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Merge changes from trunk.

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FossilOrigin-Name: c80e9e8e8cc1e7676d7c782ee0827726875db79e
This commit is contained in:
drh
2015-08-27 16:07:02 +00:00
parent bb52308f3d a3f108e93d
commit b377020ca9
4 changed files with 32 additions and 33 deletions
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46
src/where.c
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@@ -171,37 +171,37 @@ static void createMask(WhereMaskSet *pMaskSet, int iCursor){
*/
static WhereTerm *whereScanNext(WhereScan *pScan){
int iCur; /* The cursor on the LHS of the term */
int iColumn; /* The column on the LHS of the term. -1 for IPK */
i16 iColumn; /* The column on the LHS of the term. -1 for IPK */
Expr *pX; /* An expression being tested */
WhereClause *pWC; /* Shorthand for pScan->pWC */
WhereTerm *pTerm; /* The term being tested */
int k = pScan->k; /* Where to start scanning */
while( pScan->iEquiv<=pScan->nEquiv ){
iCur = pScan->aEquiv[pScan->iEquiv-2];
iColumn = pScan->aEquiv[pScan->iEquiv-1];
iCur = pScan->aiCur[pScan->iEquiv-1];
iColumn = pScan->aiColumn[pScan->iEquiv-1];
while( (pWC = pScan->pWC)!=0 ){
for(pTerm=pWC->a+k; k<pWC->nTerm; k++, pTerm++){
if( pTerm->leftCursor==iCur
&& pTerm->u.leftColumn==iColumn
&& (pScan->iEquiv<=2 || !ExprHasProperty(pTerm->pExpr, EP_FromJoin))
&& (pScan->iEquiv<=1 || !ExprHasProperty(pTerm->pExpr, EP_FromJoin))
){
if( (pTerm->eOperator & WO_EQUIV)!=0
&& pScan->nEquiv<ArraySize(pScan->aEquiv)
&& pScan->nEquiv<ArraySize(pScan->aiCur)
){
int j;
pX = sqlite3ExprSkipCollate(pTerm->pExpr->pRight);
assert( pX->op==TK_COLUMN );
for(j=0; j<pScan->nEquiv; j+=2){
if( pScan->aEquiv[j]==pX->iTable
&& pScan->aEquiv[j+1]==pX->iColumn ){
for(j=0; j<pScan->nEquiv; j++){
if( pScan->aiCur[j]==pX->iTable
&& pScan->aiColumn[j]==pX->iColumn ){
break;
}
}
if( j==pScan->nEquiv ){
pScan->aEquiv[j] = pX->iTable;
pScan->aEquiv[j+1] = pX->iColumn;
pScan->nEquiv += 2;
pScan->aiCur[j] = pX->iTable;
pScan->aiColumn[j] = pX->iColumn;
pScan->nEquiv++;
}
}
if( (pTerm->eOperator & pScan->opMask)!=0 ){
@@ -223,8 +223,8 @@ static WhereTerm *whereScanNext(WhereScan *pScan){
}
if( (pTerm->eOperator & (WO_EQ|WO_IS))!=0
&& (pX = pTerm->pExpr->pRight)->op==TK_COLUMN
&& pX->iTable==pScan->aEquiv[0]
&& pX->iColumn==pScan->aEquiv[1]
&& pX->iTable==pScan->aiCur[0]
&& pX->iColumn==pScan->aiColumn[0]
){
testcase( pTerm->eOperator & WO_IS );
continue;
@@ -239,7 +239,7 @@ static WhereTerm *whereScanNext(WhereScan *pScan){
}
pScan->pWC = pScan->pOrigWC;
k = 0;
pScan->iEquiv += 2;
pScan->iEquiv++;
}
return 0;
}
@@ -286,10 +286,10 @@ static WhereTerm *whereScanInit(
}
pScan->opMask = opMask;
pScan->k = 0;
pScan->aEquiv[0] = iCur;
pScan->aEquiv[1] = iColumn;
pScan->nEquiv = 2;
pScan->iEquiv = 2;
pScan->aiCur[0] = iCur;
pScan->aiColumn[0] = iColumn;
pScan->nEquiv = 1;
pScan->iEquiv = 1;
return whereScanNext(pScan);
}
@@ -305,12 +305,10 @@ static WhereTerm *whereScanInit(
** The term returned might by Y=<expr> if there is another constraint in
** the WHERE clause that specifies that X=Y. Any such constraints will be
** identified by the WO_EQUIV bit in the pTerm->eOperator field. The
** aEquiv[] array holds X and all its equivalents, with each SQL variable
** taking up two slots in aEquiv[]. The first slot is for the cursor number
** and the second is for the column number. There are 22 slots in aEquiv[]
** so that means we can look for X plus up to 10 other equivalent values.
** Hence a search for X will return <expr> if X=A1 and A1=A2 and A2=A3
** and ... and A9=A10 and A10=<expr>.
** aiCur[]/iaColumn[] arrays hold X and all its equivalents. There are 11
** slots in aiCur[]/aiColumn[] so that means we can look for X plus up to 10
** other equivalent values. Hence a search for X will return <expr> if X=A1
** and A1=A2 and A2=A3 and ... and A9=A10 and A10=<expr>.
**
** If there are multiple terms in the WHERE clause of the form "X <op> <expr>"
** then try for the one with no dependencies on <expr> - in other words where