO stats VALUES ('a',1),('a',2),('a',3), ('b',11),('b',12),('b',20),('b',30),('b',60); SELECT category, STDDEV_POP(x), STDDEV_SAMP(x), VAR_POP(x) FROM stats GROUP BY category; +----------+---------------+----------------+------------+ | category | STDDEV_POP(x) | STDDEV_SAMP(x) | VAR_POP(x) | +----------+---------------+----------------+------------+ | a | 0.8165 | 1.0000 | 0.6667 | | b | 18.0400 | 20.1693 | 325.4400 | +----------+---------------+----------------+------------+ ``` As a [window function](../window-functions/index): ``` CREATE OR REPLACE TABLE student_test (name CHAR(10), test CHAR(10), score TINYINT); INSERT INTO student_test VALUES ('Chun', 'SQL', 75), ('Chun', 'Tuning', 73), ('Esben', 'SQL', 43), ('Esben', 'Tuning', 31), ('Kaolin', 'SQL', 56), ('Kaolin', 'Tuning', 88), ('Tatiana', 'SQL', 87); SELECT name, test, score, STDDEV_POP(score) OVER (PARTITION BY test) AS stddev_results FROM student_test; +---------+--------+-------+----------------+ | name | test | score | stddev_results | +---------+--------+-------+----------------+ | Chun | SQL | 75 | 16.9466 | | Chun | Tuning | 73 | 24.1247 | | Esben | SQL | 43 | 16.9466 | | Esben | Tuning | 31 | 24.1247 | | Kaolin | SQL | 56 | 16.9466 | | Kaolin | Tuning | 88 | 24.1247 | | Tatiana | SQL | 87 | 16.9466 | +---------+--------+-------+----------------+ ``` See Also -------- * [STDDEV\_POP](../stddev_pop/index) (equivalent, standard SQL) * [STD](../std/index) (equivalent, non-standard SQL) * [VAR\_POP](../var_pop/index) (variance) * [STDDEV\_SAMP](../stddev_samp/index) (sample standard deviation) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb MariaDB ColumnStore software upgrade 1.1.3 GA to 1.1.4 GA MariaDB ColumnStore software upgrade 1.1.3 GA to 1.1.4 GA ========================================================= MariaDB ColumnStore software upgrade 1.1.3 GA to 1.1.4 GA --------------------------------------------------------- Additional Dependency Packages exist for 1.1.4, so make sure you install those based on the "Preparing for ColumnStore Installation" Guide. Note: Columnstore.xml modifications you manually made are not automatically carried forward on an upgrade. These modifications will need to be incorporated back into .XML once the upgrade has occurred. The previous configuration file will be saved as /usr/local/mariadb/columnstore/etc/Columnstore.xml.rpmsave. If you have specified a root database password (which is good practice), then you must configure a .my.cnf file with user credentials for the upgrade process to use. Create a .my.cnf file in the user home directory with 600 file permissions with the following content (updating PASSWORD as appropriate): ``` [mysqladmin] user = root password = PASSWORD ``` ### Choosing the type of upgrade As noted on the Preparing guide, you can installing MariaDB ColumnStore with the use of soft-links. If you have the softlinks be setup at the Data Directory Levels, like mariadb/columnstore/data and mariadb/columnstore/dataX, then your upgrade will happen without any issues. In the case where you have a softlink at the top directory, like /usr/local/mariadb, you will need to upgrade using the binary package. If you updating using the rpm package and tool, this softlink will be deleted when you perform the upgrade process and the upgrade will fail. #### Root User Installs #### Upgrading MariaDB ColumnStore using RPMs tar package Upgrade MariaDB ColumnStore as user root on the server designated as PM1: **Download the package mariadb-columnstore-1.1.4-1-centos#.x86\_64.rpm.tar.gz to the PM1 server where you are installing MariaDB ColumnStore.** Shutdown the MariaDB ColumnStore system: ``` # mcsadmin shutdownsystem y ``` * Unpack the tarball, which will generate a set of RPMs that will reside in the /root/ directory. ``` # tar -zxf mariadb-columnstore-1.1.4-1-centos#.x86_64.rpm.tar.gz ``` * Upgrade the RPMs. The MariaDB ColumnStore software will be installed in /usr/local/. ``` # rpm -e --nodeps $(rpm -qa | grep '^mariadb-columnstore') # rpm -ivh mariadb-columnstore-*1.1.4*rpm ``` * Run postConfigure using the upgrade option, which will utilize the configuration from the Columnstore.xml.rpmsave ``` # /usr/local/mariadb/columnstore/bin/postConfigure -u ``` For RPM Upgrade, the previous configuration file will be saved as: /usr/local/mariadb/columnstore/etc/Columnstore.xml.rpmsave #### Upgrading MariaDB ColumnStore using RPM Package Repositories The system can be upgrade when it was previously installed from the Package Repositories. This will need to be run on each module in the system Additional information can be found in this document on how to setup and install using the 'yum' package repo command: [https://mariadb.com/kb/en/library/installing-mariadb-ax-from-the-package-repositories](../library/installing-mariadb-ax-from-the-package-repositories) Upgrade MariaDB ColumnStore as user root on the server designated as PM1: **Shutdown the MariaDB ColumnStore system:** ``` # mcsadmin shutdownsystem y ``` * Uninstall MariaDB ColumnStore Packages ``` # yum remove mariadb-columnstore* ``` * Install MariaDB ColumnStore Packages ``` # yum --enablerepo=mariadb-columnstore clean metadata # yum install mariadb-columnstore* ``` NOTE: On the non-pm1 module, start the columnstore service ``` # /usr/local/mariadb/columnstore/bin/columnstore start ``` * Run postConfigure using the upgrade and non-distributed options, which will utilize the configuration from the Columnstore.xml.rpmsave ``` # /usr/local/mariadb/columnstore/bin/postConfigure -u -n ``` For RPM Upgrade, the previous configuration file will be saved as: /usr/local/mariadb/columnstore/etc/Columnstore.xml.rpmsave ### Initial download/install of MariaDB ColumnStore binary package Upgrade MariaDB ColumnStore as user root on the server designated as PM1: * Download the package into the /usr/local directory -mariadb-columnstore-1.1.4-1.x86\_64.bin.tar.gz (Binary 64-BIT)to the server where you are installing MariaDB ColumnStore. * Shutdown the MariaDB ColumnStore system: ``` # mcsadmin shutdownsystem y ``` * Run pre-uninstall script ``` # /usr/local/mariadb/columnstore/bin/pre-uninstall ``` * Unpack the tarball, in the /usr/local/ directory. ``` # tar -zxvf mariadb-columnstore-1.1.4-1.x86_64.bin.tar.gz ``` * Run post-install scripts ``` # /usr/local/mariadb/columnstore/bin/post-install ``` * Run postConfigure using the upgrade option, which will utilize the configuration from the Columnstore.xml,rpmsave ``` # /usr/local/mariadb/columnstore/bin/postConfigure -u ``` ### Upgrading MariaDB ColumnStore using the DEB package A DEB upgrade would be done on a system that supports DEBs like Debian or Ubuntu systems. Upgrade MariaDB ColumnStore as user root on the server designated as PM1: * Download the package into the /root directory mariadb-columnstore-1.1.4-1.amd64.deb.tar.gz (DEB 64-BIT) to the server where you are installing MariaDB ColumnStore. * Shutdown the MariaDB ColumnStore system: ``` # mcsadmin shutdownsystem y ``` * Unpack the tarball, which will generate DEBs. ``` # tar -zxf mariadb-columnstore-1.1.4-1.amd64.deb.tar.gz ``` * Remove, purge and install all MariaDB ColumnStore debs ``` # cd /root/ # dpkg -r $(dpkg --list | grep 'mariadb-columnstore' | awk '{print $2}') # dpkg -P $(dpkg --list | grep 'mariadb-columnstore' | awk '{print $2}') # dpkg --install mariadb-columnstore-*1.1.4-1*deb ``` * Run postConfigure using the upgrade option, which will utilize the configuration from the Columnstore.xml,rpmsave ``` # /usr/local/mariadb/columnstore/bin/postConfigure -u ``` #### Upgrading MariaDB ColumnStore using DEB Package Repositories The system can be upgrade when it was previously installed from the Package Repositories. This will need to be run on each module in the system Additional information can be found in this document on how to setup and install using the 'apt-get' package repo command: [https://mariadb.com/kb/en/library/installing-mariadb-ax-from-the-package-repositories](../library/installing-mariadb-ax-from-the-package-repositories) Upgrade MariaDB ColumnStore as user root on the server designated as PM1: **Shutdown the MariaDB ColumnStore system:** ``` # mcsadmin shutdownsystem y ``` * Uninstall MariaDB ColumnStore Packages ``` # apt-get remove mariadb-columnstore* ``` * Install MariaDB ColumnStore Packages ``` # apt-get update # sudo apt-get install mariadb-columnstore* ``` NOTE: On the non-pm1 module, start the columnstore service ``` # /usr/local/mariadb/columnstore/bin/columnstore start ``` * Run postConfigure using the upgrade and non-distributed options, which will utilize the configuration from the Columnstore.xml.rpmsave ``` # /usr/local/mariadb/columnstore/bin/postConfigure -u -n ``` For RPM Upgrade, the previous configuration file will be saved as: /usr/local/mariadb/columnstore/etc/Columnstore.xml.rpmsave #### Non-Root User Installs ### Initial download/install of MariaDB ColumnStore binary package Upgrade MariaDB ColumnStore as user root on the server designated as PM1: * Download the package into the /home/'non-root-user" directory mariadb-columnstore-1.1.4-1.x86\_64.bin.tar.gz (Binary 64-BIT)to the server where you are installing MariaDB ColumnStore. * Shutdown the MariaDB ColumnStore system: ``` # mcsadmin shutdownsystem y ``` * Run pre-uninstall script ``` # $HOME/mariadb/columnstore/bin/pre-uninstall --installdir= /home/guest/mariadb/columnstore ``` * Unpack the tarball, which will generate the $HOME/ directory. ``` # tar -zxvf mariadb-columnstore-1.1.4-1.x86_64.bin.tar.gz ``` * Run post-install scripts ``` # $HOME/mariadb/columnstore/bin/post-install --installdir=/home/guest/mariadb/columnstore ``` * Run postConfigure using the upgrade option, which will utilize the configuration from the Columnstore.xml,rpmsave ``` # $HOME/mariadb/columnstore/bin/postConfigure -u -i /home/guest/mariadb/columnstore ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Aggregate Functions as Window Functions Aggregate Functions as Window Functions ======================================= **MariaDB starting with [10.2](../what-is-mariadb-102/index)**[Window functions](../window-functions/index) were first introduced in [MariaDB 10.2.0](https://mariadb.com/kb/en/mariadb-1020-release-notes/). It is possible to use [aggregate functions](../aggregate-functions/index) as window functions. An aggregate function used as a window function must have the `OVER` clause. For example, here's [COUNT()](../count/index) used as a window function: ``` select COUNT(*) over (order by column) from table; ``` MariaDB currently allows these aggregate functions to be used as window functions: * [AVG](../avg/index) * [BIT\_AND](../bit_and/index) * [BIT\_OR](../bit_or/index) * [BIT\_XOR](../bit_xor/index) * [COUNT](../count/index) * [JSON\_ARRAYAGG](../json_arrayagg/index) * [JSON\_OBJECTAGG](../json_objectagg/index) * [MAX](../max/index) * [MIN](../min/index) * [STD](../std/index) * [STDDEV](../stddev/index) * [STDDEV\_POP](../stddev_pop/index) * [STDDEV\_SAMP](../stddev_samp/index) * [SUM](../sum/index) * [VAR\_POP](../var_pop/index) * [VAR\_SAMP](../var_samp/index) * [VARIANCE](../variance/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb ALTER PROCEDURE ALTER PROCEDURE =============== Syntax ------ ``` ALTER PROCEDURE proc_name [characteristic ...] characteristic: { CONTAINS SQL | NO SQL | READS SQL DATA | MODIFIES SQL DATA } | SQL SECURITY { DEFINER | INVOKER } | COMMENT 'string' ``` Description ----------- This statement can be used to change the characteristics of a [stored procedure](../stored-procedures/index). More than one change may be specified in an `ALTER PROCEDURE` statement. However, you cannot change the parameters or body of a stored procedure using this statement. To make such changes, you must drop and re-create the procedure using either [CREATE OR REPLACE PROCEDURE](../create-procedure/index) (since [MariaDB 10.1.3](https://mariadb.com/kb/en/mariadb-1013-release-notes/)) or [DROP PROCEDURE](../drop-procedure/index) and [CREATE PROCEDURE](../create-procedure/index) ([MariaDB 10.1.2](https://mariadb.com/kb/en/mariadb-1012-release-notes/) and before). You must have the `ALTER ROUTINE` privilege for the procedure. By default, that privilege is granted automatically to the procedure creator. See [Stored Routine Privileges](../stored-routine-privileges/index). Example ------- ``` ALTER PROCEDURE simpleproc SQL SECURITY INVOKER; ``` See Also -------- * [Stored Procedure Overview](../stored-procedure-overview/index) * [CREATE PROCEDURE](../create-procedure/index) * [SHOW CREATE PROCEDURE](../show-create-procedure/index) * [DROP PROCEDURE](../drop-procedure/index) * [SHOW CREATE PROCEDURE](../show-create-procedure/index) * [SHOW PROCEDURE STATUS](../show-procedure-status/index) * [Stored Routine Privileges](../stored-routine-privileges/index) * [Information Schema ROUTINES Table](../information-schema-routines-table/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Puppet hiera Configuration System Puppet hiera Configuration System ================================= hiera is part of [Puppet](../automated-mariadb-deployment-and-administration-puppet-and-mariadb/index). It is a hierarchical configuration system that allows us to: * Store configuration in separate files; * Include the relevant configuration files for every server we automate with Puppet. hiera Configuration Files ------------------------- Each hierarchy allows to one choose the proper configuration file for a resource, based on certain criteria. For example criteria may include node names, node groups, operating systems, or datacenters. Hierarchies are defined in a `hiera.yaml` file, which also defines a path for the files in each hierarchy. Puppet facts are commonly used to select the proper files to use. For example, a path may be defined as `"os/%{facts.os.name}.yaml"`. In this case, each resource will use a file named after the operating system it uses, in the os directory. You may need to use custom facts, for example to check which microservices will use a MariaDB server, or in which datacenter it runs. We do not have to create a file for each possible value of a certain fact. We can define a default configuration file with settings that are reasonable for most resources. Other files, when included, will override some of the default settings. A hiera configuration file will look like this: ``` version: 5 defaults: datadir: global data_hash: yaml_data hierarchy: - name: "Node data" path: "nodes/%{trusted.certname}.yaml" - name: "OS data" path: "os/%{facts.os.family}.yaml" - name: "Per-datacenter business group data" # Uses custom facts. path: "location/%{facts.whereami}/%{facts.group}.yaml" ``` This file would include the global files, the OS-specific files and the node-specific files. Each hierarchy will override settings from previous hierarchies. We can actually have several hiera configuration files. `hiera.yaml` is the global file. But we will typically have additional hiera configuration files for each environment. So we can include the configuration files that apply to production, staging, etc, plus global configuration files that should be included for every environment. Importantly, we can also have hiera configuration files for each module. So, for example, a separate `mariadb/hiera.yaml` file may defined the hierarchies for MariaDB servers. This allow us to define, for example, different configuration files for MariaDB and for MaxScale, as most of the needed settings are typically different. Configuration files ------------------- You probably noticed that, in the previous example, we defined `data_hash: yaml_data`, which indicates that configuration files are written in YAML. Other allowed formats are JSON and HOCON. The `data_hash` setting is defined in `defaults`, but it can be overridden by hierarchies. --- Content initially contributed by [Vettabase Ltd](https://vettabase.com/). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb LCASE LCASE ===== Syntax ------ ``` LCASE(str) ``` Description ----------- LCASE() is a synonym for [LOWER()](../lower/index). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Information Schema INNODB_MUTEXES Table Information Schema INNODB\_MUTEXES Table ======================================== The `INNODB_MUTEXES` table monitors mutex and rw locks waits. It has the following columns: | Column | Description | | --- | --- | | `NAME` | Name of the lock, as it appears in the source code. | | `CREATE_FILE` | File name of the mutex implementation. | | `CREATE_LINE` | Line number of the mutex implementation. | | `OS_WAITS` | How many times the mutex occurred. | The `CREATE_FILE` and `CREATE_LINE` columns depend on the InnoDB/XtraDB version. Note that since [MariaDB 10.2.2](https://mariadb.com/kb/en/mariadb-1022-release-notes/), the table has only been providing information about rw\_lock\_t, not any mutexes. From [MariaDB 10.2.2](https://mariadb.com/kb/en/mariadb-1022-release-notes/) until [MariaDB 10.2.32](https://mariadb.com/kb/en/mariadb-10232-release-notes/), [MariaDB 10.3.23](https://mariadb.com/kb/en/mariadb-10323-release-notes/), [MariaDB 10.4.13](https://mariadb.com/kb/en/mariadb-10413-release-notes/) and [MariaDB 10.5.1](https://mariadb.com/kb/en/mariadb-1051-release-notes/), the `NAME` column was not populated ([MDEV-21636](https://jira.mariadb.org/browse/MDEV-21636)). The [SHOW ENGINE INNODB STATUS](../show-engine/index#show-engine-innodb-mutex) statement provides similar information. Examples -------- ``` SELECT * FROM INNODB_MUTEXES; +------------------------------+---------------------+-------------+----------+ | NAME | CREATE_FILE | CREATE_LINE | OS_WAITS | +------------------------------+---------------------+-------------+----------+ | &dict_sys->mutex | dict0dict.cc | 989 | 2 | | &buf_pool->flush_state_mutex | buf0buf.cc | 1388 | 1 | | &log_sys->checkpoint_lock | log0log.cc | 1014 | 2 | | &block->lock | combined buf0buf.cc | 1120 | 1 | +------------------------------+---------------------+-------------+----------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb Block-Based Join Algorithms Block-Based Join Algorithms =========================== In the versions of MariaDB/MySQL before 5.3 only one block-based join algorithm was implemented: the Block Nested Loops (BNL) join algorithm which could only be used for inner joins. [MariaDB 5.3](../what-is-mariadb-53/index) enhanced the implementation of BNL joins and provides a variety of block-based join algorithms that can be used for inner joins, outer joins, and semi-joins. Block-based join algorithms in MariaDB employ a join buffer to accumulate records of the first join operand before they start looking for matches in the second join operand. This page documents the various block-based join algorithms. * Block Nested Loop (BNL) join * Block Nested Loop Hash (BNLH) join * Block Index join known as Batch Key Access (BKA) join * Block Index Hash join known as Batch Key Access Hash (BKAH) join Block Nested Loop Join ---------------------- The major difference between the implementation of BNL join in [MariaDB 5.3](../what-is-mariadb-53/index) compared to earlier versions of MariaDB/MySQL is that the former uses a new format for records written into join buffers. This new format allows: * More efficient use of buffer space for null field values and field values of flexible length types (like the varchar type) * Support for so-called *incremental* join buffers saving buffer space for multi-way joins * Use of the algorithm for outer joins and semi-joins ### How Block Nested Loop Join Works The algorithm performs a join operation of tables t1 and t2 according to the following schema. The records of the first operand are written into the join buffer one by one until the buffer is full. The records of the second operand are read from the base/temporary table one by one. For every read record r2 of table t2 the join buffer is scanned, and, for any record r1 from the buffer such that r2 matches r1 the concatenation of the interesting fields of r1 and r2 is sent to the result stream of the corresponding partial join. To read the records of t2 a full table scan, a full index scan or a range index scan is performed. Only the records that meet the condition pushed to table t2 are checked for a match of the records from the join buffer. When the scan of the table t2 is finished a new portion of the records of the first operand fills the buffer and matches for these records are looked for in t2. The buffer refills and scans of the second operand that look for matches in the join buffer are performed again and again until the records of first operand are exhausted. In total the algorithm scans the second operand as many times as many refills of the join buffer occur. ### More Efficient Usage of Join Buffer Space No join buffer space is used for null field values. Any field value of a flexible length type is not padded by 0 up to the maximal field size anymore. ### Incremental Join Buffers If we have a query with a join of three tables t1, t2, t3 such that table t1 is joined with table t2 and the result of this join operation is joined with table t3 then two join buffers can be used to execute the query. The first join buffer B1 is used to store the records comprising interesting fields of table t1, while the second join buffer B2 contains the records with fields from the partial join of t1 and t2. The interesting fields of any record r1 from B1 are copied into B2 for any record record r1,r2 from the partial join of t1 and t2. One could suggest storing in B2 just a pointer to the position of the r1 fields in B1 together with the interesting fields from t2. So for any record r2 matching the record r1 the buffer B2 would contain a reference to the fields of r1 in B1 and the fields of r2. In this case the buffer B2 is called incremental. Incremental buffers allow to avoid copying field values from one buffer into another. They also allow to save a significant amount of buffer space if for a record from t1 several matches from t2 are expected. ### Using Join Buffers for Simple Outer Joins and Semi-joins If a join buffer is used for a simple left outer join of tables t1 and t1 t1 LEFT JOIN t2 ON P(t1,t2) then each record r1 stored in the buffer is provided with a match flag. Initially this flag is set off. As soon as the first match for r1 is found this flag is set on. When all matching candidates from t2 have been check, the record the join buffer are scanned and for those of them that still have there match flags off null-complemented rows are generated. The same match flag is used for any record in the join buffer is a semi-join operation t1 SEMI JOIN t2 ON P(t1,t2) is performed with a block based join algorithm. When this match flag is set to on for a record r1 in the buffer no matches from table t2 for record r1 are looked for anymore. Block Hash Join --------------- Block based hash join algorithm is a new option to be used for join operations in [MariaDB 5.3](../what-is-mariadb-53/index). It can be employed in the cases when there are equi-join sub-condition for the joined tables, in the other words when equalities of the form t2.f1= e1(t1),...,t2.fn=en(t1) can be extracted from the full join condition. As any block based join algorithm this one used a join buffer filled with the records of the first operand and looks through the records of the second operand to find matches for the records in the buffer. ### How Block Hash Join Works For each refill of the join buffer and each record r1 from it the algorithm builds a hash table with the keys constructed over the values e1(r1),...en(r1). Then the records of t2 are looked through. For each record r2 from t2 that the condition pushed to the table t2 a hash key over the fields r2.f1,..., r2.fn is calculated to probe into the hash table. The probing returns those records from the buffer to which r2 matches. As for BNL join algorithm this algorithm scans the second operand as many time as many refills of the buffer occur. Yet it has to look only through the records of one bucket in the hash table when looking for the records to which a record from t2 matches, not through all records in the join buffer as BNL join algorithm does. The implementation of this algorithm in MariaDB builds the hash table with hash keys at the very end of the join buffer. That's why the number of records written into the buffer at one refill is less then for BNL join algorithms. However a much shorter list of possible matching candidates makes this the block hash join algorithm usually much faster then BNL join. Batch Key Access Join --------------------- Batch Keys Access join algorithm performs index look-ups when looking for possible matching candidates provided by the second join operand. With this respect the algorithm behave itself as the regular join algorithm. Yet BKA performs index look-ups for a batch of the records from the join buffer. For conventional database engines like InnoDB/MyISAM it allows to fetch matching candidates in an optimal way. For the engines with remote data store such as FederateX/Spider the algorithm allows to save on transfers between the MySQL node and the data store nodes. ### How Batch Keys Access Join Works The implementation of the algorithm in 5.3 heavily exploits the multi-range-read interface and its properties. The interface hides the actual mechanism of fetching possible candidates for matching records from the table to be joined. As any block based join algorithm the BKA join repeatedly fills the join buffer with records of the first operand and for each refill it finds records from the join table that could match the records in the buffer. To find such records it asks the MRR interface to perform index look-ups with the keys constructed over all records from the buffer. Together with each key the interface receives a return address - a reference to the record over which this key has been constructed. The actual implementation functions of the MRR interface organize and optimize somehow the process of fetching the records of the joined table by the received keys. Each fetched record r2 is appended with the return address associated with the key by which the record has been found and the result is passed to the BKA join procedure. The procedure takes the record r1 from the join buffer by the return address, joins it with r2 and checks the join condition. If the condition is evaluated to true the joined records is sent to the result stream of the join operation. So for each record returned by the MRR interface only one record from the join buffer is accessed. The number of records from table t2 fetched by the BKA join is exactly the same as for the regular nested loops join algorithm. Yet BKA join allows to optimize the order in which the records are fetched. ### Interaction of BKA Join With the MRR Functions BKA join interacts with the MRR functions respecting the following contract. The join procedure calls the MRR function multi\_range\_read\_init passing it the callback functions that allows to initialize reading keys for the records in the join buffer and to iterate over these keys. It also passes the parameters of the buffer for MRR needs allocated within the join buffer space. Then BKA join repeatedly calls the MRR function multi\_range\_read\_next. The function works as an iterator function over the records fetched by index look-ups with the keys produced by a callback function set in the call of multi\_range\_read\_init. A call of the function multi\_range\_read\_next returns the next fetched record through the dedicated record buffer, and the associated reference to the matched record from the join buffer as the output parameter of the function. Managing Usage of Block-Based Join Algorithms --------------------------------------------- Currently 4 different types of block-based join algorithms are supported. For a particular join operation each of them can be employed with a regular (flat) join buffer or with an incremental join buffer. Three optimizer switches - `join_cache_incremental`, `join_cache_hashed`, `join_cache_bka` – and the system variable [join\_cache\_level](../server-system-variables/index#join_cache_level) control which of the 8 variants of the block-based algorithms will be used for join operations. If `join_cache_bka` is off then BKA and BKAH join algorithms are not allowed. If `join_cache_hashed` is off then BNLH and BKAH join algorithms are not allowed. If `join_cache_incremental` is off then no incremental variants of the block-based join algorithms are allowed. By default the switches `join_cache_incremental`, `join_cache_hashed`, `join_cache_bka` are set to 'on'. However it does not mean that by default any of block-based join algorithms is allowed to be used. All of them are allowed only if the system variable [join\_cache\_level](../server-system-variables/index#join_cache_level) is set to 8. This variable can take an integer value in the interval from 0 to 8. If the value is set to 8 no block-based algorithm can be used for a join operation. The values from 1 to 8 correspond to the following variants of block-based join algorithms : * 1 – Flat BNL * 2 – Incremental BNL * 3 – Flat BNLH * 4 – Incremental BNLH * 5 – Flat BKA * 6 – Incremental BKA * 7 – Flat BKAH * 8 – Incremental BKAH If the value of [join\_cache\_level](../server-system-variables/index#join_cache_level) is set to N, any of block-based algorithms with the level greater than N is disallowed. So if [join\_cache\_level](../server-system-variables/index#join_cache_level) is set to 5, no usage of BKAH is allowed and usage of incremental BKA is not allowed either while usage of all remaining variants are controlled by the settings of the optimizer switches `join_cache_incremental`, `join_cache_hashed`, `join_cache_bka`. By default [join\_cache\_level](../server-system-variables/index#join_cache_level) is set to 2. In other words only usage of flat or incremental BNL is allowed. By default block-based algorithms can be used only for regular (inner) join operations. To allow them for outer join operations (left outer joins and right outer joins) the optimizer switch `outer_join_with_cache` has to be set to 'on'. Setting the optimizer switch `semijoin_with_cache` to 'on' allows using these algorithms for semi-join operations. Currently, only incremental variants of the block-based join algorithms can be used for nested outer joins and nested semi-joins. ### Size of Join Buffers The maximum size of join buffers used by block-based algorithms is controlled by setting the [join\_buffer\_size](../server-system-variables/index#join_buffer_size) system variable. This value must be large enough in order for the join buffer employed for a join operation to contain all relevant fields for at least one joined record. [MariaDB 5.3](../what-is-mariadb-53/index) introduced the system variable [join\_buffer\_space\_limit](../server-system-variables/index#join_buffer_space_limit) that limits the total memory used for join buffers in a query. To optimize the usage of the join buffers within the limit set by `join_buffer_space_limit`, one should use the [optimizer switch](../server-system-variables/index#optimizer_switch) `optimize_join_buffer_size=on`. When this flag is set to 'off' (default until [MariaDB 10.4.2](https://mariadb.com/kb/en/mariadb-1042-release-notes/)), the size of the used join buffer is taken directly from the [join\_buffer\_size](../server-system-variables/index#join_buffer_size) system variable. When this flag is set to 'on' (default from [MariaDB 10.4.3](https://mariadb.com/kb/en/mariadb-1043-release-notes/)) then the size of the buffer depends on the estimated number of rows in the partial join whose records are to be stored in the buffer. ### Related MRR Settings To use BKA/BKAH join algorithms for InnoDB/MyISAM, one must set the optimizer switch `mrr` to 'on'. When using these algorithms for InnoDB/MyISAM the overall performance of the join operations can be dramatically improved if the optimizer switch `mrr_sort_keys` is set 'on'. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Managing ColumnStore Managing ColumnStore ===================== Documentation for the latest release of Columnstore is not available on the Knowledge Base. Instead, see: * [Release Notes](https://mariadb.com/docs/release-notes/mariadb-columnstore-1-5-2-release-notes/) * [Deployment Instructions](https://mariadb.com/docs/deploy/community-single-columnstore/) | Title | Description | | --- | --- | | [Managing ColumnStore Database Environment](../managing-columnstore-database-environment/index) | Managing MariaDB ColumnStore Database Environment | | [Managing ColumnStore System](../managing-columnstore-system/index) | Managing MariaDB ColumnStore System | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Using Git Using Git ========= Just Getting the Source ----------------------- If you just want to get the latest source and you don't require the ability to push changes to the MariaDB repository, you can use the following command to check out the latest 10.5 branch: ``` git clone -b 10.5 https://github.com/MariaDB/server.git ``` Setup up git for MariaDB ------------------------ * Set your name with git ``` git config --global user.name "Ivan Ivanov" git config --global user.email "[email protected]" ``` * Go to <https://github.com/settings/ssh> and add your public SSH key ([GitHub Help](https://help.github.com/articles/generating-ssh-keys/#step-3-add-your-ssh-key-to-github)). * Clone the repository ``` git clone [email protected]:MariaDB/server.git cd server git checkout 10.5 ``` * Config repository pull and alias for fast forward: ``` git config pull.ff only git config --global alias.ff "merge --ff-only" ``` Commit comments --------------- In git commit messages are normally formatted as ``` subject body more body ... ``` That is, the first line is considered a \*subject\*, much like email subject. Many git commands and pages on github only show the commit subject, not the complete comment. After the subject goes an empty line, then the detailed description of the comment. Please, structure your commit comments this way, don't forget the empty line. Branches -------- This is an important concept, and git branches do not have equivalents in bzr. In Bazaar, we all used to have one shared repository, within which there were many branches. This seems to be impossible with git? In Git, each repository has only one branch that is currently checked out. ``` git branch ``` ### List Existing Branches To see which branches exists locally and remotely: ``` git branch --all ``` ### To Move to Work on a Specific Branch ``` git checkout branch-name ``` Note that if the output from `git branch --all` is `remotes/origin/XXX` you should just use `XXX` as branch name. ### Making a Local Copy of a Branch (Like bzr clone) ``` branch clone old_directory new_directory cd new_directory git remote set-url origin [email protected]:MariaDB/server.git git pull ``` ### Remove Last Commit From a Branch ``` git reset --hard HEAD^ ``` ### Fetch a Branch Someone Has Done a Rebase on If you get the following error on pull: ``` shell> git pull X11 forwarding request failed on channel 0 fatal: Not possible to fast-forward, aborting. ``` Instead of removing your copy and then clone, you can do: ``` git reset --hard origin/##branch-name## ``` ### Other Things About Branches * Note: branches whose names start with `bb-` are automatically put into the buildbot. Equivalents For Some bzr Commands --------------------------------- CAVEAT UTILITOR. Check the manual before running! * `bzr status` is `git status` * `bzr diff` is `git diff` * `bzr log` is `git log` * `bzr revert` is `git reset --hard` * `bzr revert filename` is `git checkout filename` * `bzr parent` is `git remote -v` (but there are more detailed commands) * `bzr parent to-default-mariadb-repo` git remote set-url origin [email protected]:MariaDB/server.git * `bzr push` is `git push REMOTENAME BRANCHNAME`. REMOTENAME is typically "origin", for example: `git push origin HEAD:10.3-new-feature`. The HEAD: stands for "from current branch". * `bzr clean-tree --ignored` is `git clean -Xdf` (note the capital X!) * `bzr root` is `git rev-parse --show-toplevel` * `bzr missing --mine-only` is `git cherry -v origin` (kind-of). GUIs * `bzr gcommit` is `git citool` * `bzr viz` is `gitk` * `bzr gannotate` is `git gui blame` Commit Emails ------------- In the MariaDB project, it is a good idea (and a long tradition since MySQL Ab) to have all your commits sent to a [email protected] mailing list. It allows others to follow the progress, comment, etc. A script and instructions on how to setup commit triggers in Git are here: <http://bazaar.launchpad.net/~maria-captains/mariadb-tools/trunk/files/head:/git_template/> . Jira task for commit trigger was [MDEV-6278](https://jira.mariadb.org/browse/MDEV-6278). Attributing Code to Someone Else -------------------------------- If you add code on behalf of someone else, please attribute the code to the original author: * Run `git citool` and move changed files to staged. * Don't `commit`, abort instead * run `git commit --author="Original author name <email_address>"` The above is needed as `git citool` can't handle the `--author` option. Applying a Pull Request ----------------------- At the end of the pull request page there is a button "Merge pull request" and next to it a link "command line instructions". Click the link, you'll see something like Step 1: From your project repository, check out a new branch and test the changes. ``` git checkout -b mariadb-server-joeuser-cool-feature 10.3 git pull https://github.com/joeuser/mariadb-server cool-feature ``` Step 2: Merge the changes and update on GitHub. ``` git checkout 10.3 git merge --no-ff mariadb-server-joeuser-cool-feature git push origin 10.3 ``` Note where to pull from — **https:/​/github.com/joeuser/mariadb-server cool-feature**. Now, checkout the branch you want to merge it to, say, bb-10.3-stage, and do the following ``` git fetch https://github.com/joeuser/mariadb-server cool-feature git checkout FETCH_HEAD git rebase @{-1} ``` Now's the time to compile the code, test it, fix, if necessary. Then ``` git checkout @{-1} git ff @{-1} ``` If you want to do small changes to the pull request, do it in a separate commit, after `git rebase @{-1}` above. If you want to do *big* changes to the pull request, perhaps you shouldn't merge it in the first place, but ask the contributor to fix it? Examples -------- ### Diff For Last Commit ``` git show ``` ### Applying New Code From Main Tree to a Branch You are working on a branch (`NEW_FEATURE`) and would like to have into that branch all changes from the main branch (`10.1`). ``` git checkout 10.1 git pull git checkout NEW_FEATURE git rebase 10.1 ``` ### Applying a Bugfix in the Main Branch You've just fixed and committed a bug in the main 10.1 branch and want to merge it with the latest 10.1. Often a rebase is better in this case. Assuming your current checked out branch is 10.1: ``` git fetch origin git rebase origin/10.1 ``` This will work even if you have done multiple commits in your local 10.1 tree. ### Dealing With Conflicts When One Tries to Push What to do when you have fixed a bug in the main tree but notices that someone has changed the tree since you pulled last time. This approach ensures that your patch is done in one block and not spread out over several change sets. ``` git clone 10.1 cd 10.1 < fix a bug here> git citool git push # ^ and the above fails, because someone has pushed to 10.1 in between git branch tmp # ^ copy our work to branch named 'tmp' get checkout 10.1 git reset --hard HEAD^ # ^ remove our work from '10.1' local branch' git pull # ^ get changes from remote git checkout tmp git rebase 10.1 # ^ switch to 'tmp' and try to rebase 'tmp' branch on top of 10.1 branch. # here you will be asked to merge if necessary git checkout 10.1 git pull --ff . tmp # ^ switch back to the '10.1' branch, and pull from 'tmp' branch. git branch -D tmp #^ this removes the tmp. branch git push ``` Finding in Which MariaDB Version a Commit Exists ------------------------------------------------ ``` sh> git tag --contain e65f667bb60244610512efd7491fc77eccceb9db mariadb-10.0.30 mariadb-10.1.22 mariadb-10.1.23 mariadb-10.2.5 mariadb-10.3.0 mariadb-galera-10.0.30 ``` See Also -------- * <http://agateau.com/talks/2010/git-for-bzr-users_uds-natty/git-for-bzr-users.pdf> * [Sergei's "Using GIT" presentation. Malaga Meeting, January 2015](https://mariadb.com/kb/en/usare-git/+attachment/using-git "Sergei's \"Using GIT\" presentation. Malaga Meeting, January 2015") Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb Miscellaneous Functions Miscellaneous Functions ======================== Miscellaneous functions include DEFAULT, GET\_LOCK, SLEEP, UUID, etc. | Title | Description | | --- | --- | | [GET\_LOCK](../get_lock/index) | Obtain LOCK. | | [INET6\_ATON](../inet6_aton/index) | Given an IPv6 or IPv4 network address, returns a VARBINARY numeric value. | | [INET6\_NTOA](../inet6_ntoa/index) | Given an IPv6 or IPv4 network address, returns the address as a nonbinary string. | | [INET\_ATON](../inet_aton/index) | Returns numeric value of IPv4 address. | | [INET\_NTOA](../inet_ntoa/index) | Returns dotted-quad representation of IPv4 address. | | [IS\_FREE\_LOCK](../is_free_lock/index) | Checks whether lock is free to use. | | [IS\_IPV4](../is_ipv4/index) | Whether or not an expression is a valid IPv4 address. | | [IS\_IPV4\_COMPAT](../is_ipv4_compat/index) | Whether or not an IPv6 address is IPv4-compatible. | | [IS\_IPV4\_MAPPED](../is_ipv4_mapped/index) | Whether an IPv6 address is a valid IPv4-mapped address. | | [IS\_IPV6](../is_ipv6/index) | Whether or not an expression is a valid IPv6 address. | | [IS\_USED\_LOCK](../is_used_lock/index) | Check if lock is in use. | | [MASTER\_GTID\_WAIT](../master_gtid_wait/index) | Wait until slave reaches the GTID position. | | [MASTER\_POS\_WAIT](../master_pos_wait/index) | Blocks until the replica has applied all specified updates. | | [NAME\_CONST](../name_const/index) | Returns the given value. | | [RELEASE\_ALL\_LOCKS](../release_all_locks/index) | Releases all named locks held by the current session. | | [RELEASE\_LOCK](../release_lock/index) | Releases lock obtained with GET\_LOCK(). | | [SLEEP](../sleep/index) | Pauses for the given number of seconds. | | [SYS\_GUID](../sys_guid/index) | Returns a globally unique identifier (GUID). | | [UUID](../uuid/index) | Returns a Universal Unique Identifier. | | [UUID\_SHORT](../uuid_short/index) | Return short universal identifier. | | [VALUES / VALUE](../values-value/index) | Refer to columns in INSERT ... ON DUPLICATE KEY UPDATE. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Information Schema ROUTINES Table Information Schema ROUTINES Table ================================= The [Information Schema](../information_schema/index) `ROUTINES` table stores information about [stored procedures](../stored-procedures/index) and [stored functions](../stored-functions/index). It contains the following columns: | Column | Description | | --- | --- | | `SPECIFIC_NAME` | | | `ROUTINE_CATALOG` | Always `def`. | | `ROUTINE_SCHEMA` | Database name associated with the routine. | | `ROUTINE_NAME` | Name of the routine. | | `ROUTINE_TYPE` | Whether the routine is a `PROCEDURE` or a `FUNCTION`. | | `DATA_TYPE` | The return value's [data type](../data-types/index) (for stored functions). | | `CHARACTER_MAXIMUM_LENGTH` | Maximum length. | | `CHARACTER_OCTET_LENGTH` | Same as the `CHARACTER_MAXIMUM_LENGTH` except for multi-byte [character sets](../data-types-character-sets-and-collations/index). | | `NUMERIC_PRECISION` | For numeric types, the precision (number of significant digits) for the column. `NULL` if not a numeric field. | | `NUMERIC_SCALE` | For numeric types, the scale (significant digits to the right of the decimal point). NULL if not a numeric field. | | `DATETIME_PRECISION` | Fractional-seconds precision, or NULL if not a [time data type](../date-and-time-data-types/index). | | `CHARACTER_SET_NAME` | [Character set](../data-types-character-sets-and-collations/index) if a non-binary [string data type](../string-data-types/index), otherwise `NULL`. | | `COLLATION_NAME` | [Collation](../data-types-character-sets-and-collations/index) if a non-binary [string data type](../string-data-types/index), otherwise NULL. | | `DATA_TYPE` | The column's [data type](../data-types/index). | | `ROUTINE_BODY` | Always `SQL`. | | `ROUTINE_DEFINITION` | Definition of the routine. | | `EXTERNAL_NAME` | Always `NULL`. | | `EXTERNAL_LANGUAGE` | Always `SQL`. | | `PARAMETER_STYLE` | Always `SQL`. | | `IS_DETERMINISTIC` | Whether the routine is deterministic (can produce only one result for a given list of parameters) or not. | | `SQL_DATA_ACCESS` | One of `READS SQL DATA`, `MODIFIES SQL DATA`, `CONTAINS SQL`, or `NO SQL`. | | `SQL_PATH` | Always `NULL`. | | `SECURITY_TYPE` | `INVOKER` or `DEFINER`. Indicates which user's privileges apply to this routine. | | `CREATED` | Date and time the routine was created. | | `LAST_ALTERED` | Date and time the routine was last changed. | | `SQL_MODE` | The `[SQL\_MODE](../sql-mode/index)` at the time the routine was created. | | `ROUTINE_COMMENT` | Comment associated with the routine. | | `DEFINER` | If the `SECURITY_TYPE` is `DEFINER`, this value indicates which user defined this routine. | | `CHARACTER_SET_CLIENT` | The [character set](../data-types-character-sets-and-collations/index) used by the client that created the routine. | | `COLLATION_CONNECTION` | The [collation](../data-types-character-sets-and-collations/index) (and character set) used by the connection that created the routine. | | `DATABASE_COLLATION` | The default [collation](../data-types-character-sets-and-collations/index) (and character set) for the database, at the time the routine was created. | It provides information similar to, but more complete, than the `[SHOW PROCEDURE STATUS](../show-procedure-status/index)` and `[SHOW FUNCTION STATUS](../show-function-status/index)` statements. For information about the parameters accepted by the routine, you can query the `[information\_schema.PARAMETERS](../information-schema-parameters-table/index)` table. See also -------- * [Stored Function Overview](../stored-function-overview/index) * [Stored Procedure Overview](../stored-procedure-overview/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Migrating to MariaDB from Oracle Migrating to MariaDB from Oracle ================================= | Title | Description | | --- | --- | | [Oracle XE 11.2. and MariaDB 10.1 integration on Ubuntu 14.04 and Debian systems](../oracle-xe-112-and-mariadb-101-integration-on-ubuntu-1404-and-debian-systems/index) | 1) Sign up for Oracle downloads and download Oracle Express at: http://www... | | [SQL\_MODE=ORACLE](../sql_modeoracle/index) | MariaDB understands a subset of Oracle's PL/SQL language. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb InnoDB REDUNDANT Row Format InnoDB REDUNDANT Row Format =========================== The `REDUNDANT` row format is the original non-compacted row format. The `REDUNDANT` row format was the only available row format before MySQL 5.0.3. In that release, this row format was retroactively named the `REDUNDANT` row format. In the same release, the `COMPACT` row format was introduced as the new default row format. Using the `REDUNDANT` Row Format -------------------------------- The easiest way to create an InnoDB table that uses the `REDUNDANT` row format is by setting the [ROW\_FORMAT](../create-table/index#row_format) table option to `REDUNDANT` in a [CREATE TABLE](../create-table/index) or [ALTER TABLE](../alter-table/index) statement. It is recommended to set the [innodb\_strict\_mode](../innodb-system-variables/index#innodb_strict_mode) system variable to `ON` when using this format. The `REDUNDANT` row format is supported by both the `Antelope` and the `Barracuda` [file formats](../innodb-file-format/index), so tables with this row format can be created regardless of the value of the [innodb\_file\_format](../innodb-system-variables/index#innodb_file_format) system variable. For example: ``` SET SESSION innodb_strict_mode=ON; CREATE TABLE tab ( id int, str varchar(50) ) ENGINE=InnoDB ROW_FORMAT=REDUNDANT; ``` Index Prefixes with the `REDUNDANT` Row Format ---------------------------------------------- The `REDUNDANT` row format supports index prefixes up to 767 bytes. Overflow Pages with the `REDUNDANT` Row Format ---------------------------------------------- All InnoDB row formats can store certain kinds of data in overflow pages. This allows for the maximum row size of an InnoDB table to be larger than the maximum amount of data that can be stored in the row's main data page. See [Maximum Row Size](../innodb-row-formats-overview/index#maximum-row-size) for more information about the other factors that can contribute to the maximum row size for InnoDB tables. In the `REDUNDANT` row format variable-length columns, such as columns using the [VARBINARY](../varbinary/index), [VARCHAR](../varchar/index), [BLOB](../blob/index) and [TEXT](../text/index) data types, can be partially stored in overflow pages. InnoDB only considers using overflow pages if the table's row size is greater than half of [innodb\_page\_size](../innodb-system-variables/index#innodb_page_size). If the row size is greater than this, then InnoDB chooses variable-length columns to be stored on overflow pages until the row size is less than half of [innodb\_page\_size](../innodb-system-variables/index#innodb_page_size). For [VARBINARY](../varbinary/index), [VARCHAR](../varchar/index), [BLOB](../blob/index) and [TEXT](../text/index) columns, only values longer than 767 bytes are considered for for storage on overflow pages. Bytes that are stored to track a value's length do not count towards this limit. This limit is only based on the length of the actual column's data. Fixed-length columns greater than 767 bytes are encoded as variable-length columns, so they can also be stored in overflow pages if the table's row size is greater than half of [innodb\_page\_size](../innodb-system-variables/index#innodb_page_size). Even though a column using the [CHAR](../char/index) data type can hold at most 255 characters, a [CHAR](../char/index) column can still exceed 767 bytes in some cases. For example, a `char(255)` column can exceed 767 bytes if the [character set](../character-sets/index) is `utf8mb4`. If a column is chosen to be stored on overflow pages, then the first 767 bytes of the column's value and a 20-byte pointer to the column's first overflow page are stored on the main page. Each overflow page is the size of [innodb-system-variables#innodb\_page\_size|innodb\_page\_size]]. If a column is too large to be stored on a single overflow page, then it is stored on multiple overflow pages. Each overflow page contains part of the data and a 20-byte pointer to the next overflow page, if a next page exists. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb format_statement format\_statement ================= Syntax ------ ``` sys.format_statement(statement) ``` Description ----------- Returns a reduced length string. The length is specified by the [statement\_truncate\_len configuration option](../sys-schema-sys_config-table/index) (default 64), and the removed part of the string (if any) is replaced with an ellipsis (three dots). The function is intended for use in formatting lengthy SQL statements to a fixed length. Examples -------- Default truncation length 64: ``` SELECT sys.format_statement( 'SELECT field1, field2, field3, field4, field5, field6 FROM table1' ) AS formatted_statement; +-------------------------------------------------------------------+ | formatted_statement | +-------------------------------------------------------------------+ | SELECT field1, field2, field3, ... d4, field5, field6 FROM table1 | +-------------------------------------------------------------------+ ``` Reducing the truncation length to 48: ``` SET @sys.statement_truncate_len = 48; SELECT sys.format_statement( 'SELECT field1, field2, field3, field4, field5, field6 FROM table1' ) AS formatted_statement; +---------------------------------------------------+ | formatted_statement | +---------------------------------------------------+ | SELECT field1, field2, ... d5, field6 FROM table1 | +---------------------------------------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb BINLOG_GTID_POS BINLOG\_GTID\_POS ================= Syntax ------ ``` BINLOG_GTID_POS(binlog_filename,binlog_offset) ``` Description ----------- The BINLOG\_GTID\_POS() function takes as input an old-style [binary log](../binary-log/index) position in the form of a file name and a file offset. It looks up the position in the current binlog, and returns a string representation of the corresponding [GTID](../global-transaction-id/index) position. If the position is not found in the current binlog, NULL is returned. Examples -------- ``` SELECT BINLOG_GTID_POS("master-bin.000001", 600); ``` See Also -------- * [SHOW BINLOG EVENTS](../show-binlog-events/index) - Show events and their positions in the binary log Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Information Schema ROCKSDB_COMPACTION_STATS Table Information Schema ROCKSDB\_COMPACTION\_STATS Table =================================================== The [Information Schema](../information_schema/index) `ROCKSDB_COMPACTION_STATS` table is included as part of the [MyRocks](../myrocks/index) storage engine. The `PROCESS` [privilege](../grant/index) is required to view the table. It contains the following columns: | Column | Description | | --- | --- | | `CF_NAME` | | | `LEVEL` | | | `TYPE` | | | `VALUE` | | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb = = = Syntax ------ ``` left_expr = right_expr ``` Description ----------- Equal operator. Evaluates both SQL expressions and returns 1 if they are equal, 0 if they are not equal, or `[NULL](../null-values-in-mariadb/index)` if either expression is NULL. If the expressions return different data types (for example, a number and a string), a type conversion is performed. When used in row comparisons these two queries are synonymous and return the same results: ``` SELECT (t1.a, t1.b) = (t2.x, t2.y) FROM t1 INNER JOIN t2; SELECT (t1.a = t2.x) AND (t1.b = t2.y) FROM t1 INNER JOIN t2; ``` To perform a NULL-safe comparison, use the `[<=>](../null-safe-equal/index)` operator. `=` can also be used as an [assignment operator](../assignment-operators-assignment-operator/index). Examples -------- ``` SELECT 1 = 0; +-------+ | 1 = 0 | +-------+ | 0 | +-------+ SELECT '0' = 0; +---------+ | '0' = 0 | +---------+ | 1 | +---------+ SELECT '0.0' = 0; +-----------+ | '0.0' = 0 | +-----------+ | 1 | +-----------+ SELECT '0.01' = 0; +------------+ | '0.01' = 0 | +------------+ | 0 | +------------+ SELECT '.01' = 0.01; +--------------+ | '.01' = 0.01 | +--------------+ | 1 | +--------------+ SELECT (5 * 2) = CONCAT('1', '0'); +----------------------------+ | (5 * 2) = CONCAT('1', '0') | +----------------------------+ | 1 | +----------------------------+ SELECT 1 = NULL; +----------+ | 1 = NULL | +----------+ | NULL | +----------+ SELECT NULL = NULL; +-------------+ | NULL = NULL | +-------------+ | NULL | +-------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Bolt Examples Bolt Examples ============= This page shows some examples of what we can do with Bolt to administer a set of MariaDB servers. Bolt is a tool that is part of the [Puppet](../automated-mariadb-deployment-and-administration-puppet-and-mariadb/index) ecosystem. For information about installing Bolt, see [Installing Bolt](https://puppet.com/docs/bolt/latest/bolt_installing.html) in Bolt documentation. Inventory Files --------------- The simplest way to call Bolt and instruct it to do something on some remote targets is the following: ``` bolt ... --nodes 100.100.100.100,200.200.200.200,300,300,300,300 ``` However, for non-trivial setups it is usually better to use an inventory file. An example: ``` targets: - uri: maria-1.example.com name: maria_1 alias: mariadb_main ... ``` In this way, it will be possible to refer the target by name or alias. We can also define groups, followed by the group members. For example: ``` groups: - name: mariadb-staging targets: - uri: maria-1.example.com name: maria_1 - uri: maria-2.example.com name: maria_2 - name: mariadb-production targets: ... ... ``` With an inventory of this type, it will be possible to run Bolt actions against all the targets that are members of a group: ``` bolt ... --nodes mariadb-staging ``` In the examples in the rest of the page, the `--targets` parameter will be indicated in this way, for simplicity: `--targets <targets>`. Running Commands on Targets --------------------------- The simplest way to run a command remotely is the following: ``` bolt command run 'mariadb-admin start-all-slaves' --targets <targets> ``` Copying Files ------------- To copy a file or a whole directory to targets: ``` bolt file upload /path/to/source /path/to/destination --targets <targets> ``` To copy a file or a whole directory from the targets to the local host: ``` bolt file download /path/to/source /path/to/destination --targets <targets> ``` Running Scripts on Targets -------------------------- We can use Bolt to run a local script on remote targets. Bolt will temporarily copy the script to the targets, run it, and delete it from the targets. This is convenient for scripts that are meant to only run once. ``` bolt script run rotate_logs.sh --targets <targets> ``` Running Tasks on Targets ------------------------ Puppet tasks are not always as powerful as custom scripts, but they are simpler and many of them are idempotent. The following task stops MariaDB replication: ``` bolt task run mysql::sql --targets <targets> sql="STOP REPLICA" ``` Applying Puppet Code on Targets ------------------------------- It is also possible to apply whole manifests or portions of Puppet code (resources) on the targets. To apply a manifest: ``` bolt apply manifests/server.pp --targets <targets> ``` To apply a resource description: ``` bolt apply --execute "file { '/etc/mysql/my.cnf': ensure => present }" --targets <targets> ``` Bolt Resources and References ----------------------------- * [Bolt documentation](https://puppet.com/docs/bolt/latest/bolt.html). * [Bolt on GitHub](https://github.com/puppetlabs/bolt). Further information about the concepts explained in this page can be found in Bolt documentation: * [Inventory Files](https://puppet.com/docs/bolt/latest/inventory_file_v2.html) in Bolt documentation. * [Applying Puppet code](https://puppet.com/docs/bolt/latest/applying_manifest_blocks.html) in Bolt documentation. --- Content initially contributed by [Vettabase Ltd](https://vettabase.com/). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb Plans for MariaDB 10.8 Plans for MariaDB 10.8 ====================== [MariaDB 10.8](../what-is-mariadb-108/index) is stable, so no new features will be added. See [Plans for MariaDB 10.9](../plans-for-mariadb-109/index) instead. JIRA ---- We manage our development plans in JIRA, so the definitive list will be there. [This search](https://jira.mariadb.org/issues/?jql=project+%3D+MDEV+AND+issuetype+%3D+Task+AND+fixVersion+in+%2810.7%29+ORDER+BY+priority+DESC) shows what we **currently** plan for 10.8. It shows all tasks with the **Fix-Version** being 10.8. Not all these tasks will really end up in 10.8 but tasks with the "red" priorities have a much higher chance of being done in time for 10.8. Practically, you can think of these tasks as "features that **will** be in 10.8". Tasks with the "green" priorities probably won't be in 10.8. Think of them as "bonus features that would be **nice to have** in 10.8". Contributing ------------ If you want to be part of developing any of these features, see [Contributing to the MariaDB Project](../contributing-to-the-mariadb-project/index). You can also add new features to this list or to [JIRA](../jira-project-planning-and-tracking/index). See Also -------- * [Current tasks for 10.8](https://jira.mariadb.org/issues/?jql=project%20%3D%20MDEV%20AND%20issuetype%20%3D%20Task%20AND%20fixVersion%20in%20(10.8)%20ORDER%20BY%20priority%20DESC) * [10.8 Features/fixes by vote](https://jira.mariadb.org/issues/?jql=project%20%3D%20MDEV%20AND%20issuetype%20%3D%20Task%20AND%20fixVersion%20in%20(10.8)%20ORDER%20BY%20votes%20DESC%2C%20priority%20DESC) * [What is MariaDB 10.7?](../what-is-mariadb-107/index) * [What is MariaDB 10.6?](../what-is-mariadb-106/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Buildbot Setup for Virtual Machines - Fedora 17 Buildbot Setup for Virtual Machines - Fedora 17 =============================================== Base install ------------ ``` qemu-img create -f qcow2 /kvm/vms/vm-fedora17-i386-serial.qcow2 10G qemu-img create -f qcow2 /kvm/vms/vm-fedora17-amd64-serial.qcow2 10G ``` Start each VM booting from the server install iso one at a time and perform the following install steps: ``` kvm -m 1024 -hda /kvm/vms/vm-fedora17-i386-serial.qcow2 -cdrom /kvm/iso/fedora/Fedora-17-i386-DVD.iso -redir tcp:2265::22 -boot d -smp 2 -cpu qemu32,-nx -net nic,model=virtio -net user kvm -m 1024 -hda /kvm/vms/vm-fedora17-amd64-serial.qcow2 -cdrom /kvm/iso/fedora/Fedora-17-x86_64-DVD.iso -redir tcp:2266::22 -boot d -smp 2 -cpu qemu64 -net nic,model=virtio -net user ``` Once running you can connect to the VNC server from your local host with: ``` vncviewer -via ${remote-host} localhost ``` Replace ${remote-host} with the host the vm is running on. **Note:** When you activate the install, vncviewer may disconnect with a complaint about the rect being too large. This is fine. The Fedora installer has just resized the vnc screen. Simply reconnect. Install, picking default options mostly, with the following notes: * The Installer will throw up a "Storage Device Warning", choose "Yes, discard any data" * Set the hostname to fedora17-amd64 (or fedora17-i386) * Click the "Configure Network" button on the Hostname screen. + Edit System eth0 to "connect automatically" + Apply and then close the "Network Connections" window * When partitioning disks, choose "Use All Space" + **uncheck** the "Use LVM" checkbox + **do not** check the "Encrypt system" checkbox * Minimal install * Customize Later When the install is finished, you will be prompted to reboot. Go ahead and do so, but it will fail. Kill the VM (after the reboot fails) and start it up again: ``` kvm -m 1024 -hda /kvm/vms/vm-fedora17-i386-serial.qcow2 -redir tcp:2265::22 -boot c -smp 2 -cpu qemu64 -net nic,model=virtio -net user kvm -m 1024 -hda /kvm/vms/vm-fedora17-amd64-serial.qcow2 -redir tcp:2266::22 -boot c -smp 2 -cpu qemu64 -net nic,model=virtio -net user ``` Until the extra user is installed you must connect via VNC as before. SSH is preferred, so that's what we'll do first. Login as root. ``` ssh -p 2265 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -i ~/.ssh/buildbot.id_dsa root@localhost ssh -p 2266 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -i ~/.ssh/buildbot.id_dsa root@localhost ``` After logging in as root, install proper ssh and then create a local user: ``` /sbin/chkconfig --level 35 network on ifup eth0 yum install openssh-server openssh-clients adduser ${username} usermod -a -G wheel ${username} passwd ${username} ``` Enable password-less sudo and serial console: ``` visudo # Uncomment the line "%wheel ALL=(ALL) NOPASSWD: ALL" # Comment out this line: # Defaults requiretty ``` Still logged in as root, add to /boot/grub/menu.lst: Editing /boot/grub/menu.lst: ``` sudo vi /etc/default/grub # Add/edit these entries: GRUB_CMDLINE_LINUX_DEFAULT="console=tty0 console=ttyS0,115200n8" GRUB_TERMINAL="serial" GRUB_SERIAL_COMMAND="serial --unit=0 --speed=115200 --word=8 --parity=no --stop=1" grub2-mkconfig -o /boot/grub2/grub.cfg ``` Logout as root, and then, from the VM host server: Create a .ssh folder: ``` ssh -t -p 2265 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -i ~/.ssh/buildbot.id_dsa localhost "mkdir -v .ssh" ssh -t -p 2266 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -i ~/.ssh/buildbot.id_dsa localhost "mkdir -v .ssh" ``` Copy over the authorized keys file: ``` scp -P 2265 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no /kvm/vms/authorized_keys localhost:.ssh/ scp -P 2266 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no /kvm/vms/authorized_keys localhost:.ssh/ ``` Set permissions on the .ssh folder correctly: ``` ssh -t -p 2265 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -i ~/.ssh/buildbot.id_dsa localhost "chmod -R go-rwx .ssh" ssh -t -p 2266 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -i ~/.ssh/buildbot.id_dsa localhost "chmod -R go-rwx .ssh" ``` Create the buildbot user: ``` ssh -p 2265 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no localhost 'chmod -R go-rwx .ssh; sudo adduser buildbot; sudo usermod -a -G wheel buildbot; sudo mkdir ~buildbot/.ssh; sudo cp -vi .ssh/authorized_keys ~buildbot/.ssh/; sudo chown -vR buildbot:buildbot ~buildbot/.ssh; sudo chmod -vR go-rwx ~buildbot/.ssh' ssh -p 2266 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no localhost 'chmod -R go-rwx .ssh; sudo adduser buildbot; sudo usermod -a -G wheel buildbot; sudo mkdir ~buildbot/.ssh; sudo cp -vi .ssh/authorized_keys ~buildbot/.ssh/; sudo chown -vR buildbot:buildbot ~buildbot/.ssh; sudo chmod -vR go-rwx ~buildbot/.ssh' ``` su to the local buildbot user and ssh to the vm to put the key in known\_hosts: For i386: ``` sudo su - buildbot ssh -p 2265 buildbot@localhost # exit, then exit again ``` For amd64: ``` sudo su - buildbot ssh -p 2266 buildbot@localhost # exit, then exit again ``` Upload the ttyS0 file and put it where it goes: ``` scp -P 2265 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no /kvm/vms/ttyS0 buildbot@localhost: scp -P 2266 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no /kvm/vms/ttyS0 buildbot@localhost: ssh -p 2265 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no buildbot@localhost 'sudo mkdir -v /etc/event.d;sudo mv -vi ttyS0 /etc/event.d/;' ssh -p 2266 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no buildbot@localhost 'sudo mkdir -v /etc/event.d;sudo mv -vi ttyS0 /etc/event.d/;' ``` Update the VM: ``` ssh -p 2265 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no buildbot@localhost ssh -p 2266 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no buildbot@localhost ``` Once logged in: ``` sudo yum update ``` After updating, shut down the VM: ``` sudo shutdown -h now ``` VMs for building .rpms ---------------------- On the VM host server: ``` qemu-img create -b /kvm/vms/vm-fedora17-i386-serial.qcow2 -f qcow2 /kvm/vms/vm-fedora17-i386-build.qcow2 qemu-img create -b /kvm/vms/vm-fedora17-amd64-serial.qcow2 -f qcow2 /kvm/vms/vm-fedora17-amd64-build.qcow2 ``` Boot the VMs with: ``` kvm -m 1024 -hda /kvm/vms/vm-fedora17-i386-build.qcow2 -redir tcp:2265::22 -boot c -smp 2 -cpu qemu64 -net nic,model=virtio -net user -nographic kvm -m 1024 -hda /kvm/vms/vm-fedora17-amd64-build.qcow2 -redir tcp:2266::22 -boot c -smp 2 -cpu qemu64 -net nic,model=virtio -net user -nographic ``` Copy over the boost tar file: ``` scp -P 2265 -i /kvm/vms/ssh-keys/id_dsa -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null /kvm/boost_1_49_0.tar.gz buildbot@localhost:/dev/shm/ scp -P 2266 -i /kvm/vms/ssh-keys/id_dsa -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null /kvm/boost_1_49_0.tar.gz buildbot@localhost:/dev/shm/ ``` Login to the VMs: ``` ssh -p 2265 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no buildbot@localhost ssh -p 2266 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no buildbot@localhost ``` Once logged in: ``` sudo yum -y groupinstall 'Development Tools' sudo yum -y install tar wget tree gperf readline-devel ncurses-devel zlib-devel pam-devel libaio-devel openssl-devel perl perl\(DBI\) sudo yum -y remove systemtap-sdt-dev sudo mkdir -vp /usr/src/redhat/SOURCES /usr/src/redhat/SPECS /usr/src/redhat/RPMS /usr/src/redhat/SRPMS # cmake wget http://www.cmake.org/files/v2.8/cmake-2.8.8.tar.gz;tar -zxvf cmake-2.8.8.tar.gz;cd cmake-2.8.8;./configure;make;sudo make install # boost cd /usr/local/src;sudo tar zxf /dev/shm/boost_1_49_0.tar.gz;cd /usr/local/include/;sudo ln -s ../src/boost_1_49_0/boost . # shutdown the VM sudo shutdown -h now ``` VMs for install testing. ------------------------ On the VM host server: ``` qemu-img create -b /kvm/vms/vm-fedora17-i386-serial.qcow2 -f qcow2 /kvm/vms/vm-fedora17-i386-install.qcow2 qemu-img create -b /kvm/vms/vm-fedora17-amd64-serial.qcow2 -f qcow2 /kvm/vms/vm-fedora17-amd64-install.qcow2 ``` Boot the VMs with: ``` kvm -m 1024 -hda /kvm/vms/vm-fedora17-i386-install.qcow2 -redir tcp:2265::22 -boot c -smp 2 -cpu qemu64 -net nic,model=virtio -net user -nographic kvm -m 1024 -hda /kvm/vms/vm-fedora17-amd64-install.qcow2 -redir tcp:2266::22 -boot c -smp 2 -cpu qemu64 -net nic,model=virtio -net user -nographic ``` Login to the VMs: ``` ssh -p 2265 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no buildbot@localhost ssh -p 2266 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no buildbot@localhost ``` Once logged in: ``` sudo yum -y update sudo yum -y install patch tar libaio perl perl-Time-HiRes perl-DBI # shutdown the VM sudo shutdown -h now ``` VMs for MySQL upgrade testing ----------------------------- On the VM host server: ``` qemu-img create -b /kvm/vms/vm-fedora17-i386-serial.qcow2 -f qcow2 /kvm/vms/vm-fedora17-i386-upgrade.qcow2 qemu-img create -b /kvm/vms/vm-fedora17-amd64-serial.qcow2 -f qcow2 /kvm/vms/vm-fedora17-amd64-upgrade.qcow2 ``` Boot the VMs with: ``` kvm -m 1024 -hda /kvm/vms/vm-fedora17-i386-upgrade.qcow2 -redir tcp:2265::22 -boot c -smp 2 -cpu qemu64 -net nic,model=virtio -net user -nographic kvm -m 1024 -hda /kvm/vms/vm-fedora17-amd64-upgrade.qcow2 -redir tcp:2266::22 -boot c -smp 2 -cpu qemu64 -net nic,model=virtio -net user -nographic ``` Login to the VMs: ``` ssh -p 2265 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no buildbot@localhost ssh -p 2266 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no buildbot@localhost ``` Once logged in: ``` sudo yum -y update sudo yum -y install tar mysql-server sudo systemctl enable mysqld.service sudo systemctl start mysqld.service mysql -uroot -e "create database mytest; use mytest; create table t(a int primary key); insert into t values (1); select * from t" # shutdown the VM sudo shutdown -h now ``` The MariaDB upgrade testing VMs were not built. Once we have MariaDB Fedora 17 RPMs, then I will attempt building this VM. For now, the placeholder text below is copied from the [Buildbot Setup for Virtual Machines - CentOS 6.2](../buildbot-setup-for-virtual-machines-centos-62/index) page. VMs for MariaDB upgrade testing ------------------------------- ``` for i in '/kvm/vms/vm-fedora17-amd64-serial.qcow2 2266 qemu64' '/kvm/vms/vm-fedora17-i386-serial.qcow2 2265 qemu64' ; do \ set $i; \ runvm --user=buildbot --logfile=kernel_$2.log --base-image=$1 --port=$2 --cpu=$3 "$(echo $1 | sed -e 's/serial/upgrade2/')" \ 'sudo yum -y update' \ "= scp -P $2 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no /kvm/vms/MariaDB.repo buildbot@localhost:/tmp/" \ 'sudo rpm --verbose --import http://downloads.mariadb.org/repo/RPM-GPG-KEY-MariaDB' \ 'sudo mv -vi /tmp/MariaDB.repo /etc/yum.repos.d/' \ 'sudo yum -y remove mysql-libs' \ 'sudo yum -y install MariaDB-server MariaDB-client MariaDB-test' \ 'sudo yum -y install cronie cronie-anacron crontabs.noarch postfix' \ 'sudo /etc/init.d/mysqld start' \ 'mysql -uroot -prootpass -e "create database mytest; use mytest; create table t(a int primary key); insert into t values (1); select * from t"' \ 'sudo rm -v /etc/yum.repos.d/MariaDB.repo' \ "= scp -P $2 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no /kvm/vms/MariaDB.local.repo buildbot@localhost:/tmp/" \ 'sudo mv -vi /tmp/MariaDB.local.repo /etc/yum.repos.d/'; \ done ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Password Validation Plugins Password Validation Plugins ============================ | Title | Description | | --- | --- | | [Simple Password Check Plugin](../simple-password-check-plugin/index) | This plugin checks that passwords meet certain simple criteria. | | [Cracklib Password Check Plugin](../cracklib-password-check-plugin/index) | This plugin checks password strength using the CrackLib library. | | [Password Reuse Check Plugin](../password-reuse-check-plugin/index) | Plugin for preventing password reuse. | | [Password Validation Plugin API](../password-validation/index) | Allows the creation of password validation plugins to check user passwords as they are set. | | [password\_reuse\_check\_interval](../password_reuse_check_interval/index) | Retention period for password history. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Stored Procedures Stored Procedures ================== A stored procedure is a routine invoked with a CALL statement. It may have input parameters, output parameters and parameters that are both input parameters and output parameters. | Title | Description | | --- | --- | | [Stored Procedure Overview](../stored-procedure-overview/index) | A Stored Procedure is a routine invoked with a CALL statement. | | [Stored Routine Privileges](../stored-routine-privileges/index) | Privileges associated with stored functions and stored procedures. | | [CREATE PROCEDURE](../create-procedure/index) | Creates a stored procedure. | | [ALTER PROCEDURE](../alter-procedure/index) | Change stored procedure characteristics. | | [DROP PROCEDURE](../drop-procedure/index) | Drop stored procedure. | | [SHOW CREATE PROCEDURE](../show-create-procedure/index) | Returns the string used for creating a stored procedure. | | [SHOW PROCEDURE CODE](../show-procedure-code/index) | Display internal implementation of a stored procedure. | | [SHOW PROCEDURE STATUS](../show-procedure-status/index) | Stored procedure characteristics. | | [Binary Logging of Stored Routines](../binary-logging-of-stored-routines/index) | Stored routines require extra consideration when binary logging. | | [Information Schema ROUTINES Table](../information-schema-routines-table/index) | Stored procedures and stored functions information | | [SQL\_MODE=ORACLE](../sql_modeoracle/index) | MariaDB understands a subset of Oracle's PL/SQL language. | | [Stored Procedure Internals](../stored-procedure-internals/index) | Internal implementation of MariaDB stored procedures. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb GeomCollFromText GeomCollFromText ================ A synonym for [ST\_GeomCollFromText](../st_geomcollfromtext/index). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Plugin Overview Plugin Overview =============== Plugins are server components that enhance MariaDB in some way. These can be anything from new storage engines, plugins for enhancing full-text parsing, or even small enhancements, such as a plugin to get a timestamp as an integer. Querying Plugin Information --------------------------- There are a number of ways to see which plugins are currently active. A server almost always has a large number of active plugins, because the server contains a large number of built-in plugins, which are active by default and cannot be uninstalled. ### Querying Plugin Information with `SHOW PLUGINS` The [SHOW PLUGINS](../show-plugins/index) statement can be used to query information about all active plugins. For example: ``` SHOW PLUGINS\G; ********************** 1. row ********************** Name: binlog Status: ACTIVE Type: STORAGE ENGINE Library: NULL License: GPL ********************** 2. row ********************** Name: mysql_native_password Status: ACTIVE Type: AUTHENTICATION Library: NULL License: GPL ********************** 3. row ********************** Name: mysql_old_password Status: ACTIVE Type: AUTHENTICATION Library: NULL License: GPL ... ``` If a plugin's `Library` column has a `NULL` value, then the plugin is built-in, and it cannot be uninstalled. ### Querying Plugin Information with information\_schema.PLUGINS The [information\_schema.PLUGINS](../information_schemaplugins-table/index) table can be queried to get more detailed information about plugins. For example: ``` SELECT * FROM information_schema.PLUGINS\G ... *************************** 6. row *************************** PLUGIN_NAME: CSV PLUGIN_VERSION: 1.0 PLUGIN_STATUS: ACTIVE PLUGIN_TYPE: STORAGE ENGINE PLUGIN_TYPE_VERSION: 100003.0 PLUGIN_LIBRARY: NULL PLUGIN_LIBRARY_VERSION: NULL PLUGIN_AUTHOR: Brian Aker, MySQL AB PLUGIN_DESCRIPTION: CSV storage engine PLUGIN_LICENSE: GPL LOAD_OPTION: FORCE PLUGIN_MATURITY: Stable PLUGIN_AUTH_VERSION: 1.0 *************************** 7. row *************************** PLUGIN_NAME: MEMORY PLUGIN_VERSION: 1.0 PLUGIN_STATUS: ACTIVE PLUGIN_TYPE: STORAGE ENGINE PLUGIN_TYPE_VERSION: 100003.0 PLUGIN_LIBRARY: NULL PLUGIN_LIBRARY_VERSION: NULL PLUGIN_AUTHOR: MySQL AB PLUGIN_DESCRIPTION: Hash based, stored in memory, useful for temporary tables PLUGIN_LICENSE: GPL LOAD_OPTION: FORCE PLUGIN_MATURITY: Stable PLUGIN_AUTH_VERSION: 1.0 ... ``` If a plugin's `PLUGIN_LIBRARY` column has the `NULL` value, then the plugin is built-in, and it cannot be uninstalled. ### Querying Plugin Information with `mysql.plugin` The [mysql.plugin](../mysqlplugin-table/index) table can be queried to get information about installed plugins. This table only contains information about plugins that have been installed via the following methods: * The [INSTALL SONAME](../install-soname/index) statement. * The [INSTALL PLUGIN](../install-plugin/index) statement. * The [mysql\_plugin](../mysql_plugin/index) utility. This table does not contain information about: * Built-in plugins. * Plugins loaded with the [--plugin-load-add](../mysqld-options/index#-plugin-load-add) option. * Plugins loaded with the [--plugin-load](../mysqld-options/index#-plugin-load) option. This table only contains enough information to reload the plugin when the server is restarted, which means it only contains the plugin name and the plugin library. For example: ``` SELECT * FROM mysql.plugin; +------+------------+ | name | dl | +------+------------+ | PBXT | libpbxt.so | +------+------------+ ``` Installing a Plugin ------------------- There are three primary ways to install a plugin: * A plugin can be installed dynamically with an SQL statement. * A plugin can be installed with a [mysqld](../mysqld-options/index) option, but it requires a server restart. * A plugin can be installed with the [mysql\_plugin](../mysql_plugin/index) utility, while the server is completely offline. When you are installing a plugin, you also have to ensure that: * The server's plugin directory is properly configured, and the plugin's library is in the plugin directory. * The server's minimum plugin maturity is properly configured, and the plugin is mature enough to be installed. ### Installing a Plugin Dynamically A plugin can be installed dynamically by executing either the [INSTALL SONAME](../install-soname/index) or the [INSTALL PLUGIN](../install-plugin/index) statement. If a plugin is installed with one of these statements, then a record will be added to the [mysql.plugins](../mysqlplugin-table/index) table for the plugin. This means that the plugin will automatically be loaded every time the server restarts, unless specifically uninstalled or deactivated. #### Installing a Plugin with `INSTALL SONAME` You can install a plugin dynamically by executing the [INSTALL SONAME](../install-soname/index) statement. [INSTALL SONAME](../install-soname/index) installs all plugins from the given plugin library. This could be required for some plugin libraries. For example, to install all plugins in the `server_audit` plugin library (which is currently only the [server\_audit](../mariadb-audit-plugin/index) audit plugin), you could execute the following: ``` INSTALL SONAME 'server_audit'; ``` #### Installing a Plugin with `INSTALL PLUGIN` You can install a plugin dynamically by executing the [INSTALL PLUGIN](../install-plugin/index) statement. [INSTALL PLUGIN](../install-plugin/index) installs a single plugin from the given plugin library. For example, to install the [server\_audit](../mariadb-audit-plugin/index) audit plugin from the `server_audit` plugin library, you could execute the following: ``` INSTALL PLUGIN server_audit SONAME 'server_audit'; ``` ### Installing a Plugin with Plugin Load Options A plugin can be installed with a [mysqld](../mysqld-options/index) option by providing either the [--plugin-load-add](../mysqld-options/index#-plugin-load-add) or the [--plugin-load](../mysqld-options/index#-plugin-load) option. If a plugin is installed with one of these options, then a record will **not** be added to the [mysql.plugins](../mysqlplugin-table/index) table for the plugin. This means that if the server is restarted without the same option set, then the plugin will **not** automatically be loaded. #### Installing a Plugin with `--plugin-load-add` You can install a plugin with the `[--plugin-load-add](../mysqld-options/index#-plugin-load-add)` option by specifying the option as a command-line argument to `[mysqld](../mysqld-options/index)` or by specifying the option in a relevant server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index). The `[--plugin-load-add](../mysqld-options/index#-plugin-load-add)` option uses the following format: * Plugins can be specified in the format `name=library`, where `name` is the plugin name and `library` is the plugin library. This format installs a single plugin from the given plugin library. * Plugins can also be specified in the format `library`, where `library` is the plugin library. This format installs all plugins from the given plugin library. * Multiple plugins can be specified by separating them with semicolons. For example, to install all plugins in the `server_audit` plugin library (which is currently only the `[server\_audit](../mariadb-audit-plugin/index)` audit plugin) and also the `[ed25519](../authentication-plugin-ed25519/index)` authentication plugin from the `auth_ed25519` plugin library, you could set the option to the following values on the command-line: ``` $ mysqld --user=mysql --plugin-load-add='server_audit' --plugin-load-add='ed25519=auth_ed25519' ``` You could also set the option to the same values in an [option file](../configuring-mariadb-with-option-files/index): ``` [mariadb] ... plugin_load_add = server_audit plugin_load_add = ed25519=auth_ed25519 ``` Special care must be taken when specifying both the `[--plugin-load](../mysqld-options/index#-plugin-load)` option and the `[--plugin-load-add](../mysqld-options/index#-plugin-load-add)` option together. The `[--plugin-load](../mysqld-options/index#-plugin-load)` option resets the plugin load list, and this can cause unexpected problems if you are not aware. The `[--plugin-load-add](../mysqld-options/index#-plugin-load-add)` option does **not** reset the plugin load list, so it is much safer to use. See [Specifying Multiple Plugin Load Options](#specifying-multiple-plugin-load-options) for more information. #### Installing a Plugin with `--plugin-load` You can install a plugin with the `[--plugin-load](../mysqld-options/index#-plugin-load)` option by specifying the option as a command-line argument to `[mysqld](../mysqld-options/index)` or by specifying the option in a relevant server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index). The `[--plugin-load](../mysqld-options/index#-plugin-load)` option uses the following format: * Plugins can be specified in the format `name=library`, where `name` is the plugin name and `library` is the plugin library. This format installs a single plugin from the given plugin library. * Plugins can also be specified in the format `library`, where `library` is the plugin library. This format installs all plugins from the given plugin library. * Multiple plugins can be specified by separating them with semicolons. For example, to install all plugins in the `server_audit` plugin library (which is currently only the `[server\_audit](../mariadb-audit-plugin/index)` audit plugin) and also the `[ed25519](../authentication-plugin-ed25519/index)` authentication plugin from the `auth_ed25519` plugin library, you could set the option to the following values on the command-line: ``` $ mysqld --user=mysql --plugin-load='server_audit;ed25519=auth_ed25519' ``` You could also set the option to the same values in an [option file](../configuring-mariadb-with-option-files/index): ``` [mariadb] ... plugin_load = server_audit;ed25519=auth_ed25519 ``` Special care must be taken when specifying the `[--plugin-load](../mysqld-options/index#-plugin-load)` option multiple times, or when specifying both the `[--plugin-load](../mysqld-options/index#-plugin-load)` option and the `[--plugin-load-add](../mysqld-options/index#-plugin-load-add)` option together. The `[--plugin-load](../mysqld-options/index#-plugin-load)` option resets the plugin load list, and this can cause unexpected problems if you are not aware. The `[--plugin-load-add](../mysqld-options/index#-plugin-load-add)` option does **not** reset the plugin load list, so it is much safer to use. See [Specifying Multiple Plugin Load Options](#specifying-multiple-plugin-load-options) for more information. #### Specifying Multiple Plugin Load Options Special care must be taken when specifying the `[--plugin-load](../mysqld-options/index#-plugin-load)` option multiple times, or when specifying both the `[--plugin-load](../mysqld-options/index#-plugin-load)` option and the `[--plugin-load-add](../mysqld-options/index#-plugin-load-add)` option. The `[--plugin-load](../mysqld-options/index#-plugin-load)` option resets the plugin load list, and this can cause unexpected problems if you are not aware. The `[--plugin-load-add](../mysqld-options/index#-plugin-load-add)` option does **not** reset the plugin load list, so it is much safer to use. This can have the following consequences: * If the `[--plugin-load](../mysqld-options/index#-plugin-load)` option is specified **multiple times**, then only the last instance will have any effect. For example, in the following case, the first instance of the option is reset: ``` [mariadb] ... plugin_load = server_audit plugin_load = ed25519=auth_ed25519 ``` * If the `[--plugin-load](../mysqld-options/index#-plugin-load)` option is specified **after** the `[--plugin-load-add](../mysqld-options/index#-plugin-load-add)` option, then it will also reset the changes made by that option. For example, in the following case, the `[--plugin-load-add](../mysqld-options/index#-plugin-load-add)` option does not do anything, because the subsequent `[--plugin-load](../mysqld-options/index#-plugin-load)` option resets the plugin load list: ``` [mariadb] ... plugin_load_add = server_audit plugin_load = ed25519=auth_ed25519 ``` * In contrast, if the `[--plugin-load](../mysqld-options/index#-plugin-load)` option is specified **before** the `[--plugin-load-add](../mysqld-options/index#-plugin-load-add)` option, then it will work fine, because the `[--plugin-load-add](../mysqld-options/index#-plugin-load-add)` option does not reset the plugin load list. For example, in the following case, both plugins are properly loaded: ``` [mariadb] ... plugin_load = server_audit plugin_load_add = ed25519=auth_ed25519 ``` ### Installing a Plugin with `mysql_plugin` A plugin can be installed with the `[mysql\_plugin](../mysql_plugin/index)` utility if the server is completely offline. The syntax is: ``` mysql_plugin [options] <plugin> ENABLE|DISABLE ``` For example, to install the `[server\_audit](../mariadb-audit-plugin/index)` audit plugin, you could execute the following: ``` mysql_plugin server_audit ENABLE ``` If a plugin is installed with this utility, then a record will be added to the `[mysql.plugins](../mysqlplugin-table/index)` table for the plugin. This means that the plugin will automatically be loaded every time the server restarts, unless specifically uninstalled or deactivated. ### Configuring the Plugin Directory When a plugin is being installed, the server looks for the plugin's library in the server's plugin directory. This directory is configured by the `[plugin\_dir](../server-system-variables/index#plugin_dir)` system variable. This can be specified as a command-line argument to `[mysqld](../mysqld-options/index)` or it can be specified in a relevant server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index). For example: ``` [mariadb] ... plugin_dir = /usr/lib64/mysql/plugin ``` ### Configuring the Minimum Plugin Maturity When a plugin is being installed, the server compares the plugin's maturity level against the server's minimum allowed plugin maturity. This can help prevent users from using unstable plugins on production servers. This minimum plugin maturity is configured by the `[plugin\_maturity](../server-system-variables/index#plugin_maturity)` system variable. This can be specified as a command-line argument to `[mysqld](../mysqld-options/index)` or it can be specified in a relevant server [option group](../configuring-mariadb-with-option-files/index#option-groups) in an [option file](../configuring-mariadb-with-option-files/index). For example: ``` [mariadb] ... plugin_maturity = stable ``` ### Configuring Plugin Activation at Server Startup A plugin will be loaded by default when the server starts if: * The plugin was installed with the `[INSTALL SONAME](../install-soname/index)` statement. * The plugin was installed with the `[INSTALL PLUGIN](../install-plugin/index)` statement. * The plugin was installed with the `[mysql\_plugin](../mysql_plugin/index)` utility. * The server is configured to load the plugin with the `[--plugin-load-add](../mysqld-options/index#-plugin-load-add)` option. * The server is configured to load the plugin with the `[--plugin-load](../mysqld-options/index#-plugin-load)` option. This behavior can be changed with special options that take the form `--plugin-name`. For example, for the `[server\_audit](../mariadb-audit-plugin/index)` audit plugin, the special option is called `[--server-audit](../mariadb-audit-plugin-system-variables/index#server_audit)`. The possible values for these special options are: | Option Value | Description | | --- | --- | | `OFF` | Disables the plugin without removing it from the `[mysql.plugins](../mysqlplugin-table/index)` table. | | `ON` | Enables the plugin. If the plugin cannot be initialized, then the server will still continue starting up, but the plugin will be disabled. | | `FORCE` | Enables the plugin. If the plugin cannot be initialized, then the server will fail to start with an error. | | `FORCE_PLUS_PERMANENT` | Enables the plugin. If the plugin cannot be initialized, then the server will fail to start with an error. In addition, the plugin cannot be uninstalled with `[UNINSTALL SONAME](../uninstall-soname/index)` or `[UNINSTALL PLUGIN](../uninstall-plugin/index)` while the server is running. | A plugin's status can be found by looking at the `PLUGIN_STATUS` column of the `[information\_schema.PLUGINS](../information_schemaplugins-table/index)` table. Uninstalling Plugins -------------------- Plugins that are found in the mysql.plugin table, that is those that were installed with [INSTALL SONAME](../install-soname/index), [INSTALL PLUGIN](../install-plugin/index) or [mysql\_plugin](../mysql_plugin/index) can be uninstalled in one of two ways: * The [UNINSTALL SONAME](../uninstall-soname/index) or the [UNINSTALL PLUGIN](../uninstall-plugin/index) statement while the server is running * With [mysql\_plugin](../mysql_plugin/index) while the server is offline. Plugins that were enabled as a `--plugin-load` option do not need to be uninstalled. If `--plugin-load` is omitted the next time the server starts, or the plugin is not listed as one of the `--plugin-load` entries, the plugin will not be loaded. [UNINSTALL PLUGIN](../uninstall-plugin/index) uninstalls a single installed plugin, while [UNINSTALL SONAME](../uninstall-soname/index) uninstalls all plugins belonging to a given library. See Also -------- * [List of Plugins](../list-of-plugins/index) * [INSTALL PLUGIN](../install-plugin/index) * [INSTALL SONAME](../install-soname/index) * [UNINSTALL PLUGIN](../uninstall-plugin/index) * [UNINSTALL SONAME](../uninstall-soname/index) * [SHOW PLUGINS](../show-plugins/index) * [INFORMATION\_SCHEMA.PLUGINS Table](../plugins-table-information-schema/index) * [mysql\_plugin](../mysql_plugin/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb DOUBLE PRECISION DOUBLE PRECISION ================ Syntax ------ ``` DOUBLE PRECISION[(M,D)] [SIGNED | UNSIGNED | ZEROFILL] REAL[(M,D)] [SIGNED | UNSIGNED | ZEROFILL] ``` Description ----------- REAL and DOUBLE PRECISION are synonyms for [DOUBLE](../double/index). Exception: If the REAL\_AS\_FLOAT [SQL mode](../sql_mode/index) is enabled, REAL is a synonym for [FLOAT](../float/index) rather than [DOUBLE](../double/index). Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Derived Table Merge Optimization Derived Table Merge Optimization ================================ Background ---------- Users of "big" database systems are used to using `FROM` subqueries as a way to structure their queries. For example, if one's first thought was to select cities with population greater than 10,000 people, and then that from these cities to select those that are located in Germany, one could write this SQL: ``` SELECT * FROM (SELECT * FROM City WHERE Population > 10*1000) AS big_city WHERE big_city.Country='DEU' ``` For MySQL, using such syntax was taboo. If you run `[EXPLAIN](../explain/index)` for this query, you can see why: ``` mysql> EXPLAIN SELECT * FROM (SELECT * FROM City WHERE Population > 1*1000) AS big_city WHERE big_city.Country='DEU' ; +----+-------------+------------+------+---------------+------+---------+------+------+-------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+------------+------+---------------+------+---------+------+------+-------------+ | 1 | PRIMARY | <derived2> | ALL | NULL | NULL | NULL | NULL | 4068 | Using where | | 2 | DERIVED | City | ALL | Population | NULL | NULL | NULL | 4079 | Using where | +----+-------------+------------+------+---------------+------+---------+------+------+-------------+ 2 rows in set (0.60 sec) ``` It plans to do the following actions: From left to right: 1. Execute the subquery: `(SELECT * FROM City WHERE Population > 1*1000)`, exactly as it was written in the query. 2. Put result of the subquery into a temporary table. 3. Read back, and apply a `WHERE` condition from the upper select, `big_city.Country='DEU'` Executing a subquery like this is very inefficient, because the highly-selective condition from the parent select, (`Country='DEU'`) is not used when scanning the base table `City`. We read too many records from the `City` table, and then we have to write them into a temporary table and read them back again, before finally filtering them out. Derived table merge in action ----------------------------- If one runs this query in MariaDB/MySQL 5.6, they get this: ``` MariaDB [world]> EXPLAIN SELECT * FROM (SELECT * FROM City WHERE Population > 1*1000) AS big_city WHERE big_city.Country='DEU'; +----+-------------+-------+------+--------------------+---------+---------+-------+------+------------------------------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+-------+------+--------------------+---------+---------+-------+------+------------------------------------+ | 1 | SIMPLE | City | ref | Population,Country | Country | 3 | const | 90 | Using index condition; Using where | +----+-------------+-------+------+--------------------+---------+---------+-------+------+------------------------------------+ 1 row in set (0.00 sec) ``` From the above, one can see that: 1. The output has only one line. This means that the subquery has been merged into the top-level `SELECT`. 2. Table `City` is accessed through an index on the `Country` column. Apparently, the `Country='DEU'` condition was used to construct `ref` access on the table. 3. The query will read about 90 rows, which is a big improvement over the 4079 row reads plus 4068 temporary table reads/writes we had before. Factsheet --------- * Derived tables (subqueries in the `FROM` clause) can be merged into their parent select when they have no grouping, aggregates, or `ORDER BY ... LIMIT` clauses. These requirements are the same as requirements for `VIEW`s to allow `algorithm=merge`. * The optimization is enabled by default. It can be disabled with: ``` set @@optimizer_switch='derived_merge=OFF' ``` * Versions of MySQL and MariaDB which do not have support for this optimization will execute subqueries even when running `EXPLAIN`. This can result in a well-known problem (see e.g. [MySQL Bug #44802](http://bugs.mysql.com/bug.php?id=44802)) of `EXPLAIN` statements taking a very long time. Starting from [MariaDB 5.3](../what-is-mariadb-53/index)+ and MySQL 5.6+ `EXPLAIN` commands execute instantly, regardless of the `derived_merge` setting. See Also -------- * FAQ entry: [Why is ORDER BY in a FROM subquery ignored?](../why-is-order-by-in-a-from-subquery-ignored/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Triggers and Implicit Locks Triggers and Implicit Locks =========================== A [trigger](../triggers/index) may reference multiple tables, and if a `[LOCK TABLES](../lock-tables/index)` statement is used on one of the tables, other tables may at the same time also implicitly be locked due to the trigger. If the trigger only reads from the other table, that table will be read locked. If the trigger writes to the other table, it will be write locked. If a table is read-locked for reading via `LOCK TABLES`, but needs to be write-locked because it could be modified by a trigger, a write lock is taken. All locks are acquired together when the `LOCK TABLES` statement is issued and they are released together on `UNLOCK TABLES`. Example ------- ``` LOCK TABLE table1 WRITE ``` Assume `table1` contains the following trigger: ``` CREATE TRIGGER trigger1 AFTER INSERT ON table1 FOR EACH ROW BEGIN INSERT INTO table2 VALUES (1); UPDATE table3 SET writes = writes+1 WHERE id = NEW.id AND EXISTS (SELECT id FROM table4); END; ``` Not only is `table1` write locked, `table2` and `table3` are also write locked, due to the possible `[INSERT](../insert/index)` and `[UPDATE](../update/index)`, while `table4` is read locked due to the `[SELECT](../select/index)`. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb 10.2.13 Release Upgrade Tests 10.2.13 Release Upgrade Tests ============================= ### Tested revision 00f0c039d2f4213ccf0a0202349ecb162a799989 ### Test date 2018-02-15 22:17:40 ### Summary Some tests failed due to [MDEV-13103](https://jira.mariadb.org/browse/MDEV-13103), [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094) as usual. ### Details | type | pagesize | OLD version | file format | encrypted | compressed | | NEW version | file format | encrypted | compressed | readonly | result | notes | | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | | recovery | 16 | 10.2.13 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | recovery | 16 | 10.2.13 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13103](https://jira.mariadb.org/browse/MDEV-13103)(1) | | recovery | 4 | 10.2.13 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | recovery | 4 | 10.2.13 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13103](https://jira.mariadb.org/browse/MDEV-13103)(1) | | recovery | 32 | 10.2.13 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13103](https://jira.mariadb.org/browse/MDEV-13103)(1) | | recovery | 32 | 10.2.13 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | recovery | 64 | 10.2.13 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | recovery | 64 | 10.2.13 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13103](https://jira.mariadb.org/browse/MDEV-13103)(1) | | recovery | 8 | 10.2.13 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | recovery | 8 | 10.2.13 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13103](https://jira.mariadb.org/browse/MDEV-13103)(1) | | recovery | 16 | 10.2.13 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | recovery | 16 | 10.2.13 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | recovery | 4 | 10.2.13 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | recovery | 4 | 10.2.13 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | recovery | 32 | 10.2.13 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | recovery | 32 | 10.2.13 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | recovery | 64 | 10.2.13 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | recovery | 64 | 10.2.13 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | recovery | 8 | 10.2.13 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | recovery | 8 | 10.2.13 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo-recovery | 16 | 10.2.13 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | undo-recovery | 4 | 10.2.13 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | undo-recovery | 32 | 10.2.13 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | undo-recovery | 64 | 10.2.13 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | undo-recovery | 8 | 10.2.13 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | undo-recovery | 16 | 10.2.13 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | undo-recovery | 4 | 10.2.13 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | undo-recovery | 32 | 10.2.13 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | undo-recovery | 64 | 10.2.13 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | undo-recovery | 8 | 10.2.13 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | undo-recovery | 16 | 10.2.13 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13103](https://jira.mariadb.org/browse/MDEV-13103)(1) | | undo-recovery | 4 | 10.2.13 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13103](https://jira.mariadb.org/browse/MDEV-13103)(1) | | undo-recovery | 32 | 10.2.13 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13103](https://jira.mariadb.org/browse/MDEV-13103)(1) | | undo-recovery | 64 | 10.2.13 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13103](https://jira.mariadb.org/browse/MDEV-13103)(1) | | undo-recovery | 8 | 10.2.13 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13103](https://jira.mariadb.org/browse/MDEV-13103)(1) | | undo-recovery | 16 | 10.2.13 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo-recovery | 4 | 10.2.13 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo-recovery | 32 | 10.2.13 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo-recovery | 64 | 10.2.13 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo-recovery | 8 | 10.2.13 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | normal | 16 | 10.2.12 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 16 | 10.2.12 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 4 | 10.2.12 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 4 | 10.2.12 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 32 | 10.2.12 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 32 | 10.2.12 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 64 | 10.2.12 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 64 | 10.2.12 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 8 | 10.2.12 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 8 | 10.2.12 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 16 | 10.2.12 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 16 | 10.2.12 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 4 | 10.2.12 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 4 | 10.2.12 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 32 | 10.2.12 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 32 | 10.2.12 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 64 | 10.2.12 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 64 | 10.2.12 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 8 | 10.2.12 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 8 | 10.2.12 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | crash | 16 | 10.2.12 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | crash | 16 | 10.2.12 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13103](https://jira.mariadb.org/browse/MDEV-13103)(1) | | crash | 4 | 10.2.12 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | crash | 4 | 10.2.12 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13103](https://jira.mariadb.org/browse/MDEV-13103)(1) | | crash | 32 | 10.2.12 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13103](https://jira.mariadb.org/browse/MDEV-13103)(1) | | crash | 32 | 10.2.12 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | crash | 64 | 10.2.12 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | crash | 64 | 10.2.12 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13103](https://jira.mariadb.org/browse/MDEV-13103)(1) | | crash | 8 | 10.2.12 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | crash | 8 | 10.2.12 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13103](https://jira.mariadb.org/browse/MDEV-13103)(1) | | crash | 16 | 10.2.12 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | crash | 16 | 10.2.12 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | crash | 4 | 10.2.12 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | crash | 4 | 10.2.12 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | crash | 32 | 10.2.12 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | crash | 32 | 10.2.12 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | crash | 64 | 10.2.12 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | crash | 64 | 10.2.12 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | crash | 8 | 10.2.12 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | crash | 8 | 10.2.12 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 16 | 10.2.12 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 4 | 10.2.12 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 32 | 10.2.12 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 64 | 10.2.12 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 8 | 10.2.12 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 16 | 10.2.12 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 4 | 10.2.12 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 32 | 10.2.12 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 64 | 10.2.12 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 8 | 10.2.12 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 16 | 10.2.12 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 4 | 10.2.12 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 32 | 10.2.12 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 64 | 10.2.12 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 8 | 10.2.12 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 16 | 10.2.12 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 4 | 10.2.12 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 32 | 10.2.12 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 64 | 10.2.12 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 8 | 10.2.12 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | normal | 16 | 10.2.6 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 16 | 10.2.6 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 4 | 10.2.6 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 4 | 10.2.6 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 32 | 10.2.6 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 32 | 10.2.6 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 64 | 10.2.6 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 64 | 10.2.6 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 8 | 10.2.6 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 8 | 10.2.6 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 16 | 10.2.6 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 16 | 10.2.6 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 4 | 10.2.6 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 4 | 10.2.6 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 32 | 10.2.6 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 32 | 10.2.6 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 64 | 10.2.6 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 64 | 10.2.6 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 8 | 10.2.6 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | normal | 8 | 10.2.6 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13094](https://jira.mariadb.org/browse/MDEV-13094)(1) | | crash | 16 | 10.2.6 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | crash | 16 | 10.2.6 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13103](https://jira.mariadb.org/browse/MDEV-13103)(1) | | crash | 4 | 10.2.6 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | crash | 4 | 10.2.6 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13103](https://jira.mariadb.org/browse/MDEV-13103)(1) | | crash | 32 | 10.2.6 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13103](https://jira.mariadb.org/browse/MDEV-13103)(1) | | crash | 32 | 10.2.6 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | crash | 64 | 10.2.6 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | crash | 64 | 10.2.6 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13103](https://jira.mariadb.org/browse/MDEV-13103)(1) | | crash | 8 | 10.2.6 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | crash | 8 | 10.2.6 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | **FAIL** | KNOWN\_BUGS [MDEV-13103](https://jira.mariadb.org/browse/MDEV-13103)(1) | | crash | 16 | 10.2.6 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | crash | 16 | 10.2.6 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | crash | 4 | 10.2.6 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | crash | 4 | 10.2.6 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | crash | 32 | 10.2.6 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | crash | 32 | 10.2.6 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | crash | 64 | 10.2.6 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | crash | 64 | 10.2.6 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | crash | 8 | 10.2.6 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | crash | 8 | 10.2.6 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 16 | 10.2.6 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 4 | 10.2.6 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 32 | 10.2.6 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 64 | 10.2.6 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 8 | 10.2.6 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 16 | 10.2.6 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 4 | 10.2.6 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 32 | 10.2.6 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 64 | 10.2.6 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 8 | 10.2.6 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 16 | 10.2.6 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 4 | 10.2.6 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 32 | 10.2.6 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 64 | 10.2.6 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 8 | 10.2.6 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 16 | 10.2.6 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 4 | 10.2.6 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 32 | 10.2.6 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 64 | 10.2.6 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 8 | 10.2.6 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | normal | 16 | 10.1.31 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | normal | 16 | 10.1.31 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | OK | | | normal | 4 | 10.1.31 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | normal | 4 | 10.1.31 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | OK | | | normal | 32 | 10.1.31 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | OK | | | normal | 32 | 10.1.31 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | normal | 64 | 10.1.31 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | normal | 64 | 10.1.31 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | OK | | | normal | 8 | 10.1.31 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | normal | 8 | 10.1.31 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | OK | | | normal | 16 | 10.1.31 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | normal | 16 | 10.1.31 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | normal | 4 | 10.1.31 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | normal | 4 | 10.1.31 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | normal | 32 | 10.1.31 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | normal | 32 | 10.1.31 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | normal | 64 | 10.1.31 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | normal | 64 | 10.1.31 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | normal | 8 | 10.1.31 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | normal | 8 | 10.1.31 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 16 | 10.1.31 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 4 | 10.1.31 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 32 | 10.1.31 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 64 | 10.1.31 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 8 | 10.1.31 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 16 | 10.1.31 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 4 | 10.1.31 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 32 | 10.1.31 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 64 | 10.1.31 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 8 | 10.1.31 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 16 | 10.1.31 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 4 | 10.1.31 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 32 | 10.1.31 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 64 | 10.1.31 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 8 | 10.1.31 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 16 | 10.1.31 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 4 | 10.1.31 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 32 | 10.1.31 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 64 | 10.1.31 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 8 | 10.1.31 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | normal | 16 | 10.1.13 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | normal | 16 | 10.1.13 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | OK | | | normal | 4 | 10.1.13 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | normal | 4 | 10.1.13 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | OK | | | normal | 32 | 10.1.13 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | OK | | | normal | 32 | 10.1.13 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | normal | 64 | 10.1.13 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | normal | 64 | 10.1.13 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | OK | | | normal | 8 | 10.1.13 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | normal | 8 | 10.1.13 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | OK | | | normal | 16 | 10.1.10 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | normal | 16 | 10.1.10 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | normal | 4 | 10.1.10 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | normal | 4 | 10.1.10 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | normal | 32 | 10.1.10 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | normal | 32 | 10.1.10 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | normal | 64 | 10.1.10 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | normal | 64 | 10.1.10 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | normal | 8 | 10.1.10 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | normal | 8 | 10.1.10 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 16 | 10.1.22 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 4 | 10.1.22 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 32 | 10.1.22 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 64 | 10.1.22 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 8 | 10.1.22 (inbuilt) | Barracuda | on | - | => | 10.2.13 (inbuilt) | Barracuda | on | - | - | OK | | | undo | 16 | 10.1.22 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 4 | 10.1.22 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 32 | 10.1.22 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 64 | 10.1.22 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 8 | 10.1.22 (inbuilt) | Barracuda | - | - | => | 10.2.13 (inbuilt) | Barracuda | - | - | - | OK | | | undo | 16 | 10.1.22 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 4 | 10.1.22 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 32 | 10.1.22 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 64 | 10.1.22 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 8 | 10.1.22 (inbuilt) | Barracuda | on | zlib | => | 10.2.13 (inbuilt) | Barracuda | on | zlib | - | OK | | | undo | 16 | 10.1.22 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 4 | 10.1.22 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 32 | 10.1.22 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 64 | 10.1.22 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | undo | 8 | 10.1.22 (inbuilt) | Barracuda | - | zlib | => | 10.2.13 (inbuilt) | Barracuda | - | zlib | - | OK | | | normal | 4 | 10.0.34 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | - | - | - | OK | | | normal | 8 | 10.0.34 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | - | - | - | OK | | | normal | 16 | 10.0.34 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | - | - | - | OK | | | normal | 16 | 10.0.34 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | on | - | - | OK | | | normal | 4 | 10.0.34 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | on | - | - | OK | | | normal | 8 | 10.0.34 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | on | - | - | OK | | | undo | 16 | 10.0.34 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | on | - | - | OK | | | undo | 4 | 10.0.34 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | on | - | - | OK | | | undo | 8 | 10.0.34 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | on | - | - | OK | | | undo | 16 | 10.0.34 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | - | - | - | OK | | | undo | 4 | 10.0.34 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | - | - | - | OK | | | undo | 8 | 10.0.34 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | - | - | - | OK | | | normal | 4 | 10.0.14 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | - | - | - | OK | | | normal | 8 | 10.0.14 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | - | - | - | OK | | | normal | 16 | 10.0.14 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | - | - | - | OK | | | normal | 16 | 10.0.14 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | on | - | - | OK | | | normal | 4 | 10.0.14 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | on | - | - | OK | | | normal | 8 | 10.0.14 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | on | - | - | OK | | | undo | 16 | 10.0.18 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | on | - | - | OK | | | undo | 4 | 10.0.18 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | on | - | - | OK | | | undo | 8 | 10.0.18 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | on | - | - | OK | | | undo | 16 | 10.0.18 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | - | - | - | OK | | | undo | 4 | 10.0.18 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | - | - | - | OK | | | undo | 8 | 10.0.18 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | - | - | - | OK | | | normal | 64 | 5.7.21 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | - | - | - | OK | | | normal | 8 | 5.7.21 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | - | - | - | OK | | | normal | 16 | 5.7.21 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | - | - | - | OK | | | normal | 32 | 5.7.21 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | - | - | - | OK | | | normal | 4 | 5.7.21 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | - | - | - | OK | | | normal | 4 | 5.7.21 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | on | - | - | OK | | | normal | 8 | 5.7.21 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | on | - | - | OK | | | normal | 16 | 5.7.21 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | on | - | - | OK | | | normal | 64 | 5.7.21 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | on | - | - | OK | | | normal | 32 | 5.7.21 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | on | - | - | OK | | | crash | 64 | 5.7.21 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | - | - | - | OK | | | crash | 8 | 5.7.21 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | - | - | - | OK | | | crash | 16 | 5.7.21 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | - | - | - | OK | | | crash | 32 | 5.7.21 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | - | - | - | OK | | | crash | 4 | 5.7.21 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | - | - | - | OK | | | crash | 4 | 5.7.21 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | on | - | - | OK | | | crash | 8 | 5.7.21 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | on | - | - | OK | | | crash | 16 | 5.7.21 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | on | - | - | OK | | | crash | 64 | 5.7.21 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | on | - | - | OK | | | crash | 32 | 5.7.21 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | on | - | - | OK | | | undo | 16 | 5.7.21 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | on | - | - | OK | | | undo | 4 | 5.7.21 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | on | - | - | OK | | | undo | 32 | 5.7.21 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | on | - | - | OK | | | undo | 64 | 5.7.21 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | on | - | - | OK | | | undo | 8 | 5.7.21 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | on | - | - | OK | | | undo | 16 | 5.7.21 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | - | - | - | OK | | | undo | 4 | 5.7.21 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | - | - | - | OK | | | undo | 32 | 5.7.21 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | - | - | - | OK | | | undo | 64 | 5.7.21 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | - | - | - | OK | | | undo | 8 | 5.7.21 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | - | - | - | OK | | | normal | 4 | 5.6.39 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | - | - | - | OK | | | normal | 8 | 5.6.39 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | - | - | - | OK | | | normal | 16 | 5.6.39 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | - | - | - | OK | | | normal | 16 | 5.6.39 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | on | - | - | OK | | | normal | 4 | 5.6.39 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | on | - | - | OK | | | normal | 8 | 5.6.39 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | on | - | - | OK | | | undo | 16 | 5.6.39 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | on | - | - | OK | | | undo | 4 | 5.6.39 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | on | - | - | OK | | | undo | 8 | 5.6.39 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | on | - | - | OK | | | undo | 16 | 5.6.39 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | - | - | - | OK | | | undo | 4 | 5.6.39 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | - | - | - | OK | | | undo | 8 | 5.6.39 (inbuilt) | | - | - | => | 10.2.13 (inbuilt) | | - | - | - | OK | | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs
mariadb SHOW INNODB STATUS (removed) SHOW INNODB STATUS (removed) ============================ Syntax ------ ``` SHOW INNODB STATUS ``` Description ----------- This was a deprecated synonym for `[SHOW ENGINE INNODB STATUS](../show-engine/index)`. It was removed in MariaDB and MySQL 5.5. Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Dynamic Columns Functions Dynamic Columns Functions ========================== [Dynamic columns](../dynamic-columns/index) is a feature that allows one to store different sets of columns for each row in a table. It works by storing a set of columns in a blob and having a small set of functions to manipulate it. | Title | Description | | --- | --- | | [COLUMN\_ADD](../column_add/index) | Adds or updates dynamic columns. | | [COLUMN\_CHECK](../column_check/index) | Checks if a dynamic column blob is valid | | [COLUMN\_CREATE](../column_create/index) | Returns a dynamic columns blob. | | [COLUMN\_DELETE](../column_delete/index) | Deletes a dynamic column. | | [COLUMN\_EXISTS](../column_exists/index) | Checks is a column exists. | | [COLUMN\_GET](../column_get/index) | Gets a dynamic column value by name. | | [COLUMN\_JSON](../column_json/index) | Returns a JSON representation of dynamic column blob data | | [COLUMN\_LIST](../column_list/index) | Returns comma-separated list of columns names. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb << << == Syntax ------ ``` value1 << value2 ``` Description ----------- Converts a longlong ([BIGINT](../bigint/index)) number (*value1*) to binary and shifts *value2* units to the left. Examples -------- ``` SELECT 1 << 2; +--------+ | 1 << 2 | +--------+ | 4 | +--------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Delayed Replication Delayed Replication =================== The terms *master* and *slave* have historically been used in replication, but the terms terms *primary* and *replica* are now preferred. The old terms are used still used in parts of the documentation, and in MariaDB commands, although [MariaDB 10.5](../what-is-mariadb-105/index) has begun the process of renaming. The documentation process is ongoing. See [MDEV-18777](https://jira.mariadb.org/browse/MDEV-18777) to follow progress on this effort. **MariaDB starting with [10.2.3](https://mariadb.com/kb/en/mariadb-1023-release-notes/)**Delayed replication was introduced in [MariaDB 10.2.3](https://mariadb.com/kb/en/mariadb-1023-release-notes/). When using older versions, a 3rd party tool called [pt-slave-delay](https://www.percona.com/doc/percona-toolkit/LATEST/pt-slave-delay.html) can be used. It is part of the Percona Toolkit. Note that pt-slave-delay does not support MariaDB multi-channel replication syntax. Delayed replication allows specifying that a replication slave should lag behind the master by (at least) a specified amount of time (specified in seconds). Before executing an event, the slave will first wait, if necessary, until the given time has passed since the event was created on the master. The result is that the slave will reflect the state of the master some time back in the past. The default is zero, or no delay, and the maximum value is 2147483647, or about 68 years. Delayed replication is enabled using the MASTER\_DELAY option to [CHANGE MASTER](../change-master-to/index): ``` CHANGE MASTER TO master_delay=3600; ``` A zero delay disables delayed replication. The slave must be stopped when changing the delay value. Three fields in [SHOW SLAVE STATUS](../show-slave-status/index) are associated with delayed replication: 1. SQL\_Delay: This is the value specified by MASTER\_DELAY in CHANGE MASTER (or 0 if none). 2. SQL\_Remaining\_Delay. When the slave is delaying the execution of an event due to MASTER\_DELAY, this is the number of seconds of delay remaining before the event will be applied. Otherwise, the value is NULL. 3. Slave\_SQL\_Running\_State. This shows the state of the SQL driver threads, same as in [SHOW PROCESSLIST](../show-processlist/index). When the slave is delaying the execution of an event due to MASTER\_DELAY, this fields displays: "Waiting until MASTER\_DELAY seconds after master executed event". Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Trigger Limitations Trigger Limitations =================== The following restrictions apply to [triggers](../triggers/index). * All of the restrictions listed in [Stored Routine Limitations](../stored-routine-limitations/index). * All of the restrictions listed in [Stored Function Limitations](../stored-function-limitations/index). * Until [MariaDB 10.2.3](https://mariadb.com/kb/en/mariadb-1023-release-notes/), each table can have only one trigger for each timing/event combination (ie: you can't define two BEFORE INSERT triggers for the same table). * Triggers are always executed for each row. The standard `FOR EACH STATEMENT` option is not supported in MariaDB, * Triggers cannot operate on any tables in the mysql, information\_schema or performance\_schema database. * Cannot return a resultset. * The [RETURN](../return/index) statement is not permitted, since triggers don't return any values. Use [LEAVE](../leave/index) to immediately exit a trigger. * Triggers are not activated by [foreign key](../foreign-keys/index) actions. * If a trigger is loaded into cache, it is not automatically reloaded when the table metadata changes. In this case a trigger can operate using the outdated metadata. * By default, with row-based replication, triggers run on the master, and the effects of their executions are replicated to the slaves. However, starting from [MariaDB 10.1.1](https://mariadb.com/kb/en/mariadb-1011-release-notes/), it is possible to run triggers on the slaves. See [Running triggers on the slave for Row-based events](../running-triggers-on-the-slave-for-row-based-events/index). See Also -------- * [Trigger Overview](../trigger-overview/index) * [CREATE TRIGGER](../create-trigger/index) * [DROP TRIGGER](../drop-trigger/index) * [Information Schema TRIGGERS Table](../information-schema-triggers-table/index) * [SHOW TRIGGERS](../show-triggers/index) * [SHOW CREATE TRIGGER](../show-create-trigger/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Upgrading from MariaDB 10.0 to MariaDB 10.1 Upgrading from MariaDB 10.0 to MariaDB 10.1 =========================================== What You Need to Know --------------------- There are no changes in table or index formats between [MariaDB 10.0](../what-is-mariadb-100/index) and [MariaDB 10.1](../what-is-mariadb-101/index), so on most servers the upgrade should be painless. ### How to Upgrade For Windows, see [Upgrading MariaDB on Windows](../upgrading-mariadb-on-windows/index) instead. For MariaDB Galera Cluster, see [Upgrading from MariaDB Galera Cluster 10.0 to MariaDB 10.1 with Galera Cluster](../upgrading-galera-cluster-upgrading-from-mariadb-galera-cluster-100-to-maria/index) instead. Before you upgrade, it would be best to take a backup of your database. This is always a good idea to do before an upgrade. We would recommend [Percona XtraBackup](../backup-restore-and-import-clients-percona-xtrabackup/index). The suggested upgrade procedure is: 1. Modify the repository configuration, so the system's package manager installs [MariaDB 10.1](../what-is-mariadb-101/index). For example, * On Debian, Ubuntu, and other similar Linux distributions, see [Updating the MariaDB APT repository to a New Major Release](../installing-mariadb-deb-files/index#updating-the-mariadb-apt-repository-to-a-new-major-release) for more information. * On RHEL, CentOS, Fedora, and other similar Linux distributions, see [Updating the MariaDB YUM repository to a New Major Release](../yum/index#updating-the-mariadb-yum-repository-to-a-new-major-release) for more information. * On SLES, OpenSUSE, and other similar Linux distributions, see [Updating the MariaDB ZYpp repository to a New Major Release](../installing-mariadb-with-zypper/index#updating-the-mariadb-zypp-repository-to-a-new-major-release) for more information. 2. Set `[innodb\_fast\_shutdown](../xtradbinnodb-server-system-variables/index#innodb_fast_shutdown)` to `0`. It can be changed dynamically with `[SET GLOBAL](../set/index#global-session)`. For example: `SET GLOBAL innodb_fast_shutdown=0;` 3. [Stop MariaDB](../starting-and-stopping-mariadb-automatically/index). 4. Uninstall the old version of MariaDB. * On Debian, Ubuntu, and other similar Linux distributions, execute the following: `sudo apt-get remove mariadb-server` * On RHEL, CentOS, Fedora, and other similar Linux distributions, execute the following: `sudo yum remove MariaDB-server` * On SLES, OpenSUSE, and other similar Linux distributions, execute the following: `sudo zypper remove MariaDB-server` 5. Install the new version of MariaDB. * On Debian, Ubuntu, and other similar Linux distributions, see [Installing MariaDB Packages with APT](../installing-mariadb-deb-files/index#installing-mariadb-packages-with-apt) for more information. * On RHEL, CentOS, Fedora, and other similar Linux distributions, see [Installing MariaDB Packages with YUM](../yum/index#installing-mariadb-packages-with-yum) for more information. * On SLES, OpenSUSE, and other similar Linux distributions, see [Installing MariaDB Packages with ZYpp](../installing-mariadb-with-zypper/index#installing-mariadb-packages-with-zypp) for more information. 6. Make any desired changes to configuration options in [option files](../configuring-mariadb-with-option-files/index), such as `my.cnf`. This includes removing any options that are no longer supported. 7. [Start MariaDB](../starting-and-stopping-mariadb-automatically/index). 8. Run `[mysql\_upgrade](../mysql_upgrade/index)`. * `mysql_upgrade` does two things: 1. Ensures that the system tables in the `[mysq](../the-mysql-database-tables/index)l` database are fully compatible with the new version. 2. Does a very quick check of all tables and marks them as compatible with the new version of MariaDB . ### Incompatible Changes Between 10.0 and 10.1 As mentioned previously, on most servers upgrading from 10.0 should be painless. However, there are some things that have changed which could affect an upgrade: #### Storage Engines * The [ARCHIVE](../archive/index) storage engine is no longer enabled by default, and the plugin needs to be specifically enabled. * The [BLACKHOLE](../blackhole/index) storage engine is no longer enabled by default, and the plugin needs to be specifically enabled. #### Replication * [MariaDB 10.1](../what-is-mariadb-101/index) introduces new, standards-compliant behavior for dealing with [primary keys over nullable columns](../primary-keys-with-nullable-columns/index). In certain edge cases this could cause replication issues when replicating from a [MariaDB 10.0](../what-is-mariadb-100/index) master to a [MariaDB 10.1](../what-is-mariadb-101/index) slave using [statement-based replication](../binary-log-formats/index#statement-based). See [MDEV-12248](https://jira.mariadb.org/browse/MDEV-12248). #### Options That Have Changed Default Values Most of the following options have increased in value to give better performance. | Option | Old default value | New default value | | --- | --- | --- | | [innodb\_log\_compressed\_pages](../xtradbinnodb-server-system-variables/index#innodb_log_compressed_pages) | `ON` | `OFF` | | [join\_buffer\_size](../server-system-variables/index#join_buffer_size) | `128K` | `256K` | | [max\_allowed\_packet](../server-system-variables/index#max_allowed_packet) | `1M` | `4M` | | [query\_alloc\_block\_size](../server-system-variables/index#query_alloc_block_size) | `8192` | `16384` | | [query\_cache\_size](../server-system-variables/index#query_cache_size) | `0` | `1M` | | [query\_cache\_type](../server-system-variables/index#query_cache_type) | `ON` | `OFF` | | [sync\_master\_info](../replication-and-binary-log-server-system-variables/index#sync_master_info) | `0` | `10000` | | [sync\_relay\_log](../replication-and-binary-log-server-system-variables/index#sync_relay_log) | `0` | `10000` | | [sync\_relay\_log\_info](../replication-and-binary-log-server-system-variables/index#sync_relay_log_info) | `0` | `10000` | | [query\_prealloc\_size](../server-system-variables/index#query_prealloc_size) | `8192` | `24576` | | [secure\_auth](../server-system-variables/index#secure_auth) | `OFF` | `ON` | | [sql\_log\_bin](../replication-and-binary-log-server-system-variables/index#sql_log_bin) | | No longer affects replication of events in a Galera cluster. | | [sql\_mode](../server-system-variables/index#sql_mode) | `empty` | `NO_AUTO_CREATE_USER, NO_ENGINE_SUBSTITUTION` | | [table\_open\_cache](../server-system-variables/index#table_open_cache) | `400` | `2000` | | [thread\_pool\_max\_threads](../server-system-variables/index#thread_pool_max_threads) | `500` | `1000` | #### Options That Have Been Removed or Renamed The following options should be removed or renamed if you use them in your config files: | Option | Reason | | --- | --- | | [rpl\_recovery\_rank](../server-system-variables/index#rpl_recovery_rank) | Unused in 10.0 | #### Other Issues Note that explicit or implicit casts from MAX(string) to INT, DOUBLE or DECIMAL now produce warnings ([MDEV-8852](https://jira.mariadb.org/browse/MDEV-8852)). ### Major New Features To Consider You might consider using the following major new features in [MariaDB 10.1](../what-is-mariadb-101/index): * [Galera Cluster](../galera/index) is now included by default. * [Encryption](../data-at-rest-encryption/index) * [InnoDB/XtraDB Page Compression](../compression/index) Notes ----- See Also -------- * [The features in MariaDB 10.1](../what-is-mariadb-101/index) * [Upgrading from MariaDB Galera Cluster 10.0 to MariaDB 10.1 with Galera Cluster](../upgrading-galera-cluster-upgrading-from-mariadb-galera-cluster-100-to-maria/index) * [Upgrading from MariaDB 10.1 to MariaDB 10.2](../upgrading-from-mariadb-101-to-mariadb-102/index) * [Upgrading from MariaDB 5.5 to MariaDB 10.0](../upgrading-from-mariadb-55-to-mariadb-100/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb DAYOFMONTH DAYOFMONTH ========== Syntax ------ ``` DAYOFMONTH(date) ``` Description ----------- Returns the day of the month for date, in the range `1` to `31`, or `0` for dates such as `'0000-00-00'` or `'2008-00-00'` which have a zero day part. DAY() is a synonym. Examples -------- ``` SELECT DAYOFMONTH('2007-02-03'); +--------------------------+ | DAYOFMONTH('2007-02-03') | +--------------------------+ | 3 | +--------------------------+ ``` ``` CREATE TABLE t1 (d DATETIME); INSERT INTO t1 VALUES ("2007-01-30 21:31:07"), ("1983-10-15 06:42:51"), ("2011-04-21 12:34:56"), ("2011-10-30 06:31:41"), ("2011-01-30 14:03:25"), ("2004-10-07 11:19:34"); ``` ``` SELECT d FROM t1 where DAYOFMONTH(d) = 30; +---------------------+ | d | +---------------------+ | 2007-01-30 21:31:07 | | 2011-10-30 06:31:41 | | 2011-01-30 14:03:25 | +---------------------+ ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Control Flow Functions Control Flow Functions ======================= Built-In functions for assessing data to determine what results to return. | Title | Description | | --- | --- | | [CASE OPERATOR](../case-operator/index) | Returns the result where value=compare\_value or for the first condition that is true. | | [DECODE](../decode/index) | Decrypts a string encoded with ENCODE(), or, in Oracle mode, matches expressions. | | [DECODE\_ORACLE](../decode_oracle/index) | Synonym for the Oracle mode version of DECODE(). | | [IF Function](../if-function/index) | If expr1 is TRUE, returns expr2; otherwise it returns expr3. | | [IFNULL](../ifnull/index) | Check whether an expression is NULL. | | [NULLIF](../nullif/index) | Returns NULL if expr1 = expr2. | | [NVL](../nvl/index) | Synonym for IFNULL. | | [NVL2](../nvl2/index) | Returns a value based on whether a specified expression is NULL or not. | Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb IGNORE INDEX IGNORE INDEX ============ Syntax ------ ``` IGNORE INDEX [{FOR {JOIN|ORDER BY|GROUP BY}] ([index_list]) ``` Description ----------- You can tell the optimizer to not consider a particular index with the IGNORE INDEX option. The benefit of using IGNORE\_INDEX instead of [USE\_INDEX](../use-index/index) is that it will not disable a new index which you may add later. Also see [Ignored Indexes](../ignored-indexes/index) for an option to specify in the index definition that indexes should be ignored. ### Index Prefixes When using index hints (USE, FORCE or IGNORE INDEX), the index name value can also be an unambiguous prefix of an index name. Example ------- This is used after the table name in the FROM clause: ``` CREATE INDEX Name ON City (Name); CREATE INDEX CountryCode ON City (Countrycode); EXPLAIN SELECT Name FROM City IGNORE INDEX (Name) WHERE name="Helsingborg" AND countrycode="SWE"; ``` This produces: ``` id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE City ref CountryCode CountryCode 3 const 14 Using where ``` See Also -------- * See [Index Hints: How to Force Query Plans](../index-hints-how-to-force-query-plans/index) for more details * [USE INDEX](../use-index/index) * [FORCE INDEX](../force-index/index) * [Ignored Indexes](../ignored-indexes/index) Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party. mariadb Buildbot Setup for Virtual Machines - Ubuntu 11.10 "oneiric" Buildbot Setup for Virtual Machines - Ubuntu 11.10 "oneiric" ============================================================ Base install ------------ ``` qemu-img create -f qcow2 /kvm/vms/vm-oneiric-amd64-serial.qcow2 8G qemu-img create -f qcow2 /kvm/vms/vm-oneiric-i386-serial.qcow2 8G # Start each VM booting from the server install iso one at a time and perform # the following install steps: kvm -m 1024 -hda /kvm/vms/vm-oneiric-amd64-serial.qcow2 -cdrom /kvm/iso/ubuntu-11.10-server-amd64.iso -redir tcp:2255::22 -boot d -smp 2 -cpu qemu64 -net nic,model=virtio -net user kvm -m 1024 -hda /kvm/vms/vm-oneiric-i386-serial.qcow2 -cdrom /kvm/iso/ubuntu-11.10-server-i386.iso -redir tcp:2256::22 -boot d -smp 2 -cpu qemu32,-nx -net nic,model=virtio -net user # Once running you can connect to the VNC server from your local host with: # # vncviewer -via ${remote-host} localhost # # (replace ${remote-host} with the host the vm is running on) # Install, picking default options mostly, with the following notes: # * Set the hostname to ubuntu-oneiric # * When partitioning disks, choose "Guided - use entire disk" (we do not want LVM) # * No automatic updates # * Choose software to install: OpenSSH server # Now that the VM is installed, it's time to configure it. # If you have the memory you can do the following simultaneously: kvm -m 1024 -hda /kvm/vms/vm-oneiric-amd64-serial.qcow2 -cdrom /kvm/iso/ubuntu-11.10-server-amd64.iso -redir tcp:2255::22 -boot c -smp 2 -cpu qemu64 -net nic,model=virtio -net user -nographic kvm -m 1024 -hda /kvm/vms/vm-oneiric-i386-serial.qcow2 -cdrom /kvm/iso/ubuntu-11.10-server-i386.iso -redir tcp:2256::22 -boot c -smp 2 -cpu qemu64 -net nic,model=virtio -net user -nographic ssh -p 2255 localhost # edit /boot/grub/menu.lst and visudo, see below ssh -p 2256 localhost # edit /boot/grub/menu.lst and visudo, see below ssh -t -p 2255 localhost "mkdir -v .ssh; sudo addgroup $USER sudo" ssh -t -p 2256 localhost "mkdir -v .ssh; sudo addgroup $USER sudo" scp -P 2255 /kvm/vms/authorized_keys localhost:.ssh/ scp -P 2256 /kvm/vms/authorized_keys localhost:.ssh/ echo $'Buildbot\n\n\n\n\ny' | ssh -p 2255 localhost 'chmod -R go-rwx .ssh; sudo adduser --disabled-password buildbot; sudo addgroup buildbot sudo; sudo mkdir ~buildbot/.ssh; sudo cp -vi .ssh/authorized_keys ~buildbot/.ssh/; sudo chown -vR buildbot:buildbot ~buildbot/.ssh; sudo chmod -vR go-rwx ~buildbot/.ssh' echo $'Buildbot\n\n\n\n\ny' | ssh -p 2256 localhost 'chmod -R go-rwx .ssh; sudo adduser --disabled-password buildbot; sudo addgroup buildbot sudo; sudo mkdir ~buildbot/.ssh; sudo cp -vi .ssh/authorized_keys ~buildbot/.ssh/; sudo chown -vR buildbot:buildbot ~buildbot/.ssh; sudo chmod -vR go-rwx ~buildbot/.ssh' scp -P 2255 /kvm/vms/ttyS0.conf buildbot@localhost: scp -P 2256 /kvm/vms/ttyS0.conf buildbot@localhost: ssh -p 2255 buildbot@localhost 'sudo cp -vi ttyS0.conf /etc/init/; rm -v ttyS0.conf; sudo shutdown -h now' ssh -p 2256 buildbot@localhost 'sudo cp -vi ttyS0.conf /etc/init/; rm -v ttyS0.conf; sudo shutdown -h now' ``` Enabling passwordless sudo: ``` sudo VISUAL=vi visudo # Add line at end: `%sudo ALL=NOPASSWD: ALL' ``` Editing /boot/grub/menu.lst: ``` sudo vi /etc/default/grub # Add/edit these entries: GRUB_CMDLINE_LINUX_DEFAULT="console=tty0 console=ttyS0,115200n8" GRUB_TERMINAL="serial" GRUB_SERIAL_COMMAND="serial --unit=0 --speed=115200 --word=8 --parity=no --stop=1" sudo update-grub ``` VMs for building .debs ---------------------- ``` for i in '/kvm/vms/vm-oneiric-amd64-serial.qcow2 2255 qemu64' '/kvm/vms/vm-oneiric-i386-serial.qcow2 2256 qemu64' ; do \ set $i; \ runvm --user=buildbot --logfile=kernel_$2.log --base-image=$1 --port=$2 --cpu=$3 "$(echo $1 | sed -e 's/serial/build/')" \ "sudo DEBIAN_FRONTEND=noninteractive apt-get update" \ "sudo DEBIAN_FRONTEND=noninteractive apt-get -y build-dep mysql-server-5.1" \ "sudo DEBIAN_FRONTEND=noninteractive apt-get install -y devscripts hardening-wrapper fakeroot doxygen texlive-latex-base ghostscript libevent-dev libssl-dev zlib1g-dev libreadline6-dev" ; \ done ``` Install cmake (required for [MariaDB 5.5](../what-is-mariadb-55/index)) with: ``` kvm -m 1024 -hda ${vm} -redir tcp:22565::22 -boot c -smp 2 -cpu qemu64 -net nic,model=virtio -net user -nographic ssh -o IdentityFile=.ssh/buildbot.id_dsa -p 22565 buildbot@localhost wget http://www.cmake.org/files/v2.8/cmake-2.8.6.tar.gz tar -zxvf cmake-2.8.6.tar.gz cd cmake-2.8.6;./configure make sudo make install sudo /sbin/shutdown -h now ``` Also: * [Installing the Boost library needed for the OQGraph storage engine](../installing-the-boost-library-needed-for-the-oqgraph-storage-engine/index) VMs for install testing. ------------------------ See above for how to obtain my.seed and sources.append. ``` for i in '/kvm/vms/vm-oneiric-amd64-serial.qcow2 2255 qemu64' '/kvm/vms/vm-oneiric-i386-serial.qcow2 2256 qemu64' ; do \ set $i; \ runvm --user=buildbot --logfile=kernel_$2.log --base-image=$1 --port=$2 --cpu=$3 "$(echo $1 | sed -e 's/serial/install/')" \ "sudo DEBIAN_FRONTEND=noninteractive apt-get update" \ "sudo DEBIAN_FRONTEND=noninteractive apt-get install -y debconf-utils" \ "= scp -P $2 /kvm/vms/my.seed /kvm/vms/sources.append buildbot@localhost:/tmp/" \ "sudo debconf-set-selections /tmp/my.seed" \ "sudo sh -c 'cat /tmp/sources.append >> /etc/apt/sources.list'"; \ done ``` VMs for MySQL upgrade testing ----------------------------- ``` for i in '/kvm/vms/vm-oneiric-amd64-install.qcow2 2255 qemu64' '/kvm/vms/vm-oneiric-i386-install.qcow2 2256 qemu64' ; do \ set $i; \ runvm --user=buildbot --logfile=kernel_$2.log --base-image=$1 --port=$2 --cpu=$3 "$(echo $1 | sed -e 's/install/upgrade/')" \ 'sudo DEBIAN_FRONTEND=noninteractive apt-get install -y mysql-server-5.1' \ 'mysql -uroot -prootpass -e "create database mytest; use mytest; create table t(a int primary key); insert into t values (1); select * from t"' ;\ done ``` VMs for MariaDB upgrade testing ------------------------------- *The steps below are based on the Natty steps on [Installing VM images for testing .deb upgrade between versions](../installing-vm-images-for-testing-deb-upgrade-between-versions/index).* 64-bit Ubuntu oneiric: ``` qemu-img create -b vm-oneiric-amd64-install.qcow2 -f qcow2 vm-oneiric-amd64-upgrade2.qcow2 kvm -m 512 -hda vm-oneiric-amd64-upgrade2.qcow2 -redir 'tcp:2200::22' -boot c -smp 1 -cpu qemu64 -net nic,model=virtio -net user -nographic ssh -p 2200 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no buildbot@localhost sudo sh -c 'cat > /etc/apt/sources.list.d/tmp.list' deb http://ftp.osuosl.org/pub/mariadb/repo/5.2/ubuntu natty main deb-src http://ftp.osuosl.org/pub/mariadb/repo/5.2/ubuntu natty main sudo apt-key adv --recv-keys --keyserver keyserver.ubuntu.com 1BB943DB sudo apt-get update sudo DEBIAN_FRONTEND=noninteractive apt-get install -y --allow-unauthenticated mariadb-server mariadb-test libmariadbclient-dev sudo rm /etc/apparmor.d/usr.sbin.mysqld sudo /etc/init.d/apparmor restart sudo apt-get -f install mysql -uroot -prootpass -e "create database mytest; use mytest; create table t(a int primary key); insert into t values (1); select * from t" sudo rm /etc/apt/sources.list.d/tmp.list sudo apt-get update sudo DEBIAN_FRONTEND=noninteractive apt-get upgrade -y sudo shutdown -h now ``` 32-bit Ubuntu oneiric: ``` qemu-img create -b vm-oneiric-i386-install.qcow2 -f qcow2 vm-oneiric-i386-upgrade2.qcow2 kvm -m 512 -hda vm-oneiric-i386-upgrade2.qcow2 -redir 'tcp:2200::22' -boot c -smp 1 -cpu qemu64 -net nic,model=virtio -net user -nographic ssh -p 2200 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no buildbot@localhost sudo sh -c 'cat > /etc/apt/sources.list.d/tmp.list' deb http://ftp.osuosl.org/pub/mariadb/repo/5.2/ubuntu natty main deb-src http://ftp.osuosl.org/pub/mariadb/repo/5.2/ubuntu natty main sudo apt-key adv --recv-keys --keyserver keyserver.ubuntu.com 1BB943DB sudo apt-get update sudo DEBIAN_FRONTEND=noninteractive apt-get install -y --allow-unauthenticated mariadb-server mariadb-test libmariadbclient-dev sudo rm /etc/apparmor.d/usr.sbin.mysqld sudo /etc/init.d/apparmor restart sudo apt-get -f install mysql -uroot -prootpass -e "create database mytest; use mytest; create table t(a int primary key); insert into t values (1); select * from t" sudo rm /etc/apt/sources.list.d/tmp.list sudo apt-get update sudo DEBIAN_FRONTEND=noninteractive apt-get upgrade -y sudo shutdown -h now ``` Content reproduced on this site is the property of its respective owners, and this content is not reviewed in advance by MariaDB. The views, information and opinions expressed by this content do not necessarily represent those of MariaDB or any other party.
programming_docs