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Overview
Comment: | Reduce the size of the stack required by the codeOneLoopStart() function in where.c. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA1: |
eb6d4278b8516e0571269049d1eaa550 |
User & Date: | drh 2013-07-30 15:10:32.747 |
Context
2013-07-31
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19:55 | The MAX_PATH constant in windows is measured in characters, so multiple by 3 to get the number of bytes assuming worst-case UTF8 pathnames. (check-in: bb06e15790 user: drh tags: trunk) | |
18:12 | Here begins an experimental branch for exploring the idea of a partial index. This check-in is able to parse a WHERE clause on a CREATE INDEX statement, but does not actually do anythingn with that WHERE clause yet. (check-in: 6794b2dcb4 user: drh tags: partial-indices) | |
2013-07-30
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15:10 | Reduce the size of the stack required by the codeOneLoopStart() function in where.c. (check-in: eb6d4278b8 user: drh tags: trunk) | |
2013-07-29
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19:03 | For the MSVC makefile, recompile vdbe.lo and parse.lo first. (check-in: 9e819f0f12 user: mistachkin tags: trunk) | |
Changes
Changes to src/where.c.
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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 | int omitTable; /* True if we use the index only */ int bRev; /* True if we need to scan in reverse order */ WhereLevel *pLevel; /* The where level to be coded */ WhereLoop *pLoop; /* The WhereLoop object being coded */ WhereClause *pWC; /* Decomposition of the entire WHERE clause */ WhereTerm *pTerm; /* A WHERE clause term */ Parse *pParse; /* Parsing context */ Vdbe *v; /* The prepared stmt under constructions */ struct SrcList_item *pTabItem; /* FROM clause term being coded */ int addrBrk; /* Jump here to break out of the loop */ int addrCont; /* Jump here to continue with next cycle */ int iRowidReg = 0; /* Rowid is stored in this register, if not zero */ int iReleaseReg = 0; /* Temp register to free before returning */ Bitmask newNotReady; /* Return value */ pParse = pWInfo->pParse; v = pParse->pVdbe; pWC = &pWInfo->sWC; pLevel = &pWInfo->a[iLevel]; pLoop = pLevel->pWLoop; pTabItem = &pWInfo->pTabList->a[pLevel->iFrom]; iCur = pTabItem->iCursor; bRev = (pWInfo->revMask>>iLevel)&1; omitTable = (pLoop->wsFlags & WHERE_IDX_ONLY)!=0 && (pWInfo->wctrlFlags & WHERE_FORCE_TABLE)==0; | > > | 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 | int omitTable; /* True if we use the index only */ int bRev; /* True if we need to scan in reverse order */ WhereLevel *pLevel; /* The where level to be coded */ WhereLoop *pLoop; /* The WhereLoop object being coded */ WhereClause *pWC; /* Decomposition of the entire WHERE clause */ WhereTerm *pTerm; /* A WHERE clause term */ Parse *pParse; /* Parsing context */ sqlite3 *db; /* Database connection */ Vdbe *v; /* The prepared stmt under constructions */ struct SrcList_item *pTabItem; /* FROM clause term being coded */ int addrBrk; /* Jump here to break out of the loop */ int addrCont; /* Jump here to continue with next cycle */ int iRowidReg = 0; /* Rowid is stored in this register, if not zero */ int iReleaseReg = 0; /* Temp register to free before returning */ Bitmask newNotReady; /* Return value */ pParse = pWInfo->pParse; v = pParse->pVdbe; pWC = &pWInfo->sWC; db = pParse->db; pLevel = &pWInfo->a[iLevel]; pLoop = pLevel->pWLoop; pTabItem = &pWInfo->pTabList->a[pLevel->iFrom]; iCur = pTabItem->iCursor; bRev = (pWInfo->revMask>>iLevel)&1; omitTable = (pLoop->wsFlags & WHERE_IDX_ONLY)!=0 && (pWInfo->wctrlFlags & WHERE_FORCE_TABLE)==0; |
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3547 3548 3549 3550 3551 3552 3553 | } /* 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,bRev,nExtraReg,&zStartAff); | | | 3549 3550 3551 3552 3553 3554 3555 3556 3557 3558 3559 3560 3561 3562 3563 | } /* 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,bRev,nExtraReg,&zStartAff); zEndAff = sqlite3DbStrDup(db, zStartAff); addrNxt = pLevel->addrNxt; /* 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( (nEq<pIdx->nColumn && bRev==(pIdx->aSortOrder[nEq]==SQLITE_SO_ASC)) |
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3632 3633 3634 3635 3636 3637 3638 | zEndAff[nEq] = SQLITE_AFF_NONE; } } codeApplyAffinity(pParse, regBase, nEq+1, zEndAff); nConstraint++; testcase( pRangeEnd->wtFlags & TERM_VIRTUAL ); /* EV: R-30575-11662 */ } | | | | 3634 3635 3636 3637 3638 3639 3640 3641 3642 3643 3644 3645 3646 3647 3648 3649 | zEndAff[nEq] = SQLITE_AFF_NONE; } } codeApplyAffinity(pParse, regBase, nEq+1, zEndAff); nConstraint++; testcase( pRangeEnd->wtFlags & TERM_VIRTUAL ); /* EV: R-30575-11662 */ } sqlite3DbFree(db, zStartAff); sqlite3DbFree(db, zEndAff); /* 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 ); |
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3760 3761 3762 3763 3764 3765 3766 | ** by this loop in the a[0] slot and all notReady tables in a[1..] slots. ** This becomes the SrcList in the recursive call to sqlite3WhereBegin(). */ if( pWInfo->nLevel>1 ){ int nNotReady; /* The number of notReady tables */ struct SrcList_item *origSrc; /* Original list of tables */ nNotReady = pWInfo->nLevel - iLevel - 1; | | | 3762 3763 3764 3765 3766 3767 3768 3769 3770 3771 3772 3773 3774 3775 3776 | ** by this loop in the a[0] slot and all notReady tables in a[1..] slots. ** This becomes the SrcList in the recursive call to sqlite3WhereBegin(). */ if( pWInfo->nLevel>1 ){ int nNotReady; /* The number of notReady tables */ struct SrcList_item *origSrc; /* Original list of tables */ nNotReady = pWInfo->nLevel - iLevel - 1; pOrTab = sqlite3StackAllocRaw(db, sizeof(*pOrTab)+ nNotReady*sizeof(pOrTab->a[0])); if( pOrTab==0 ) return notReady; pOrTab->nAlloc = (u8)(nNotReady + 1); pOrTab->nSrc = pOrTab->nAlloc; memcpy(pOrTab->a, pTabItem, sizeof(*pTabItem)); origSrc = pWInfo->pTabList->a; for(k=1; k<=nNotReady; k++){ |
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3814 3815 3816 3817 3818 3819 3820 | int iTerm; for(iTerm=0; iTerm<pWC->nTerm; iTerm++){ Expr *pExpr = pWC->a[iTerm].pExpr; if( &pWC->a[iTerm] == pTerm ) continue; if( ExprHasProperty(pExpr, EP_FromJoin) ) continue; if( pWC->a[iTerm].wtFlags & (TERM_ORINFO) ) continue; if( (pWC->a[iTerm].eOperator & WO_ALL)==0 ) continue; | | | | | 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 | int iTerm; for(iTerm=0; iTerm<pWC->nTerm; iTerm++){ Expr *pExpr = pWC->a[iTerm].pExpr; if( &pWC->a[iTerm] == pTerm ) continue; if( ExprHasProperty(pExpr, EP_FromJoin) ) continue; if( pWC->a[iTerm].wtFlags & (TERM_ORINFO) ) continue; if( (pWC->a[iTerm].eOperator & WO_ALL)==0 ) continue; pExpr = sqlite3ExprDup(db, pExpr, 0); 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 ){ WhereInfo *pSubWInfo; /* Info for single OR-term scan */ Expr *pOrExpr = pOrTerm->pExpr; 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 ); if( (pWInfo->wctrlFlags & WHERE_DUPLICATES_OK)==0 ){ int iSet = ((ii==pOrWc->nTerm-1)?-1:ii); |
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3890 3891 3892 3893 3894 3895 3896 | } } } pLevel->u.pCovidx = pCov; if( pCov ) pLevel->iIdxCur = iCovCur; if( pAndExpr ){ pAndExpr->pLeft = 0; | | | | 3892 3893 3894 3895 3896 3897 3898 3899 3900 3901 3902 3903 3904 3905 3906 3907 3908 3909 3910 3911 3912 | } } } pLevel->u.pCovidx = pCov; if( pCov ) pLevel->iIdxCur = iCovCur; if( pAndExpr ){ pAndExpr->pLeft = 0; sqlite3ExprDelete(db, pAndExpr); } sqlite3VdbeChangeP1(v, iRetInit, sqlite3VdbeCurrentAddr(v)); sqlite3VdbeAddOp2(v, OP_Goto, 0, pLevel->addrBrk); sqlite3VdbeResolveLabel(v, iLoopBody); if( pWInfo->nLevel>1 ) sqlite3StackFree(db, pOrTab); if( !untestedTerms ) disableTerm(pLevel, pTerm); }else #endif /* SQLITE_OMIT_OR_OPTIMIZATION */ { /* Case 6: There is no usable index. We must do a complete ** scan of the entire table. |
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3951 3952 3953 3954 3955 3956 3957 | ** ** Example: If the WHERE clause contains "t1.a=t2.b" and "t2.b=123" ** and we are coding the t1 loop and the t2 loop has not yet coded, ** then we cannot use the "t1.a=t2.b" constraint, but we can code ** the implied "t1.a=123" constraint. */ for(pTerm=pWC->a, j=pWC->nTerm; j>0; j--, pTerm++){ | | < > > | | | > > | 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 | ** ** Example: If the WHERE clause contains "t1.a=t2.b" and "t2.b=123" ** and we are coding the t1 loop and the t2 loop has not yet coded, ** then we cannot use the "t1.a=t2.b" constraint, but we can code ** the implied "t1.a=123" constraint. */ for(pTerm=pWC->a, j=pWC->nTerm; j>0; j--, pTerm++){ Expr *pE, *pEAlt; WhereTerm *pAlt; if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue; if( pTerm->eOperator!=(WO_EQUIV|WO_EQ) ) continue; if( pTerm->leftCursor!=iCur ) continue; if( pLevel->iLeftJoin ) continue; pE = pTerm->pExpr; assert( !ExprHasProperty(pE, EP_FromJoin) ); assert( (pTerm->prereqRight & newNotReady)!=0 ); pAlt = findTerm(pWC, iCur, pTerm->u.leftColumn, notReady, WO_EQ|WO_IN, 0); if( pAlt==0 ) continue; if( pAlt->wtFlags & (TERM_CODED) ) continue; testcase( pAlt->eOperator & WO_EQ ); testcase( pAlt->eOperator & WO_IN ); VdbeNoopComment((v, "begin transitive constraint")); pEAlt = sqlite3StackAllocRaw(db, sizeof(*pEAlt)); if( pEAlt ){ *pEAlt = *pAlt->pExpr; pEAlt->pLeft = pE->pLeft; sqlite3ExprIfFalse(pParse, pEAlt, addrCont, SQLITE_JUMPIFNULL); sqlite3StackFree(db, pEAlt); } } /* For a LEFT OUTER JOIN, generate code that will record the fact that ** at least one row of the right table has matched the left table. */ if( pLevel->iLeftJoin ){ pLevel->addrFirst = sqlite3VdbeCurrentAddr(v); |
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