File size: 165,860 Bytes
e09f0d6 |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 2496 2497 2498 2499 2500 2501 2502 2503 2504 2505 2506 2507 2508 2509 2510 2511 2512 2513 2514 2515 2516 2517 2518 2519 2520 2521 2522 2523 2524 2525 2526 2527 2528 2529 2530 2531 2532 2533 2534 2535 2536 2537 2538 2539 2540 2541 2542 2543 2544 2545 2546 2547 2548 2549 2550 2551 2552 2553 2554 2555 2556 2557 2558 2559 2560 2561 2562 2563 2564 2565 2566 2567 2568 2569 2570 2571 2572 2573 2574 2575 2576 2577 2578 2579 2580 2581 2582 2583 2584 2585 2586 2587 2588 2589 2590 2591 2592 2593 2594 2595 2596 2597 2598 2599 2600 2601 2602 2603 2604 2605 2606 2607 2608 2609 2610 2611 2612 2613 2614 2615 2616 2617 2618 2619 2620 2621 2622 2623 2624 2625 2626 2627 2628 2629 2630 2631 2632 2633 2634 2635 2636 2637 2638 2639 2640 2641 2642 2643 2644 2645 2646 2647 2648 2649 2650 2651 2652 2653 2654 2655 2656 2657 2658 2659 2660 2661 2662 2663 2664 2665 2666 2667 2668 2669 2670 2671 2672 2673 2674 2675 2676 2677 2678 2679 2680 2681 2682 2683 2684 2685 2686 2687 2688 2689 2690 2691 2692 2693 2694 2695 2696 2697 2698 2699 2700 2701 2702 2703 2704 2705 2706 2707 2708 2709 2710 2711 2712 2713 2714 2715 2716 2717 2718 2719 2720 2721 2722 2723 2724 2725 2726 2727 2728 2729 2730 2731 2732 2733 2734 2735 2736 2737 2738 2739 2740 2741 2742 2743 2744 2745 2746 2747 2748 2749 2750 2751 2752 2753 2754 2755 2756 2757 2758 2759 2760 2761 2762 2763 2764 2765 2766 2767 2768 2769 2770 2771 2772 2773 2774 2775 2776 2777 2778 2779 2780 2781 2782 2783 2784 2785 2786 2787 2788 2789 2790 2791 2792 2793 2794 2795 2796 2797 2798 2799 2800 2801 2802 2803 2804 2805 2806 2807 2808 2809 2810 2811 2812 2813 2814 2815 2816 2817 2818 2819 2820 2821 2822 2823 2824 2825 2826 2827 2828 2829 2830 2831 2832 2833 2834 2835 2836 2837 2838 2839 2840 2841 2842 2843 2844 2845 2846 2847 2848 2849 2850 2851 2852 2853 2854 2855 2856 2857 2858 2859 2860 2861 2862 2863 2864 2865 2866 2867 2868 2869 2870 2871 2872 2873 2874 2875 2876 2877 2878 2879 2880 2881 2882 2883 2884 2885 2886 2887 2888 2889 2890 2891 2892 2893 2894 2895 2896 2897 2898 2899 2900 2901 2902 2903 2904 2905 2906 2907 2908 2909 2910 2911 2912 2913 2914 2915 2916 2917 2918 2919 2920 2921 2922 2923 2924 2925 2926 2927 2928 2929 2930 2931 2932 2933 2934 2935 2936 2937 2938 2939 2940 2941 2942 2943 2944 2945 2946 2947 2948 2949 2950 2951 2952 2953 2954 2955 2956 2957 2958 2959 2960 2961 2962 2963 2964 2965 2966 2967 2968 2969 2970 2971 2972 2973 2974 2975 2976 2977 2978 2979 2980 2981 2982 2983 2984 2985 2986 2987 2988 2989 2990 2991 2992 2993 2994 2995 2996 2997 2998 2999 3000 3001 3002 3003 3004 3005 3006 3007 3008 3009 3010 3011 3012 3013 3014 3015 3016 3017 3018 3019 3020 3021 3022 3023 3024 3025 3026 3027 3028 3029 3030 3031 3032 3033 3034 3035 3036 3037 3038 3039 3040 3041 3042 3043 3044 3045 3046 3047 3048 3049 3050 3051 3052 3053 3054 3055 3056 3057 3058 3059 3060 3061 3062 3063 3064 3065 3066 3067 3068 3069 3070 3071 3072 3073 3074 3075 3076 3077 3078 3079 3080 3081 3082 3083 3084 3085 3086 3087 3088 3089 3090 3091 3092 3093 3094 3095 3096 3097 3098 3099 3100 3101 3102 3103 3104 3105 3106 3107 3108 3109 3110 3111 3112 3113 3114 3115 3116 3117 3118 3119 3120 3121 3122 3123 3124 3125 3126 3127 3128 3129 3130 3131 3132 3133 3134 3135 3136 3137 3138 3139 3140 3141 3142 3143 3144 3145 3146 3147 3148 3149 3150 3151 3152 3153 3154 3155 3156 3157 3158 3159 3160 3161 3162 3163 3164 3165 3166 3167 3168 3169 3170 3171 3172 3173 3174 3175 3176 3177 3178 3179 3180 3181 3182 3183 3184 3185 3186 3187 3188 3189 3190 3191 3192 3193 3194 3195 3196 3197 3198 3199 3200 3201 3202 3203 3204 3205 3206 3207 3208 3209 3210 3211 3212 3213 3214 3215 3216 3217 3218 3219 3220 3221 3222 3223 3224 3225 3226 3227 3228 3229 3230 3231 3232 3233 3234 3235 3236 3237 3238 3239 3240 3241 3242 3243 3244 3245 3246 3247 3248 3249 3250 3251 3252 3253 3254 3255 3256 3257 3258 3259 3260 3261 3262 3263 3264 3265 3266 3267 3268 3269 3270 3271 3272 3273 3274 3275 3276 3277 3278 3279 3280 3281 3282 3283 3284 3285 3286 3287 3288 3289 3290 3291 3292 3293 3294 3295 3296 3297 3298 3299 3300 3301 3302 3303 3304 3305 3306 3307 3308 3309 3310 3311 3312 3313 3314 3315 3316 3317 3318 3319 3320 3321 3322 3323 3324 3325 3326 3327 3328 3329 3330 3331 3332 3333 3334 3335 3336 3337 3338 3339 3340 3341 3342 3343 3344 3345 3346 3347 3348 3349 3350 3351 3352 3353 3354 3355 3356 3357 3358 3359 3360 3361 3362 3363 3364 3365 3366 3367 3368 3369 3370 3371 3372 3373 3374 3375 3376 3377 3378 3379 3380 3381 3382 3383 3384 3385 3386 3387 3388 3389 3390 3391 3392 3393 3394 3395 3396 3397 3398 3399 3400 3401 3402 3403 3404 3405 3406 3407 3408 3409 3410 3411 3412 3413 3414 3415 3416 3417 3418 3419 3420 3421 3422 3423 3424 3425 3426 3427 3428 3429 3430 3431 3432 3433 3434 3435 3436 3437 3438 3439 3440 3441 3442 3443 3444 3445 3446 3447 3448 3449 3450 3451 3452 3453 3454 3455 3456 3457 3458 3459 3460 3461 3462 3463 3464 3465 3466 3467 3468 3469 3470 3471 3472 3473 3474 3475 3476 3477 3478 3479 3480 3481 3482 3483 3484 3485 3486 3487 3488 3489 3490 3491 3492 3493 3494 3495 3496 3497 3498 3499 3500 3501 3502 3503 3504 3505 3506 3507 3508 3509 3510 3511 3512 3513 3514 3515 3516 3517 3518 3519 3520 3521 3522 3523 3524 3525 3526 3527 3528 3529 3530 3531 3532 3533 3534 3535 3536 3537 3538 3539 3540 3541 3542 3543 3544 3545 3546 3547 3548 3549 3550 3551 3552 3553 3554 3555 3556 3557 3558 3559 3560 3561 3562 3563 3564 3565 3566 3567 3568 3569 3570 3571 3572 3573 3574 3575 3576 3577 3578 3579 3580 3581 3582 3583 3584 3585 3586 3587 3588 3589 3590 3591 3592 3593 3594 3595 3596 3597 3598 3599 3600 3601 3602 3603 3604 3605 3606 3607 3608 3609 3610 3611 3612 3613 3614 3615 3616 3617 3618 3619 3620 3621 3622 3623 3624 3625 3626 3627 3628 3629 3630 3631 3632 3633 3634 3635 3636 3637 3638 3639 3640 3641 3642 3643 3644 3645 3646 3647 3648 3649 3650 3651 3652 3653 3654 3655 3656 3657 3658 3659 3660 3661 3662 3663 3664 3665 3666 3667 3668 3669 3670 3671 3672 3673 3674 3675 3676 3677 3678 3679 3680 3681 3682 3683 3684 3685 3686 3687 3688 3689 3690 3691 3692 3693 3694 3695 3696 3697 3698 3699 3700 3701 3702 3703 3704 3705 3706 3707 3708 3709 3710 3711 3712 3713 3714 3715 3716 3717 3718 3719 3720 3721 3722 3723 3724 3725 3726 3727 3728 3729 3730 3731 3732 3733 3734 3735 3736 3737 3738 3739 3740 3741 3742 3743 3744 3745 3746 3747 3748 3749 3750 3751 3752 3753 3754 3755 3756 3757 3758 3759 3760 3761 3762 3763 3764 3765 3766 3767 3768 3769 3770 3771 3772 3773 3774 3775 3776 3777 3778 3779 3780 3781 3782 3783 3784 3785 3786 3787 3788 3789 3790 3791 3792 3793 3794 3795 3796 3797 3798 3799 3800 3801 3802 3803 3804 3805 3806 3807 3808 3809 3810 3811 3812 3813 3814 3815 3816 3817 3818 3819 3820 3821 3822 3823 3824 3825 3826 3827 3828 3829 3830 3831 3832 3833 3834 3835 3836 3837 3838 3839 3840 3841 3842 3843 3844 3845 3846 3847 3848 3849 3850 3851 3852 3853 3854 3855 3856 3857 3858 3859 3860 3861 3862 3863 3864 3865 3866 3867 3868 3869 3870 3871 3872 3873 3874 3875 3876 3877 3878 3879 3880 3881 3882 3883 3884 3885 3886 3887 3888 3889 3890 3891 3892 3893 3894 3895 3896 3897 3898 3899 3900 3901 3902 3903 3904 3905 3906 3907 3908 3909 3910 3911 3912 3913 3914 3915 3916 3917 3918 3919 3920 3921 3922 3923 3924 3925 3926 3927 3928 3929 3930 3931 3932 3933 3934 3935 3936 3937 3938 3939 3940 3941 3942 3943 3944 3945 3946 3947 3948 3949 3950 3951 3952 3953 3954 3955 3956 3957 3958 3959 3960 3961 3962 3963 3964 3965 3966 3967 3968 3969 3970 3971 3972 3973 3974 3975 3976 3977 3978 3979 3980 3981 3982 3983 3984 3985 3986 3987 3988 3989 3990 3991 3992 3993 3994 3995 3996 3997 3998 3999 4000 4001 4002 4003 4004 4005 4006 4007 4008 4009 4010 4011 4012 4013 4014 4015 4016 4017 4018 4019 4020 4021 4022 4023 4024 4025 4026 4027 4028 4029 4030 4031 4032 4033 4034 4035 4036 4037 4038 4039 4040 4041 4042 4043 4044 4045 4046 4047 4048 4049 4050 4051 4052 4053 4054 4055 4056 4057 4058 4059 4060 4061 4062 4063 4064 4065 4066 4067 4068 4069 4070 4071 4072 4073 4074 4075 4076 4077 4078 4079 4080 4081 4082 4083 4084 4085 4086 4087 4088 4089 4090 4091 4092 4093 4094 4095 4096 4097 4098 4099 4100 4101 4102 4103 4104 4105 4106 4107 4108 4109 4110 4111 4112 4113 4114 4115 4116 4117 4118 4119 4120 4121 4122 4123 4124 4125 4126 4127 4128 4129 4130 |
From [email protected] Tue Sep 10 02:40:47 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP id 6DA40475C8B
for <[email protected]>;
Tue, 10 Sep 2002 02:40:46 -0400 (EDT)
Received: from ns1.officenet.no (ns1.officenet.no [193.212.174.3])
by postgresql.org (Postfix) with ESMTP id B8F35475C45
for <[email protected]>;
Tue, 10 Sep 2002 02:40:45 -0400 (EDT)
Received: from [193.212.174.117] (helo=jeb.officenet.no)
by ns1.officenet.no with esmtp (Exim 3.36 #3) id 17oehY-0000Yq-00
for [email protected]; Tue, 10 Sep 2002 08:40:44 +0200
Content-Type: text/plain;
charset="us-ascii"
From: Andreas Joseph Krogh <andreak@officenet.no>
Organization: OfficeNet AS
To: [email protected]
Subject: subscribe
Date: Tue, 10 Sep 2002 08:40:44 +0200
User-Agent: KMail/1.4.3
MIME-Version: 1.0
Content-Transfer-Encoding: quoted-printable
Message-Id: <200209100840.44400.andreak@officenet.no>
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1
X-Sequence-Number: 1
From [email protected] Tue Sep 10 08:31:09 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP id 7769A4761AF
for <[email protected]>;
Tue, 10 Sep 2002 08:31:08 -0400 (EDT)
Received: from dune.aardvarkmedia.co.uk (unknown [195.224.39.132])
by postgresql.org (Postfix) with ESMTP id 97E5B476092
for <[email protected]>;
Tue, 10 Sep 2002 08:31:07 -0400 (EDT)
Received: from [192.168.168.13] (helo=Gavin)
by dune.aardvarkmedia.co.uk with smtp (Exim 3.33 #1)
id 17okAe-0006ek-00
for [email protected]; Tue, 10 Sep 2002 13:31:08 +0100
From: "Gavin Love" <[email protected]>
To: <[email protected]>
Subject: subscribe
Date: Tue, 10 Sep 2002 13:31:10 +0100
Message-ID: <[email protected]>
MIME-Version: 1.0
Content-Type: text/plain;
charset="iso-8859-1"
Content-Transfer-Encoding: 7bit
X-Priority: 3 (Normal)
X-MSMail-Priority: Normal
X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2911.0)
X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4522.1200
Importance: Normal
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/2
X-Sequence-Number: 2
subscribe
From [email protected] Tue Sep 10 11:20:22 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP id 8FE8D47671C
for <[email protected]>;
Tue, 10 Sep 2002 11:20:19 -0400 (EDT)
Received: from mail.arcamax.com (mail.arcamax.com [209.96.210.69])
by postgresql.org (Postfix) with SMTP id 02ABE476711
for <[email protected]>;
Tue, 10 Sep 2002 11:20:18 -0400 (EDT)
Received: (qmail 11924 invoked by uid 526); 10 Sep 2002 15:20:20 -0000
Received: from unknown (HELO arcamax.com) (192.168.0.32)
by 0 with SMTP; 10 Sep 2002 15:20:20 -0000
Message-ID: <3D7E0DB7.9040108@arcamax.com>
Date: Tue, 10 Sep 2002 11:20:23 -0400
From: Bryan White <[email protected]>
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US;
rv:1.1) Gecko/20020826
X-Accept-Language: en-us, en
MIME-Version: 1.0
To: [email protected]
Subject: subscribe
Content-Type: text/plain; charset=us-ascii; format=flowed
Content-Transfer-Encoding: 7bit
X-Virus-Scanned: by AMaViS perl-11
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/4
X-Sequence-Number: 4
From [email protected] Tue Sep 10 12:02:04 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP id B3FB6476534
for <[email protected]>;
Tue, 10 Sep 2002 12:02:00 -0400 (EDT)
Received: from h009.c021.snv.cp.net (h009.c021.snv.cp.net [209.228.35.179])
by postgresql.org (Postfix) with ESMTP id 2E6BC476515
for <[email protected]>;
Tue, 10 Sep 2002 12:02:00 -0400 (EDT)
Received: from vengabox.candlefire.org (12.255.22.43) by h009.c021.snv.cp.net
(5.6.0.25) (authenticated as [email protected])
id 3D1DA655000EB024 for [email protected];
Tue, 10 Sep 2002 09:02:05 -0700
Date: Tue, 10 Sep 2002 10:07:06 -0600
From: Jason k Larson <[email protected]>
X-Mailer: The Bat! (v1.53d)
Reply-To: Jason k Larson <[email protected]>
Organization: CandleFire Productions
X-Priority: 3 (Normal)
Message-ID: <1472247656.20020910100706@candlefire.org>
To: [email protected]
Subject: subscribe
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/5
X-Sequence-Number: 5
subscribe
From [email protected] Tue Sep 10 09:53:58 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP id 801B74763D4
for <[email protected]>;
Tue, 10 Sep 2002 09:53:57 -0400 (EDT)
Received: from pop.e-it.com (unknown [216.187.113.82])
by postgresql.org (Postfix) with SMTP id 767EA4762D0
for <[email protected]>;
Tue, 10 Sep 2002 09:53:53 -0400 (EDT)
Received: (qmail 4651 invoked from network); 10 Sep 2002 13:53:56 -0000
Received: from unknown (HELO did-it.com) (66.246.13.35)
by 0 with SMTP; 10 Sep 2002 13:53:56 -0000
Message-ID: <3D7E2526.7040307@did-it.com>
Date: Tue, 10 Sep 2002 10:00:22 -0700
From: Ericson Smith <[email protected]>
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US;
rv:1.1) Gecko/20020826
X-Accept-Language: en-us, en
MIME-Version: 1.0
To: [email protected]
Subject: subscribe
Content-Type: text/plain; charset=us-ascii; format=flowed
Content-Transfer-Encoding: 7bit
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/3
X-Sequence-Number: 3
subscribe
From [email protected] Tue Sep 10 22:07:14 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP id BC01D476503
for <[email protected]>;
Tue, 10 Sep 2002 22:07:12 -0400 (EDT)
Received: from gateway.heart.com.au (unknown [202.44.184.121])
by postgresql.org (Postfix) with ESMTP id CFF27476314
for <[email protected]>;
Tue, 10 Sep 2002 22:07:08 -0400 (EDT)
Received: from tardis.heart.com.au (IDENT:[email protected]
[192.168.0.42])
by gateway.heart.com.au (8.11.6/8.11.2) with ESMTP id g8B2ZKI18868
for <[email protected]>; Wed, 11 Sep 2002 12:35:20 +1000
Received: from heart.com.au ([192.168.0.53])
by tardis.heart.com.au (8.9.3/8.8.7) with ESMTP id MAA17630
for <[email protected]>; Wed, 11 Sep 2002 12:07:01 +1000
Message-ID: <3D7EA4E4.40106@heart.com.au>
Date: Wed, 11 Sep 2002 12:05:24 +1000
From: Keith Gray <[email protected]>
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US;
rv:0.9.4.1) Gecko/20020508 Netscape6/6.2.3
X-Accept-Language: en-us
MIME-Version: 1.0
To: [email protected]
Subject: subscribe
Content-Type: text/plain; charset=us-ascii; format=flowed
Content-Transfer-Encoding: 7bit
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/6
X-Sequence-Number: 6
--
Keith Gray
Technical Services Manager
Heart Consulting Services
From [email protected] Wed Sep 11 04:47:03 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP id AFD06475D57
for <[email protected]>;
Wed, 11 Sep 2002 04:46:59 -0400 (EDT)
Received: from mail.berusoft.li (ns2.berusoft.li [194.208.67.154])
by postgresql.org (Postfix) with SMTP id E3104475E13
for <[email protected]>;
Wed, 11 Sep 2002 04:46:55 -0400 (EDT)
Received: (qmail 2444 invoked by uid 99); 11 Sep 2002 10:49:33 -0000
Date: 11 Sep 2002 10:49:33 -0000
Message-ID: <20020911104933.2443[email protected]>
Reply-To: "BeruSoft AG" <[email protected]>
From: "BeruSoft AG" <[email protected]>
To: [email protected]
Subject: subscribe
X-Mailer: [web.office] by BeruSoft AG
MIME-Version: 1.0
Content-Type: text/plain; charset="iso-8859-1"
Content-Transfer-Encoding: 7bit
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/7
X-Sequence-Number: 7
From [email protected] Wed Sep 11 04:57:28 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP id E5D86475D57
for <[email protected]>;
Wed, 11 Sep 2002 04:57:27 -0400 (EDT)
Received: from mail.berusoft.li (ns2.berusoft.li [194.208.67.154])
by postgresql.org (Postfix) with SMTP id 9C152475CB6
for <[email protected]>;
Wed, 11 Sep 2002 04:57:25 -0400 (EDT)
Received: (qmail 2596 invoked by uid 99); 11 Sep 2002 11:00:03 -0000
Date: 11 Sep 2002 11:00:03 -0000
Message-ID: <20020911110003.2595[email protected]>
Reply-To: [email protected]
From: [email protected]
To: [email protected]
Subject: subscribe
X-Mailer: [web.office] by BeruSoft AG
MIME-Version: 1.0
Content-Type: text/plain; charset="iso-8859-1"
Content-Transfer-Encoding: 7bit
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/8
X-Sequence-Number: 8
subscribe
From [email protected] Wed Sep 11 07:09:17 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP id 62E4A4759F5
for <[email protected]>;
Wed, 11 Sep 2002 07:09:16 -0400 (EDT)
Received: from out-mta3.plasa.com (out-mta2.plasa.com [202.134.0.198])
by postgresql.org (Postfix) with ESMTP id B79CA476506
for <[email protected]>;
Wed, 11 Sep 2002 07:09:13 -0400 (EDT)
Received: from [61.5.9.21] (helo=portab)
by out-mta3.plasa.com with smtp (Exim 4.04) id 17p5Mv-000nOk-00
for [email protected]; Wed, 11 Sep 2002 18:09:13 +0700
Message-ID: <006e01c25984$0e0292c0$1509053d@portab>
From: "kopra" <[email protected]>
To: <[email protected]>
Subject: subscribe
Date: Wed, 11 Sep 2002 18:05:35 +0700
MIME-Version: 1.0
Content-Type: text/plain;
charset="iso-8859-1"
Content-Transfer-Encoding: 7bit
X-Priority: 3
X-MSMail-Priority: Normal
X-Mailer: Microsoft Outlook Express 6.00.2600.0000
X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/9
X-Sequence-Number: 9
subscribe
------------------------------------------------------------------------------
> Khusus Pelanggan Telepon DIVRE 2, Tekan 166 untuk mendengarkan pesan Anda
------------------------------------------------------------------------------
From [email protected] Fri Sep 13 20:16:03 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP id D4C364760BC
for <[email protected]>;
Fri, 13 Sep 2002 20:16:00 -0400 (EDT)
Received: from smtp3.ihug.com.au (smtp3.ihug.com.au [203.109.250.76])
by postgresql.org (Postfix) with ESMTP id EBF80475E22
for <[email protected]>;
Fri, 13 Sep 2002 20:15:58 -0400 (EDT)
Received: from p568-tnt1.mel.ihug.com.au (postgresql.org) [203.173.162.60]
by smtp3.ihug.com.au with esmtp (Exim 3.22 #1 (Debian))
id 17q0bQ-00077B-00; Sat, 14 Sep 2002 10:16:00 +1000
Message-ID: <3D827FBF.4[email protected]>
Date: Sat, 14 Sep 2002 10:15:59 +1000
From: Justin Clift <[email protected]>
X-Mailer: Mozilla 4.79 [en] (WinNT; U)
X-Accept-Language: en
MIME-Version: 1.0
To: PostgreSQL Performance Mailing List <[email protected]>
Subject: Anyone have any find grained benchmark data?
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/10
X-Sequence-Number: 10
Hi everyone,
There are PostgreSQL servers around that are handling 2,000 simultaneous
client connections (in real life) without problems, but no-one obvious
seems to have yet taken the time to do fine grained testing of the
servers which can take this kind of load, to accurately model their
performance characteristics.
Does anyone here happen to have fine grained benchmark/performance
figures hanging around which get into this range of performance?
Preferably with pretty precise details of how the system was configured,
etc.
:-)
Regards and best wishes,
Justin Clift
--
"My grandfather once told me that there are two kinds of people: those
who work and those who take the credit. He told me to try to be in the
first group; there was less competition there."
- Indira Gandhi
From [email protected] Tue Sep 17 06:50:17 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP id 9B7E1475B33
for <[email protected]>;
Tue, 17 Sep 2002 06:50:15 -0400 (EDT)
Received: from out-mta3.plasa.com (out-mta3.plasa.com [202.134.0.198])
by postgresql.org (Postfix) with ESMTP id CC016475D91
for <[email protected]>;
Tue, 17 Sep 2002 06:50:13 -0400 (EDT)
Received: from [61.5.16.47] (helo=portab)
by out-mta3.plasa.com with smtp (Exim 4.10) id 17rFvo-000YjM-00
for [email protected]; Tue, 17 Sep 2002 17:50:12 +0700
Message-ID: <000101c25e38$66df87a0$2f10053d@portab>
From: "kopra" <[email protected]>
To: <[email protected]>
Subject: subscribe
Date: Sat, 14 Sep 2002 19:28:03 +0700
MIME-Version: 1.0
Content-Type: text/plain;
charset="iso-8859-1"
Content-Transfer-Encoding: 7bit
X-Priority: 3
X-MSMail-Priority: Normal
X-Mailer: Microsoft Outlook Express 6.00.2600.0000
X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/11
X-Sequence-Number: 11
subscribe
------------------------------------------------------------------------------
> Khusus Pelanggan Telepon DIVRE 2, Tekan 166 untuk mendengarkan pesan Anda
------------------------------------------------------------------------------
From [email protected] Thu Sep 26 04:35:33 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP id 51FFF4763DE
for <[email protected]>;
Thu, 26 Sep 2002 04:35:20 -0400 (EDT)
Received: from www.pspl.co.in (www.pspl.co.in [202.54.11.65])
by postgresql.org (Postfix) with ESMTP id 9222E476065
for <[email protected]>;
Thu, 26 Sep 2002 04:35:15 -0400 (EDT)
Received: (from root@localhost)
by www.pspl.co.in (8.11.6/8.11.6) id g8Q8aVq12622
for <[email protected]>; Thu, 26 Sep 2002 14:06:31 +0530
Received: from daithan (daithan.intranet.pspl.co.in [192.168.7.161])
by www.pspl.co.in (8.11.6/8.11.0) with ESMTP id g8Q8aUv12612;
Thu, 26 Sep 2002 14:06:31 +0530
From: "Shridhar Daithankar" <[email protected].in>
To: [email protected], [email protected]
Date: Thu, 26 Sep 2002 14:05:44 +0530
MIME-Version: 1.0
Subject: Performance while loading data and indexing
Reply-To: [email protected].in
Message-ID: <3D931438.22010.133ADAFA@localhost>
X-mailer: Pegasus Mail for Windows (v4.02)
Content-type: text/plain; charset=US-ASCII
Content-transfer-encoding: 7BIT
Content-description: Mail message body
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1161
X-Sequence-Number: 30742
Hello all,
Some time back I posted a query to build a site with 150GB of database. In last
couple of weeks, lots of things were tested at my place and there are some
results and again some concerns.
This is a long post. Please be patient and read thr. If we win this, I guess we
have a good marketing/advocacy case here..;-)
First the problems (For those who do not read beyond first page)
1) Database load time from flat file using copy is very high
2) Creating index takes huge amount of time.
3) Any suggsestions for runtime as data load and query will be going in
parallel.
Now the details. Note that this is a test run only..
Platform:- 4x Xeon2.4GHz/4GB RAM/4x48 SCSI RAID5/72 GB SCSI
RedHat7.2/PostgreSQL7.1.3
Database in flat file:
125,000,000 records of around 100 bytes each.
Flat file size 12GB
Load time: 14581 sec/~8600 rows persec/~ an MB of data per sec.
Create unique composite index on 2 char and a timestamp field: 25226 sec.
Database size on disk: 26GB
Select query: 1.5 sec. for approx. 150 rows.
Important postgresql.conf settings
sort_mem = 12000
shared_buffers = 24000
fsync=true (Sad but true. Left untouched.. Will that make a difference on
SCSI?)
wal_buffers = 65536
wal_files = 64
Now the requirements
Initial flat data load: 250GB of data. This has gone up since last query. It
was 150GB earlier..
Ongoing inserts: 5000/sec.
Number of queries: 4800 queries/hour
Query response time: 10 sec.
Now questions.
1) Instead of copying from a single 12GB data file, will a parallel copy from
say 5 files will speed up the things?
Couple MB of data per sec. to disk is just not saturating it. It's a RAID 5
setup..
2) Sort mem.=12K i.e. 94MB, sounds good enough to me. Does this need further
addition to improve create index performance?
3) 5K concurrent inserts with an index on, will this need a additional CPU
power? Like deploying it on dual RISC CPUs etc?
4) Query performance is not a problem. Though 4.8K queries per sec. expected
response time from each query is 10 sec. But my guess is some serius CPU power
will be chewed there too..
5)Will upgrading to 7.2.2/7.3 beta help?
All in all, in the test, we didn't see the performance where hardware is
saturated to it's limits. So effectively we are not able to get postgresql
making use of it. Just pushing WAL and shared buffers does not seem to be the
solution.
If you guys have any suggestions. let me know. I need them all..
Mysql is almost out because it's creating index for last 17 hours. I don't
think it will keep up with 5K inserts per sec. with index. SAP DB is under
evaluation too. But postgresql is most favourite as of now because it works. So
I need to come up with solutions to problems that will occur in near future..
;-)
TIA..
Bye
Shridhar
--
Law of Procrastination: Procrastination avoids boredom; one never has the
feeling that there is nothing important to do.
From [email protected] Thu Sep 26 04:53:43 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP id E56844768FD
for <[email protected]>;
Thu, 26 Sep 2002 04:53:40 -0400 (EDT)
Received: from www.pspl.co.in (www.pspl.co.in [202.54.11.65])
by postgresql.org (Postfix) with ESMTP id 2B51C4767DC
for <[email protected]>;
Thu, 26 Sep 2002 04:53:39 -0400 (EDT)
Received: (from root@localhost)
by www.pspl.co.in (8.11.6/8.11.6) id g8Q8snQ14266
for <[email protected]>; Thu, 26 Sep 2002 14:24:49 +0530
Received: from daithan (daithan.intranet.pspl.co.in [192.168.7.161])
by www.pspl.co.in (8.11.6/8.11.0) with ESMTP id g8Q8snv14256;
Thu, 26 Sep 2002 14:24:49 +0530
From: "Shridhar Daithankar" <[email protected]>
To: [email protected], [email protected]
Date: Thu, 26 Sep 2002 14:24:02 +0530
MIME-Version: 1.0
Subject: Re: [HACKERS] Performance while loading data and indexing
Reply-To: [email protected]
Message-ID: <3D931882.31859.134B9E4C@localhost>
In-reply-to: <3D931438.22010.133ADAFA@localhost>
X-mailer: Pegasus Mail for Windows (v4.02)
Content-type: text/plain; charset=US-ASCII
Content-transfer-encoding: 7BIT
Content-description: Mail message body
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1162
X-Sequence-Number: 30743
On 26 Sep 2002 at 14:05, Shridhar Daithankar wrote:
> Some time back I posted a query to build a site with 150GB of database. In last
> couple of weeks, lots of things were tested at my place and there are some
> results and again some concerns.
> 2) Creating index takes huge amount of time.
> Load time: 14581 sec/~8600 rows persec/~ an MB of data per sec.
> Create unique composite index on 2 char and a timestamp field: 25226 sec.
> Database size on disk: 26GB
> Select query: 1.5 sec. for approx. 150 rows.
> 2) Sort mem.=12K i.e. 94MB, sounds good enough to me. Does this need further
> addition to improve create index performance?
Just a thought. If I sort the table before making an index, would it be faster
than creating index on raw table? And/or if at all, how do I sort the table
without duplicating it?
Just a wild thought..
Bye
Shridhar
--
linux: the choice of a GNU generation([email protected] put this on Tshirts in
'93)
From [email protected] Thu Sep 26 05:06:18 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP
id A48884761EA; Thu, 26 Sep 2002 05:06:16 -0400 (EDT)
Received: from svana.org (t1-1-076.dialup.apex.net.au [203.20.62.76])
by postgresql.org (Postfix) with ESMTP
id B99B24760CD; Thu, 26 Sep 2002 05:06:15 -0400 (EDT)
Received: from kleptog by svana.org with local (Exim 3.35 #1 (Debian))
id 17uUaF-0002nB-00; Thu, 26 Sep 2002 19:05:19 +1000
Date: Thu, 26 Sep 2002 19:05:19 +1000
From: Martijn van Oosterhout <[email protected]>
To: Shridhar Daithankar <[email protected].in>
Cc: [email protected], [email protected]
Subject: Re: Performance while loading data and indexing
Message-ID: <20020926090519.[email protected]>
Reply-To: Martijn van Oosterhout <[email protected]>
Mail-Followup-To: Shridhar Daithankar <[email protected].in>,
[email protected], [email protected]
References: <3D931438.22010.133ADAFA@localhost>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <3D931438.22010.133ADAFA@localhost>
User-Agent: Mutt/1.3.28i
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1163
X-Sequence-Number: 30744
I'll preface this by saying that while I have a large database, it doesn't
require quite the performace you're talking about here.
On Thu, Sep 26, 2002 at 02:05:44PM +0530, Shridhar Daithankar wrote:
> 1) Database load time from flat file using copy is very high
> 2) Creating index takes huge amount of time.
> 3) Any suggsestions for runtime as data load and query will be going in
> parallel.
You're loading all the data in one copy. I find that INSERTs are mostly
limited by indexes. While index lookups are cheap, they are not free and
each index needs to be updated for each row.
I fond using partial indexes to only index the rows you actually use can
help with the loading. It's a bit obscure though.
As for parallel loading, you'll be limited mostly by your I/O bandwidth.
Have you measured it to take sure it's up to speed?
> Now the details. Note that this is a test run only..
>
> Platform:- 4x Xeon2.4GHz/4GB RAM/4x48 SCSI RAID5/72 GB SCSI
> RedHat7.2/PostgreSQL7.1.3
>
> Database in flat file:
> 125,000,000 records of around 100 bytes each.
> Flat file size 12GB
>
> Load time: 14581 sec/~8600 rows persec/~ an MB of data per sec.
> Create unique composite index on 2 char and a timestamp field: 25226 sec.
> Database size on disk: 26GB
> Select query: 1.5 sec. for approx. 150 rows.
So you're loading at a rate of 860KB per sec. That's not too fast. How many
indexes are active at that time? Triggers and foreign keys also take their
toll.
> Important postgresql.conf settings
>
> sort_mem = 12000
> shared_buffers = 24000
> fsync=true (Sad but true. Left untouched.. Will that make a difference on
> SCSI?)
> wal_buffers = 65536
> wal_files = 64
fsync IIRC only affects the WAL buffers now but it may be quite expensive,
especially considering it's running on every transaction commit. Oh, your
WAL files are on a seperate disk from the data?
> Initial flat data load: 250GB of data. This has gone up since last query. It
> was 150GB earlier..
> Ongoing inserts: 5000/sec.
> Number of queries: 4800 queries/hour
> Query response time: 10 sec.
That looks quite acheivable.
> 1) Instead of copying from a single 12GB data file, will a parallel copy from
> say 5 files will speed up the things?
Limited by I/O bandwidth. On linux vmstat can tell you how many blocks are
being loaded and stored per second. Try it. As long as sync() doesn't get
done too often, it should be help.
> Couple MB of data per sec. to disk is just not saturating it. It's a RAID 5
> setup..
No, it's not. You should be able to do better.
> 2) Sort mem.=12K i.e. 94MB, sounds good enough to me. Does this need further
> addition to improve create index performance?
Should be fine. Admittedly your indexes are taking rather long to build.
> 3) 5K concurrent inserts with an index on, will this need a additional CPU
> power? Like deploying it on dual RISC CPUs etc?
It shouldn't. Do you have an idea of what your CPU usage is? ps aux should
give you a decent idea.
> 4) Query performance is not a problem. Though 4.8K queries per sec. expected
> response time from each query is 10 sec. But my guess is some serius CPU power
> will be chewed there too..
Should be fine.
> 5)Will upgrading to 7.2.2/7.3 beta help?
Possibly, though it may be wirth it just for the features/bugfixes.
> All in all, in the test, we didn't see the performance where hardware is
> saturated to it's limits. So effectively we are not able to get postgresql
> making use of it. Just pushing WAL and shared buffers does not seem to be the
> solution.
>
> If you guys have any suggestions. let me know. I need them all..
Find the bottleneck: CPU, I/O or memory?
> Mysql is almost out because it's creating index for last 17 hours. I don't
> think it will keep up with 5K inserts per sec. with index. SAP DB is under
> evaluation too. But postgresql is most favourite as of now because it works. So
> I need to come up with solutions to problems that will occur in near future..
> ;-)
17 hours! Ouch. Either way, you should be able to do much better. Hope this
helps,
--
Martijn van Oosterhout <[email protected]> http://svana.org/kleptog/
> There are 10 kinds of people in the world, those that can do binary
> arithmetic and those that can't.
From [email protected] Thu Sep 26 05:12:58 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP id 34B1A47616F
for <[email protected]>;
Thu, 26 Sep 2002 05:12:56 -0400 (EDT)
Received: from www.pspl.co.in (www.pspl.co.in [202.54.11.65])
by postgresql.org (Postfix) with ESMTP id 3DF80475F47
for <[email protected]>;
Thu, 26 Sep 2002 05:12:53 -0400 (EDT)
Received: (from root@localhost)
by www.pspl.co.in (8.11.6/8.11.6) id g8Q9E6m15849
for <[email protected]>; Thu, 26 Sep 2002 14:44:06 +0530
Received: from daithan (daithan.intranet.pspl.co.in [192.168.7.161])
by www.pspl.co.in (8.11.6/8.11.0) with ESMTP id g8Q9E6v15839;
Thu, 26 Sep 2002 14:44:06 +0530
From: "Shridhar Daithankar" <[email protected]>
To: [email protected]
Date: Thu, 26 Sep 2002 14:43:20 +0530
MIME-Version: 1.0
Subject: Re: Performance while loading data and indexing
Reply-To: [email protected]
Cc: [email protected]
Message-ID: <3D931D08.1695.135D474B@localhost>
In-reply-to:
<19138.194.185.48.247.1033030286.squirrel@mail.talentwebsolutions.com>
References: <3D931882.31859.134B9E4C@localhost>
X-mailer: Pegasus Mail for Windows (v4.02)
Content-type: text/plain; charset=US-ASCII
Content-transfer-encoding: 7BIT
Content-description: Mail message body
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1525
X-Sequence-Number: 29482
On 26 Sep 2002 at 10:51, [email protected] wrote:
> Hi,
> it seems you have to cluster it, I don't think you have another choise.
Hmm.. That didn't occur to me...I guess some real time clustering like usogres
would do. Unless it turns out to be a performance hog..
But this is just insert and select. No updates no deletes(Unless customer makes
a 180 degree turn) So I doubt if clustering will help. At the most I can
replicate data across machines and spread queries on them. Replication overhead
as a down side and low query load on each machine as upside..
> I'm retrieving the configuration of our postgres servers (I'm out of office
> now), so I can send it to you. I was quite disperate about performance, and
> I was thinking to migrate the data on an oracle database. Then I found this
> configuration on the net, and I had a succesfull increase of performance.
In this case, we are upto postgresql because we/our customer wants to keep the
costs down..:-) Even they are asking now if it's possible to keep hardware
costs down as well. That's getting some funny responses here but I digress..
> Maybe this can help you.
>
> Why you use copy to insert records? I usually use perl scripts, and they
> work well .
Performance reasons. As I said in one of my posts earlier, putting upto 100K
records in one transaction in steps of 10K did not reach performance of copy.
As Tom said rightly, it was a 4-1 ratio despite using transactions..
Thanks once again..
Bye
Shridhar
--
Secretary's Revenge: Filing almost everything under "the".
From [email protected] Thu Sep 26 05:17:41 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP
id C6DFF4763DE; Thu, 26 Sep 2002 05:17:39 -0400 (EDT)
Received: from new-smtp2.ihug.com.au (new-smtp2.ihug.com.au [203.109.250.28])
by postgresql.org (Postfix) with ESMTP
id 24E4847631F; Thu, 26 Sep 2002 05:17:39 -0400 (EDT)
Received: from p555-tnt2.mel.ihug.com.au (postgresql.org) [203.173.166.47]
by new-smtp2.ihug.com.au with esmtp (Exim 3.22 #1 (Debian))
id 17uUm7-00005d-00; Thu, 26 Sep 2002 19:17:35 +1000
Message-ID: <3[email protected]>
Date: Thu, 26 Sep 2002 19:17:32 +1000
From: Justin Clift <[email protected]>
X-Mailer: Mozilla 4.79 [en] (WinNT; U)
X-Accept-Language: en
MIME-Version: 1.0
To: [email protected].in
Cc: [email protected], [email protected]
Subject: Re: Performance while loading data and indexing
References: <3D931438.22010.133ADAFA@localhost>
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1164
X-Sequence-Number: 30745
Hi Shridhar,
Shridhar Daithankar wrote:
<snip>
> 3) Any suggsestions for runtime as data load and query will be going in
> parallel.
That sounds unusual. From reading this, it *sounds* like you'll be
running queries against an incomplete dataset, or maybe just running the
queries that affect the tables loaded thus far (during the initial
load).
<snip>
> fsync=true (Sad but true. Left untouched.. Will that make a difference on
> SCSI?)
Definitely. Have directly measured a ~ 2x tps throughput increase on
FreeBSD when leaving fsync off whilst performance measuring stuff
recently (PG 7.2.2). Like anything it'll depend on workload, phase of
moon, etc, but it's a decent indicator.
<snip>
> Now questions.
>
> 1) Instead of copying from a single 12GB data file, will a parallel copy from
> say 5 files will speed up the things?
Not sure yet. Haven't get done enough performance testing (on the cards
very soon though).
> Couple MB of data per sec. to disk is just not saturating it. It's a RAID 5
> setup..
fsync = off would help during the data load, but not a good idea if
you're going to be running queries against it at the same time.
Am still getting the hang of performance tuning stuff. Have a bunch of
Ultra160 hardware for the Intel platform, and am testing against it as
time permits.
Not as high end as I'd like, but it's a start.
:-)
Regards and best wishes,
Justin Clift
<snip>
> Bye
> Shridhar
--
"My grandfather once told me that there are two kinds of people: those
who work and those who take the credit. He told me to try to be in the
first group; there was less competition there."
- Indira Gandhi
From [email protected] Thu Sep 26 05:35:14 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP id C25DF47644C
for <[email protected]>;
Thu, 26 Sep 2002 05:35:13 -0400 (EDT)
Received: from www.pspl.co.in (www.pspl.co.in [202.54.11.65])
by postgresql.org (Postfix) with ESMTP id 0925D47616F
for <[email protected]>;
Thu, 26 Sep 2002 05:35:10 -0400 (EDT)
Received: (from root@localhost)
by www.pspl.co.in (8.11.6/8.11.6) id g8Q9aQg18125
for <[email protected]>; Thu, 26 Sep 2002 15:06:26 +0530
Received: from daithan (daithan.intranet.pspl.co.in [192.168.7.161])
by www.pspl.co.in (8.11.6/8.11.0) with ESMTP id g8Q9aQv18115;
Thu, 26 Sep 2002 15:06:26 +0530
From: "Shridhar Daithankar" <[email protected].in>
To: [email protected], [email protected]
Date: Thu, 26 Sep 2002 15:05:40 +0530
MIME-Version: 1.0
Subject: Re: Performance while loading data and indexing
Reply-To: [email protected].in
Message-ID: <3D932244.13502.1371B9CA@localhost>
In-reply-to: <3[email protected]>
X-mailer: Pegasus Mail for Windows (v4.02)
Content-type: text/plain; charset=US-ASCII
Content-transfer-encoding: 7BIT
Content-description: Mail message body
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1166
X-Sequence-Number: 30747
On 26 Sep 2002 at 19:17, Justin Clift wrote:
> Shridhar Daithankar wrote:
> <snip>
> > 3) Any suggsestions for runtime as data load and query will be going in
> > parallel.
>
> That sounds unusual. From reading this, it *sounds* like you'll be
> running queries against an incomplete dataset, or maybe just running the
> queries that affect the tables loaded thus far (during the initial
> load).
That's correct. Load the data so far and keep inserting data as and when it
generates.
They don't mind running against data so far. It's not very accurate stuff
IMO...
> > fsync=true (Sad but true. Left untouched.. Will that make a difference on
> > SCSI?)
>
> Definitely. Have directly measured a ~ 2x tps throughput increase on
> FreeBSD when leaving fsync off whilst performance measuring stuff
> recently (PG 7.2.2). Like anything it'll depend on workload, phase of
> moon, etc, but it's a decent indicator.
I didn't know even that matters with SCSI..Will check out..
> fsync = off would help during the data load, but not a good idea if
> you're going to be running queries against it at the same time.
That's OK for the reasons mentioned above. It wouldn't be out of place to
expect a UPS to such an installation...
Bye
Shridhar
--
Hoare's Law of Large Problems: Inside every large problem is a small problem
struggling to get out.
From [email protected] Thu Sep 26 05:46:29 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP id 75E39476B20
for <[email protected]>;
Thu, 26 Sep 2002 05:46:27 -0400 (EDT)
Received: from www.pspl.co.in (www.pspl.co.in [202.54.11.65])
by postgresql.org (Postfix) with ESMTP id 548F847644C
for <[email protected]>;
Thu, 26 Sep 2002 05:46:23 -0400 (EDT)
Received: (from root@localhost)
by www.pspl.co.in (8.11.6/8.11.6) id g8Q9la019303
for <[email protected]>; Thu, 26 Sep 2002 15:17:36 +0530
Received: from daithan (daithan.intranet.pspl.co.in [192.168.7.161])
by www.pspl.co.in (8.11.6/8.11.0) with ESMTP id g8Q9lav19293;
Thu, 26 Sep 2002 15:17:36 +0530
From: "Shridhar Daithankar" <[email protected]>
To: [email protected], [email protected]
Date: Thu, 26 Sep 2002 15:16:50 +0530
MIME-Version: 1.0
Subject: Re: Performance while loading data and indexing
Reply-To: [email protected]
Message-ID: <3D9324E2.30195.137BF348@localhost>
In-reply-to: <[email protected]>
References: <3D931438.22010.133ADAFA@localhost>
X-mailer: Pegasus Mail for Windows (v4.02)
Content-type: text/plain; charset=US-ASCII
Content-transfer-encoding: 7BIT
Content-description: Mail message body
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1167
X-Sequence-Number: 30748
On 26 Sep 2002 at 19:05, Martijn van Oosterhout wrote:
> On Thu, Sep 26, 2002 at 02:05:44PM +0530, Shridhar Daithankar wrote:
> > 1) Database load time from flat file using copy is very high
> > 2) Creating index takes huge amount of time.
> > 3) Any suggsestions for runtime as data load and query will be going in
> > parallel.
>
> You're loading all the data in one copy. I find that INSERTs are mostly
> limited by indexes. While index lookups are cheap, they are not free and
> each index needs to be updated for each row.
>
> I fond using partial indexes to only index the rows you actually use can
> help with the loading. It's a bit obscure though.
>
> As for parallel loading, you'll be limited mostly by your I/O bandwidth.
> Have you measured it to take sure it's up to speed?
Well. It's like this, as of now.. CreateDB->create table->create index->Select.
So loading is not slowed by index. As of your hint of vmstat, will check it
out.
> So you're loading at a rate of 860KB per sec. That's not too fast. How many
> indexes are active at that time? Triggers and foreign keys also take their
> toll.
Nothing except the table where data os loaded..
> fsync IIRC only affects the WAL buffers now but it may be quite expensive,
> especially considering it's running on every transaction commit. Oh, your
> WAL files are on a seperate disk from the data?
No. Same RAID 5 disks..
> It shouldn't. Do you have an idea of what your CPU usage is? ps aux should
> give you a decent idea.
I guess we forgot to monitor system parameters. Next on my list is running
vmstat, top and tuning bdflush.
> Find the bottleneck: CPU, I/O or memory?
Understood..
>
> > Mysql is almost out because it's creating index for last 17 hours. I don't
> > think it will keep up with 5K inserts per sec. with index. SAP DB is under
> > evaluation too. But postgresql is most favourite as of now because it works. So
> > I need to come up with solutions to problems that will occur in near future..
> > ;-)
>
> 17 hours! Ouch. Either way, you should be able to do much better. Hope this
> helps,
Heh.. no wonder this evaluation is taking more than 2 weeks.. Mysql was running
out of disk space while creating index and crashin. An upgrade to mysql helped
there but no numbers as yet..
Thanks once again...
Bye
Shridhar
--
Boren's Laws: (1) When in charge, ponder. (2) When in trouble, delegate. (3)
When in doubt, mumble.
From [email protected] Thu Sep 26 05:59:51 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP id 13499476C17
for <[email protected]>;
Thu, 26 Sep 2002 05:59:51 -0400 (EDT)
Received: from anchor-post-39.mail.demon.net (anchor-post-39.mail.demon.net
[194.217.242.80])
by postgresql.org (Postfix) with ESMTP id 76F3C476C01
for <[email protected]>;
Thu, 26 Sep 2002 05:59:50 -0400 (EDT)
Received: from mwynhau.demon.co.uk ([193.237.186.96]
helo=mainbox.archonet.com)
by anchor-post-39.mail.demon.net with esmtp (Exim 3.36 #2)
id 17uVR1-0003WF-0U; Thu, 26 Sep 2002 10:59:51 +0100
Received: from localhost (localhost.localdomain [127.0.0.1])
by mainbox.archonet.com (Postfix) with ESMTP
id 5B12716378; Thu, 26 Sep 2002 10:49:02 +0100 (BST)
Received: from client.archonet.com (client.archonet.com [192.168.1.16])
by mainbox.archonet.com (Postfix) with ESMTP
id AE86216367; Thu, 26 Sep 2002 10:49:01 +0100 (BST)
Content-Type: text/plain;
charset="iso-8859-1"
From: Richard Huxton <[email protected]>
Organization: Archonet Ltd
To: [email protected],
[email protected]
Subject: Re: Performance while loading data and indexing
Date: Thu, 26 Sep 2002 10:48:06 +0100
User-Agent: KMail/1.4.1
References: <3D931438.22010.133ADAFA@localhost>
In-Reply-To: <3D931438.22010.133ADAFA@localhost>
MIME-Version: 1.0
Content-Transfer-Encoding: quoted-printable
Message-Id: <[email protected]>
X-Virus-Scanned: by AMaViS snapshot-20020531
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1172
X-Sequence-Number: 30753
On Thursday 26 Sep 2002 9:35 am, Shridhar Daithankar wrote:
[questions re: large database]
Before reading my advice please bear in mind you are operating way beyond t=
he=20
scale of anything I have ever built.
> Now the details. Note that this is a test run only..
>
> Platform:- 4x Xeon2.4GHz/4GB RAM/4x48 SCSI RAID5/72 GB SCSI
> RedHat7.2/PostgreSQL7.1.3
>
> Database in flat file:
> 125,000,000 records of around 100 bytes each.
> Flat file size 12GB
>
> Load time: 14581 sec/~8600 rows persec/~ an MB of data per sec.
> Create unique composite index on 2 char and a timestamp field: 25226 sec.
> Database size on disk: 26GB
> Select query: 1.5 sec. for approx. 150 rows.
>
> Important postgresql.conf settings
[snipped setting details for moment]
Have you tried putting the wal files, syslog etc on separate disks/volumes?=
If=20
you've settled on Intel, about the only thing you can optimise further is t=
he=20
disks.
Oh - and the OS - make sure you're running a (good) recent kernel for that=
=20
sort of hardware, I seem to remember some substantial changes in the 2.4=20
series regarding multi-processor.
> Now the requirements
>
> Initial flat data load: 250GB of data. This has gone up since last query.
> It was 150GB earlier..
> Ongoing inserts: 5000/sec.
> Number of queries: 4800 queries/hour
> Query response time: 10 sec.
Is this 5000 rows in say 500 transactions or 5000 insert transactions per=
=20
second. How many concurrent clients is this? Similarly for the 4800 queries=
,=20
how many concurrent clients is this? Are they expected to return approx 150=
=20
rows as in your test?
> Now questions.
>
> 1) Instead of copying from a single 12GB data file, will a parallel copy
> from say 5 files will speed up the things?
If the CPU is the bottle-neck then it should, but it's difficult to say=20
without figures.
> Couple MB of data per sec. to disk is just not saturating it. It's a RAID=
5
> setup..
What is saturating during the flat-file load? Something must be maxed in to=
p /=20
iostat / vmstat.
[snip]
>
> 5)Will upgrading to 7.2.2/7.3 beta help?
It's unlikely to hurt.
> All in all, in the test, we didn't see the performance where hardware is
> saturated to it's limits.
Something *must* be.
What are your disaster recovery plans? I can see problems with taking backu=
ps=20
if this beast is live 24/7.
- Richard Huxton
From [email protected] Thu Sep 26 05:50:02 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP
id 6D16F4761DF; Thu, 26 Sep 2002 05:50:00 -0400 (EDT)
Received: from new-smtp2.ihug.com.au (new-smtp2.ihug.com.au [203.109.250.28])
by postgresql.org (Postfix) with ESMTP
id 79EAE47616F; Thu, 26 Sep 2002 05:49:59 -0400 (EDT)
Received: from p555-tnt2.mel.ihug.com.au (postgresql.org) [203.173.166.47]
by new-smtp2.ihug.com.au with esmtp (Exim 3.22 #1 (Debian))
id 17uVHP-000184-00; Thu, 26 Sep 2002 19:49:55 +1000
Message-ID: <3D92D841.3E02[email protected]>
Date: Thu, 26 Sep 2002 19:49:53 +1000
From: Justin Clift <[email protected]>
X-Mailer: Mozilla 4.79 [en] (WinNT; U)
X-Accept-Language: en
MIME-Version: 1.0
To: [email protected].in
Cc: [email protected], [email protected]
Subject: Re: [HACKERS] Performance while loading data and indexing
References: <3D932244.13502.1371B9CA@localhost>
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1168
X-Sequence-Number: 30749
Shridhar Daithankar wrote:
<snip>
> > > fsync=true (Sad but true. Left untouched.. Will that make a difference on
> > > SCSI?)
> >
> > Definitely. Have directly measured a ~ 2x tps throughput increase on
> > FreeBSD when leaving fsync off whilst performance measuring stuff
> > recently (PG 7.2.2). Like anything it'll depend on workload, phase of
> > moon, etc, but it's a decent indicator.
>
> I didn't know even that matters with SCSI..Will check out..
Cool. When testing it had FreeBSD 4.6.2 installed on one drive along
with the PostgreSQL 7.2.2 binaries, it had the data on a second drive
(mounted as /pgdata), and it had the pg_xlog directory mounted on a
third drive. Swap had it's own drive as well.
Everything is UltraSCSI, etc. Haven't yet tested for a performance
difference through moving the indexes to another drive after creation
though. That apparently has the potential to help as well.
:-)
Regards and best wishes,
Justin Clift
--
"My grandfather once told me that there are two kinds of people: those
who work and those who take the credit. He told me to try to be in the
first group; there was less competition there."
- Indira Gandhi
From [email protected] Thu Sep 26 05:56:37 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP
id 7E7F9476B72; Thu, 26 Sep 2002 05:56:36 -0400 (EDT)
Received: from new-smtp2.ihug.com.au (new-smtp2.ihug.com.au [203.109.250.28])
by postgresql.org (Postfix) with ESMTP
id 4AB45476B45; Thu, 26 Sep 2002 05:56:34 -0400 (EDT)
Received: from p555-tnt2.mel.ihug.com.au (postgresql.org) [203.173.166.47]
by new-smtp2.ihug.com.au with esmtp (Exim 3.22 #1 (Debian))
id 17uVNr-0001Ml-00; Thu, 26 Sep 2002 19:56:35 +1000
Message-ID: <[email protected]>
Date: Thu, 26 Sep 2002 19:56:34 +1000
From: Justin Clift <[email protected]>
X-Mailer: Mozilla 4.79 [en] (WinNT; U)
X-Accept-Language: en
MIME-Version: 1.0
To: [email protected]
Cc: [email protected], [email protected]
Subject: Re: [HACKERS] Performance while loading data and indexing
References: <3D931438.22010.133ADAFA@localhost>
<3D9324E2.30195.137BF348@localhost>
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1171
X-Sequence-Number: 30752
Shridhar Daithankar wrote:
>
> On 26 Sep 2002 at 19:05, Martijn van Oosterhout wrote:
<snip>
> > fsync IIRC only affects the WAL buffers now but it may be quite expensive,
> > especially considering it's running on every transaction commit. Oh, your
> > WAL files are on a seperate disk from the data?
>
> No. Same RAID 5 disks..
Not sure if this is a good idea. Would have to think deeply about the
controller and drive optimisation/load characteristics.
If it's any help, when I was testing recently with WAL on a separate
drive, the WAL logs were doing more read&writes per second than the main
data drive. This would of course be affected by the queries you are
running against the database. I was just running Tatsuo's TPC-B stuff,
and the OSDB AS3AP tests.
> I guess we forgot to monitor system parameters. Next on my list is running
> vmstat, top and tuning bdflush.
That'll just be the start of it for serious performance tuning and
learning how PostgreSQL works. :)
<snip>
> Thanks once again...
> Bye
> Shridhar
--
"My grandfather once told me that there are two kinds of people: those
who work and those who take the credit. He told me to try to be in the
first group; there was less competition there."
- Indira Gandhi
From [email protected] Thu Sep 26 10:34:21 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP
id 05F75476AA7; Thu, 26 Sep 2002 10:34:20 -0400 (EDT)
Received: from sss.pgh.pa.us (unknown [192.204.191.242])
by postgresql.org (Postfix) with ESMTP
id 6AFEC4767D7; Thu, 26 Sep 2002 10:34:18 -0400 (EDT)
Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1])
by sss.pgh.pa.us (8.12.5/8.12.5) with ESMTP id g8QEXwhR003937;
Thu, 26 Sep 2002 10:33:58 -0400 (EDT)
To: [email protected]
Cc: [email protected], [email protected]
Subject: Re: Performance while loading data and indexing
In-reply-to: <3D931438.22010.133ADAFA@localhost>
References: <3D931438.22010.133ADAFA@localhost>
Comments: In-reply-to "Shridhar Daithankar"
<[email protected]>
message dated "Thu, 26 Sep 2002 14:05:44 +0530"
Date: Thu, 26 Sep 2002 10:33:58 -0400
Message-ID: <[email protected]>
From: Tom Lane <[email protected]>
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1181
X-Sequence-Number: 30762
"Shridhar Daithankar" <[email protected]> writes:
> RedHat7.2/PostgreSQL7.1.3
I'd suggest a newer release of Postgres ... 7.1.3 is pretty old ...
> Create unique composite index on 2 char and a timestamp field: 25226 sec.
What do you mean by "char" exactly? If it's really char(N), how much
are you paying in padding space? There are very very few cases where
I'd not say to use varchar(N), or text, instead. Also, does it have to
be character data? If you could use an integer or float datatype
instead the index operations should be faster (though I can't say by
how much). Have you thought carefully about the order in which the
composite index columns are listed?
> sort_mem = 12000
To create an index of this size, you want to push sort_mem as high as it
can go without swapping. 12000 sounds fine for the global setting, but
in the process that will create the index, try setting sort_mem to some
hundreds of megs or even 1Gb. (But be careful: the calculation of space
actually used by CREATE INDEX is off quite a bit in pre-7.3 releases
:-(. You should probably expect the actual process size to grow to two
or three times what you set sort_mem to. Don't let it get so big as to
swap.)
> wal_buffers = 65536
The above is a complete waste of memory space, which would be better
spent on letting the kernel expand its disk cache. There's no reason
for wal_buffers to be more than a few dozen.
regards, tom lane
From [email protected] Thu Sep 26 10:42:11 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP
id 45ACE476D3D; Thu, 26 Sep 2002 10:42:11 -0400 (EDT)
Received: from sss.pgh.pa.us (unknown [192.204.191.242])
by postgresql.org (Postfix) with ESMTP
id B5B5B476D3A; Thu, 26 Sep 2002 10:42:10 -0400 (EDT)
Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1])
by sss.pgh.pa.us (8.12.5/8.12.5) with ESMTP id g8QEg8hR004032;
Thu, 26 Sep 2002 10:42:09 -0400 (EDT)
To: Justin Clift <[email protected]>
Cc: [email protected],
[email protected], [email protected]
Subject: Re: [HACKERS] Performance while loading data and indexing
In-reply-to: <[email protected]>
References: <3D931438.22010.133ADAFA@localhost>
<3D9324E2.30195.137BF348@localhost>
<[email protected]>
Comments: In-reply-to Justin Clift <[email protected]>
message dated "Thu, 26 Sep 2002 19:56:34 +1000"
Date: Thu, 26 Sep 2002 10:42:08 -0400
Message-ID: <[email protected]>
From: Tom Lane <[email protected]>
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1183
X-Sequence-Number: 30764
Justin Clift <[email protected]> writes:
>> On 26 Sep 2002 at 19:05, Martijn van Oosterhout wrote:
>>> fsync IIRC only affects the WAL buffers now but it may be quite expensive,
>>> especially considering it's running on every transaction commit. Oh, your
>>> WAL files are on a seperate disk from the data?
> Not sure if this is a good idea. Would have to think deeply about the
> controller and drive optimisation/load characteristics.
> If it's any help, when I was testing recently with WAL on a separate
> drive, the WAL logs were doing more read&writes per second than the main
> data drive.
... but way fewer seeks. For anything involving lots of updating
transactions (and certainly 5000 separate insertions per second would
qualify; can those be batched??), it should be a win to put WAL on its
own spindle, just to get locality of access to the WAL.
regards, tom lane
From [email protected] Thu Sep 26 10:51:34 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP id DEDD4475EE4
for <[email protected]>;
Thu, 26 Sep 2002 10:51:33 -0400 (EDT)
Received: from www.pspl.co.in (www.pspl.co.in [202.54.11.65])
by postgresql.org (Postfix) with ESMTP id 4CAFB475CB4
for <[email protected]>;
Thu, 26 Sep 2002 10:51:32 -0400 (EDT)
Received: (from root@localhost)
by www.pspl.co.in (8.11.6/8.11.6) id g8QEqqK15165
for <[email protected]>; Thu, 26 Sep 2002 20:22:52 +0530
Received: from daithan (daithan.intranet.pspl.co.in [192.168.7.161])
by www.pspl.co.in (8.11.6/8.11.0) with ESMTP id g8QEqqv15154;
Thu, 26 Sep 2002 20:22:52 +0530
From: "Shridhar Daithankar" <[email protected]>
To: [email protected], [email protected]
Date: Thu, 26 Sep 2002 20:22:05 +0530
MIME-Version: 1.0
Subject: Re: Performance while loading data and indexing
Reply-To: [email protected]
Message-ID: <3D936C6D.12380.14936AEC@localhost>
References: <3D931438.22010.133ADAFA@localhost>
In-reply-to: <[email protected]>
X-mailer: Pegasus Mail for Windows (v4.02)
Content-type: text/plain; charset=US-ASCII
Content-transfer-encoding: 7BIT
Content-description: Mail message body
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1187
X-Sequence-Number: 30768
On 26 Sep 2002 at 10:33, Tom Lane wrote:
> "Shridhar Daithankar" <[email protected]> writes:
> > RedHat7.2/PostgreSQL7.1.3
>
> I'd suggest a newer release of Postgres ... 7.1.3 is pretty old ...
I agree.. downloadind 7.2.2 right away..
> > Create unique composite index on 2 char and a timestamp field: 25226 sec.
>
> What do you mean by "char" exactly? If it's really char(N), how much
> are you paying in padding space? There are very very few cases where
> I'd not say to use varchar(N), or text, instead. Also, does it have to
> be character data? If you could use an integer or float datatype
> instead the index operations should be faster (though I can't say by
> how much). Have you thought carefully about the order in which the
> composite index columns are listed?
I have forwarded the idea of putting things into number. If it causes speedup
in index lookup/creation, it would do. Looks like bigint is the order of the
day..
>
> > sort_mem = 12000
>
> To create an index of this size, you want to push sort_mem as high as it
> can go without swapping. 12000 sounds fine for the global setting, but
> in the process that will create the index, try setting sort_mem to some
> hundreds of megs or even 1Gb. (But be careful: the calculation of space
> actually used by CREATE INDEX is off quite a bit in pre-7.3 releases
> :-(. You should probably expect the actual process size to grow to two
> or three times what you set sort_mem to. Don't let it get so big as to
> swap.)
Great. I was skeptical to push it beyond 100MB. Now I can push it to corners..
> > wal_buffers = 65536
>
> The above is a complete waste of memory space, which would be better
> spent on letting the kernel expand its disk cache. There's no reason
> for wal_buffers to be more than a few dozen.
That was a rather desparate move. Nothing was improving performance and then we
started pushing numbers.. WIll get it back.. Same goes for 64 WAL files.. A GB
looks like waste to me..
I might have found the bottleneck, although by accident. Mysql was running out
of space while creating index. So my friend shut down mysql and tried to move
things by hand to create links. He noticed that even things like cp were
terribly slow and it hit us.. May be the culprit is the file system. Ext3 in
this case.
My friend argues for ext2 to eliminate journalling overhead but I favour
reiserfs personally having used it in pgbench with 10M rows on paltry 20GB IDE
disk for 25 tps..
We will be attempting raiserfs and/or XFS if required. I know how much speed
difference exists between resiserfs and ext2. Would not be surprised if
everythng just starts screaming in one go..
Bye
Shridhar
--
Cropp's Law: The amount of work done varies inversly with the time spent in the
office.
From [email protected] Thu Sep 26 10:57:42 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP id 79B71476141
for <[email protected]>;
Thu, 26 Sep 2002 10:57:41 -0400 (EDT)
Received: from www.pspl.co.in (www.pspl.co.in [202.54.11.65])
by postgresql.org (Postfix) with ESMTP id 0C288475FBD
for <[email protected]>;
Thu, 26 Sep 2002 10:57:40 -0400 (EDT)
Received: (from root@localhost)
by www.pspl.co.in (8.11.6/8.11.6) id g8QEww115498
for <[email protected]>; Thu, 26 Sep 2002 20:28:58 +0530
Received: from daithan (daithan.intranet.pspl.co.in [192.168.7.161])
by www.pspl.co.in (8.11.6/8.11.0) with ESMTP id g8QEwwv15488;
Thu, 26 Sep 2002 20:28:58 +0530
From: "Shridhar Daithankar" <[email protected].in>
To: [email protected], [email protected]
Date: Thu, 26 Sep 2002 20:28:11 +0530
MIME-Version: 1.0
Subject: Re: [HACKERS] Performance while loading data and indexing
Reply-To: [email protected].in
Message-ID: <3D936DDB.26585.14990280@localhost>
References: <3D92D9D2.64[email protected]>
In-reply-to: <4031.1033051328@sss.pgh.pa.us>
X-mailer: Pegasus Mail for Windows (v4.02)
Content-type: text/plain; charset=US-ASCII
Content-transfer-encoding: 7BIT
Content-description: Mail message body
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1188
X-Sequence-Number: 30769
On 26 Sep 2002 at 10:42, Tom Lane wrote:
> Justin Clift <[email protected]> writes:
> > If it's any help, when I was testing recently with WAL on a separate
> > drive, the WAL logs were doing more read&writes per second than the main
> > data drive.
>
> ... but way fewer seeks. For anything involving lots of updating
> transactions (and certainly 5000 separate insertions per second would
> qualify; can those be batched??), it should be a win to put WAL on its
> own spindle, just to get locality of access to the WAL.
Probably they will be a single transcation. If possible we will bunch more of
them together.. like 5 seconds of data pushed down in a single transaction but
not sure it's possible..
This is bit like replication but from live oracle machine to postgres, from
information I have. So there should be some chance of tuning there..
Bye
Shridhar
--
Langsam's Laws: (1) Everything depends. (2) Nothing is always. (3) Everything
is sometimes.
From [email protected] Thu Sep 26 11:07:07 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP
id B7B27476D50; Thu, 26 Sep 2002 11:07:06 -0400 (EDT)
Received: from mx.webmailstation.com (mx.webmailstation.com [64.23.55.10])
by postgresql.org (Postfix) with ESMTP
id 24B2C476D4E; Thu, 26 Sep 2002 11:07:06 -0400 (EDT)
Received: from dyp (localhost.localdomain [127.0.0.1])
by mx.webmailstation.com (Postfix) with ESMTP
id 202E51F85F; Thu, 26 Sep 2002 07:04:18 -0400 (EDT)
Content-Type: text/plain;
charset="iso-8859-1"
From: Denis Perchine <[email protected]>
Organization: AcademSoft Ltd.
To: [email protected],
[email protected], [email protected]
Subject: Re: [HACKERS] Performance while loading data and indexing
Date: Thu, 26 Sep 2002 22:04:41 +0700
User-Agent: KMail/1.4.3
References: <3D931438.22010.133ADAFA@localhost>
<3D936C6D.12380.14936AEC@localhost>
In-Reply-To: <3D936C6D.12380.14936AEC@localhost>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Message-Id: <[email protected]>
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1189
X-Sequence-Number: 30770
On Thursday 26 September 2002 21:52, Shridhar Daithankar wrote:
> I might have found the bottleneck, although by accident. Mysql was running
> out of space while creating index. So my friend shut down mysql and tried
> to move things by hand to create links. He noticed that even things like cp
> were terribly slow and it hit us.. May be the culprit is the file system.
> Ext3 in this case.
>
> My friend argues for ext2 to eliminate journalling overhead but I favour
> reiserfs personally having used it in pgbench with 10M rows on paltry 20GB
> IDE disk for 25 tps..
>
> We will be attempting raiserfs and/or XFS if required. I know how much
> speed difference exists between resiserfs and ext2. Would not be surprised
> if everythng just starts screaming in one go..
As it was found by someone before any non-journaling FS is faster than
journaling one. This due to double work done by FS and database.
Try it on ext2 and compare.
--
Denis
From [email protected] Thu Sep 26 11:12:48 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP
id E29E6476D79; Thu, 26 Sep 2002 11:12:47 -0400 (EDT)
Received: from new-smtp2.ihug.com.au (new-smtp2.ihug.com.au [203.109.250.28])
by postgresql.org (Postfix) with ESMTP
id 1E9DC476D76; Thu, 26 Sep 2002 11:12:47 -0400 (EDT)
Received: from p407-tnt2.mel.ihug.com.au (postgresql.org) [203.173.165.153]
by new-smtp2.ihug.com.au with esmtp (Exim 3.22 #1 (Debian))
id 17uaJu-00033K-00; Fri, 27 Sep 2002 01:12:50 +1000
Message-ID: <[email protected]>
Date: Fri, 27 Sep 2002 01:12:49 +1000
From: Justin Clift <[email protected]>
X-Mailer: Mozilla 4.79 [en] (WinNT; U)
X-Accept-Language: en
MIME-Version: 1.0
To: [email protected],
PostgreSQL Performance Mailing List <[email protected]>
Cc: PostgreSQL Hackers Mailing List <[email protected]>,
PostgreSQL General Mailing List <[email protected]>
Subject: Re: Performance while loading data and indexing
References: <3D931438.22010.133ADAFA@localhost>
<3D936C6D.12380.14936AEC@localhost>
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1191
X-Sequence-Number: 30772
Shridhar Daithankar wrote:
<snip>
> My friend argues for ext2 to eliminate journalling overhead but I favour
> reiserfs personally having used it in pgbench with 10M rows on paltry 20GB IDE
> disk for 25 tps..
If it's any help, the setup I mentioned before with differnt disks for
the data and the WAL files was getting an average of about 72 tps with
200 concurrent users on pgbench. Haven't tuned it in a hard core way at
all, and it only has 256MB DDR RAM in it at the moment (single CPU
AthonXP 1600). These are figures made during the 2.5k+ test runs of
pgbench done when developing pg_autotune recently.
As a curiosity point, how predictable are the queries you're going to be
running on your database? They sound very simple and very predicatable.
The pg_autotune tool might be your friend here. It can deal with
arbitrary SQL instead of using the pg_bench stuff of Tatsuos, and it can
also deal with an already loaded database. You'd just have to tweak the
names of the tables that it vacuums and the names of the indexes that it
reindexes between each run, to get some idea of your overall server
performance at different load points.
Probably worth taking a good look at if you're not afraid of editing
variables in C code. :)
> We will be attempting raiserfs and/or XFS if required. I know how much speed
> difference exists between resiserfs and ext2. Would not be surprised if
> everythng just starts screaming in one go..
We'd all probably be interested to hear this. Added the PostgreSQL
"Performance" mailing list to this thread too, Just In Case. (wow that's
a lot of cross posting now).
Regards and best wishes,
Justin Clift
> Bye
> Shridhar
>
> --
> Cropp's Law: The amount of work done varies inversly with the time spent in the
> office.
>
> ---------------------------(end of broadcast)---------------------------
> TIP 3: if posting/reading through Usenet, please send an appropriate
> subscribe-nomail command to [email protected] so that your
> message can get through to the mailing list cleanly
--
"My grandfather once told me that there are two kinds of people: those
who work and those who take the credit. He told me to try to be in the
first group; there was less competition there."
- Indira Gandhi
From [email protected] Thu Sep 26 11:28:32 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP id 48544476CC6
for <[email protected]>;
Thu, 26 Sep 2002 11:28:30 -0400 (EDT)
Received: from www.pspl.co.in (www.pspl.co.in [202.54.11.65])
by postgresql.org (Postfix) with ESMTP id 42D14476B61
for <[email protected]>;
Thu, 26 Sep 2002 11:28:28 -0400 (EDT)
Received: (from root@localhost)
by www.pspl.co.in (8.11.6/8.11.6) id g8QFTm217943
for <[email protected]>; Thu, 26 Sep 2002 20:59:48 +0530
Received: from daithan (daithan.intranet.pspl.co.in [192.168.7.161])
by www.pspl.co.in (8.11.6/8.11.0) with ESMTP id g8QFTmv17928;
Thu, 26 Sep 2002 20:59:48 +0530
From: "Shridhar Daithankar" <[email protected]>
To: PostgreSQL Performance Mailing List <[email protected]>
Date: Thu, 26 Sep 2002 20:59:01 +0530
MIME-Version: 1.0
Subject: Re: Performance while loading data and indexing
Reply-To: [email protected]
Cc: PostgreSQL Hackers Mailing List <[email protected]>,
PostgreSQL General Mailing List <[email protected]>
Message-ID: <3D937515.11546.14B53C07@localhost>
In-reply-to: <[email protected]>
X-mailer: Pegasus Mail for Windows (v4.02)
Content-type: text/plain; charset=US-ASCII
Content-transfer-encoding: 7BIT
Content-description: Mail message body
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1193
X-Sequence-Number: 30774
On 27 Sep 2002 at 1:12, Justin Clift wrote:
> Shridhar Daithankar wrote:
> As a curiosity point, how predictable are the queries you're going to be
> running on your database? They sound very simple and very predicatable.
Mostly predictable selects. Not a domain expert on telecom so not very sure.
But in my guess prepare statement in 7.3 should come pretty handy. i.e. by the
time we finish evaluation and test deployment, 7.3 will be out in next couple
of months to say so. So I would recommend doing it 7.3 way only..
>
> The pg_autotune tool might be your friend here. It can deal with
> arbitrary SQL instead of using the pg_bench stuff of Tatsuos, and it can
> also deal with an already loaded database. You'd just have to tweak the
> names of the tables that it vacuums and the names of the indexes that it
> reindexes between each run, to get some idea of your overall server
> performance at different load points.
>
> Probably worth taking a good look at if you're not afraid of editing
> variables in C code. :)
Gladly. We started with altering pgbench here for testing and rapidly settled
to perl generated random queries. Once postgresql wins the evaluation match and
things come to implementation, pg_autotune would be a handy tool. Just that
can't do it right now. Have to fight mysql and SAP DB before that..
BTW any performance figures on SAP DB? People here are as it frustrated with it
with difficulties in setting it up. But still..
>
> > We will be attempting raiserfs and/or XFS if required. I know how much speed
> > difference exists between resiserfs and ext2. Would not be surprised if
> > everythng just starts screaming in one go..
>
> We'd all probably be interested to hear this. Added the PostgreSQL
> "Performance" mailing list to this thread too, Just In Case. (wow that's
> a lot of cross posting now).
I know..;-) Glad that PG list does not have strict policies like no non-
subscriber posting or no attachments.. etc..
IMO reiserfs, though journalling one, is faster than ext2 etc. because the way
it handles metadata. Personally I haven't come across ext2 being faster than
reiserfs on few machine here for day to day use.
I guess I should have a freeBSD CD handy too.. Just to give it a try. If it
comes down to a better VM.. though using 2.4.19 here.. so souldn't matter
much..
I will keep you guys posted on file system stuff... Glad that we have much
flexibility with postgresql..
Bye
Shridhar
--
Bilbo's First Law: You cannot count friends that are all packed up in barrels.
From [email protected] Thu Sep 26 11:41:47 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP
id 26ED6476D61; Thu, 26 Sep 2002 11:41:46 -0400 (EDT)
Received: from CopelandConsulting.Net (dsl-24293-ld.customer.centurytel.net
[209.142.135.135]) by postgresql.org (Postfix) with ESMTP
id E26AF476D7B; Thu, 26 Sep 2002 11:41:44 -0400 (EDT)
Received: from mouse.copelandconsulting.net (mouse.copelandconsulting.net
[192.168.1.2])
by CopelandConsulting.Net (8.10.1/8.10.1) with ESMTP id g8QFfWu10941;
Thu, 26 Sep 2002 10:41:32 -0500 (CDT)
X-Trade-Id: <CCC.Thu, 26 Sep 2002 10:41:32 -0500 (CDT).Thu,
26 Sep 2002 10:41:32 -0500
(CDT).200209261541[email protected].
Subject: Re: [HACKERS] Performance while loading data and indexing
From: Greg Copeland <[email protected]>
To: [email protected].in
Cc: PostgresSQL Hackers Mailing List <[email protected]>,
PostgresSQL General Mailing List <[email protected]>
In-Reply-To: <3D936C6D.12380.14936AEC@localhost>
References: <3D931438.22010.133ADAFA@localhost>
<3D936C6D.12380.14936AEC@localhost>
Content-Type: multipart/signed; micalg=pgp-sha1;
protocol="application/pgp-signature";
boundary="=-u8SGzlKGiTZg+qY+QPln"
X-Mailer: Ximian Evolution 1.0.8
Date: 26 Sep 2002 10:41:37 -0500
Message-Id: <1033054898.17282.9[email protected]>
Mime-Version: 1.0
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1196
X-Sequence-Number: 30777
--=-u8SGzlKGiTZg+qY+QPln
Content-Type: text/plain
Content-Transfer-Encoding: quoted-printable
On Thu, 2002-09-26 at 09:52, Shridhar Daithankar wrote:
> My friend argues for ext2 to eliminate journalling overhead but I favour=
=20
> reiserfs personally having used it in pgbench with 10M rows on paltry 20G=
B IDE=20
> disk for 25 tps..
>=20
> We will be attempting raiserfs and/or XFS if required. I know how much sp=
eed=20
> difference exists between resiserfs and ext2. Would not be surprised if=
=20
> everythng just starts screaming in one go..
>=20
I'm not sure about reiserfs or ext3 but with XFS, you can create your
log on another disk. Also worth noting is that you can also configure
the size and number of log buffers. There are also some other
performance type enhancements you can fiddle with if you don't mind
risking time stamp consistency in the event of a crash. If your setup
allows for it, you might want to consider using XFS in this
configuration.
While I have not personally tried moving XFS' log to another device,
I've heard that performance gains can be truly stellar. Assuming memory
allows, twiddling with the log buffering is said to allow for large
strides in performance as well.
If you do try this, I'd love to hear back about your results and
impressions.
Greg
--=-u8SGzlKGiTZg+qY+QPln
Content-Type: application/pgp-signature; name=signature.asc
Content-Description: This is a digitally signed message part
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.0.7 (GNU/Linux)
iD8DBQA9kyqx4lr1bpbcL6kRApydAJ46EfAEimKL7eDNSS7ZMdZlo3VptACfcPL0
ByvQOwuqz/14LUVP1Oewjsk=
=VHX7
-----END PGP SIGNATURE-----
--=-u8SGzlKGiTZg+qY+QPln--
From [email protected] Thu Sep 26 12:42:01 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP
id F1D0F475E83; Thu, 26 Sep 2002 12:41:58 -0400 (EDT)
Received: from candle.pha.pa.us (momjian.navpoint.com [207.106.42.251])
by postgresql.org (Postfix) with ESMTP
id 3A9EB476EAE; Thu, 26 Sep 2002 12:41:55 -0400 (EDT)
Received: (from pgman@localhost)
by candle.pha.pa.us (8.11.6/8.10.1) id g8QGfYc04099;
Thu, 26 Sep 2002 12:41:34 -0400 (EDT)
From: Bruce Momjian <[email protected]>
Message-Id: <[email protected]>
Subject: Re: Performance while loading data and indexing
In-Reply-To: <3D936C6D.12380.14936AEC@localhost>
To: [email protected]
Date: Thu, 26 Sep 2002 12:41:34 -0400 (EDT)
Cc: [email protected], [email protected]
X-Mailer: ELM [version 2.4ME+ PL99 (25)]
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Content-Type: text/plain; charset=US-ASCII
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1202
X-Sequence-Number: 30783
Shridhar Daithankar wrote:
> I might have found the bottleneck, although by accident. Mysql was running out
> of space while creating index. So my friend shut down mysql and tried to move
> things by hand to create links. He noticed that even things like cp were
> terribly slow and it hit us.. May be the culprit is the file system. Ext3 in
> this case.
I just added a file system and multi-cpu section to my performance
tuning paper:
http://www.ca.postgresql.org/docs/momjian/hw_performance/
The paper does recommend ext3, but the differences between file systems
are very small. If you are seeing 'cp' as slow, I wonder if it may be
something more general, like poorly tuned hardware or something. You can
use 'dd' to throw some data around the file system and see if that is
showing slowness; compare those numbers to another machine that has
different hardware/OS.
Also, though ext3 is slower, turning fsync off should make ext3 function
similar to ext2. That would be an interesting test if you suspect ext3.
--
Bruce Momjian | http://candle.pha.pa.us
[email protected] | (610) 359-1001
+ If your life is a hard drive, | 13 Roberts Road
+ Christ can be your backup. | Newtown Square, Pennsylvania 19073
From [email protected] Thu Sep 26 13:17:12 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP
id E040F476E77; Thu, 26 Sep 2002 13:17:08 -0400 (EDT)
Received: from varsoon.wireboard.com (www.wireboard.com [216.151.155.101])
by postgresql.org (Postfix) with ESMTP
id 8FF09476DFA; Thu, 26 Sep 2002 13:17:07 -0400 (EDT)
Received: from doug by varsoon.wireboard.com with local (Exim 3.35 #1)
id 17ucFg-0006dh-00; Thu, 26 Sep 2002 13:16:36 -0400
To: Greg Copeland <[email protected]>
From: Doug cNaught <[email protected]>
Cc: [email protected],
PostgresSQL Hackers Mailing List <[email protected]>,
PostgresSQL General Mailing List <[email protected]>
Subject: Re: [HACKERS] Performance while loading data and indexing
References: <3D931438.22010.133ADAFA@localhost>
<3D936C6D.12380.14936AEC@localhost>
<[email protected]>
Date: 26 Sep 2002 13:16:36 -0400
In-Reply-To: Greg Copeland's message of "26 Sep 2002 10:41:37 -0500"
Message-ID: <[email protected]>
Lines: 25
User-Agent: Gnus/5.0806 (Gnus v5.8.6) Emacs/20.7
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1206
X-Sequence-Number: 30787
Greg Copeland <[email protected]> writes:
> I'm not sure about reiserfs or ext3 but with XFS, you can create your
> log on another disk. Also worth noting is that you can also configure
> the size and number of log buffers. There are also some other
> performance type enhancements you can fiddle with if you don't mind
> risking time stamp consistency in the event of a crash. If your setup
> allows for it, you might want to consider using XFS in this
> configuration.
You can definitely put the ext3 log on a different disk with 2.4
kernels.
Also, if you put the WAL logs on a different disk from the main
database, and mount that partition with 'data=writeback' (ie
metadata-only journaling) ext3 should be pretty fast, since WAL files
are preallocated and there will therefore be almost no metadata
updates.
You should be able to mount the main database with "data=ordered" (the
default) for good performance and reasonable safety.
I think putting WAL on its own disk(s) is one of the keys here.
-Doug
From [email protected] Thu Sep 26 14:14:21 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP
id 8779F476D31; Thu, 26 Sep 2002 13:37:58 -0400 (EDT)
Received: from CopelandConsulting.Net (dsl-24293-ld.customer.centurytel.net
[209.142.135.135]) by postgresql.org (Postfix) with ESMTP
id 61C82476D2E; Thu, 26 Sep 2002 13:37:57 -0400 (EDT)
Received: from mouse.copelandconsulting.net (mouse.copelandconsulting.net
[192.168.1.2])
by CopelandConsulting.Net (8.10.1/8.10.1) with ESMTP id g8QHapu12099;
Thu, 26 Sep 2002 12:36:51 -0500 (CDT)
X-Trade-Id: <CCC.Thu, 26 Sep 2002 12:36:51 -0500 (CDT).Thu,
26 Sep 2002 12:36:51 -0500
(CDT).200209261736[email protected].
Subject: Re: [HACKERS] Performance while loading data and indexing
From: Greg Copeland <[email protected]>
To: Bruce Momjian <[email protected]>
Cc: [email protected].in,
PostgresSQL Hackers Mailing List <[email protected]>,
PostgresSQL General Mailing List <[email protected]>
In-Reply-To: <200209261641.[email protected]>
References: <200209261641.[email protected]>
Content-Type: multipart/signed; micalg=pgp-sha1;
protocol="application/pgp-signature";
boundary="=-tyawsElsu3INch108LXq"
X-Mailer: Ximian Evolution 1.0.8
Date: 26 Sep 2002 12:36:57 -0500
Message-Id: <1033061818.23390.12[email protected]>
Mime-Version: 1.0
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1208
X-Sequence-Number: 30789
--=-tyawsElsu3INch108LXq
Content-Type: text/plain
Content-Transfer-Encoding: quoted-printable
On Thu, 2002-09-26 at 11:41, Bruce Momjian wrote:
> Shridhar Daithankar wrote:
> > I might have found the bottleneck, although by accident. Mysql was runn=
ing out=20
> > of space while creating index. So my friend shut down mysql and tried t=
o move=20
> > things by hand to create links. He noticed that even things like cp wer=
e=20
> > terribly slow and it hit us.. May be the culprit is the file system. Ex=
t3 in=20
> > this case.=20
>=20
> I just added a file system and multi-cpu section to my performance
> tuning paper:
>=20
> http://www.ca.postgresql.org/docs/momjian/hw_performance/
>=20
> The paper does recommend ext3, but the differences between file systems
> are very small. If you are seeing 'cp' as slow, I wonder if it may be
> something more general, like poorly tuned hardware or something. You can
> use 'dd' to throw some data around the file system and see if that is
> showing slowness; compare those numbers to another machine that has
> different hardware/OS.
That's a good point. Also, if you're using IDE, you do need to verify
that you're using DMA and proper PIO mode if at possible. Also, big
performance improvements can be seen by making sure your IDE bus speed
has been properly configured. The drivetweak-gtk and hdparm utilities
can make huge difference in performance. Just be sure you know what the
heck your doing when you mess with those.
Greg
--=-tyawsElsu3INch108LXq
Content-Type: application/pgp-signature; name=signature.asc
Content-Description: This is a digitally signed message part
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.0.7 (GNU/Linux)
iD8DBQA9k0W54lr1bpbcL6kRAsTSAJ410S530QfaeTjTxEaICSnzhUbNOwCeNGvr
tTGuXDVz190FH55un7vEjrc=
=HFjK
-----END PGP SIGNATURE-----
--=-tyawsElsu3INch108LXq--
From [email protected] Thu Sep 26 14:13:31 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP
id 27240476DA8; Thu, 26 Sep 2002 13:45:12 -0400 (EDT)
Received: from CopelandConsulting.Net (dsl-24293-ld.customer.centurytel.net
[209.142.135.135]) by postgresql.org (Postfix) with ESMTP
id D8262476D8F; Thu, 26 Sep 2002 13:45:10 -0400 (EDT)
Received: from mouse.copelandconsulting.net (mouse.copelandconsulting.net
[192.168.1.2])
by CopelandConsulting.Net (8.10.1/8.10.1) with ESMTP id g8QHiGu14092;
Thu, 26 Sep 2002 12:44:16 -0500 (CDT)
X-Trade-Id: <CCC.Thu, 26 Sep 2002 12:44:16 -0500 (CDT).Thu,
26 Sep 2002 12:44:16 -0500
(CDT)[email protected].
Subject: Re: [HACKERS] Performance while loading data and indexing
From: Greg Copeland <[email protected]>
To: Bruce Momjian <[email protected]>
Cc: [email protected],
PostgresSQL Hackers Mailing List <[email protected]>,
PostgresSQL General Mailing List <[email protected]>
In-Reply-To: <[email protected]>
References: <[email protected]>
Content-Type: multipart/signed; micalg=pgp-sha1;
protocol="application/pgp-signature";
boundary="=-6mav3WK9RCaVOqe8tRq/"
X-Mailer: Ximian Evolution 1.0.8
Date: 26 Sep 2002 12:44:22 -0500
Message-Id: <[email protected]>
Mime-Version: 1.0
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1207
X-Sequence-Number: 30788
--=-6mav3WK9RCaVOqe8tRq/
Content-Type: text/plain
Content-Transfer-Encoding: quoted-printable
On Thu, 2002-09-26 at 11:41, Bruce Momjian wrote:
> Shridhar Daithankar wrote:
> > I might have found the bottleneck, although by accident. Mysql was runn=
ing out=20
> > of space while creating index. So my friend shut down mysql and tried t=
o move=20
> > things by hand to create links. He noticed that even things like cp wer=
e=20
> > terribly slow and it hit us.. May be the culprit is the file system. Ex=
t3 in=20
> > this case.=20
>=20
> I just added a file system and multi-cpu section to my performance
> tuning paper:
>=20
> http://www.ca.postgresql.org/docs/momjian/hw_performance/
>=20
> The paper does recommend ext3, but the differences between file systems
> are very small. If you are seeing 'cp' as slow, I wonder if it may be
> something more general, like poorly tuned hardware or something. You can
> use 'dd' to throw some data around the file system and see if that is
> showing slowness; compare those numbers to another machine that has
> different hardware/OS.
>=20
> Also, though ext3 is slower, turning fsync off should make ext3 function
> similar to ext2. That would be an interesting test if you suspect ext3.
I'm curious as to why you recommended ext3 versus some other (JFS,
XFS). Do you have tests which validate that recommendation or was it a
simple matter of getting the warm fuzzies from familiarity?
Greg
--=-6mav3WK9RCaVOqe8tRq/
Content-Type: application/pgp-signature; name=signature.asc
Content-Description: This is a digitally signed message part
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.0.7 (GNU/Linux)
iD8DBQA9k0d24lr1bpbcL6kRAkGfAJ0en60jxkx1LsCX8HIzsjHgA8MnKQCffW/S
m+nGg6nihDZ/JABT4dNcuGo=
=Itl1
-----END PGP SIGNATURE-----
--=-6mav3WK9RCaVOqe8tRq/--
From [email protected] Thu Sep 26 14:46:12 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP
id 583924762C6; Thu, 26 Sep 2002 14:46:11 -0400 (EDT)
Received: from mail1.ihs.com (mail1.ihs.com [170.207.70.222])
by postgresql.org (Postfix) with ESMTP
id 9179947606A; Thu, 26 Sep 2002 14:46:09 -0400 (EDT)
Received: from css120.ihs.com (css120.ihs.com [170.207.105.120])
by mail1.ihs.com (8.12.6/8.12.6) with ESMTP id g8QIjU0P015223;
Thu, 26 Sep 2002 12:45:30 -0600 (MDT)
Date: Thu, 26 Sep 2002 12:41:55 -0600 (MDT)
From: "scott.marlowe" <[email protected]>
To: Shridhar Daithankar <[email protected].in>
Cc: <[email protected]>, <[email protected]>
Subject: Re: [HACKERS] Performance while loading data and indexing
In-Reply-To: <3D931882.31859.134B9E4C@localhost>
Message-ID: <Pine.LNX.4.33.0209261241070.7533-100000@css120.ihs.com>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
X-MailBodyFilter: Message body has not been filtered
X-MailScanner: Found to be clean
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1209
X-Sequence-Number: 30790
If you are seeing very slow performance on a drive set, check dmesg to see
if you're getting SCSI bus errors or something similar. If your drives
aren't properly terminated then the performance will suffer a great deal.
From [email protected] Thu Sep 26 16:01:20 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP
id 09482476052; Thu, 26 Sep 2002 16:01:18 -0400 (EDT)
Received: from candle.pha.pa.us (momjian.navpoint.com [207.106.42.251])
by postgresql.org (Postfix) with ESMTP
id A0F8D474E5C; Thu, 26 Sep 2002 16:01:14 -0400 (EDT)
Received: (from pgman@localhost)
by candle.pha.pa.us (8.11.6/8.10.1) id g8QK0mG10553;
Thu, 26 Sep 2002 16:00:48 -0400 (EDT)
From: Bruce Momjian <[email protected]>
Message-Id: <200209262000.[email protected]>
Subject: Re: [HACKERS] Performance while loading data and indexing
In-Reply-To: <1033062262.23475.16[email protected]>
To: Greg Copeland <[email protected]>
Date: Thu, 26 Sep 2002 16:00:48 -0400 (EDT)
Cc: [email protected].in,
PostgresSQL Hackers Mailing List <[email protected]>,
PostgresSQL General Mailing List <[email protected]>
X-Mailer: ELM [version 2.4ME+ PL99 (25)]
MIME-Version: 1.0
Content-Type: multipart/mixed; boundary=ELM1033070448-26881-0_
Content-Transfer-Encoding: 7bit
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1211
X-Sequence-Number: 30792
--ELM1033070448-26881-0_
Content-Transfer-Encoding: 7bit
Content-Type: text/plain; charset=US-ASCII
Greg Copeland wrote:
> > The paper does recommend ext3, but the differences between file systems
> > are very small. If you are seeing 'cp' as slow, I wonder if it may be
> > something more general, like poorly tuned hardware or something. You can
> > use 'dd' to throw some data around the file system and see if that is
> > showing slowness; compare those numbers to another machine that has
> > different hardware/OS.
> >
> > Also, though ext3 is slower, turning fsync off should make ext3 function
> > similar to ext2. That would be an interesting test if you suspect ext3.
>
> I'm curious as to why you recommended ext3 versus some other (JFS,
> XFS). Do you have tests which validate that recommendation or was it a
> simple matter of getting the warm fuzzies from familiarity?
I used the attached email as a reference. I just changed the wording to
be:
File system choice is particularly difficult on Linux because there are
so many file system choices, and none of them are optimal: ext2 is not
entirely crash-safe, ext3 and xfs are journal-based, and Reiser is
optimized for small files. Fortunately, the journaling file systems
aren't significantly slower than ext2 so they are probably the best
choice.
so I don't specifically recommend ext3 anymore. As I remember, ext3 is
good only in that it can read ext2 file systems. I think XFS may be the
best bet.
Can anyone clarify if "data=writeback" is safe for PostgreSQL.
Specifically, are the data files recovered properly or is this option
only for a filesystem containing WAL?
--
Bruce Momjian | http://candle.pha.pa.us
[email protected] | (610) 359-1001
+ If your life is a hard drive, | 13 Roberts Road
+ Christ can be your backup. | Newtown Square, Pennsylvania 19073
--ELM1033070448-26881-0_
Content-Transfer-Encoding: 7bit
Content-Type: text/plain
Content-Disposition: inline; filename="/bjm/perf"
--ELM1033070448-26881-0_--
From [email protected] Thu Sep 26 16:42:13 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP
id 5B9B147676D; Thu, 26 Sep 2002 16:42:12 -0400 (EDT)
Received: from bob.samurai.com (bob.samurai.com [205.207.28.75])
by postgresql.org (Postfix) with ESMTP
id E1D784762B7; Thu, 26 Sep 2002 16:42:11 -0400 (EDT)
Received: from boston.samurai.com (DU179.N224.ResNet.QueensU.CA
[130.15.224.179]) by bob.samurai.com (Postfix) with ESMTP
id E9B1A1EAC; Thu, 26 Sep 2002 16:42:10 -0400 (EDT)
To: Bruce Momjian <[email protected]>
Cc: [email protected],
[email protected], [email protected]
Subject: Re: [HACKERS] Performance while loading data and indexing
References: <[email protected]>
From: Neil Conway <[email protected]>
In-Reply-To: <[email protected]>
Date: 26 Sep 2002 16:41:49 -0400
Message-ID: <[email protected]>
Lines: 20
User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.2
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1212
X-Sequence-Number: 30793
Bruce Momjian <[email protected]> writes:
> The paper does recommend ext3, but the differences between file systems
> are very small.
Well, I only did a very rough benchmark (a few runs of pgbench), but
the results I found were drastically different: ext2 was significantly
faster (~50%) than ext3-writeback, which was in turn significantly
faster (~25%) than ext3-ordered.
> Also, though ext3 is slower, turning fsync off should make ext3 function
> similar to ext2.
Why would that be?
Cheers,
Neil
--
Neil Conway <[email protected]> || PGP Key ID: DB3C29FC
From [email protected] Thu Sep 26 16:46:10 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP
id AD961476147; Thu, 26 Sep 2002 16:46:07 -0400 (EDT)
Received: from candle.pha.pa.us (momjian.navpoint.com [207.106.42.251])
by postgresql.org (Postfix) with ESMTP
id C734B476052; Thu, 26 Sep 2002 16:46:05 -0400 (EDT)
Received: (from pgman@localhost)
by candle.pha.pa.us (8.11.6/8.10.1) id g8QKjtv21744;
Thu, 26 Sep 2002 16:45:55 -0400 (EDT)
From: Bruce Momjian <[email protected]>
Message-Id: <[email protected]>
Subject: Re: [HACKERS] Performance while loading data and indexing
In-Reply-To: <[email protected]>
To: Neil Conway <[email protected]>
Date: Thu, 26 Sep 2002 16:45:54 -0400 (EDT)
Cc: [email protected],
[email protected], [email protected]
X-Mailer: ELM [version 2.4ME+ PL99 (25)]
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Content-Type: text/plain; charset=US-ASCII
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1213
X-Sequence-Number: 30794
Neil Conway wrote:
> Bruce Momjian <[email protected]> writes:
> > The paper does recommend ext3, but the differences between file systems
> > are very small.
>
> Well, I only did a very rough benchmark (a few runs of pgbench), but
> the results I found were drastically different: ext2 was significantly
> faster (~50%) than ext3-writeback, which was in turn significantly
> faster (~25%) than ext3-ordered.
Wow. That leaves no good Linux file system alternatives. PostgreSQL
just wants an ordinary file system that has reliable recovery from a
crash.
> > Also, though ext3 is slower, turning fsync off should make ext3 function
> > similar to ext2.
>
> Why would that be?
I assumed it was the double fsync for the normal and journal that made
the journalling file systems slog.
--
Bruce Momjian | http://candle.pha.pa.us
[email protected] | (610) 359-1001
+ If your life is a hard drive, | 13 Roberts Road
+ Christ can be your backup. | Newtown Square, Pennsylvania 19073
From [email protected] Thu Sep 26 16:50:43 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP id 59D4D476083
for <[email protected]>;
Thu, 26 Sep 2002 16:50:42 -0400 (EDT)
Received: from bachata.cybertec.at (unknown [62.116.21.146])
by postgresql.org (Postfix) with SMTP id 1856E474E5C
for <[email protected]>;
Thu, 26 Sep 2002 16:50:41 -0400 (EDT)
Received: (qmail 26347 invoked from network); 26 Sep 2002 20:50:47 -0000
Received: from unknown (HELO cybertec.at) (62.116.21.147)
by 62.116.21.146 with SMTP; 26 Sep 2002 20:50:47 -0000
Message-ID: <[email protected]>
Date: Thu, 26 Sep 2002 22:55:30 +0200
From: =?ISO-8859-1?Q?Hans-J=FCrgen_Sch=F6nig?= <[email protected]>
Reply-To: [email protected]
User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.1) Gecko/20020827
X-Accept-Language: en-us, en
MIME-Version: 1.0
To: Neil Conway <[email protected]>, [email protected]
Subject: Re: [GENERAL] Performance while loading data and indexing
References: <[email protected]>
<[email protected]>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1576
X-Sequence-Number: 29533
I have seen various benchmarks where XFS seems to perform best when it
comes to huge amounts of data and many files (due to balanced internal
b+ trees).
also, XFS seems to be VERY mature and very stable.
ext2/3 don't seem to be that fast in most of the benchmarks.
i did some testing with reiser some time ago. the problem is that it
seems to restore a very historic consistent snapshot of the data. XFS
seems to be much better in this respect.
i have not tested JFS yet (but on this damn AIX beside me)
from my point of view i strongly recommend XFS (maybe somebody from
RedHat should think about it).
Hans
Neil Conway wrote:
>Bruce Momjian <[email protected]> writes:
>
>
>>The paper does recommend ext3, but the differences between file systems
>>are very small.
>>
>>
>
>Well, I only did a very rough benchmark (a few runs of pgbench), but
>the results I found were drastically different: ext2 was significantly
>faster (~50%) than ext3-writeback, which was in turn significantly
>faster (~25%) than ext3-ordered.
>
>
>
>>Also, though ext3 is slower, turning fsync off should make ext3 function
>>similar to ext2.
>>
>>
>
>Why would that be?
>
>Cheers,
>
>Neil
>
>
>
--
*Cybertec Geschwinde u Schoenig*
Ludo-Hartmannplatz 1/14, A-1160 Vienna, Austria
Tel: +43/1/913 68 09; +43/664/233 90 75
www.postgresql.at <http://www.postgresql.at>, cluster.postgresql.at
<http://cluster.postgresql.at>, www.cybertec.at
<http://www.cybertec.at>, kernel.cybertec.at <http://kernel.cybertec.at>
From [email protected] Thu Sep 26 16:57:22 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP
id D2740476F59; Thu, 26 Sep 2002 16:57:21 -0400 (EDT)
Received: from candle.pha.pa.us (momjian.navpoint.com [207.106.42.251])
by postgresql.org (Postfix) with ESMTP
id AF1B947702E; Thu, 26 Sep 2002 16:57:14 -0400 (EDT)
Received: (from pgman@localhost)
by candle.pha.pa.us (8.11.6/8.10.1) id g8QKv3Z22867;
Thu, 26 Sep 2002 16:57:03 -0400 (EDT)
From: Bruce Momjian <[email protected]>
Message-Id: <200209262057.[email protected]>
Subject: Re: [HACKERS] Performance while loading data and indexing
In-Reply-To: <871[email protected]>
To: Neil Conway <[email protected]>
Date: Thu, 26 Sep 2002 16:57:03 -0400 (EDT)
Cc: [email protected].in,
[email protected], [email protected]
X-Mailer: ELM [version 2.4ME+ PL99 (25)]
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Content-Type: text/plain; charset=US-ASCII
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1215
X-Sequence-Number: 30796
Neil Conway wrote:
> Bruce Momjian <[email protected]> writes:
> > The paper does recommend ext3, but the differences between file systems
> > are very small.
>
> Well, I only did a very rough benchmark (a few runs of pgbench), but
> the results I found were drastically different: ext2 was significantly
> faster (~50%) than ext3-writeback, which was in turn significantly
> faster (~25%) than ext3-ordered.
>
> > Also, though ext3 is slower, turning fsync off should make ext3 function
> > similar to ext2.
>
> Why would that be?
OK, I changed the text to:
File system choice is particularly difficult on Linux because there are
so many file system choices, and none of them are optimal: ext2 is not
entirely crash-safe, ext3, xfs, and jfs are journal-based, and Reiser is
optimized for small files and does journalling. The journalling file
systems can be significantly slower than ext2 but when crash recovery is
required, ext2 isn't an option.
--
Bruce Momjian | http://candle.pha.pa.us
[email protected] | (610) 359-1001
+ If your life is a hard drive, | 13 Roberts Road
+ Christ can be your backup. | Newtown Square, Pennsylvania 19073
From [email protected] Thu Sep 26 17:03:41 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP
id 8D545476FB9; Thu, 26 Sep 2002 17:03:40 -0400 (EDT)
Received: from bob.samurai.com (bob.samurai.com [205.207.28.75])
by postgresql.org (Postfix) with ESMTP
id 1A27A476F86; Thu, 26 Sep 2002 17:03:40 -0400 (EDT)
Received: from boston.samurai.com (DU179.N224.ResNet.QueensU.CA
[130.15.224.179]) by bob.samurai.com (Postfix) with ESMTP
id 0015F1EAB; Thu, 26 Sep 2002 17:03:39 -0400 (EDT)
To: Bruce Momjian <[email protected]>
Cc: Neil Conway <[email protected]>,
[email protected], [email protected],
[email protected]
Subject: Re: [HACKERS] Performance while loading data and indexing
References: <[email protected]>
From: Neil Conway <[email protected]>
In-Reply-To: <[email protected]>
Date: 26 Sep 2002 17:03:26 -0400
Message-ID: <[email protected]>
Lines: 29
User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.2
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1217
X-Sequence-Number: 30798
Bruce Momjian <[email protected]> writes:
> Wow. That leaves no good Linux file system alternatives.
> PostgreSQL just wants an ordinary file system that has reliable
> recovery from a crash.
I'm not really familiar with the reasoning behind ext2's reputation as
recovering poorly from crashes; if we fsync a WAL record to disk
before we lose power, can't we recover reliably, even with ext2?
> > > Also, though ext3 is slower, turning fsync off should make ext3
> > > function similar to ext2.
> >
> > Why would that be?
>
> I assumed it was the double fsync for the normal and journal that
> made the journalling file systems slog.
Well, a journalling file system would need to write a journal entry
and flush that to disk, even if fsync is disabled -- whereas without
fsync enabled, ext2 doesn't have to flush anything to disk. ISTM that
the performance advantage of ext2 over ext3 is should be even larger
when fsync is not enabled.
Cheers,
Neil
--
Neil Conway <[email protected]> || PGP Key ID: DB3C29FC
From [email protected] Thu Sep 26 17:04:07 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP id CF22C477069
for <[email protected]>;
Thu, 26 Sep 2002 17:04:06 -0400 (EDT)
Received: from CopelandConsulting.Net (dsl-24293-ld.customer.centurytel.net
[209.142.135.135])
by postgresql.org (Postfix) with ESMTP id 9BEAA476C0B
for <[email protected]>;
Thu, 26 Sep 2002 17:03:54 -0400 (EDT)
Received: from mouse.copelandconsulting.net (mouse.copelandconsulting.net
[192.168.1.2])
by CopelandConsulting.Net (8.10.1/8.10.1) with ESMTP id g8QL3hu15120;
Thu, 26 Sep 2002 16:03:44 -0500 (CDT)
X-Trade-Id: <CCC.Thu, 26 Sep 2002 16:03:44 -0500 (CDT).Thu,
26 Sep 2002 16:03:44 -0500
(CDT)[email protected].
Subject: Re: [GENERAL] Performance while loading data and indexing
From: Greg Copeland <[email protected]>
To: [email protected]
Cc: PostgresSQL Hackers Mailing List <[email protected]>
In-Reply-To: <[email protected]>
References: <[email protected]>
<[email protected]> <[email protected]>
Content-Type: multipart/signed; micalg=pgp-sha1;
protocol="application/pgp-signature";
boundary="=-ZqXCINKzOxv8OZvLp8ID"
X-Mailer: Ximian Evolution 1.0.8
Date: 26 Sep 2002 16:03:51 -0500
Message-Id: <[email protected]>
Mime-Version: 1.0
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1582
X-Sequence-Number: 29539
--=-ZqXCINKzOxv8OZvLp8ID
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: quoted-printable
I tend to agree with this though I have nothing to back up it with. My
impression is that XFS does very well for large files. Accepting that
as fact?, my impression is that XFS historically does well for
database's. Again, I have nothing to back that up other than hear-say
and conjecture.
Greg
On Thu, 2002-09-26 at 15:55, Hans-J=FCrgen Sch=F6nig wrote:
> I have seen various benchmarks where XFS seems to perform best when it=20
> comes to huge amounts of data and many files (due to balanced internal=20
> b+ trees).
> also, XFS seems to be VERY mature and very stable.
> ext2/3 don't seem to be that fast in most of the benchmarks.
>=20
> i did some testing with reiser some time ago. the problem is that it=20
> seems to restore a very historic consistent snapshot of the data. XFS=20
> seems to be much better in this respect.
>=20
> i have not tested JFS yet (but on this damn AIX beside me)
> from my point of view i strongly recommend XFS (maybe somebody from=20
> RedHat should think about it).
>=20
> Hans
>=20
>=20
> Neil Conway wrote:
>=20
> >Bruce Momjian <[email protected]> writes:
> >=20=20
> >
> >>The paper does recommend ext3, but the differences between file systems
> >>are very small.
> >>=20=20=20=20
> >>
> >
> >Well, I only did a very rough benchmark (a few runs of pgbench), but
> >the results I found were drastically different: ext2 was significantly
> >faster (~50%) than ext3-writeback, which was in turn significantly
> >faster (~25%) than ext3-ordered.
> >
> >=20=20
> >
> >>Also, though ext3 is slower, turning fsync off should make ext3 function
> >>similar to ext2.
> >>=20=20=20=20
> >>
> >
> >Why would that be?
> >
> >Cheers,
> >
> >Neil
> >
> >=20=20
> >
>=20
>=20
> --=20
> *Cybertec Geschwinde u Schoenig*
> Ludo-Hartmannplatz 1/14, A-1160 Vienna, Austria
> Tel: +43/1/913 68 09; +43/664/233 90 75
> www.postgresql.at <http://www.postgresql.at>, cluster.postgresql.at=20
> <http://cluster.postgresql.at>, www.cybertec.at=20
> <http://www.cybertec.at>, kernel.cybertec.at <http://kernel.cybertec.at>
>=20
>=20
> ---------------------------(end of broadcast)---------------------------
> TIP 1: subscribe and unsubscribe commands go to [email protected]
--=-ZqXCINKzOxv8OZvLp8ID
Content-Type: application/pgp-signature; name=signature.asc
Content-Description: This is a digitally signed message part
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.0.7 (GNU/Linux)
iD8DBQA9k3Y34lr1bpbcL6kRAlvSAJ9DicilkkEypigomt/wfiO5nHyqqQCeOTHL
krIfkgUxrfgr50wh8oI93Lc=
=pUiE
-----END PGP SIGNATURE-----
--=-ZqXCINKzOxv8OZvLp8ID--
From [email protected] Sat Sep 28 13:29:40 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP
id A7844476EEB; Thu, 26 Sep 2002 17:01:28 -0400 (EDT)
Received: from gatekeeper.d2000.com (gatekeeper.d2000.com [208.32.117.78])
by postgresql.org (Postfix) with ESMTP
id AE297476E66; Thu, 26 Sep 2002 17:01:27 -0400 (EDT)
Received: (from bin@localhost) by gatekeeper.d2000.com (8.9.3/8.7.3) id
QAA41714; Thu, 26 Sep 2002 16:01:19 -0500 (CDT)
X-Authentication-Warning: gatekeeper.d2000.com: bin set sender to
<[email protected]> using -f
Received: from <[email protected]> (nt.d2000.com [205.164.66.20]) by
gatekeeper.d2000.com via smap (V2.1)
id xma041690; Thu, 26 Sep 02 16:00:47 -0500
Received: from xl.d2000.com (unverified) by nt.d2000.com
(Content Technologies SMTPRS 4.1.5) with ESMTP id
<[email protected]>;
Thu, 26 Sep 2002 16:00:45 -0500
Received: from materialpcow5r (backup.d2000.com [205.164.66.13]) by
xl.d2000.com (8.8.8/8.7.3) with SMTP id QAA05701;
Thu, 26 Sep 2002 16:00:33 -0500 (CDT)
From: "James Maes" <[email protected]>
To: "Bruce Momjian" <[email protected]>,
"Neil Conway" <[email protected]>
Cc: <[email protected]>,
<[email protected]>, <[email protected]>
Subject: Re: [GENERAL] Performance while loading data and indexing
Date: Thu, 26 Sep 2002 16:06:07 -0500
Message-ID: <[email protected]>
MIME-Version: 1.0
Content-Type: text/plain;
charset="us-ascii"
Content-Transfer-Encoding: 7bit
X-Priority: 3 (Normal)
X-MSMail-Priority: Normal
X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2910.0)
X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4807.1700
Importance: Normal
In-Reply-To: <[email protected]>
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1669
X-Sequence-Number: 29626
Has there been any thought of providing RAW disk support to bypass the fs?
-----Original Message-----
From: [email protected]
[mailto:[email protected]]On Behalf Of Bruce Momjian
Sent: Thursday, September 26, 2002 3:57 PM
To: Neil Conway
Cc: [email protected]; [email protected];
[email protected]
Subject: Re: [HACKERS] [GENERAL] Performance while loading data and
indexing
Neil Conway wrote:
> Bruce Momjian <[email protected]> writes:
> > The paper does recommend ext3, but the differences between file systems
> > are very small.
>
> Well, I only did a very rough benchmark (a few runs of pgbench), but
> the results I found were drastically different: ext2 was significantly
> faster (~50%) than ext3-writeback, which was in turn significantly
> faster (~25%) than ext3-ordered.
>
> > Also, though ext3 is slower, turning fsync off should make ext3 function
> > similar to ext2.
>
> Why would that be?
OK, I changed the text to:
File system choice is particularly difficult on Linux because there are
so many file system choices, and none of them are optimal: ext2 is not
entirely crash-safe, ext3, xfs, and jfs are journal-based, and Reiser is
optimized for small files and does journalling. The journalling file
systems can be significantly slower than ext2 but when crash recovery is
required, ext2 isn't an option.
--
Bruce Momjian | http://candle.pha.pa.us
[email protected] | (610) 359-1001
+ If your life is a hard drive, | 13 Roberts Road
+ Christ can be your backup. | Newtown Square, Pennsylvania 19073
---------------------------(end of broadcast)---------------------------
TIP 5: Have you checked our extensive FAQ?
http://www.postgresql.org/users-lounge/docs/faq.html
From [email protected] Thu Sep 26 17:08:13 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP
id 3B9ED4769E6; Thu, 26 Sep 2002 17:08:13 -0400 (EDT)
Received: from candle.pha.pa.us (momjian.navpoint.com [207.106.42.251])
by postgresql.org (Postfix) with ESMTP
id 2AD5C476241; Thu, 26 Sep 2002 17:08:11 -0400 (EDT)
Received: (from pgman@localhost)
by candle.pha.pa.us (8.11.6/8.10.1) id g8QL7vN25965;
Thu, 26 Sep 2002 17:07:57 -0400 (EDT)
From: Bruce Momjian <[email protected]>
Message-Id: <200209262107.[email protected]>
Subject: Re: [HACKERS] Performance while loading data and indexing
In-Reply-To: <87[email protected]>
To: Neil Conway <[email protected]>
Date: Thu, 26 Sep 2002 17:07:57 -0400 (EDT)
Cc: [email protected].in,
[email protected], [email protected]
X-Mailer: ELM [version 2.4ME+ PL99 (25)]
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Content-Type: text/plain; charset=US-ASCII
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1218
X-Sequence-Number: 30799
Neil Conway wrote:
> Bruce Momjian <[email protected]> writes:
> > Wow. That leaves no good Linux file system alternatives.
> > PostgreSQL just wants an ordinary file system that has reliable
> > recovery from a crash.
>
> I'm not really familiar with the reasoning behind ext2's reputation as
> recovering poorly from crashes; if we fsync a WAL record to disk
> before we lose power, can't we recover reliably, even with ext2?
>
> > > > Also, though ext3 is slower, turning fsync off should make ext3
> > > > function similar to ext2.
> > >
> > > Why would that be?
> >
> > I assumed it was the double fsync for the normal and journal that
> > made the journalling file systems slog.
>
> Well, a journalling file system would need to write a journal entry
> and flush that to disk, even if fsync is disabled -- whereas without
> fsync enabled, ext2 doesn't have to flush anything to disk. ISTM that
> the performance advantage of ext2 over ext3 is should be even larger
> when fsync is not enabled.
Yes, it is still double-writing. I just thought that if that wasn't
happening while the db was waiting for a commit that it wouldn't be too
bad.
Is it just me or do all the Linux file systems seem like they are
lacking something when PostgreSQL is concerned? We just want a UFS-like
file system on Linux and no one has it.
--
Bruce Momjian | http://candle.pha.pa.us
[email protected] | (610) 359-1001
+ If your life is a hard drive, | 13 Roberts Road
+ Christ can be your backup. | Newtown Square, Pennsylvania 19073
From [email protected] Thu Sep 26 17:09:32 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP
id 4AD7A476FCC; Thu, 26 Sep 2002 17:09:31 -0400 (EDT)
Received: from CopelandConsulting.Net (dsl-24293-ld.customer.centurytel.net
[209.142.135.135]) by postgresql.org (Postfix) with ESMTP
id 22CE6476FC8; Thu, 26 Sep 2002 17:09:30 -0400 (EDT)
Received: from mouse.copelandconsulting.net (mouse.copelandconsulting.net
[192.168.1.2])
by CopelandConsulting.Net (8.10.1/8.10.1) with ESMTP id g8QL97u03616;
Thu, 26 Sep 2002 16:09:07 -0500 (CDT)
X-Trade-Id: <CCC.Thu, 26 Sep 2002 16:09:07 -0500 (CDT).Thu,
26 Sep 2002 16:09:07 -0500
(CDT).200209262109[email protected].
Subject: Re: [HACKERS] Performance while loading data and indexing
From: Greg Copeland <[email protected]>
To: Neil Conway <[email protected]>
Cc: Bruce Momjian <[email protected]>,
[email protected].in,
PostgresSQL Hackers Mailing List <[email protected]>,
PostgresSQL General Mailing List <[email protected]>
In-Reply-To: <87[email protected]>
References: <200209262045.[email protected]>
<87[email protected]>
Content-Type: multipart/signed; micalg=pgp-sha1;
protocol="application/pgp-signature";
boundary="=-ukBN/VLqUCvLMvEd/iTv"
X-Mailer: Ximian Evolution 1.0.8
Date: 26 Sep 2002 16:09:15 -0500
Message-Id: <1033074555.23344.48[email protected]>
Mime-Version: 1.0
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1219
X-Sequence-Number: 30800
--=-ukBN/VLqUCvLMvEd/iTv
Content-Type: text/plain
Content-Transfer-Encoding: quoted-printable
On Thu, 2002-09-26 at 16:03, Neil Conway wrote:
> Bruce Momjian <[email protected]> writes:
> > Wow. That leaves no good Linux file system alternatives.
> > PostgreSQL just wants an ordinary file system that has reliable
> > recovery from a crash.
>=20
> I'm not really familiar with the reasoning behind ext2's reputation as
> recovering poorly from crashes; if we fsync a WAL record to disk
> before we lose power, can't we recover reliably, even with ext2?
Well, I have experienced data loss from ext2 before. Also, recovery
from crashes on large file systems take a very, very long time. I can't
imagine anyone running a production database on an ext2 file system
having 10's or even 100's of GB. Ouch. Recovery would take forever!=20
Even recovery on small file systems (2-8G) can take extended periods of
time. Especially so on IDE systems. Even then manual intervention is
not uncommon.
While I can't say that x, y or z is the best FS to use on Linux, I can
say that ext2 is probably an exceptionally poor choice from a
reliability and/or uptime perspective.
Greg
--=-ukBN/VLqUCvLMvEd/iTv
Content-Type: application/pgp-signature; name=signature.asc
Content-Description: This is a digitally signed message part
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.0.7 (GNU/Linux)
iD8DBQA9k3d74lr1bpbcL6kRAttbAJ44dhAlrsYjtTfGuieCrbJBqLV7PwCfWElV
QDa/ABmzxCPU/REOuseR7bo=
=Sg1u
-----END PGP SIGNATURE-----
--=-ukBN/VLqUCvLMvEd/iTv--
From [email protected] Thu Sep 26 17:17:43 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP
id 4E5B1474E5C; Thu, 26 Sep 2002 17:17:42 -0400 (EDT)
Received: from bob.samurai.com (bob.samurai.com [205.207.28.75])
by postgresql.org (Postfix) with ESMTP
id 3C927476F34; Thu, 26 Sep 2002 17:17:41 -0400 (EDT)
Received: from boston.samurai.com (DU179.N224.ResNet.QueensU.CA
[130.15.224.179]) by bob.samurai.com (Postfix) with ESMTP
id 066721ECE; Thu, 26 Sep 2002 17:17:42 -0400 (EDT)
To: Greg Copeland <[email protected]>
Cc: Neil Conway <[email protected]>, Bruce Momjian <[email protected]>,
[email protected],
PostgresSQL Hackers Mailing List <[email protected]>,
PostgresSQL General Mailing List <[email protected]>
Subject: Re: [HACKERS] Performance while loading data and indexing
References: <[email protected]>
<[email protected]>
<[email protected]>
From: Neil Conway <[email protected]>
In-Reply-To: <[email protected]>
Date: 26 Sep 2002 17:17:30 -0400
Message-ID: <[email protected]>
Lines: 24
User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.2
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1220
X-Sequence-Number: 30801
Greg Copeland <[email protected]> writes:
> On Thu, 2002-09-26 at 16:03, Neil Conway wrote:
> > I'm not really familiar with the reasoning behind ext2's
> > reputation as recovering poorly from crashes; if we fsync a WAL
> > record to disk before we lose power, can't we recover reliably,
> > even with ext2?
>
> Well, I have experienced data loss from ext2 before. Also, recovery
> from crashes on large file systems take a very, very long time.
Yes, but wouldn't you face exactly the same issues if you ran a
UFS-like filesystem in asynchronous mode? Albeit it's not the default,
but performance in synchronous mode is usually pretty poor.
The fact that ext2 defaults to asynchronous mode and UFS (at least on
the BSDs) defaults to synchronous mode seems like a total non-issue to
me. Is there any more to the alleged difference in reliability?
Cheers,
Neil
--
Neil Conway <[email protected]> || PGP Key ID: DB3C29FC
From [email protected] Thu Sep 26 17:32:17 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP
id 938DE4769BA; Thu, 26 Sep 2002 17:32:15 -0400 (EDT)
Received: from varsoon.wireboard.com (www.wireboard.com [216.151.155.101])
by postgresql.org (Postfix) with ESMTP
id 0DC964769AE; Thu, 26 Sep 2002 17:32:15 -0400 (EDT)
Received: from doug by varsoon.wireboard.com with local (Exim 3.35 #1)
id 17ugEl-0006nF-00; Thu, 26 Sep 2002 17:31:55 -0400
To: Bruce Momjian <[email protected]>
From: Doug McNaught <[email protected]>
Cc: Greg Copeland <[email protected]>,
[email protected].in,
PostgresSQL Hackers Mailing List <[email protected]>,
PostgresSQL General Mailing List <[email protected]>
Subject: Re: [HACKERS] Performance while loading data and indexing
References: <200209262000.[email protected]>
Date: 26 Sep 2002 17:31:55 -0400
In-Reply-To: Bruce Momjian's message of "Thu,
26 Sep 2002 16:00:48 -0400 (EDT)"
Message-ID: <[email protected]>
Lines: 24
User-Agent: Gnus/5.0806 (Gnus v5.8.6) Emacs/20.7
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1221
X-Sequence-Number: 30802
Bruce Momjian <[email protected]> writes:
> Can anyone clarify if "data=writeback" is safe for PostgreSQL.
> Specifically, are the data files recovered properly or is this option
> only for a filesystem containing WAL?
"data=writeback" means that no data is journaled, just metadata (which
is like XFS or Reiser). An fsync() call should still do what it
normally does, commit the writes to disk before returning.
"data=journal" journals all data and is the slowest and safest.
"data=ordered" writes out data blocks before committing a journal
transaction, which is faster than full data journaling (since data
doesn't get written twice) and almost as safe. "data=writeback" is
noted to keep obsolete data in the case of some crashes (since the
data may not have been written yet) but a completed fsync() should
ensure that the data is valid.
So I guess I'd probably use data=ordered for an all-on-one-fs
installation, and data=writeback for a WAL-only drive.
Hope this helps...
-Doug
From [email protected] Thu Sep 26 17:32:39 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP id 9C0C4477044
for <[email protected]>;
Thu, 26 Sep 2002 17:32:38 -0400 (EDT)
Received: from sss.pgh.pa.us (unknown [192.204.191.242])
by postgresql.org (Postfix) with ESMTP id 591CA476F89
for <[email protected]>;
Thu, 26 Sep 2002 17:32:26 -0400 (EDT)
Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1])
by sss.pgh.pa.us (8.12.5/8.12.5) with ESMTP id g8QLW1hR012931;
Thu, 26 Sep 2002 17:32:01 -0400 (EDT)
To: Neil Conway <[email protected]>
Cc: Bruce Momjian <[email protected]>,
[email protected], [email protected],
[email protected]
Subject: Re: [HACKERS] Performance while loading data and indexing
In-reply-to: <[email protected]>
References: <[email protected]>
<[email protected]>
Comments: In-reply-to Neil Conway <[email protected]>
message dated "26 Sep 2002 17:03:26 -0400"
Date: Thu, 26 Sep 2002 17:32:01 -0400
Message-ID: <[email protected]>
From: Tom Lane <[email protected]>
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1222
X-Sequence-Number: 30803
Neil Conway <[email protected]> writes:
> I'm not really familiar with the reasoning behind ext2's reputation as
> recovering poorly from crashes; if we fsync a WAL record to disk
> before we lose power, can't we recover reliably, even with ext2?
Up to a point. We do assume that the filesystem won't lose checkpointed
(sync'd) writes to data files. To the extent that the filesystem is
vulnerable to corruption of its own metadata for a file (indirect blocks
or whatever ext2 uses), that's not a completely safe assumption.
We'd be happiest with a filesystem that journals its own metadata and
not the user data in the file(s). I dunno if there are any.
Hmm, maybe this is why Oracle likes doing their own filesystem on a raw
device...
regards, tom lane
From [email protected] Thu Sep 26 17:37:39 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP
id F267E476FCC; Thu, 26 Sep 2002 17:37:38 -0400 (EDT)
Received: from varsoon.wireboard.com (www.wireboard.com [216.151.155.101])
by postgresql.org (Postfix) with ESMTP
id 1DF13476FC3; Thu, 26 Sep 2002 17:37:38 -0400 (EDT)
Received: from doug by varsoon.wireboard.com with local (Exim 3.35 #1)
id 17ugJq-0006nf-00; Thu, 26 Sep 2002 17:37:10 -0400
To: Tom Lane <[email protected]>
From: Doug McNaught <[email protected]>
Cc: Neil Conway <[email protected]>, Bruce Momjian <[email protected]>,
[email protected].in, [email protected],
[email protected]
Subject: Re: [HACKERS] Performance while loading data and indexing
References: <200209262045.[email protected]>
<87[email protected]> <12930.1033075921@sss.pgh.pa.us>
Date: 26 Sep 2002 17:37:10 -0400
In-Reply-To: Tom Lane's message of "Thu, 26 Sep 2002 17:32:01 -0400"
Message-ID: <[email protected]>
Lines: 8
User-Agent: Gnus/5.0806 (Gnus v5.8.6) Emacs/20.7
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1223
X-Sequence-Number: 30804
Tom Lane <[email protected]> writes:
> We'd be happiest with a filesystem that journals its own metadata and
> not the user data in the file(s). I dunno if there are any.
ext3 with data=writeback? (See my previous message to Bruce).
-Doug
From [email protected] Thu Sep 26 17:39:35 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP
id 0C3B54760BD; Thu, 26 Sep 2002 17:39:35 -0400 (EDT)
Received: from candle.pha.pa.us (momjian.navpoint.com [207.106.42.251])
by postgresql.org (Postfix) with ESMTP
id 7E8AC4770C8; Thu, 26 Sep 2002 17:39:31 -0400 (EDT)
Received: (from pgman@localhost)
by candle.pha.pa.us (8.11.6/8.10.1) id g8QLdEE08861;
Thu, 26 Sep 2002 17:39:14 -0400 (EDT)
From: Bruce Momjian <[email protected]>
Message-Id: <200209262139.[email protected]>
Subject: Re: [HACKERS] Performance while loading data and indexing
In-Reply-To: <87[email protected]>
To: Neil Conway <[email protected]>
Date: Thu, 26 Sep 2002 17:39:14 -0400 (EDT)
Cc: Greg Copeland <[email protected]>,
[email protected].in,
PostgresSQL Hackers Mailing List <[email protected]>,
PostgresSQL General Mailing List <[email protected]>
X-Mailer: ELM [version 2.4ME+ PL99 (25)]
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Content-Type: text/plain; charset=US-ASCII
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1224
X-Sequence-Number: 30805
Neil Conway wrote:
> Greg Copeland <[email protected]> writes:
> > On Thu, 2002-09-26 at 16:03, Neil Conway wrote:
> > > I'm not really familiar with the reasoning behind ext2's
> > > reputation as recovering poorly from crashes; if we fsync a WAL
> > > record to disk before we lose power, can't we recover reliably,
> > > even with ext2?
> >
> > Well, I have experienced data loss from ext2 before. Also, recovery
> > from crashes on large file systems take a very, very long time.
>
> Yes, but wouldn't you face exactly the same issues if you ran a
> UFS-like filesystem in asynchronous mode? Albeit it's not the default,
> but performance in synchronous mode is usually pretty poor.
Yes, before UFS had soft updates, the synchronous nature of UFS made it
slower than ext2, but now with soft updates, that performance difference
is gone so you have two files systems, ext2 and ufs, similar peformance,
but one is crash-safe and the other is not.
And, when comparing the journalling file systems, you have UFS vs.
XFS/ext3/JFS/Reiser, and UFS is faster. The only thing the journalling
file system give you is more rapid reboot, but frankly, if your OS goes
down often enough so that is an issue, you have bigger problems than
fsync time.
The big problem is that Linux went from non-crash safe right to
crash-safe and reboot quick. We need a middle ground, which is where
UFS/soft updates is.
> The fact that ext2 defaults to asynchronous mode and UFS (at least on
> the BSDs) defaults to synchronous mode seems like a total non-issue to
> me. Is there any more to the alleged difference in reliability?
The reliability problem isn't alleged. ext2 developers admits ext2
isn't 100% crash-safe. They will say it is usually crash-safe, but that
isn't good enough for PostgreSQL.
I wish I was wrong.
--
Bruce Momjian | http://candle.pha.pa.us
[email protected] | (610) 359-1001
+ If your life is a hard drive, | 13 Roberts Road
+ Christ can be your backup. | Newtown Square, Pennsylvania 19073
From [email protected] Thu Sep 26 17:42:05 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP
id 969E9476FEF; Thu, 26 Sep 2002 17:42:02 -0400 (EDT)
Received: from candle.pha.pa.us (momjian.navpoint.com [207.106.42.251])
by postgresql.org (Postfix) with ESMTP
id 97422476FDB; Thu, 26 Sep 2002 17:42:00 -0400 (EDT)
Received: (from pgman@localhost)
by candle.pha.pa.us (8.11.6/8.10.1) id g8QLfMr09064;
Thu, 26 Sep 2002 17:41:22 -0400 (EDT)
From: Bruce Momjian <[email protected]>
Message-Id: <200209262141.[email protected]>
Subject: Re: [HACKERS] Performance while loading data and indexing
In-Reply-To: <[email protected]>
To: Doug McNaught <[email protected]>
Date: Thu, 26 Sep 2002 17:41:22 -0400 (EDT)
Cc: Tom Lane <[email protected]>, Neil Conway <[email protected]>,
[email protected].in, [email protected],
[email protected]
X-Mailer: ELM [version 2.4ME+ PL99 (25)]
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Content-Type: text/plain; charset=US-ASCII
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1225
X-Sequence-Number: 30806
Doug McNaught wrote:
> Tom Lane <[email protected]> writes:
>
> > We'd be happiest with a filesystem that journals its own metadata and
> > not the user data in the file(s). I dunno if there are any.
>
> ext3 with data=writeback? (See my previous message to Bruce).
OK, so that makes ext3 crash safe without lots of overhead?
--
Bruce Momjian | http://candle.pha.pa.us
[email protected] | (610) 359-1001
+ If your life is a hard drive, | 13 Roberts Road
+ Christ can be your backup. | Newtown Square, Pennsylvania 19073
From [email protected] Thu Sep 26 17:45:16 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP
id 460CF477047; Thu, 26 Sep 2002 17:45:14 -0400 (EDT)
Received: from squire.barchord.com (squire.barchord.com [216.194.67.18])
by postgresql.org (Postfix) with ESMTP
id CA66D477042; Thu, 26 Sep 2002 17:45:13 -0400 (EDT)
Received: from [192.168.1.253]
(CPE00508b028d7d-CM00803785c5e0.cpe.net.cable.rogers.com
[24.103.51.175]) by squire.barchord.com (Postfix) with ESMTP
id 454C542C; Thu, 26 Sep 2002 17:45:15 -0400 (EDT)
Subject: Re: [GENERAL] Performance while loading data and indexing
From: Rod Taylor <[email protected]>
To: Bruce Momjian <[email protected]>
Cc: Neil Conway <[email protected]>,
Greg Copeland <[email protected]>,
[email protected],
PostgresSQL Hackers Mailing List <[email protected]>,
PostgresSQL General Mailing List <[email protected]>
In-Reply-To: <[email protected]>
References: <[email protected]>
Content-Type: text/plain
Content-Transfer-Encoding: 7bit
X-Mailer: Ximian Evolution 1.0.8
Date: 26 Sep 2002 17:45:23 -0400
Message-Id: <1033076723.27772.4.camel@jester>
Mime-Version: 1.0
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1598
X-Sequence-Number: 29555
On Thu, 2002-09-26 at 17:39, Bruce Momjian wrote:
> Neil Conway wrote:
> > Greg Copeland <[email protected]> writes:
> > > On Thu, 2002-09-26 at 16:03, Neil Conway wrote:
> > > > I'm not really familiar with the reasoning behind ext2's
> > > > reputation as recovering poorly from crashes; if we fsync a WAL
> > > > record to disk before we lose power, can't we recover reliably,
> > > > even with ext2?
> > >
> > > Well, I have experienced data loss from ext2 before. Also, recovery
> > > from crashes on large file systems take a very, very long time.
> >
> > Yes, but wouldn't you face exactly the same issues if you ran a
> > UFS-like filesystem in asynchronous mode? Albeit it's not the default,
> > but performance in synchronous mode is usually pretty poor.
>
> Yes, before UFS had soft updates, the synchronous nature of UFS made it
> slower than ext2, but now with soft updates, that performance difference
> is gone so you have two files systems, ext2 and ufs, similar peformance,
> but one is crash-safe and the other is not.
Note entirely true. ufs is both crash-safe and quick-rebootable. You
do need to fsck at some point, but not prior to mounting it. Any
corrupt blocks are empty, and are easy to avoid.
Someone just needs to implement a background fsck that will run on a
mounted filesystem.
--
Rod Taylor
From [email protected] Thu Sep 26 17:48:03 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP
id 42A774767DA; Thu, 26 Sep 2002 17:48:03 -0400 (EDT)
Received: from candle.pha.pa.us (momjian.navpoint.com [207.106.42.251])
by postgresql.org (Postfix) with ESMTP
id 5FC1E476212; Thu, 26 Sep 2002 17:48:01 -0400 (EDT)
Received: (from pgman@localhost)
by candle.pha.pa.us (8.11.6/8.10.1) id g8QLlhU10159;
Thu, 26 Sep 2002 17:47:43 -0400 (EDT)
From: Bruce Momjian <[email protected]>
Message-Id: <200209262147.[email protected]>
Subject: Re: [HACKERS] Performance while loading data and indexing
In-Reply-To: <1033076723.27772.4.camel@jester>
To: Rod Taylor <[email protected]>
Date: Thu, 26 Sep 2002 17:47:43 -0400 (EDT)
Cc: Neil Conway <[email protected]>,
Greg Copeland <[email protected]>,
[email protected].in,
PostgresSQL Hackers Mailing List <[email protected]>,
PostgresSQL General Mailing List <[email protected]>
X-Mailer: ELM [version 2.4ME+ PL99 (25)]
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Content-Type: text/plain; charset=US-ASCII
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1227
X-Sequence-Number: 30808
Rod Taylor wrote:
> > Yes, before UFS had soft updates, the synchronous nature of UFS made it
> > slower than ext2, but now with soft updates, that performance difference
> > is gone so you have two files systems, ext2 and ufs, similar peformance,
> > but one is crash-safe and the other is not.
>
> Note entirely true. ufs is both crash-safe and quick-rebootable. You
> do need to fsck at some point, but not prior to mounting it. Any
> corrupt blocks are empty, and are easy to avoid.
I am assuming you need to mount the drive as part of the reboot. Of
course you can boot fast with any file system if you don't have to mount
it. :-)
--
Bruce Momjian | http://candle.pha.pa.us
[email protected] | (610) 359-1001
+ If your life is a hard drive, | 13 Roberts Road
+ Christ can be your backup. | Newtown Square, Pennsylvania 19073
From [email protected] Sat Sep 28 13:41:23 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP
id 991FA47618E; Thu, 26 Sep 2002 18:03:27 -0400 (EDT)
Received: from squire.barchord.com (squire.barchord.com [216.194.67.18])
by postgresql.org (Postfix) with ESMTP
id 221B74760B7; Thu, 26 Sep 2002 18:03:27 -0400 (EDT)
Received: from [192.168.1.253]
(CPE00508b028d7d-CM00803785c5e0.cpe.net.cable.rogers.com
[24.103.51.175]) by squire.barchord.com (Postfix) with ESMTP
id 8ECED42C; Thu, 26 Sep 2002 18:03:28 -0400 (EDT)
Subject: Re: [HACKERS] Performance while loading data and indexing
From: Rod Taylor <[email protected]>
To: Bruce Momjian <[email protected]>
Cc: Neil Conway <[email protected]>,
Greg Copeland <[email protected]>,
[email protected],
PostgresSQL Hackers Mailing List <[email protected]>,
PostgresSQL General Mailing List <[email protected]>
In-Reply-To: <[email protected]>
References: <[email protected]>
Content-Type: text/plain
Content-Transfer-Encoding: 7bit
X-Mailer: Ximian Evolution 1.0.8
Date: 26 Sep 2002 18:03:36 -0400
Message-Id: <1033077816.27772.9.camel@jester>
Mime-Version: 1.0
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1330
X-Sequence-Number: 30911
On Thu, 2002-09-26 at 17:47, Bruce Momjian wrote:
> Rod Taylor wrote:
> > > Yes, before UFS had soft updates, the synchronous nature of UFS made it
> > > slower than ext2, but now with soft updates, that performance difference
> > > is gone so you have two files systems, ext2 and ufs, similar peformance,
> > > but one is crash-safe and the other is not.
> >
> > Note entirely true. ufs is both crash-safe and quick-rebootable. You
> > do need to fsck at some point, but not prior to mounting it. Any
> > corrupt blocks are empty, and are easy to avoid.
>
> I am assuming you need to mount the drive as part of the reboot. Of
> course you can boot fast with any file system if you don't have to mount
> it. :-)
Sorry, poor explanation.
Background fsck (when implemented) would operate on a currently mounted
(and active) file system. The only reason fsck is required prior to
reboot now is because no-one had done the work.
http://www.freebsd.org/cgi/man.cgi?query=fsck&sektion=8&manpath=FreeBSD+5.0-current
See the first paragraph of the above.
--
Rod Taylor
From [email protected] Thu Sep 26 18:05:13 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP
id C0E5F476FAF; Thu, 26 Sep 2002 18:05:12 -0400 (EDT)
Received: from candle.pha.pa.us (momjian.navpoint.com [207.106.42.251])
by postgresql.org (Postfix) with ESMTP
id C71D6476F95; Thu, 26 Sep 2002 18:05:10 -0400 (EDT)
Received: (from pgman@localhost)
by candle.pha.pa.us (8.11.6/8.10.1) id g8QM4qX11641;
Thu, 26 Sep 2002 18:04:52 -0400 (EDT)
From: Bruce Momjian <[email protected]>
Message-Id: <200209262204.[email protected]>
Subject: Re: [HACKERS] Performance while loading data and indexing
In-Reply-To: <1033077816.27772.9.camel@jester>
To: Rod Taylor <[email protected]>
Date: Thu, 26 Sep 2002 18:04:52 -0400 (EDT)
Cc: Neil Conway <[email protected]>,
Greg Copeland <[email protected]>,
[email protected].in,
PostgresSQL Hackers Mailing List <[email protected]>,
PostgresSQL General Mailing List <[email protected]>
X-Mailer: ELM [version 2.4ME+ PL99 (25)]
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Content-Type: text/plain; charset=US-ASCII
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1229
X-Sequence-Number: 30810
Rod Taylor wrote:
> On Thu, 2002-09-26 at 17:47, Bruce Momjian wrote:
> > Rod Taylor wrote:
> > > > Yes, before UFS had soft updates, the synchronous nature of UFS made it
> > > > slower than ext2, but now with soft updates, that performance difference
> > > > is gone so you have two files systems, ext2 and ufs, similar peformance,
> > > > but one is crash-safe and the other is not.
> > >
> > > Note entirely true. ufs is both crash-safe and quick-rebootable. You
> > > do need to fsck at some point, but not prior to mounting it. Any
> > > corrupt blocks are empty, and are easy to avoid.
> >
> > I am assuming you need to mount the drive as part of the reboot. Of
> > course you can boot fast with any file system if you don't have to mount
> > it. :-)
>
> Sorry, poor explanation.
>
> Background fsck (when implemented) would operate on a currently mounted
> (and active) file system. The only reason fsck is required prior to
> reboot now is because no-one had done the work.
>
> http://www.freebsd.org/cgi/man.cgi?query=fsck&sektion=8&manpath=FreeBSD+5.0-current
>
> See the first paragraph of the above.
Oh, yes, I have heard of that missing feature.
--
Bruce Momjian | http://candle.pha.pa.us
[email protected] | (610) 359-1001
+ If your life is a hard drive, | 13 Roberts Road
+ Christ can be your backup. | Newtown Square, Pennsylvania 19073
From [email protected] Thu Sep 26 19:26:22 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP
id 625C74763DD; Thu, 26 Sep 2002 19:26:21 -0400 (EDT)
Received: from varsoon.wireboard.com (www.wireboard.com [216.151.155.101])
by postgresql.org (Postfix) with ESMTP
id C8EF147628D; Thu, 26 Sep 2002 19:26:20 -0400 (EDT)
Received: from doug by varsoon.wireboard.com with local (Exim 3.35 #1)
id 17ui1D-0006sX-00; Thu, 26 Sep 2002 19:26:03 -0400
To: Bruce Momjian <[email protected]>
From: Doug McNaught <[email protected]>
Cc: Tom Lane <[email protected]>, Neil Conway <[email protected]>,
[email protected], [email protected],
[email protected]
Subject: Re: [HACKERS] Performance while loading data and indexing
References: <[email protected]>
Date: 26 Sep 2002 19:26:03 -0400
In-Reply-To: Bruce Momjian's message of "Thu,
26 Sep 2002 17:41:22 -0400 (EDT)"
Message-ID: <[email protected]>
Lines: 23
User-Agent: Gnus/5.0806 (Gnus v5.8.6) Emacs/20.7
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1231
X-Sequence-Number: 30812
Bruce Momjian <[email protected]> writes:
> Doug McNaught wrote:
> > Tom Lane <[email protected]> writes:
> >
> > > We'd be happiest with a filesystem that journals its own metadata and
> > > not the user data in the file(s). I dunno if there are any.
> >
> > ext3 with data=writeback? (See my previous message to Bruce).
>
> OK, so that makes ext3 crash safe without lots of overhead?
Metadata is journaled so you shouldn't lose data blocks or directory
entries. Some data blocks (that haven't been fsync()'ed) may have old
or wrong data in them, but I think that's the same as ufs, right? And
WAL replay should take care of that.
It'd be very interesting to do some tests of the various journaling
modes. I have an old K6 that I might be able to turn into a
hit-the-reset-switch-at-ramdom-times machine. What kind of tests
should be run?
-Doug
From [email protected] Thu Sep 26 22:53:21 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP id 353A4476391
for <[email protected]>;
Thu, 26 Sep 2002 22:53:21 -0400 (EDT)
Received: from corpmail.outblaze.com (202-77-223-51.outblaze.com
[202.77.223.51])
by postgresql.org (Postfix) with ESMTP id D37A247632D
for <[email protected]>;
Thu, 26 Sep 2002 22:53:19 -0400 (EDT)
Received: from yusufg.portal2.com (202-77-223-2.outblaze.com [202.77.223.2])
by corpmail.outblaze.com (8.12.6/8.12.6) with SMTP id g8R2rMm8029328
for <[email protected]>; Fri, 27 Sep 2002 02:53:22 GMT
Received: (qmail 1463 invoked by uid 500); 27 Sep 2002 02:55:10 -0000
Date: Fri, 27 Sep 2002 10:55:10 +0800
From: Yusuf Goolamabbas <[email protected]>
To: [email protected]
Subject: Would ext3 data=journal help for Postgres synchronous io mode
Message-ID: <20020927025510.[email protected]>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
User-Agent: Mutt/1.4i
X-AntiVirus: checked by Vexira Milter 1.0.0.3; VAE 6.15.0.1; VDF 6.15.0.9
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/14
X-Sequence-Number: 14
According to ext3 hackers (Stephen Tweedie, Andrew Morton). ext3
data=journal mode is much faster than any of the other mode for
workloads which do a lot of syncrhonous i/o. Personally, I have seen
dramatic improvements on moving mail queues to this mode (postfix in
particularly flies with this mode)
While this may seem contradictory (forcing journaling for the data in
addition to the metadata), it will likely improve the performance for
sync I/O loads like mail servers because it can do all of the I/O to the
journal without any seek or sync overhead while the mail is arriving.
I assume that since Postgresql does a lot of fsyncs, it would benefit
also. I have sent email to Sridhar asking if he could test this
Another thing to note is that Linux 2.4.x kernels < 2.4.20-pre4 use
bounce buffer's to do IO if the machine has > 1GB memory. Distributor
kernels such as Redhat/Suse/Mandrake are patched to do IO via DMA
to/from highmem (>1GB). According to IBM's paper @ OLS, this improves IO
performance by 40%
BTW, Is this list archived on the website
Regards, Yusuf
--
Yusuf Goolamabbas
[email protected]
From [email protected] Thu Sep 26 23:08:32 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP id 3C676477068
for <[email protected]>;
Thu, 26 Sep 2002 23:08:30 -0400 (EDT)
Received: from sss.pgh.pa.us (unknown [192.204.191.242])
by postgresql.org (Postfix) with ESMTP id 3674347703B
for <[email protected]>;
Thu, 26 Sep 2002 23:08:29 -0400 (EDT)
Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1])
by sss.pgh.pa.us (8.12.5/8.12.5) with ESMTP id g8R37jhR020360;
Thu, 26 Sep 2002 23:07:45 -0400 (EDT)
To: Doug McNaught <[email protected]>
Cc: Bruce Momjian <[email protected]>,
Greg Copeland <[email protected]>,
[email protected].in,
PostgresSQL Hackers Mailing List <[email protected]>,
PostgresSQL General Mailing List <[email protected]>
Subject: Re: [HACKERS] Performance while loading data and indexing
In-reply-to: <[email protected]>
References: <200209262000.[email protected]>
<[email protected]>
Comments: In-reply-to Doug McNaught <[email protected]>
message dated "26 Sep 2002 17:31:55 -0400"
Date: Thu, 26 Sep 2002 23:07:44 -0400
Message-ID: <20359.1033096064@sss.pgh.pa.us>
From: Tom Lane <[email protected]>
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1242
X-Sequence-Number: 30823
Doug McNaught <[email protected]> writes:
> "data=writeback" means that no data is journaled, just metadata (which
> is like XFS or Reiser). An fsync() call should still do what it
> normally does, commit the writes to disk before returning.
> "data=journal" journals all data and is the slowest and safest.
> "data=ordered" writes out data blocks before committing a journal
> transaction, which is faster than full data journaling (since data
> doesn't get written twice) and almost as safe. "data=writeback" is
> noted to keep obsolete data in the case of some crashes (since the
> data may not have been written yet) but a completed fsync() should
> ensure that the data is valid.
Thanks for the explanation.
> So I guess I'd probably use data=ordered for an all-on-one-fs
> installation, and data=writeback for a WAL-only drive.
Actually I think the ideal thing for Postgres would be data=writeback
for both data and WAL drives. We can handle loss of un-fsync'd data
for ourselves in both cases.
Of course, if you keep anything besides Postgres data files on a
partition, you'd possibly want the more secure settings.
regards, tom lane
From [email protected] Fri Sep 27 01:12:31 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP
id D61BE47714E; Fri, 27 Sep 2002 01:12:30 -0400 (EDT)
Received: from panda.center-f1.ru (panda.center-f1.ru [195.151.30.15])
by postgresql.org (Postfix) with ESMTP
id C4927477196; Fri, 27 Sep 2002 01:12:28 -0400 (EDT)
Received: from localhost (byg@localhost)
by panda.center-f1.ru (8.11.6/8.11.6) with ESMTP id g8R5Ee308324;
Fri, 27 Sep 2002 12:14:40 +0700
X-Authentication-Warning: panda.center-f1.ru: byg owned process doing -bs
Date: Fri, 27 Sep 2002 12:14:40 +0700 (NOVST)
From: Yury Bokhoncovich <[email protected]>
To: Bruce Momjian <[email protected]>
Cc: Neil Conway <[email protected]>, <[email protected].in>,
<[email protected]>, <[email protected]>
Subject: Re: [HACKERS] Performance while loading data and indexing
In-Reply-To: <200209262107.[email protected]>
Message-ID: <Pine.LNX.4.44L0.0209271201580.7775-100000@panda.center-f1.ru>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1253
X-Sequence-Number: 30834
Hello!
On Thu, 26 Sep 2002, Bruce Momjian wrote:
> > I'm not really familiar with the reasoning behind ext2's reputation as
> > recovering poorly from crashes; if we fsync a WAL record to disk
On relatively big volumes ext2 recovery can end up in formatting the fs
under certain cirrumstances.;-)
> > > I assumed it was the double fsync for the normal and journal that
> > > made the journalling file systems slog.
> >
> > Well, a journalling file system would need to write a journal entry
> > and flush that to disk, even if fsync is disabled -- whereas without
> > fsync enabled, ext2 doesn't have to flush anything to disk. ISTM that
> > the performance advantage of ext2 over ext3 is should be even larger
> > when fsync is not enabled.
>
> Yes, it is still double-writing. I just thought that if that wasn't
> happening while the db was waiting for a commit that it wouldn't be too
> bad.
>
> Is it just me or do all the Linux file systems seem like they are
> lacking something when PostgreSQL is concerned? We just want a UFS-like
> file system on Linux and no one has it.
mount -o sync an ext2 volume on Linux - and you can get a "UFS-like" fs.:)
mount -o async an FFS volume on FreeBSD - and you can get boost in fs
performance.
Personally me always mount ext2 fs where Pg is living with sync option.
Fsync in pg is off (since 6.3), this way successfully pass thru a few
serious crashes on various systems (mostly on power problems).
If fsync is on in Pg, performance gets so-oh-oh-oh-oh slowly!=)
I just have done upgrade from 2.2 kernel on ext2 to ext3 capable 2.4 one
so I'm planning to do some benchmarking. Roughly saying w/o benchmarks,
the performance have been degraded in 2/3 proportion.
"But better safe then sorry".
--
WBR, Yury Bokhoncovich, Senior System Administrator, NOC of F1 Group.
Phone: +7 (3832) 106228, ext.140, E-mail: [email protected].
Unix is like a wigwam -- no Gates, no Windows, and an Apache inside.
From [email protected] Fri Sep 27 05:42:31 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP id 95321475EDF
for <[email protected]>;
Fri, 27 Sep 2002 05:42:26 -0400 (EDT)
Received: from freemail.agrinet.ch (freemail.agrinet.ch [212.28.134.90])
by postgresql.org (Postfix) with ESMTP id 267654771AE
for <[email protected]>;
Fri, 27 Sep 2002 05:42:23 -0400 (EDT)
Received: from syydelaervli.fortytwo.ch (81.6.8.94) by freemail.agrinet.ch
(NPlex 5.1.056)
id 3D921E0A00007388 for [email protected];
Fri, 27 Sep 2002 11:42:24 +0200
Received: from atlas.acter.ch (unknown [212.126.160.108])
by syydelaervli.fortytwo.ch (Postfix) with ESMTP id 43EF52A76
for <[email protected]>;
Fri, 27 Sep 2002 11:42:23 +0200 (CEST)
Received: by atlas.acter.ch (Postfix, from userid 1047)
id 7B2A89696; Fri, 27 Sep 2002 11:42:22 +0200 (CEST)
Subject:
From: Adrian von Bidder <[email protected]>
To: PostgreSQL Performance Mailing List <[email protected]>
Content-Type: text/plain
Content-Transfer-Encoding: 7bit
X-Mailer: Ximian Evolution 1.0.8
Date: 27 Sep 2002 11:42:22 +0200
Message-Id: <1033119742.13843.9.camel@atlas>
Mime-Version: 1.0
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/15
X-Sequence-Number: 15
subscribe
--
secure email with gpg http://fortytwo.ch/gpg
NOTICE: subkey signature! request key 92082481 from keyserver.kjsl.com
From [email protected] Fri Sep 27 06:40:18 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP id 883AA475D00
for <[email protected]>;
Fri, 27 Sep 2002 06:40:17 -0400 (EDT)
Received: from news.hub.org (news.hub.org [64.49.215.80])
by postgresql.org (Postfix) with ESMTP id 3C44B475EC7
for <[email protected]>;
Fri, 27 Sep 2002 06:40:16 -0400 (EDT)
Received: by news.hub.org (Postfix, from userid 8)
id 5AC2C381683; Fri, 27 Sep 2002 06:40:15 -0400 (EDT)
From: Mats Lofkvist <[email protected]>
X-Newsgroups: comp.databases.postgresql.general,
comp.databases.postgresql.questions
Subject: Re: [HACKERS] Performance while loading data and indexing
Date: 27 Sep 2002 12:40:13 +0200
Organization: Hub.Org Networking Services (http://www.hub.org)
Lines: 29
Message-ID: <[email protected]>
References: <87[email protected]>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
X-Complaints-To: [email protected]
User-Agent: Gnus/5.0803 (Gnus v5.8.3) Emacs/20.5
To: [email protected]
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1268
X-Sequence-Number: 30849
[email protected] (Neil Conway) writes:
[snip]
> > Well, I have experienced data loss from ext2 before. Also, recovery
> > from crashes on large file systems take a very, very long time.
>
> Yes, but wouldn't you face exactly the same issues if you ran a
> UFS-like filesystem in asynchronous mode? Albeit it's not the default,
> but performance in synchronous mode is usually pretty poor.
>
> The fact that ext2 defaults to asynchronous mode and UFS (at least on
> the BSDs) defaults to synchronous mode seems like a total non-issue to
> me. Is there any more to the alleged difference in reliability?
UFS on most unix systems (BSD, solaris etc) defaults to sync
metadata, async data which is a mode that is completely missing
from ext2 as far as I know.
This is why UFS is considered safer than ext2. (Running with
'sync' is too slow to be a usable alternative in most cases.)
_
Mats Lofkvist
[email protected]
PS The BSD soft updates yields the safety of the default sync
metadata / async data mode while being at least as fast as
running fully async.
From [email protected] Fri Sep 27 06:49:23 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP id CD832476243
for <[email protected]>;
Fri, 27 Sep 2002 06:49:21 -0400 (EDT)
Received: from news.hub.org (news.hub.org [64.49.215.80])
by postgresql.org (Postfix) with ESMTP id 69480476160
for <[email protected]>;
Fri, 27 Sep 2002 06:49:21 -0400 (EDT)
Received: by news.hub.org (Postfix, from userid 8)
id 68B29381683; Fri, 27 Sep 2002 06:49:18 -0400 (EDT)
From: Mats Lofkvist <[email protected]>
X-Newsgroups: comp.databases.postgresql.general,
comp.databases.postgresql.questions
Subject: Re: Performance while loading data and indexing
Date: 27 Sep 2002 12:49:17 +0200
Organization: Hub.Org Networking Services (http://www.hub.org)
Lines: 21
Message-ID: <[email protected]>
References: <3D931438.22010.133ADAFA@localhost>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
X-Complaints-To: [email protected]
User-Agent: Gnus/5.0803 (Gnus v5.8.3) Emacs/20.5
To: [email protected]
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1269
X-Sequence-Number: 30850
[email protected].in ("Shridhar Daithankar") writes:
[snip]
>
> Couple MB of data per sec. to disk is just not saturating it. It's a RAID 5
> setup..
>
RAID5 is not the best for performance, especially write performance.
If it is software RAID it is even worse :-).
(Note also that you need to check that you are not saturating the
number of seeks the disks can handle, not just the bandwith.)
Striping should be better (combined with mirroring if you need the
safety, but with both striping and mirroring you may need multiple
SCSI channels).
_
Mats Lofkvist
[email protected]
From [email protected] Fri Sep 27 11:20:38 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP id 99F9947608D
for <[email protected]>;
Fri, 27 Sep 2002 11:20:36 -0400 (EDT)
Received: from mail1.ihs.com (mail1.ihs.com [170.207.70.222])
by postgresql.org (Postfix) with ESMTP id BAD85475FEB
for <[email protected]>;
Fri, 27 Sep 2002 11:20:35 -0400 (EDT)
Received: from css120.ihs.com (css120.ihs.com [170.207.105.120])
by mail1.ihs.com (8.12.6/8.12.6) with ESMTP id g8RFJikY015704;
Fri, 27 Sep 2002 09:19:45 -0600 (MDT)
Date: Fri, 27 Sep 2002 09:16:03 -0600 (MDT)
From: "scott.marlowe" <[email protected]>
To: Mats Lofkvist <[email protected]>
Cc: <[email protected]>
Subject: Re: Performance while loading data and indexing
In-Reply-To: <[email protected]>
Message-ID: <[email protected]>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
X-MailBodyFilter: Message body has not been filtered
X-MailScanner: Found to be clean
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1280
X-Sequence-Number: 30861
On 27 Sep 2002, Mats Lofkvist wrote:
> [email protected] ("Shridhar Daithankar") writes:
>
> [snip]
> >
> > Couple MB of data per sec. to disk is just not saturating it. It's a RAID 5
> > setup..
> >
>
> RAID5 is not the best for performance, especially write performance.
> If it is software RAID it is even worse :-).
I take exception to this. RAID5 is a great choice for most folks.
1: RAID5 only writes out the parity stripe and data stripe, not all
stripes when writing. So, in an 8 disk RAID5 array, writing to a single
64 k stripe involves one 64k read (parity stripe) and two 64k writes.
On a mirror set, writing to one 64k stripe involves two 64k writes. The
difference isn't that great, and in my testing, a large enough RAID5
provides so much faster read speads by spreading the reads across so many
heads as to more than make up for the slightly slower writes. My testing
has shown that a 4 disk RAID5 can generally run about 85% or more the
speed of a mirror set.
2: Why does EVERYONE have to jump on the bandwagon that software RAID 5
is bad. My workstation running RH 7.2 uses about 1% of the CPU during
very heavy parallel access (i.e. 50 simo pgbenchs) at most. I've seen
many hardware RAID cards that are noticeable slower than my workstation
running software RAID. You do know that hardware RAID is just software
RAID where the processing is done on a seperate CPU on a card, but it's
still software doing the work.
3: We just had a hardware RAID card mark both drives in a mirror set bad.
It wouldn't accept them back, and all the data was gone. poof. That
would never happen in Linux's kernel software RAID, I can always make
Linux take back a "bad" drive.
The only difference between RAID5 with n+1 disks and RAID0 with n disks is
that we have to write a parity stripe in RAID5. It's ability to handle
high parallel load is much better than a RAID1 set, and on average, you
actually write about the same amount with either RAID1 or RAID5.
Don't dog software RAID5, it works and it works well in Linux. Windows,
however, is another issue. There, the software RAID5 is pretty pitiful,
both in terms of performance and maintenance.
From [email protected] Fri Sep 27 15:01:43 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP id 976E6476D74
for <[email protected]>;
Fri, 27 Sep 2002 15:01:42 -0400 (EDT)
Received: from Mail.CERT.Uni-Stuttgart.DE (mail.cert.uni-stuttgart.de
[129.69.16.17]) by postgresql.org (Postfix) with ESMTP id 3F3234761C2
for <[email protected]>;
Fri, 27 Sep 2002 15:01:38 -0400 (EDT)
Received: from rusfw by Mail.CERT.Uni-Stuttgart.DE with local (Exim 4.04)
id 17v0Ms-0006Sx-00
for [email protected]; Fri, 27 Sep 2002 21:01:38 +0200
To: [email protected]
Subject: Re: [GENERAL] Performance while loading data and indexing
References: <[email protected]>
<[email protected]> <[email protected]>
Mail-Followup-To: [email protected]
From: Florian Weimer <[email protected]>
Date: Fri, 27 Sep 2002 21:01:38 +0200
In-Reply-To: <[email protected]> (Tom Lane's message of "Thu,
26 Sep 2002 17:32:01 -0400")
Message-ID: <87[email protected]>
Lines: 12
User-Agent: Gnus/5.090007 (Oort Gnus v0.07) Emacs/21.2 (i386-debian-linux-gnu)
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1630
X-Sequence-Number: 29587
Tom Lane <[email protected]> writes:
> We'd be happiest with a filesystem that journals its own metadata and
> not the user data in the file(s). I dunno if there are any.
Most journalling file systems work this way. Data journalling is not
very widespread, AFAIK.
--
Florian Weimer [email protected]
University of Stuttgart http://CERT.Uni-Stuttgart.DE/people/fw/
RUS-CERT fax +49-711-685-5898
From [email protected] Fri Sep 27 21:46:57 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP id CBFF34762B5
for <[email protected]>;
Fri, 27 Sep 2002 21:46:55 -0400 (EDT)
Received: from deborah.paradise.net.nz (deborah.paradise.net.nz
[203.96.152.32])
by postgresql.org (Postfix) with ESMTP id 107AB47626D
for <[email protected]>;
Fri, 27 Sep 2002 21:46:55 -0400 (EDT)
Received: from paradise.net.nz (203-79-74-52.adsl.paradise.net.nz
[203.79.74.52]) by deborah.paradise.net.nz (Postfix) with ESMTP
id 73EE1D1CAF; Sat, 28 Sep 2002 13:46:48 +1200 (NZST)
Message-ID: <[email protected]>
Date: Sat, 28 Sep 2002 13:38:52 +1200
From: Mark Kirkwood <[email protected]>
User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:0.9.8) Gecko/20020204
X-Accept-Language: en-us
MIME-Version: 1.0
To: "scott.marlowe" <[email protected]>
Cc: Mats Lofkvist <[email protected]>, [email protected]
Subject: Re: Performance while loading data and indexing
References: <[email protected]>
Content-Type: text/plain; charset=us-ascii; format=flowed
Content-Transfer-Encoding: 7bit
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/1319
X-Sequence-Number: 30900
scott.marlowe wrote:
>(snippage)
>I take exception to this. RAID5 is a great choice for most folks.
>
>
I agree - certainly RAID5 *used* to be rather sad, but modern cards have
improved this no end on the hardware side - e.g.
I recently benchmarked a 3Ware 8x card on a system with 4 x 15000 rpm
Maxtor 70Gb drives and achieved 120 Mb/s for (8K) reads and 60 Mb/s for
(8K) writes using RAID5. I used Redhat 7.3 + ext2. The benchmarking
program was Bonnie.
Given that the performance of a single disk was ~30 Mb/s for reads and
writes, I felt this was quite a good result ! ( Other cards I had tried
previously struggled to maintain 1/2 the write rate of a single disk in
such a configuration).
As for software RAID5, I have not tried it out.
Of course I could not get 60Mb/s while COPYing data into Postgres...
typically cpu seemed to be the bottleneck in this case (what was the
actual write rate? I hear you asking..err.. cant recall I'm afraid..
must try it out again )
cheers
Mark
From [email protected] Sat Sep 28 11:49:21 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP id 7544B475E26
for <[email protected]>;
Sat, 28 Sep 2002 11:49:20 -0400 (EDT)
Received: from kumudu.nslk.com (kumudu.nslk.com [64.247.55.254])
by postgresql.org (Postfix) with ESMTP id 01B30475E25
for <[email protected]>;
Sat, 28 Sep 2002 11:49:20 -0400 (EDT)
Received: from [203.94.93.204] (helo=W)
by kumudu.nslk.com with asmtp (Exim 3.36 #1) id 17vJqE-00034v-00
for [email protected]; Sat, 28 Sep 2002 11:49:15 -0400
Message-ID: <010801[email protected]>
Reply-To: "Waruna Geekiyanage" <[email protected]>
From: "Waruna Geekiyanage" <[email protected]>
To: <[email protected]>
Subject: INDEX
Date: Sat, 28 Sep 2002 21:50:13 +0600
MIME-Version: 1.0
Content-Type: multipart/alternative;
boundary="----=_NextPart_000_0105_01C26739.06687120"
X-Priority: 3
X-MSMail-Priority: Normal
X-Mailer: Microsoft Outlook Express 5.00.2919.6600
X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2919.6600
X-AntiAbuse: This header was added to track abuse,
please include it with any abuse report
X-AntiAbuse: Primary Hostname - kumudu.nslk.com
X-AntiAbuse: Original Domain - postgresql.org
X-AntiAbuse: Originator/Caller UID/GID - [0 0] / [0 0]
X-AntiAbuse: Sender Address Domain - nirmani.com
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/16
X-Sequence-Number: 16
This is a multi-part message in MIME format.
------=_NextPart_000_0105_01C26739.06687120
Content-Type: text/plain;
charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
When a table is created with a primary key it generates a index.
Dos the queries on that table use that index automatically?
Do I need to reindex that index after insertions?
------=_NextPart_000_0105_01C26739.06687120
Content-Type: text/html;
charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META http-equiv=3DContent-Type content=3D"text/html; charset=3Diso-8859-1">
<META content=3D"MSHTML 6.00.2479.6" name=3DGENERATOR>
<STYLE></STYLE>
</HEAD>
<BODY bgColor=3D#ffffff>
<DIV><FONT face=3DArial size=3D2>When a table is created with a primary key=
it=20
generates a index.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>Dos the queries on that table use that ind=
ex=20
automatically?</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>Do I need to reindex that index after=20
insertions?</FONT></DIV></BODY></HTML>
------=_NextPart_000_0105_01C26739.06687120--
From [email protected] Sat Sep 28 15:13:19 2002
Received: from localhost (postgresql.org [64.49.215.8])
by postgresql.org (Postfix) with ESMTP id 5E9C84762E3
for <[email protected]>;
Sat, 28 Sep 2002 15:13:18 -0400 (EDT)
Received: from mail.libertyrms.com (unknown [209.167.124.227])
by postgresql.org (Postfix) with ESMTP id B81B647612B
for <[email protected]>;
Sat, 28 Sep 2002 15:13:17 -0400 (EDT)
Received: from andrew by mail.libertyrms.com with local (Exim 3.22 #3
(Debian))
id 17vN1i-00065x-00
for <[email protected]>; Sat, 28 Sep 2002 15:13:18 -0400
Date: Sat, 28 Sep 2002 15:13:18 -0400
From: Andrew Sullivan <[email protected]>
To: [email protected]
Subject: Re: INDEX
Message-ID: <20020928151318.[email protected]>
Mail-Followup-To: [email protected]
References: <010801[email protected]>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
User-Agent: Mutt/1.2.5i
In-Reply-To: <010801[email protected]>;
from [email protected] on Sat, Sep 28, 2002 at 09:50:13PM +0600
X-Virus-Scanned: by AMaViS new-20020517
X-Archive-Number: 200209/17
X-Sequence-Number: 17
On Sat, Sep 28, 2002 at 09:50:13PM +0600, Waruna Geekiyanage wrote:
> When a table is created with a primary key it generates a index.
> Dos the queries on that table use that index automatically?
Only if you analyse the table, and it's a "win". See the various
past discussion on -general, for instance, about index use, and the
FAQ.
> Do I need to reindex that index after insertions?
No, but you need to analyse.
A
--
----
Andrew Sullivan 204-4141 Yonge Street
Liberty RMS Toronto, Ontario Canada
<[email protected]> M2P 2A8
+1 416 646 3304 x110
|