From 487e15dc239ccdb3344d1c99ce120e872bab4a74 Mon Sep 17 00:00:00 2001 From: Hans-Christoph Steiner Date: Thu, 20 Sep 2012 18:34:38 -0400 Subject: Imported Upstream version 2.0.6 --- src/where.c | 125 +++++++++++++++++++++++++++++++++++++++++------------------- 1 file changed, 86 insertions(+), 39 deletions(-) (limited to 'src/where.c') diff --git a/src/where.c b/src/where.c index 05414da..d324228 100644 --- a/src/where.c +++ b/src/where.c @@ -604,7 +604,7 @@ static WhereTerm *findTerm( && pTerm->u.leftColumn==iColumn && (pTerm->eOperator & op)!=0 ){ - if( pIdx && pTerm->eOperator!=WO_ISNULL ){ + if( iColumn>=0 && pIdx && pTerm->eOperator!=WO_ISNULL ){ Expr *pX = pTerm->pExpr; CollSeq *pColl; char idxaff; @@ -686,7 +686,10 @@ static int isLikeOrGlob( #endif pList = pExpr->x.pList; pLeft = pList->a[1].pExpr; - if( pLeft->op!=TK_COLUMN || sqlite3ExprAffinity(pLeft)!=SQLITE_AFF_TEXT ){ + if( pLeft->op!=TK_COLUMN + || sqlite3ExprAffinity(pLeft)!=SQLITE_AFF_TEXT + || IsVirtual(pLeft->pTab) + ){ /* IMP: R-02065-49465 The left-hand side of the LIKE or GLOB operator must ** be the name of an indexed column with TEXT affinity. */ return 0; @@ -1559,15 +1562,19 @@ static int isDistinctRedundant( ** list, or else the WHERE clause contains a term of the form "col=X", ** where X is a constant value. The collation sequences of the ** comparison and select-list expressions must match those of the index. + ** + ** 3. All of those index columns for which the WHERE clause does not + ** contain a "col=X" term are subject to a NOT NULL constraint. */ for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){ if( pIdx->onError==OE_None ) continue; for(i=0; inColumn; i++){ int iCol = pIdx->aiColumn[i]; - if( 0==findTerm(pWC, iBase, iCol, ~(Bitmask)0, WO_EQ, pIdx) - && 0>findIndexCol(pParse, pDistinct, iBase, pIdx, i) - ){ - break; + if( 0==findTerm(pWC, iBase, iCol, ~(Bitmask)0, WO_EQ, pIdx) ){ + int iIdxCol = findIndexCol(pParse, pDistinct, iBase, pIdx, i); + if( iIdxCol<0 || pTab->aCol[pIdx->aiColumn[i]].notNull==0 ){ + break; + } } } if( i==pIdx->nColumn ){ @@ -1715,14 +1722,25 @@ static int isSortingIndex( } if( pIdx->onError!=OE_None && i==pIdx->nColumn && (wsFlags & WHERE_COLUMN_NULL)==0 - && !referencesOtherTables(pOrderBy, pMaskSet, j, base) ){ - /* All terms of this index match some prefix of the ORDER BY clause - ** and the index is UNIQUE and no terms on the tail of the ORDER BY - ** clause reference other tables in a join. If this is all true then - ** the order by clause is superfluous. Not that if the matching - ** condition is IS NULL then the result is not necessarily unique - ** even on a UNIQUE index, so disallow those cases. */ - return 1; + && !referencesOtherTables(pOrderBy, pMaskSet, j, base) + ){ + Column *aCol = pIdx->pTable->aCol; + + /* All terms of this index match some prefix of the ORDER BY clause, + ** the index is UNIQUE, and no terms on the tail of the ORDER BY + ** refer to other tables in a join. So, assuming that the index entries + ** visited contain no NULL values, then this index delivers rows in + ** the required order. + ** + ** It is not possible for any of the first nEqCol index fields to be + ** NULL (since the corresponding "=" operator in the WHERE clause would + ** not be true). So if all remaining index columns have NOT NULL + ** constaints attached to them, we can be confident that the visited + ** index entries are free of NULLs. */ + for(i=nEqCol; inColumn; i++){ + if( aCol[pIdx->aiColumn[i]].notNull==0 ) break; + } + return (i==pIdx->nColumn); } return 0; } @@ -2005,7 +2023,6 @@ static void constructAutomaticIndex( int nByte; /* Byte of memory needed for pIdx */ Index *pIdx; /* Object describing the transient index */ Vdbe *v; /* Prepared statement under construction */ - int regIsInit; /* Register set by initialization */ int addrInit; /* Address of the initialization bypass jump */ Table *pTable; /* The table being indexed */ KeyInfo *pKeyinfo; /* Key information for the index */ @@ -2022,8 +2039,7 @@ static void constructAutomaticIndex( ** transient index on 2nd and subsequent iterations of the loop. */ v = pParse->pVdbe; assert( v!=0 ); - regIsInit = ++pParse->nMem; - addrInit = sqlite3VdbeAddOp1(v, OP_Once, regIsInit); + addrInit = sqlite3CodeOnce(pParse); /* Count the number of columns that will be added to the index ** and used to match WHERE clause constraints */ @@ -3052,10 +3068,24 @@ static void bestBtreeIndex( #endif used |= pTerm->prereqRight; } - - /* Determine the value of rangeDiv */ - if( nEqnColumn && pProbe->bUnordered==0 ){ - int j = pProbe->aiColumn[nEq]; + + /* If the index being considered is UNIQUE, and there is an equality + ** constraint for all columns in the index, then this search will find + ** at most a single row. In this case set the WHERE_UNIQUE flag to + ** indicate this to the caller. + ** + ** Otherwise, if the search may find more than one row, test to see if + ** there is a range constraint on indexed column (nEq+1) that can be + ** optimized using the index. + */ + if( nEq==pProbe->nColumn && pProbe->onError!=OE_None ){ + testcase( wsFlags & WHERE_COLUMN_IN ); + testcase( wsFlags & WHERE_COLUMN_NULL ); + if( (wsFlags & (WHERE_COLUMN_IN|WHERE_COLUMN_NULL))==0 ){ + wsFlags |= WHERE_UNIQUE; + } + }else if( pProbe->bUnordered==0 ){ + int j = (nEq==pProbe->nColumn ? -1 : pProbe->aiColumn[nEq]); if( findTerm(pWC, iCur, j, notReady, WO_LT|WO_LE|WO_GT|WO_GE, pIdx) ){ WhereTerm *pTop = findTerm(pWC, iCur, j, notReady, WO_LT|WO_LE, pIdx); WhereTerm *pBtm = findTerm(pWC, iCur, j, notReady, WO_GT|WO_GE, pIdx); @@ -3074,12 +3104,6 @@ static void bestBtreeIndex( } wsFlags |= (WHERE_COLUMN_RANGE|WHERE_ROWID_RANGE); } - }else if( pProbe->onError!=OE_None ){ - testcase( wsFlags & WHERE_COLUMN_IN ); - testcase( wsFlags & WHERE_COLUMN_NULL ); - if( (wsFlags & (WHERE_COLUMN_IN|WHERE_COLUMN_NULL))==0 ){ - wsFlags |= WHERE_UNIQUE; - } } /* If there is an ORDER BY clause and the index being considered will @@ -3097,7 +3121,9 @@ static void bestBtreeIndex( /* If there is a DISTINCT qualifier and this index will scan rows in ** order of the DISTINCT expressions, clear bDist and set the appropriate ** flags in wsFlags. */ - if( isDistinctIndex(pParse, pWC, pProbe, iCur, pDistinct, nEq) ){ + if( isDistinctIndex(pParse, pWC, pProbe, iCur, pDistinct, nEq) + && (wsFlags & WHERE_COLUMN_IN)==0 + ){ bDist = 0; wsFlags |= WHERE_ROWID_RANGE|WHERE_COLUMN_RANGE|WHERE_DISTINCT; } @@ -3690,10 +3716,12 @@ static char *explainIndexRange(sqlite3 *db, WhereLevel *pLevel, Table *pTab){ j = i; if( pPlan->wsFlags&WHERE_BTM_LIMIT ){ - explainAppendTerm(&txt, i++, aCol[aiColumn[j]].zName, ">"); + char *z = (j==pIndex->nColumn ) ? "rowid" : aCol[aiColumn[j]].zName; + explainAppendTerm(&txt, i++, z, ">"); } if( pPlan->wsFlags&WHERE_TOP_LIMIT ){ - explainAppendTerm(&txt, i, aCol[aiColumn[j]].zName, "<"); + char *z = (j==pIndex->nColumn ) ? "rowid" : aCol[aiColumn[j]].zName; + explainAppendTerm(&txt, i, z, "<"); } sqlite3StrAccumAppend(&txt, ")", 1); return sqlite3StrAccumFinish(&txt); @@ -3792,8 +3820,7 @@ static Bitmask codeOneLoopStart( WhereInfo *pWInfo, /* Complete information about the WHERE clause */ int iLevel, /* Which level of pWInfo->a[] should be coded */ u16 wctrlFlags, /* One of the WHERE_* flags defined in sqliteInt.h */ - Bitmask notReady, /* Which tables are currently available */ - Expr *pWhere /* Complete WHERE clause */ + Bitmask notReady /* Which tables are currently available */ ){ int j, k; /* Loop counters */ int iCur; /* The VDBE cursor for the table */ @@ -4051,7 +4078,7 @@ static Bitmask codeOneLoopStart( pIdx = pLevel->plan.u.pIdx; iIdxCur = pLevel->iIdxCur; - k = pIdx->aiColumn[nEq]; /* Column for inequality constraints */ + k = (nEq==pIdx->nColumn ? -1 : pIdx->aiColumn[nEq]); /* If this loop satisfies a sort order (pOrderBy) request that ** was passed to this function to implement a "SELECT min(x) ..." @@ -4097,7 +4124,9 @@ static Bitmask codeOneLoopStart( ** a forward order scan on a descending index, interchange the ** start and end terms (pRangeStart and pRangeEnd). */ - if( nEqnColumn && bRev==(pIdx->aSortOrder[nEq]==SQLITE_SO_ASC) ){ + if( (nEqnColumn && bRev==(pIdx->aSortOrder[nEq]==SQLITE_SO_ASC)) + || (bRev && pIdx->nColumn==nEq) + ){ SWAP(WhereTerm *, pRangeEnd, pRangeStart); } @@ -4330,10 +4359,25 @@ static Bitmask codeOneLoopStart( ** Then for every term xN, evaluate as the subexpression: xN AND z ** That way, terms in y that are factored into the disjunction will ** be picked up by the recursive calls to sqlite3WhereBegin() below. + ** + ** Actually, each subexpression is converted to "xN AND w" where w is + ** the "interesting" terms of z - terms that did not originate in the + ** ON or USING clause of a LEFT JOIN, and terms that are usable as + ** indices. */ if( pWC->nTerm>1 ){ - pAndExpr = sqlite3ExprAlloc(pParse->db, TK_AND, 0, 0); - pAndExpr->pRight = pWhere; + int iTerm; + for(iTerm=0; iTermnTerm; iTerm++){ + Expr *pExpr = pWC->a[iTerm].pExpr; + if( ExprHasProperty(pExpr, EP_FromJoin) ) continue; + if( pWC->a[iTerm].wtFlags & (TERM_VIRTUAL|TERM_ORINFO) ) continue; + if( (pWC->a[iTerm].eOperator & WO_ALL)==0 ) continue; + pExpr = sqlite3ExprDup(pParse->db, pExpr, 0); + pAndExpr = sqlite3ExprAnd(pParse->db, pAndExpr, pExpr); + } + if( pAndExpr ){ + pAndExpr = sqlite3PExpr(pParse, TK_AND, 0, pAndExpr, 0); + } } for(ii=0; iinTerm; ii++){ @@ -4357,7 +4401,7 @@ static Bitmask codeOneLoopStart( int iSet = ((ii==pOrWc->nTerm-1)?-1:ii); int r; r = sqlite3ExprCodeGetColumn(pParse, pTabItem->pTab, -1, iCur, - regRowid); + regRowid, 0); sqlite3VdbeAddOp4Int(v, OP_RowSetTest, regRowset, sqlite3VdbeCurrentAddr(v)+2, r, iSet); } @@ -4375,7 +4419,10 @@ static Bitmask codeOneLoopStart( } } } - sqlite3DbFree(pParse->db, pAndExpr); + if( pAndExpr ){ + pAndExpr->pLeft = 0; + sqlite3ExprDelete(pParse->db, pAndExpr); + } sqlite3VdbeChangeP1(v, iRetInit, sqlite3VdbeCurrentAddr(v)); sqlite3VdbeAddOp2(v, OP_Goto, 0, pLevel->addrBrk); sqlite3VdbeResolveLabel(v, iLoopBody); @@ -5031,7 +5078,7 @@ WhereInfo *sqlite3WhereBegin( for(i=0; ia[i]; explainOneScan(pParse, pTabList, pLevel, i, pLevel->iFrom, wctrlFlags); - notReady = codeOneLoopStart(pWInfo, i, wctrlFlags, notReady, pWhere); + notReady = codeOneLoopStart(pWInfo, i, wctrlFlags, notReady); pWInfo->iContinue = pLevel->addrCont; } -- cgit v1.2.3