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Overview
Comment: | Instead of having the planner ignore plans with unusable MATCH constraints, have FTS assign extremely high costs to such plans in order to discourage the planner from using them. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | avoid-unusable-match |
Files: | files | file ages | folders |
SHA1: |
24f84b38131866f7b435ffe641bb2f69 |
User & Date: | dan 2014-01-04 14:42:14.057 |
Context
2014-01-04
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14:46 | Have FTS assign extremely high costs to plans that feature unusable MATCH constraints. This discourages the planner from choosing such plans, which lead to "unable to use function MATCH in the requested context" errors. (check-in: fa8be488a3 user: dan tags: trunk) | |
14:42 | Instead of having the planner ignore plans with unusable MATCH constraints, have FTS assign extremely high costs to such plans in order to discourage the planner from using them. (Closed-Leaf check-in: 24f84b3813 user: dan tags: avoid-unusable-match) | |
14:16 | Have the planner detect cases where a MATCH constraint is applied to a virtual table, and ignore any plans that do not allow the virtual table implementation to implement the MATCH filtering. (check-in: 19f3208b26 user: dan tags: avoid-unusable-match) | |
Changes
Changes to ext/fts3/fts3.c.
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1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 | int argc, /* Number of elements in argv array */ const char * const *argv, /* xCreate/xConnect argument array */ sqlite3_vtab **ppVtab, /* OUT: New sqlite3_vtab object */ char **pzErr /* OUT: sqlite3_malloc'd error message */ ){ return fts3InitVtab(1, db, pAux, argc, argv, ppVtab, pzErr); } /* ** Implementation of the xBestIndex method for FTS3 tables. There ** are three possible strategies, in order of preference: ** ** 1. Direct lookup by rowid or docid. ** 2. Full-text search using a MATCH operator on a non-docid column. | > > > > > > > > > > > > > | 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 | int argc, /* Number of elements in argv array */ const char * const *argv, /* xCreate/xConnect argument array */ sqlite3_vtab **ppVtab, /* OUT: New sqlite3_vtab object */ char **pzErr /* OUT: sqlite3_malloc'd error message */ ){ return fts3InitVtab(1, db, pAux, argc, argv, ppVtab, pzErr); } /* ** Set the pIdxInfo->estimatedRows variable to nRow. Unless this ** extension is currently being used by a version of SQLite too old to ** support estimatedRows. In that case this function is a no-op. */ static void setEstimatedRows(sqlite3_index_info *pIdxInfo, i64 nRow){ #if SQLITE_VERSION_NUMBER>=3008002 if( sqlite3_libversion_number()>=3008002 ){ pIdxInfo->estimatedRows = nRow; } #endif } /* ** Implementation of the xBestIndex method for FTS3 tables. There ** are three possible strategies, in order of preference: ** ** 1. Direct lookup by rowid or docid. ** 2. Full-text search using a MATCH operator on a non-docid column. |
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1495 1496 1497 1498 1499 1500 1501 | ** strategy is possible. */ pInfo->idxNum = FTS3_FULLSCAN_SEARCH; pInfo->estimatedCost = 5000000; for(i=0; i<pInfo->nConstraint; i++){ int bDocid; /* True if this constraint is on docid */ struct sqlite3_index_constraint *pCons = &pInfo->aConstraint[i]; | | > > > > > > > > > > > > > | 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 | ** strategy is possible. */ pInfo->idxNum = FTS3_FULLSCAN_SEARCH; pInfo->estimatedCost = 5000000; for(i=0; i<pInfo->nConstraint; i++){ int bDocid; /* True if this constraint is on docid */ struct sqlite3_index_constraint *pCons = &pInfo->aConstraint[i]; if( pCons->usable==0 ){ if( pCons->op==SQLITE_INDEX_CONSTRAINT_MATCH ){ /* There exists an unusable MATCH constraint. This means that if ** the planner does elect to use the results of this call as part ** of the overall query plan the user will see an "unable to use ** function MATCH in the requested context" error. To discourage ** this, return a very high cost here. */ pInfo->idxNum = FTS3_FULLSCAN_SEARCH; pInfo->estimatedCost = 1e50; setEstimatedRows(pInfo, ((sqlite3_int64)1) << 50); return SQLITE_OK; } continue; } bDocid = (pCons->iColumn<0 || pCons->iColumn==p->nColumn+1); /* A direct lookup on the rowid or docid column. Assign a cost of 1.0. */ if( iCons<0 && pCons->op==SQLITE_INDEX_CONSTRAINT_EQ && bDocid ){ pInfo->idxNum = FTS3_DOCID_SEARCH; pInfo->estimatedCost = 1.0; |
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Changes to src/where.c.
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4334 4335 4336 4337 4338 4339 4340 | struct sqlite3_index_constraint_usage *pUsage; WhereTerm *pTerm; int i, j; int iTerm, mxTerm; int nConstraint; int seenIn = 0; /* True if an IN operator is seen */ int seenVar = 0; /* True if a non-constant constraint is seen */ | < | 4334 4335 4336 4337 4338 4339 4340 4341 4342 4343 4344 4345 4346 4347 | struct sqlite3_index_constraint_usage *pUsage; WhereTerm *pTerm; int i, j; int iTerm, mxTerm; int nConstraint; int seenIn = 0; /* True if an IN operator is seen */ int seenVar = 0; /* True if a non-constant constraint is seen */ int iPhase; /* 0: const w/o IN, 1: const, 2: no IN, 2: IN */ WhereLoop *pNew; int rc = SQLITE_OK; pWInfo = pBuilder->pWInfo; pParse = pWInfo->pParse; db = pParse->db; |
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4379 4380 4381 4382 4383 4384 4385 | case 0: /* Constants without IN operator */ pIdxCons->usable = 0; if( (pTerm->eOperator & WO_IN)!=0 ){ seenIn = 1; } if( pTerm->prereqRight!=0 ){ seenVar = 1; | < < < < | 4378 4379 4380 4381 4382 4383 4384 4385 4386 4387 4388 4389 4390 4391 4392 4393 4394 4395 4396 4397 4398 4399 4400 4401 4402 4403 4404 4405 4406 4407 4408 4409 | case 0: /* Constants without IN operator */ pIdxCons->usable = 0; if( (pTerm->eOperator & WO_IN)!=0 ){ seenIn = 1; } if( pTerm->prereqRight!=0 ){ seenVar = 1; }else if( (pTerm->eOperator & WO_IN)==0 ){ pIdxCons->usable = 1; } break; case 1: /* Constants with IN operators */ assert( seenIn ); pIdxCons->usable = (pTerm->prereqRight==0); break; case 2: /* Variables without IN */ assert( seenVar ); pIdxCons->usable = (pTerm->eOperator & WO_IN)==0; break; default: /* Variables with IN */ assert( seenVar && seenIn ); pIdxCons->usable = 1; break; } } memset(pUsage, 0, sizeof(pUsage[0])*pIdxInfo->nConstraint); if( pIdxInfo->needToFreeIdxStr ) sqlite3_free(pIdxInfo->idxStr); pIdxInfo->idxStr = 0; pIdxInfo->idxNum = 0; pIdxInfo->needToFreeIdxStr = 0; pIdxInfo->orderByConsumed = 0; pIdxInfo->estimatedCost = SQLITE_BIG_DBL / (double)2; |
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Changes to test/fts3join.test.
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55 56 57 58 59 60 61 | do_execsql_test 2.1 { SELECT * FROM ft2, ft3 WHERE x MATCH y; } {abc abc} do_execsql_test 2.2 { SELECT * FROM ft2, ft3 WHERE y MATCH x; } {abc abc} do_execsql_test 2.3 { SELECT * FROM ft3, ft2 WHERE x MATCH y; } {abc abc} do_execsql_test 2.4 { SELECT * FROM ft3, ft2 WHERE y MATCH x; } {abc abc} do_catchsql_test 2.5 { SELECT * FROM ft3, ft2 WHERE y MATCH x AND x MATCH y; | | | 55 56 57 58 59 60 61 62 63 64 65 66 | do_execsql_test 2.1 { SELECT * FROM ft2, ft3 WHERE x MATCH y; } {abc abc} do_execsql_test 2.2 { SELECT * FROM ft2, ft3 WHERE y MATCH x; } {abc abc} do_execsql_test 2.3 { SELECT * FROM ft3, ft2 WHERE x MATCH y; } {abc abc} do_execsql_test 2.4 { SELECT * FROM ft3, ft2 WHERE y MATCH x; } {abc abc} do_catchsql_test 2.5 { SELECT * FROM ft3, ft2 WHERE y MATCH x AND x MATCH y; } {1 {unable to use function MATCH in the requested context}} finish_test |