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Add in the cost of doing a table lookup on OR searches. Make test case

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changes to deal with difference in STAT3 behavior.

FossilOrigin-Name: d97898e8e3990ae8c1882c9102b57692d8810730
This commit is contained in:
drh
2013-06-19 18:01:44 +00:00
parent ad01d892a7
commit 74f91d4462
4 changed files with 55 additions and 34 deletions
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10
src/where.c
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@@ -630,8 +630,8 @@ static int whereClauseInsert(WhereClause *pWC, Expr *p, u8 wtFlags){
** the WhereClause.a[] array. The slot[] array grows as needed to contain
** all terms of the WHERE clause.
*/
static void whereSplit(WhereClause *pWC, Expr *pExpr, int op){
pWC->op = (u8)op;
static void whereSplit(WhereClause *pWC, Expr *pExpr, u8 op){
pWC->op = op;
if( pExpr==0 ) return;
if( pExpr->op!=op ){
whereClauseInsert(pWC, pExpr, 0);
@@ -4516,6 +4516,7 @@ static int whereLoopAddBtree(
pNew->iSortIdx = 0;
pNew->rSetup = 0;
pNew->prereq = mExtra;
pNew->nOut = rSize;
pNew->u.btree.pIndex = pProbe;
b = indexMightHelpWithOrderBy(pBuilder, pProbe, pSrc->iCursor);
/* The ONEPASS_DESIRED flags never occurs together with ORDER BY */
@@ -4526,7 +4527,6 @@ static int whereLoopAddBtree(
/* Full table scan */
pNew->iSortIdx = b ? iSortIdx : 0;
pNew->nOut = rSize;
/* TUNING: Cost of full table scan is 3*(N + log2(N)).
** + The extra 3 factor is to encourage the use of indexed lookups
** over full scans. A smaller constant 2 is used for covering
@@ -4549,7 +4549,6 @@ static int whereLoopAddBtree(
)
){
pNew->iSortIdx = b ? iSortIdx : 0;
pNew->nOut = rSize;
if( m==0 ){
/* TUNING: Cost of a covering index scan is 2*(N + log2(N)).
** + The extra 2 factor is to encourage the use of indexed lookups
@@ -4824,7 +4823,8 @@ static int whereLoopAddOr(WhereLoopBuilder *pBuilder, Bitmask mExtra){
pNew->aLTerm[0] = pTerm;
pNew->wsFlags = WHERE_MULTI_OR;
pNew->rSetup = 0;
pNew->rRun = rTotal;
/* TUNING: Multiple by 3.5 for the secondary table lookup */
pNew->rRun = rTotal + 18; assert( 18==whereCost(7)-whereCost(2) );
pNew->nOut = nRow;
pNew->prereq = prereq;
memset(&pNew->u, 0, sizeof(pNew->u));