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Merge latest trunk changes into this branch.

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FossilOrigin-Name: 9685880f7baeb670739fdcf2d9df08e22abaa699
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dan
2016-07-28 13:59:21 +00:00
parent d49fd4e89a 4aff119f3a
commit 34c125747d
8 changed files with 182 additions and 18 deletions
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33
src/where.c
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@@ -2539,11 +2539,11 @@ static int whereLoopAddBtreeIndex(
pNew->nSkip++;
pNew->aLTerm[pNew->nLTerm++] = 0;
pNew->wsFlags |= WHERE_SKIPSCAN;
nIter = pProbe->aiRowLogEst[saved_nEq] - pProbe->aiRowLogEst[saved_nEq+1];
nIter = pProbe->aiRowLogEst[saved_nEq]+1 - pProbe->aiRowLogEst[saved_nEq+1];
pNew->nOut -= nIter;
/* TUNING: Because uncertainties in the estimates for skip-scan queries,
** add a 1.375 fudge factor to make skip-scan slightly less likely. */
nIter += 5;
nIter += 4;
whereLoopAddBtreeIndex(pBuilder, pSrc, pProbe, nIter + nInMul);
pNew->nOut = saved_nOut;
pNew->u.btree.nEq = saved_nEq;
@@ -2838,11 +2838,34 @@ static int whereLoopAddBtree(
/* The cost of visiting the index rows is N*K, where K is
** between 1.1 and 3.0, depending on the relative sizes of the
** index and table rows. If this is a non-covering index scan,
** also add the cost of visiting table rows (N*3.0). */
** index and table rows. */
pNew->rRun = rSize + 1 + (15*pProbe->szIdxRow)/pTab->szTabRow;
if( m!=0 ){
pNew->rRun = sqlite3LogEstAdd(pNew->rRun, rSize+16);
/* If this is a non-covering index scan, add in the cost of
** doing table lookups. The cost will be 3x the number of
** lookups. Take into account WHERE clause terms that can be
** satisfied using just the index, and that do not require a
** table lookup. */
LogEst nLookup = rSize + 16; /* Base cost: N*3 */
int ii;
int iCur = pSrc->iCursor;
WhereClause *pWC = &pWInfo->sWC;
for(ii=0; ii<pWC->nTerm; ii++){
WhereTerm *pTerm = &pWC->a[ii];
if( !sqlite3ExprCoveredByIndex(pTerm->pExpr, iCur, pProbe) ){
break;
}
/* pTerm can be evaluated using just the index. So reduce
** the expected number of table lookups accordingly */
if( pTerm->truthProb<=0 ){
nLookup += pTerm->truthProb;
}else{
nLookup--;
if( pTerm->eOperator & (WO_EQ|WO_IS) ) nLookup -= 19;
}
}
pNew->rRun = sqlite3LogEstAdd(pNew->rRun, nLookup);
}
ApplyCostMultiplier(pNew->rRun, pTab->costMult);
whereLoopOutputAdjust(pWC, pNew, rSize);