Many hyperlinks are disabled.
Use anonymous login
to enable hyperlinks.
Overview
Comment: | Improved comments on the OR-optimization logic in the query planner. |
---|---|
Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA1: |
77fef5a3987fc16f84a8e755283ca6ec |
User & Date: | drh 2014-05-27 16:41:39.846 |
Context
2014-05-27
| ||
17:57 | Avoid unnecessary cursor opens and seeks when running the OR-optimization on a WITHOUT ROWID table. (check-in: 9c785c5832 user: drh tags: trunk) | |
16:41 | Improved comments on the OR-optimization logic in the query planner. (check-in: 77fef5a398 user: drh tags: trunk) | |
15:21 | Remove unused code (previously #ifdef-ed out) from btree.c. (check-in: 8bc9737112 user: drh tags: trunk) | |
Changes
Changes to src/where.c.
︙ | ︙ | |||
3397 3398 3399 3400 3401 3402 3403 3404 3405 3406 | pAndExpr = sqlite3ExprAnd(db, pAndExpr, pExpr); } if( pAndExpr ){ pAndExpr = sqlite3PExpr(pParse, TK_AND, 0, pAndExpr, 0); } } for(ii=0; ii<pOrWc->nTerm; ii++){ WhereTerm *pOrTerm = &pOrWc->a[ii]; if( pOrTerm->leftCursor==iCur || (pOrTerm->eOperator & WO_AND)!=0 ){ | > > > > | | | > > > > > | 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 | pAndExpr = sqlite3ExprAnd(db, pAndExpr, pExpr); } if( pAndExpr ){ pAndExpr = sqlite3PExpr(pParse, TK_AND, 0, pAndExpr, 0); } } /* Run a separate WHERE clause for each term of the OR clause. After ** eliminating duplicates from other WHERE clauses, the action for each ** sub-WHERE clause is to to invoke the main loop body as a subroutine. */ for(ii=0; ii<pOrWc->nTerm; ii++){ WhereTerm *pOrTerm = &pOrWc->a[ii]; if( pOrTerm->leftCursor==iCur || (pOrTerm->eOperator & WO_AND)!=0 ){ WhereInfo *pSubWInfo; /* Info for single OR-term scan */ Expr *pOrExpr = pOrTerm->pExpr; /* Current OR clause term */ int j1 = 0; /* Address of jump operation */ if( pAndExpr && !ExprHasProperty(pOrExpr, EP_FromJoin) ){ pAndExpr->pLeft = pOrExpr; pOrExpr = pAndExpr; } /* Loop through table entries that match term pOrTerm. */ pSubWInfo = sqlite3WhereBegin(pParse, pOrTab, pOrExpr, 0, 0, WHERE_OMIT_OPEN_CLOSE | WHERE_AND_ONLY | WHERE_FORCE_TABLE | WHERE_ONETABLE_ONLY, iCovCur); assert( pSubWInfo || pParse->nErr || db->mallocFailed ); if( pSubWInfo ){ WhereLoop *pSubLoop; explainOneScan( pParse, pOrTab, &pSubWInfo->a[0], iLevel, pLevel->iFrom, 0 ); /* This is the sub-WHERE clause body. First skip over ** duplicate rows from prior sub-WHERE clauses, and record the ** rowid (or PRIMARY KEY) for the current row so that the same ** row will be skipped in subsequent sub-WHERE clauses. */ if( (pWInfo->wctrlFlags & WHERE_DUPLICATES_OK)==0 ){ int r; int iSet = ((ii==pOrWc->nTerm-1)?-1:ii); if( HasRowid(pTab) ){ r = sqlite3ExprCodeGetColumn(pParse, pTab, -1, iCur, regRowid, 0); j1 = sqlite3VdbeAddOp4Int(v, OP_RowSetTest, regRowset, 0, r,iSet); VdbeCoverage(v); |
︙ | ︙ | |||
3461 3462 3463 3464 3465 3466 3467 3468 3469 3470 3471 3472 3473 3474 3475 | if( iSet ) sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT); } /* Release the array of temp registers */ sqlite3ReleaseTempRange(pParse, r, nPk); } } sqlite3VdbeAddOp2(v, OP_Gosub, regReturn, iLoopBody); if( j1 ) sqlite3VdbeJumpHere(v, j1); /* The pSubWInfo->untestedTerms flag means that this OR term ** contained one or more AND term from a notReady table. The ** terms from the notReady table could not be tested and will ** need to be tested later. */ | > > > > > | 3470 3471 3472 3473 3474 3475 3476 3477 3478 3479 3480 3481 3482 3483 3484 3485 3486 3487 3488 3489 | if( iSet ) sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT); } /* Release the array of temp registers */ sqlite3ReleaseTempRange(pParse, r, nPk); } } /* Invoke the main loop body as a subroutine */ sqlite3VdbeAddOp2(v, OP_Gosub, regReturn, iLoopBody); /* Jump here (skipping the main loop body subroutine) if the ** current sub-WHERE row is a duplicate from prior sub-WHEREs. */ if( j1 ) sqlite3VdbeJumpHere(v, j1); /* The pSubWInfo->untestedTerms flag means that this OR term ** contained one or more AND term from a notReady table. The ** terms from the notReady table could not be tested and will ** need to be tested later. */ |
︙ | ︙ |