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Overview
Comment: | Comment and variable-name cleanup in where.c. Add testcase() macros to insure adequate test coverage of table-driven logic. (CVS 5032) |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA1: |
adcef73b3925266a14a552cd9b06c14f |
User & Date: | drh 2008-04-19 14:40:44.000 |
Context
2008-04-19
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20:34 | Continuing work on journal_mode. Journal_mode=persist now appears to be working, though additional testing would be welcomed. (CVS 5033) (check-in: 277e4099ce user: drh tags: trunk) | |
14:40 | Comment and variable-name cleanup in where.c. Add testcase() macros to insure adequate test coverage of table-driven logic. (CVS 5032) (check-in: adcef73b39 user: drh tags: trunk) | |
14:06 | Fix a typo in the documentation on sqlite3_open_v2(). (CVS 5031) (check-in: f7b62daa9f user: drh tags: trunk) | |
Changes
Changes to src/where.c.
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12 13 14 15 16 17 18 | ** This module contains C code that generates VDBE code used to process ** the WHERE clause of SQL statements. This module is reponsible for ** generating the code that loops through a table looking for applicable ** rows. Indices are selected and used to speed the search when doing ** so is applicable. Because this module is responsible for selecting ** indices, you might also think of this module as the "query optimizer". ** | | | 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 | ** This module contains C code that generates VDBE code used to process ** the WHERE clause of SQL statements. This module is reponsible for ** generating the code that loops through a table looking for applicable ** rows. Indices are selected and used to speed the search when doing ** so is applicable. Because this module is responsible for selecting ** indices, you might also think of this module as the "query optimizer". ** ** $Id: where.c,v 1.302 2008/04/19 14:40:44 drh Exp $ */ #include "sqliteInt.h" /* ** The number of bits in a Bitmask. "BMS" means "BitMask Size". */ #define BMS (sizeof(Bitmask)*8) |
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1268 1269 1270 1271 1272 1273 1274 | int nTerm; WHERETRACE(("Recomputing index info for %s...\n", pTab->zName)); /* Count the number of possible WHERE clause constraints referring ** to this virtual table */ for(i=nTerm=0, pTerm=pWC->a; i<pWC->nTerm; i++, pTerm++){ if( pTerm->leftCursor != pSrc->iCursor ) continue; | > | | > | 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 | int nTerm; WHERETRACE(("Recomputing index info for %s...\n", pTab->zName)); /* Count the number of possible WHERE clause constraints referring ** to this virtual table */ for(i=nTerm=0, pTerm=pWC->a; i<pWC->nTerm; i++, pTerm++){ if( pTerm->leftCursor != pSrc->iCursor ) continue; if( (pTerm->eOperator&(pTerm->eOperator-1))==0 ); testcase( pTerm->eOperator==WO_IN ); testcase( pTerm->eOperator==WO_ISNULL ); if( pTerm->eOperator & (WO_IN|WO_ISNULL) ) continue; nTerm++; } /* If the ORDER BY clause contains only columns in the current ** virtual table then allocate space for the aOrderBy part of ** the sqlite3_index_info structure. */ |
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1316 1317 1318 1319 1320 1321 1322 | *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint = pIdxCons; *(struct sqlite3_index_orderby**)&pIdxInfo->aOrderBy = pIdxOrderBy; *(struct sqlite3_index_constraint_usage**)&pIdxInfo->aConstraintUsage = pUsage; for(i=j=0, pTerm=pWC->a; i<pWC->nTerm; i++, pTerm++){ if( pTerm->leftCursor != pSrc->iCursor ) continue; | > | | > | 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 | *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint = pIdxCons; *(struct sqlite3_index_orderby**)&pIdxInfo->aOrderBy = pIdxOrderBy; *(struct sqlite3_index_constraint_usage**)&pIdxInfo->aConstraintUsage = pUsage; for(i=j=0, pTerm=pWC->a; i<pWC->nTerm; i++, pTerm++){ if( pTerm->leftCursor != pSrc->iCursor ) continue; if( (pTerm->eOperator&(pTerm->eOperator-1))==0 ); testcase( pTerm->eOperator==WO_IN ); testcase( pTerm->eOperator==WO_ISNULL ); if( pTerm->eOperator & (WO_IN|WO_ISNULL) ) continue; pIdxCons[j].iColumn = pTerm->leftColumn; pIdxCons[j].iTermOffset = i; pIdxCons[j].op = pTerm->eOperator; /* The direct assignment in the previous line is possible only because ** the WO_ and SQLITE_INDEX_CONSTRAINT_ codes are identical. The ** following asserts verify this fact. */ assert( WO_EQ==SQLITE_INDEX_CONSTRAINT_EQ ); |
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1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 | pTerm = findTerm(pWC, iCur, k, notReady, pLevel->flags, pIdx); if( pTerm==0 ) break; assert( (pTerm->flags & TERM_CODED)==0 ); r1 = codeEqualityTerm(pParse, pTerm, pLevel, regBase+j); if( r1!=regBase+j ){ sqlite3VdbeAddOp2(v, OP_SCopy, r1, regBase+j); } if( (pTerm->eOperator & (WO_ISNULL|WO_IN))==0 ){ sqlite3VdbeAddOp2(v, OP_IsNull, regBase+j, pLevel->brk); } } return regBase; } | > > | 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 | pTerm = findTerm(pWC, iCur, k, notReady, pLevel->flags, pIdx); if( pTerm==0 ) break; assert( (pTerm->flags & TERM_CODED)==0 ); r1 = codeEqualityTerm(pParse, pTerm, pLevel, regBase+j); if( r1!=regBase+j ){ sqlite3VdbeAddOp2(v, OP_SCopy, r1, regBase+j); } testcase( pTerm->eOperator & WO_ISNULL ); testcase( pTerm->eOperator & WO_IN ); if( (pTerm->eOperator & (WO_ISNULL|WO_IN))==0 ){ sqlite3VdbeAddOp2(v, OP_IsNull, regBase+j, pLevel->brk); } } return regBase; } |
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2452 2453 2454 2455 2456 2457 2458 | sqlite3VdbeAddOp3(v, testOp, pLevel->iMem, brk, r1); sqlite3VdbeChangeP5(v, SQLITE_AFF_NUMERIC | SQLITE_JUMPIFNULL); sqlite3ReleaseTempReg(pParse, r1); } }else if( pLevel->flags & (WHERE_COLUMN_RANGE|WHERE_COLUMN_EQ) ){ /* Case 3: A scan using an index. ** | | > | > > > > | 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 | sqlite3VdbeAddOp3(v, testOp, pLevel->iMem, brk, r1); sqlite3VdbeChangeP5(v, SQLITE_AFF_NUMERIC | SQLITE_JUMPIFNULL); sqlite3ReleaseTempReg(pParse, r1); } }else if( pLevel->flags & (WHERE_COLUMN_RANGE|WHERE_COLUMN_EQ) ){ /* Case 3: A scan using an index. ** ** The WHERE clause may contain zero or more equality ** terms ("==" or "IN" operators) that refer to the N ** left-most columns of the index. It may also contain ** inequality constraints (>, <, >= or <=) on the indexed ** column that immediately follows the N equalities. Only ** the right-most column can be an inequality - the rest must ** use the "==" and "IN" operators. For example, if the ** index is on (x,y,z), then the following clauses are all ** optimized: ** ** x=5 ** x=5 AND y=10 ** x=5 AND y<10 ** x=5 AND y>5 AND y<10 ** x=5 AND y=5 AND z<=10 ** ** The z<10 term of the following cannot be used, only ** the x=5 term: ** ** x=5 AND z<10 ** ** N may be zero if there are inequality constraints. ** If there are no inequality constraints, then N is at ** least one. ** ** This case is also used when there are no WHERE clause ** constraints but an index is selected anyway, in order ** to force the output order to conform to an ORDER BY. */ int aStartOp[] = { 0, |
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2501 2502 2503 2504 2505 2506 2507 | int r1; /* Temp register */ WhereTerm *pRangeStart = 0; /* Inequality constraint at range start */ WhereTerm *pRangeEnd = 0; /* Inequality constraint at range end */ int startEq; /* True if range start uses ==, >= or <= */ int endEq; /* True if range end uses ==, >= or <= */ int start_constraints; /* Start of range is constrained */ int k = pIdx->aiColumn[nEq]; /* Column for inequality constraints */ | | | 2512 2513 2514 2515 2516 2517 2518 2519 2520 2521 2522 2523 2524 2525 2526 | int r1; /* Temp register */ WhereTerm *pRangeStart = 0; /* Inequality constraint at range start */ WhereTerm *pRangeEnd = 0; /* Inequality constraint at range end */ int startEq; /* True if range start uses ==, >= or <= */ int endEq; /* True if range end uses ==, >= or <= */ int start_constraints; /* Start of range is constrained */ int k = pIdx->aiColumn[nEq]; /* Column for inequality constraints */ int nConstraint; /* Number of constraint terms */ int op; /* Generate code to evaluate all constraint terms using == or IN ** and store the values of those terms in an array of registers ** starting at regBase. */ regBase = codeAllEqualityTerms(pParse, pLevel, &wc, notReady, 2); |
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2541 2542 2543 2544 2545 2546 2547 | pRangeStart = findTerm(&wc, iCur, k, notReady, (WO_GT|WO_GE), pIdx); } /* If we are doing a reverse order scan on an ascending index, or ** a forward order scan on a descending index, interchange the ** start and end terms (pRangeStart and pRangeEnd). */ | | > > > > | | | | | | | > > > > > > > | > | | | > > > | > | < | > > | > > | 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 | pRangeStart = findTerm(&wc, iCur, k, notReady, (WO_GT|WO_GE), pIdx); } /* If we are doing a reverse order scan on an ascending index, or ** a forward order scan on a descending index, interchange the ** start and end terms (pRangeStart and pRangeEnd). */ if( bRev==(pIdx->aSortOrder[nEq]==SQLITE_SO_ASC) ){ SWAP(WhereTerm *, pRangeEnd, pRangeStart); } testcase( pRangeStart && pRangeStart->eOperator & WO_LE ); testcase( pRangeStart && pRangeStart->eOperator & WO_GE ); testcase( pRangeEnd && pRangeEnd->eOperator & WO_LE ); testcase( pRangeEnd && pRangeEnd->eOperator & WO_GE ); startEq = !pRangeStart || pRangeStart->eOperator & (WO_LE|WO_GE); endEq = !pRangeEnd || pRangeEnd->eOperator & (WO_LE|WO_GE); start_constraints = pRangeStart || nEq>0; /* Seek the index cursor to the start of the range. */ nConstraint = nEq; if( pRangeStart ){ int dcc = pParse->disableColCache; if( pRangeEnd ){ pParse->disableColCache = 1; } sqlite3ExprCode(pParse, pRangeStart->pExpr->pRight, regBase+nEq); pParse->disableColCache = dcc; sqlite3VdbeAddOp2(v, OP_IsNull, regBase+nEq, nxt); nConstraint++; }else if( isMinQuery ){ sqlite3VdbeAddOp2(v, OP_Null, 0, regBase+nEq); nConstraint++; startEq = 0; start_constraints = 1; } codeApplyAffinity(pParse, regBase, nConstraint, pIdx); op = aStartOp[(start_constraints<<2) + (startEq<<1) + bRev]; assert( op!=0 ); testcase( op==OP_Rewind ); testcase( op==OP_Last ); testcase( op==OP_MoveGt ); testcase( op==OP_MoveGe ); testcase( op==OP_MoveLe ); testcase( op==OP_MoveLt ); sqlite3VdbeAddOp4(v, op, iIdxCur, nxt, regBase, (char*)nConstraint, P4_INT32); /* Load the value for the inequality constraint at the end of the ** range (if any). */ nConstraint = nEq; if( pRangeEnd ){ sqlite3ExprCode(pParse, pRangeEnd->pExpr->pRight, regBase+nEq); sqlite3VdbeAddOp2(v, OP_IsNull, regBase+nEq, nxt); codeApplyAffinity(pParse, regBase, nEq+1, pIdx); nConstraint++; } /* Top of the loop body */ pLevel->p2 = sqlite3VdbeCurrentAddr(v); /* Check if the index cursor is past the end of the range. */ op = aEndOp[(pRangeEnd || nEq) * (1 + bRev)]; testcase( op==OP_Noop ); testcase( op==OP_IdxGE ); testcase( op==OP_IdxLT ); sqlite3VdbeAddOp4(v, op, iIdxCur, nxt, regBase, (char*)nConstraint, P4_INT32); sqlite3VdbeChangeP5(v, endEq!=bRev); /* If there are inequality constraints, check that the value ** of the table column that the inequality contrains is not NULL. ** If it is, jump to the next iteration of the loop. */ r1 = sqlite3GetTempReg(pParse); testcase( pLevel->flags & WHERE_BTM_LIMIT ); testcase( pLevel->flags & WHERE_TOP_LIMIT ); if( pLevel->flags & (WHERE_BTM_LIMIT|WHERE_TOP_LIMIT) ){ sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, nEq, r1); sqlite3VdbeAddOp2(v, OP_IsNull, r1, cont); } /* Seek the table cursor, if required */ if( !omitTable ){ sqlite3VdbeAddOp2(v, OP_IdxRowid, iIdxCur, r1); sqlite3VdbeAddOp3(v, OP_MoveGe, iCur, 0, r1); /* Deferred seek */ } sqlite3ReleaseTempReg(pParse, r1); /* Record the instruction used to terminate the loop. Disable ** WHERE clause terms made redundant by the index range scan. */ pLevel->op = bRev ? OP_Prev : OP_Next; pLevel->p1 = iIdxCur; disableTerm(pLevel, pRangeStart); disableTerm(pLevel, pRangeEnd); }else{ /* Case 4: There is no usable index. We must do a complete ** scan of the entire table. */ assert( omitTable==0 ); assert( bRev==0 ); pLevel->op = OP_Next; pLevel->p1 = iCur; pLevel->p2 = 1 + sqlite3VdbeAddOp2(v, OP_Rewind, iCur, brk); } notReady &= ~getMask(&maskSet, iCur); /* Insert code to test every subexpression that can be completely ** computed using the current set of tables. */ for(pTerm=wc.a, j=wc.nTerm; j>0; j--, pTerm++){ Expr *pE; testcase( pTerm->flags & TERM_VIRTUAL ); testcase( pTerm->flags & TERM_CODED ); if( pTerm->flags & (TERM_VIRTUAL|TERM_CODED) ) continue; if( (pTerm->prereqAll & notReady)!=0 ) continue; pE = pTerm->pExpr; assert( pE!=0 ); if( pLevel->iLeftJoin && !ExprHasProperty(pE, EP_FromJoin) ){ continue; } |
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2652 2653 2654 2655 2656 2657 2658 2659 2660 2661 2662 2663 2664 2665 | if( pLevel->iLeftJoin ){ pLevel->top = sqlite3VdbeCurrentAddr(v); sqlite3VdbeAddOp2(v, OP_Integer, 1, pLevel->iLeftJoin); VdbeComment((v, "record LEFT JOIN hit")); sqlite3ExprClearColumnCache(pParse, pLevel->iTabCur); sqlite3ExprClearColumnCache(pParse, pLevel->iIdxCur); for(pTerm=wc.a, j=0; j<wc.nTerm; j++, pTerm++){ if( pTerm->flags & (TERM_VIRTUAL|TERM_CODED) ) continue; if( (pTerm->prereqAll & notReady)!=0 ) continue; assert( pTerm->pExpr ); sqlite3ExprIfFalse(pParse, pTerm->pExpr, cont, SQLITE_JUMPIFNULL); pTerm->flags |= TERM_CODED; } } | > > | 2682 2683 2684 2685 2686 2687 2688 2689 2690 2691 2692 2693 2694 2695 2696 2697 | if( pLevel->iLeftJoin ){ pLevel->top = sqlite3VdbeCurrentAddr(v); sqlite3VdbeAddOp2(v, OP_Integer, 1, pLevel->iLeftJoin); VdbeComment((v, "record LEFT JOIN hit")); sqlite3ExprClearColumnCache(pParse, pLevel->iTabCur); sqlite3ExprClearColumnCache(pParse, pLevel->iIdxCur); for(pTerm=wc.a, j=0; j<wc.nTerm; j++, pTerm++){ testcase( pTerm->flags & TERM_VIRTUAL ); testcase( pTerm->flags & TERM_CODED ); if( pTerm->flags & (TERM_VIRTUAL|TERM_CODED) ) continue; if( (pTerm->prereqAll & notReady)!=0 ) continue; assert( pTerm->pExpr ); sqlite3ExprIfFalse(pParse, pTerm->pExpr, cont, SQLITE_JUMPIFNULL); pTerm->flags |= TERM_CODED; } } |
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2686 2687 2688 2689 2690 2691 2692 2693 2694 2695 2696 2697 2698 2699 | nQPlan += 2; }else{ memcpy(&sqlite3_query_plan[nQPlan], z, n); nQPlan += n; } sqlite3_query_plan[nQPlan++] = ' '; } if( pLevel->flags & (WHERE_ROWID_EQ|WHERE_ROWID_RANGE) ){ memcpy(&sqlite3_query_plan[nQPlan], "* ", 2); nQPlan += 2; }else if( pLevel->pIdx==0 ){ memcpy(&sqlite3_query_plan[nQPlan], "{} ", 3); nQPlan += 3; }else{ | > > | 2718 2719 2720 2721 2722 2723 2724 2725 2726 2727 2728 2729 2730 2731 2732 2733 | nQPlan += 2; }else{ memcpy(&sqlite3_query_plan[nQPlan], z, n); nQPlan += n; } sqlite3_query_plan[nQPlan++] = ' '; } testcase( pLevel->flags & WHERE_ROWID_EQ ); testcase( pLevel->flags & WHERE_ROWID_RANGE ); if( pLevel->flags & (WHERE_ROWID_EQ|WHERE_ROWID_RANGE) ){ memcpy(&sqlite3_query_plan[nQPlan], "* ", 2); nQPlan += 2; }else if( pLevel->pIdx==0 ){ memcpy(&sqlite3_query_plan[nQPlan], "{} ", 3); nQPlan += 3; }else{ |
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