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Overview
| Comment: | Further tweaks to the ORDER BY optimizer, to fix a bug and to get the optimizer to recognize some additional cases. |
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| Downloads: | Tarball | ZIP archive | SQL archive |
| Timelines: | family | ancestors | descendants | both | qp-enhancements |
| Files: | files | file ages | folders |
| SHA1: |
bcb4f262476193cfb17818d8c62bab52 |
| User & Date: | drh 2012-10-08 20:27:35 |
Context
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2012-10-08
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| 21:01 | All test cases (veryquick.tcl and min.rc) pass. A few branch operations in ORDER BY optimization logic are untested by min.rc. (Closed-Leaf check-in: 8314fd60 user: drh tags: qp-enhancements) | |
| 20:27 | Further tweaks to the ORDER BY optimizer, to fix a bug and to get the optimizer to recognize some additional cases. (check-in: bcb4f262 user: drh tags: qp-enhancements) | |
| 19:41 | Bug fixes in the ORDER BY optimizer. (check-in: 301bbee4 user: drh tags: qp-enhancements) | |
Changes
Changes to src/where.c.
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** if there are any X= or X IS NULL constraints in the WHERE clause. */
pConstraint = findTerm(p->pWC, base, iColumn, p->notReady,
WO_EQ|WO_ISNULL|WO_IN, pIdx);
if( pConstraint==0 ){
isEq = 0;
}else if( pConstraint->eOperator==WO_IN ){
break;
}else if( pConstraint->prereqRight==0 ){
isEq = 1;
}else if( pConstraint->eOperator==WO_ISNULL ){
uniqueNotNull = 0;
isEq = 1;
}else{
Expr *pRight = pConstraint->pExpr->pRight;
if( pRight->op==TK_COLUMN ){
WHERETRACE((" .. isOrderedColumn(tab=%d,col=%d)",
pRight->iTable, pRight->iColumn));
isEq = isOrderedColumn(p, pRight->iTable, pRight->iColumn);
................................................................................
assert( iSortOrder==0 || iSortOrder==1 );
if( !isMatch ){
if( isEq==0 ){
break;
}else{
continue;
}
}else if( sortOrder==2 ){
sortOrder = termSortOrder;
}else if( termSortOrder!=sortOrder ){
break;
}
j++;
pOBItem++;
if( iColumn<0 ){
seenRowid = 1;
break;
}else if( pTab->aCol[iColumn].notNull==0 ){
uniqueNotNull = 0;
}
}
/* If we have not found at least one ORDER BY term that matches the
** index, then show no progress. */
if( pOBItem==&pOrderBy->a[nPriorSat] ) return nPriorSat;
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** if there are any X= or X IS NULL constraints in the WHERE clause. */
pConstraint = findTerm(p->pWC, base, iColumn, p->notReady,
WO_EQ|WO_ISNULL|WO_IN, pIdx);
if( pConstraint==0 ){
isEq = 0;
}else if( pConstraint->eOperator==WO_IN ){
break;
}else if( pConstraint->eOperator==WO_ISNULL ){
uniqueNotNull = 0;
isEq = 1;
}else if( pConstraint->prereqRight==0 ){
isEq = 1;
}else{
Expr *pRight = pConstraint->pExpr->pRight;
if( pRight->op==TK_COLUMN ){
WHERETRACE((" .. isOrderedColumn(tab=%d,col=%d)",
pRight->iTable, pRight->iColumn));
isEq = isOrderedColumn(p, pRight->iTable, pRight->iColumn);
................................................................................
assert( iSortOrder==0 || iSortOrder==1 );
if( !isMatch ){
if( isEq==0 ){
break;
}else{
continue;
}
}else if( isEq!=1 ){
if( sortOrder==2 ){
sortOrder = termSortOrder;
}else if( termSortOrder!=sortOrder ){
break;
}
}
j++;
pOBItem++;
if( iColumn<0 ){
seenRowid = 1;
break;
}else if( pTab->aCol[iColumn].notNull==0 && isEq==0 ){
uniqueNotNull = 0;
}
}
/* If we have not found at least one ORDER BY term that matches the
** index, then show no progress. */
if( pOBItem==&pOrderBy->a[nPriorSat] ) return nPriorSat;
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