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| Comment: | Simplification to the logic that prevents automatic indexes from being formed on constant expressions. |
|---|---|
| Downloads: | Tarball | ZIP archive | SQL archive |
| Timelines: | family | ancestors | descendants | both | autoindex-improvements |
| Files: | files | file ages | folders |
| SHA1: |
36d67e1dd2b4f4c22d02f3c3b8d37207 |
| User & Date: | drh 2014-06-17 09:52:26 |
|
2014-06-17
| ||
| 12:33 | A different approach to the autoindex problem that deletes query-planner code rather than adding it. (check-in: f270fb6e user: drh tags: autoindex-improvements) | |
| 09:52 | Simplification to the logic that prevents automatic indexes from being formed on constant expressions. (check-in: 36d67e1d user: drh tags: autoindex-improvements) | |
| 09:00 | Allow an automatic index on a WHERE constraint where the RHS is does not reference another table as long as the RHS is not a constant. (check-in: 58acc2a8 user: drh tags: autoindex-improvements) | |
Changes to src/where.c.
4525 4526 4527 4528 4529 4530 4531 4532 4533 4534 4535 4536 4537 4538 4539 4540 4541 4542 |
&& !pSrc->isRecursive
){
/* Generate auto-index WhereLoops */
WhereTerm *pTerm;
WhereTerm *pWCEnd = pWC->a + pWC->nTerm;
for(pTerm=pWC->a; rc==SQLITE_OK && pTerm<pWCEnd; pTerm++){
if( pTerm->prereqRight & pNew->maskSelf ) continue;
if( pTerm->prereqRight==0
&& sqlite3ExprIsConstant(pTerm->pExpr->pRight) ){
continue;
}
if( termCanDriveIndex(pTerm, pSrc, 0) ){
pNew->u.btree.nEq = 1;
pNew->u.btree.nSkip = 0;
pNew->u.btree.pIndex = 0;
pNew->nLTerm = 1;
pNew->aLTerm[0] = pTerm;
/* TUNING: One-time cost for computing the automatic index is
|
< | < < |
4525 4526 4527 4528 4529 4530 4531 4532 4533 4534 4535 4536 4537 4538 4539 |
&& !pSrc->isRecursive
){
/* Generate auto-index WhereLoops */
WhereTerm *pTerm;
WhereTerm *pWCEnd = pWC->a + pWC->nTerm;
for(pTerm=pWC->a; rc==SQLITE_OK && pTerm<pWCEnd; pTerm++){
if( pTerm->prereqRight & pNew->maskSelf ) continue;
if( sqlite3ExprIsConstant(pTerm->pExpr->pRight) ) continue;
if( termCanDriveIndex(pTerm, pSrc, 0) ){
pNew->u.btree.nEq = 1;
pNew->u.btree.nSkip = 0;
pNew->u.btree.pIndex = 0;
pNew->nLTerm = 1;
pNew->aLTerm[0] = pTerm;
/* TUNING: One-time cost for computing the automatic index is
|