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Improve the way that skip-scan loops are constructued. Add test cases.

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Improved the scoring of skip-scan loops.

FossilOrigin-Name: 5e75ab93881b85801cb4ebf70f2063ff7c51ac19
This commit is contained in:
drh
2013-11-13 16:58:54 +00:00
parent c2b23e7a98
commit 2e5ef4ed77
5 changed files with 56 additions and 30 deletions
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28
src/where.c
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@@ -2504,11 +2504,11 @@ static int codeAllEqualityTerms(
if( nSkip ){
int iIdxCur = pLevel->iIdxCur;
sqlite3VdbeAddOp2(v, (bRev?OP_Last:OP_Rewind), iIdxCur, pLevel->addrNxt);
pLevel->addrSkip = sqlite3VdbeCurrentAddr(v);
pLevel->opSkip = bRev ? OP_SeekLt : OP_SeekGt;
pLevel->p3Skip = regBase;
pLevel->p4Skip = nSkip;
sqlite3VdbeAddOp1(v, (bRev?OP_Last:OP_Rewind), iIdxCur);
j = sqlite3VdbeAddOp0(v, OP_Goto);
pLevel->addrSkip = sqlite3VdbeAddOp4Int(v, (bRev?OP_SeekLt:OP_SeekGt),
iIdxCur, 0, regBase, nSkip);
sqlite3VdbeJumpHere(v, j);
for(j=0; j<nSkip; j++){
sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, j, regBase+j);
assert( pIdx->aiColumn[j]>=0 );
@@ -3928,11 +3928,13 @@ static int whereLoopAddBtreeIndex(
&& saved_nEq+1<pProbe->nKeyCol
&& pProbe->aiRowEst[saved_nEq+1]>50
){
LogEst nIter;
pNew->u.btree.nEq++;
pNew->u.btree.nSkip++;
pNew->aLTerm[pNew->nLTerm++] = 0;
pNew->wsFlags |= WHERE_SKIP_SCAN;
whereLoopAddBtreeIndex(pBuilder, pSrc, pProbe, nInMul);
pNew->wsFlags |= WHERE_SKIPSCAN;
nIter = sqlite3LogEst(pProbe->aiRowEst[0]/pProbe->aiRowEst[saved_nEq+1]);
whereLoopAddBtreeIndex(pBuilder, pSrc, pProbe, nIter);
}
for(; rc==SQLITE_OK && pTerm!=0; pTerm = whereScanNext(&scan)){
int nIn = 0;
@@ -3969,8 +3971,10 @@ static int whereLoopAddBtreeIndex(
pNew->u.btree.nEq++;
pNew->nOut = nRowEst + nInMul + nIn;
}else if( pTerm->eOperator & (WO_EQ) ){
assert( (pNew->wsFlags & (WHERE_COLUMN_NULL|WHERE_COLUMN_IN))!=0
|| nInMul==0 );
assert(
(pNew->wsFlags & (WHERE_COLUMN_NULL|WHERE_COLUMN_IN|WHERE_SKIPSCAN))!=0
|| nInMul==0
);
pNew->wsFlags |= WHERE_COLUMN_EQ;
if( iCol<0
|| (pProbe->onError!=OE_None && nInMul==0
@@ -5784,11 +5788,9 @@ void sqlite3WhereEnd(WhereInfo *pWInfo){
}
sqlite3VdbeResolveLabel(v, pLevel->addrBrk);
if( pLevel->addrSkip ){
addr = sqlite3VdbeAddOp4Int(v, pLevel->opSkip, pLevel->iIdxCur, 0,
pLevel->p3Skip, pLevel->p4Skip);
sqlite3VdbeAddOp2(v, OP_Goto, 0, pLevel->addrSkip);
sqlite3VdbeJumpHere(v, pLevel->addrSkip-1);
sqlite3VdbeJumpHere(v, addr);
sqlite3VdbeJumpHere(v, pLevel->addrSkip);
sqlite3VdbeJumpHere(v, pLevel->addrSkip-2);
}
if( pLevel->iLeftJoin ){
addr = sqlite3VdbeAddOp1(v, OP_IfPos, pLevel->iLeftJoin);