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Overview
Comment: | Add an option to generate stat1 data based on a subset of the user database table contents to sqlite3_expert. |
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Timelines: | family | ancestors | descendants | both | schemalint |
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SHA3-256: |
c69c3e21db6e141f7e24226c6432f2ed |
User & Date: | dan 2017-04-20 09:54:04.700 |
Context
2017-04-20
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16:18 | Avoid adding INTEGER PRIMARY KEY columns to candidate indexes. (check-in: 4577fea5cd user: dan tags: schemalint) | |
16:08 | Avoid creating a temp table in the user database in the sqlite3_expert code. Trouble is, this makes sampling for stat1 data much slower. (check-in: c62e358243 user: dan tags: schemalint-failure) | |
09:54 | Add an option to generate stat1 data based on a subset of the user database table contents to sqlite3_expert. (check-in: c69c3e21db user: dan tags: schemalint) | |
2017-04-18
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20:10 | Have sqlite3_expert_analyze() populate the sqlite_stat1 table before running queries through the planner for the second time. (check-in: a157fcfde5 user: dan tags: schemalint) | |
Changes
Changes to ext/expert/expert.c.
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32 33 34 35 36 37 38 39 40 41 42 43 44 45 | 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 | + | fprintf(stderr, "\n"); fprintf(stderr, "Usage %s ?OPTIONS? DATABASE\n", argv[0]); fprintf(stderr, "\n"); fprintf(stderr, "Options are:\n"); fprintf(stderr, " -sql SQL (analyze SQL statements passed as argument)\n"); fprintf(stderr, " -file FILE (read SQL statements from file FILE)\n"); fprintf(stderr, " -verbose LEVEL (integer verbosity level. default 1)\n"); fprintf(stderr, " -sample PERCENT (percent of db to sample. default 100)\n"); exit(-1); } static int readSqlFromFile(sqlite3expert *p, const char *zFile, char **pzErr){ FILE *in = fopen(zFile, "rb"); long nIn; size_t nRead; |
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93 94 95 96 97 98 99 | 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 | - + + + + + + + + | char *zArg = argv[i]; int nArg = strlen(zArg); if( nArg>=2 && 0==sqlite3_strnicmp(zArg, "-file", nArg) ){ if( ++i==(argc-1) ) option_requires_argument("-file"); rc = readSqlFromFile(p, argv[i], &zErr); } |
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Changes to ext/expert/sqlite3expert.c.
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23 24 25 26 27 28 29 30 31 32 33 34 35 36 | 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 | + + + | typedef struct IdxColumn IdxColumn; typedef struct IdxConstraint IdxConstraint; typedef struct IdxScan IdxScan; typedef struct IdxStatement IdxStatement; typedef struct IdxTable IdxTable; typedef struct IdxWrite IdxWrite; #define UNIQUE_TABLE_NAME "t592690916721053953805701627921227776" /* ** A single constraint. Equivalent to either "col = ?" or "col < ?" (or ** any other type of single-ended range constraint on a column). ** ** pLink: ** Used to temporarily link IdxConstraint objects into lists while |
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123 124 125 126 127 128 129 130 131 132 133 134 135 136 | 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 | + | IdxHashEntry *aHash[IDX_HASH_SIZE]; }; /* ** sqlite3expert object. */ struct sqlite3expert { int iSample; /* Percentage of tables to sample for stat1 */ sqlite3 *db; /* User database */ sqlite3 *dbm; /* In-memory db for this analysis */ sqlite3 *dbv; /* Vtab schema for this analysis */ IdxTable *pTable; /* List of all IdxTable objects */ IdxScan *pScan; /* List of scan objects */ IdxWrite *pWrite; /* List of write objects */ IdxStatement *pStatement; /* List of IdxStatement objects */ |
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1076 1077 1078 1079 1080 1081 1082 | 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 | - - + + | } static int idxProcessOneTrigger( sqlite3expert *p, IdxWrite *pWrite, char **pzErr ){ |
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1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 | 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 | + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + | sqlite3_free(zOuter); } } } idxFinalize(&rc, pSchema); return rc; } struct IdxSampleCtx { int iTarget; double target; /* Target nRet/nRow value */ double nRow; /* Number of rows seen */ double nRet; /* Number of rows returned */ }; static void idxSampleFunc( sqlite3_context *pCtx, int argc, sqlite3_value **argv ){ struct IdxSampleCtx *p = (struct IdxSampleCtx*)sqlite3_user_data(pCtx); int bRet; assert( argc==0 ); if( p->nRow==0.0 ){ bRet = 1; }else{ bRet = (p->nRet / p->nRow) <= p->target; if( bRet==0 ){ unsigned short rnd; sqlite3_randomness(2, (void*)&rnd); bRet = ((int)rnd % 100) <= p->iTarget; } } sqlite3_result_int(pCtx, bRet); p->nRow += 1.0; p->nRet += (double)bRet; } struct IdxRemCtx { int nSlot; struct IdxRemSlot { int eType; /* SQLITE_NULL, INTEGER, REAL, TEXT, BLOB */ i64 iVal; /* SQLITE_INTEGER value */ double rVal; /* SQLITE_FLOAT value */ |
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1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 | 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 | + + + - - - + + + + + + + + | char *zOrder = 0; char *zQuery = 0; int nCol = 0; int i; sqlite3_stmt *pQuery = 0; int *aStat = 0; int rc = SQLITE_OK; assert( p->iSample>0 ); /* Formulate the query text */ sqlite3_bind_text(pIndexXInfo, 1, zIdx, -1, SQLITE_STATIC); while( SQLITE_OK==rc && SQLITE_ROW==sqlite3_step(pIndexXInfo) ){ const char *zComma = zCols==0 ? "" : ", "; const char *zName = (const char*)sqlite3_column_text(pIndexXInfo, 0); const char *zColl = (const char*)sqlite3_column_text(pIndexXInfo, 1); zCols = idxAppendText(&rc, zCols, "%sx.%Q IS rem(%d, x.%Q) COLLATE %s", zComma, zName, nCol, zName, zColl ); zOrder = idxAppendText(&rc, zOrder, "%s%d", zComma, ++nCol); } if( rc==SQLITE_OK ){ if( p->iSample==100 ){ |
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1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 | 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 | + + + + + + + + + + + + + + + + + + + + + - - + + + + + + + + + + + - - + + + + + + + + + + + + + + + + + + + | } } sqlite3_free(aStat); idxFinalize(&rc, pQuery); return rc; } static int idxBuildSampleTable(sqlite3expert *p, const char *zTab){ int rc; char *zSql; rc = sqlite3_exec(p->db, "DROP TABLE IF EXISTS temp."UNIQUE_TABLE_NAME,0,0,0); if( rc!=SQLITE_OK ) return rc; zSql = sqlite3_mprintf( "CREATE TABLE temp." UNIQUE_TABLE_NAME " AS SELECT * FROM %Q WHERE sample()" , zTab ); if( zSql==0 ) return SQLITE_NOMEM; rc = sqlite3_exec(p->db, zSql, 0, 0, 0); sqlite3_free(zSql); return rc; } /* ** This function is called as part of sqlite3_expert_analyze(). Candidate ** indexes have already been created in database sqlite3expert.dbm, this ** function populates sqlite_stat1 table in the same database. ** ** The stat1 data is generated by querying the */ static int idxPopulateStat1(sqlite3expert *p, char **pzErr){ int rc = SQLITE_OK; int nMax =0; struct IdxRemCtx *pCtx = 0; struct IdxSampleCtx samplectx; int i; i64 iPrev = -100000; sqlite3_stmt *pAllIndex = 0; sqlite3_stmt *pIndexXInfo = 0; sqlite3_stmt *pWrite = 0; |
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1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 | 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 | + + + + + + + + + + + + + + + + + + + + + + + + | ** return the new sqlite3expert handle. */ if( rc!=SQLITE_OK ){ sqlite3_expert_destroy(pNew); pNew = 0; } return pNew; } /* ** Configure an sqlite3expert object. */ int sqlite3_expert_config(sqlite3expert *p, int op, ...){ int rc = SQLITE_OK; va_list ap; va_start(ap, op); switch( op ){ case EXPERT_CONFIG_SAMPLE: { int iVal = va_arg(ap, int); if( iVal<0 ) iVal = 0; if( iVal>100 ) iVal = 100; p->iSample = iVal; break; } default: rc = SQLITE_NOTFOUND; break; } va_end(ap); return rc; } /* ** Add an SQL statement to the analysis. */ int sqlite3_expert_sql( sqlite3expert *p, /* From sqlite3_expert_new() */ const char *zSql, /* SQL statement to add */ |
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Changes to ext/expert/sqlite3expert.h.
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23 24 25 26 27 28 29 30 31 32 33 34 35 36 | 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 | + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + | ** to NULL. Or, if an error occurs, NULL is returned and (*pzErr) set to ** an English-language error message. In this case it is the responsibility ** of the caller to eventually free the error message buffer using ** sqlite3_free(). */ sqlite3expert *sqlite3_expert_new(sqlite3 *db, char **pzErr); /* ** Configure an sqlite3expert object. ** ** EXPERT_CONFIG_SAMPLE: ** By default, sqlite3_expert_analyze() generates sqlite_stat1 data for ** each candidate index. This involves scanning and sorting the entire ** contents of each user database table once for each candidate index ** associated with the table. For large databases, this can be ** prohibitively slow. This option allows the sqlite3expert object to ** be configured so that sqlite_stat1 data is instead generated based on a ** subset of each table, or so that no sqlite_stat1 data is used at all. ** ** A single integer argument is passed to this option. If the value is less ** than or equal to zero, then no sqlite_stat1 data is generated or used by ** the analysis - indexes are recommended based on the database schema only. ** Or, if the value is 100 or greater, complete sqlite_stat1 data is ** generated for each candidate index (this is the default). Finally, if the ** value falls between 0 and 100, then it represents the percentage of user ** table rows that should be considered when generating sqlite_stat1 data. ** ** Examples: ** ** // Do not generate any sqlite_stat1 data ** sqlite3_expert_config(pExpert, EXPERT_CONFIG_SAMPLE, 0); ** ** // Generate sqlite_stat1 data based on 10% of the rows in each table. ** sqlite3_expert_config(pExpert, EXPERT_CONFIG_SAMPLE, 10); */ int sqlite3_expert_config(sqlite3expert *p, int op, ...); #define EXPERT_CONFIG_SAMPLE 1 /* int */ /* ** Specify zero or more SQL statements to be included in the analysis. ** ** Buffer zSql must contain zero or more complete SQL statements. This ** function parses all statements contained in the buffer and adds them ** to the internal list of statements to analyze. If successful, SQLITE_OK ** is returned and (*pzErr) set to NULL. Or, if an error occurs - for example |
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49 50 51 52 53 54 55 56 57 58 59 60 61 62 | 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 | + | ** immediately and no statements are added to the analysis. */ int sqlite3_expert_sql( sqlite3expert *p, /* From a successful sqlite3_expert_new() */ const char *zSql, /* SQL statement(s) to add */ char **pzErr /* OUT: Error message (if any) */ ); /* ** This function is called after the sqlite3expert object has been configured ** with all SQL statements using sqlite3_expert_sql() to actually perform ** the analysis. Once this function has been called, it is not possible to ** add further SQL statements to the analysis. ** |
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