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Fix the STAT4 range scan estimates for DESC indexes.

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FossilOrigin-Name: e3fe84005259ef9a6027d25793514cebb2d4e7e0
This commit is contained in:
drh
2014-10-08 02:53:25 +00:00
parent 9a7b41d74a
commit 69afd9980e
4 changed files with 259 additions and 11 deletions
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13
src/where.c
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@@ -2207,16 +2207,22 @@ static int whereRangeScanEst(
iUpper = a[0] + a[1];
}
assert( pLower==0 || (pLower->eOperator & (WO_GT|WO_GE))!=0 );
assert( pUpper==0 || (pUpper->eOperator & (WO_LT|WO_LE))!=0 );
if( p->pKeyInfo && p->pKeyInfo->aSortOrder[nEq] ){
/* The roles of pLower and pUpper are swapped for a DESC index */
SWAP(WhereTerm*, pLower, pUpper);
}
/* If possible, improve on the iLower estimate using ($P:$L). */
if( pLower ){
int bOk; /* True if value is extracted from pExpr */
Expr *pExpr = pLower->pExpr->pRight;
assert( (pLower->eOperator & (WO_GT|WO_GE))!=0 );
rc = sqlite3Stat4ProbeSetValue(pParse, p, &pRec, pExpr, aff, nEq, &bOk);
if( rc==SQLITE_OK && bOk ){
tRowcnt iNew;
whereKeyStats(pParse, p, pRec, 0, a);
iNew = a[0] + ((pLower->eOperator & WO_GT) ? a[1] : 0);
iNew = a[0] + ((pLower->eOperator & (WO_GT|WO_LE)) ? a[1] : 0);
if( iNew>iLower ) iLower = iNew;
nOut--;
pLower = 0;
@@ -2227,12 +2233,11 @@ static int whereRangeScanEst(
if( pUpper ){
int bOk; /* True if value is extracted from pExpr */
Expr *pExpr = pUpper->pExpr->pRight;
assert( (pUpper->eOperator & (WO_LT|WO_LE))!=0 );
rc = sqlite3Stat4ProbeSetValue(pParse, p, &pRec, pExpr, aff, nEq, &bOk);
if( rc==SQLITE_OK && bOk ){
tRowcnt iNew;
whereKeyStats(pParse, p, pRec, 1, a);
iNew = a[0] + ((pUpper->eOperator & WO_LE) ? a[1] : 0);
iNew = a[0] + ((pUpper->eOperator & (WO_GT|WO_LE)) ? a[1] : 0);
if( iNew<iUpper ) iUpper = iNew;
nOut--;
pUpper = 0;