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Continuing refinements of the logic to take WHERE clause terms not used for

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indexing into account when computing the number of output rows from each
table.

FossilOrigin-Name: b65dc53415f42d8402d0ec7f4bedf59d7b39b486
This commit is contained in:
drh
2013-09-07 00:29:06 +00:00
parent fde1e6bc37
commit add5ce303f
5 changed files with 22 additions and 15 deletions
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16
src/where.c
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@@ -688,7 +688,9 @@ static int whereClauseInsert(WhereClause *pWC, Expr *p, u8 wtFlags){
pWC->nSlot = sqlite3DbMallocSize(db, pWC->a)/sizeof(pWC->a[0]);
}
pTerm = &pWC->a[idx = pWC->nTerm++];
if( p && ExprHasAnyProperty(p, EP_Hint) ){
if( wtFlags & TERM_VIRTUAL ){
pTerm->truthProb = 0;
}else if( p && ExprHasAnyProperty(p, EP_Hint) ){
pTerm->truthProb = whereCost(p->iTable) - 99;
}else{
pTerm->truthProb = -1;
@@ -4198,9 +4200,9 @@ static int whereLoopInsert(WhereLoopBuilder *pBuilder, WhereLoop *pTemplate){
assert( p->rSetup==pTemplate->rSetup );
if( p->prereq==pTemplate->prereq
&& p->nLTerm<pTemplate->nLTerm
&& (p->wsFlags & WHERE_INDEXED)!=0
&& (pTemplate->wsFlags & WHERE_INDEXED)!=0
&& p->u.btree.pIndex==pTemplate->u.btree.pIndex
&& (p->wsFlags & pTemplate->wsFlags & WHERE_INDEXED)!=0
&& (p->u.btree.pIndex==pTemplate->u.btree.pIndex
|| p->u.btree.pIndex->nColumn>=pTemplate->u.btree.pIndex->nColumn)
){
/* Overwrite an existing WhereLoop with an similar one that uses
** more terms of the index */
@@ -4215,12 +4217,12 @@ static int whereLoopInsert(WhereLoopBuilder *pBuilder, WhereLoop *pTemplate){
if( (p->prereq & pTemplate->prereq)==pTemplate->prereq
&& p->rRun>=pTemplate->rRun
&& p->nOut>=pTemplate->nOut
&& ALWAYS(p->rSetup>=pTemplate->rSetup) /* See SETUP-INVARIANT above */
){
/* Overwrite an existing WhereLoop with a better one: one that is
** better at one of (1) dependencies, (2) setup-cost, (3) run-cost
** or (4) number of output rows, and is no worse in any of those
** categories. */
assert( p->rSetup>=pTemplate->rSetup ); /* SETUP-INVARIANT above */
pNext = p->pNextLoop;
break;
}
@@ -4281,6 +4283,10 @@ static void whereLoopOutputAdjust(WhereClause *pWC, WhereLoop *pLoop, int iCur){
Bitmask notAllowed = ~(pLoop->prereq|pLoop->maskSelf);
int x = 0;
int i;
if( !OptimizationEnabled(pWC->pWInfo->pParse->db, SQLITE_AdjustOutEst) ){
return;
}
for(i=pWC->nTerm, pTerm=pWC->a; i>0; i--, pTerm++){
if( (pTerm->wtFlags & TERM_VIRTUAL)!=0 ) continue;
if( (pTerm->prereqAll & pLoop->maskSelf)==0 ) continue;