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Within a loop that uses a non-covering index test, test non-indexed terms that

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can be tested without seeking the main table cursor before those that cannot.

FossilOrigin-Name: afe68f0a8060dc5c92cb1fb32a9f22bd36140cd2c0bb5b6cea853e169c5ed444
This commit is contained in:
dan
2017-04-28 19:59:55 +00:00
parent 4b17369579
commit 6f654a40e8
4 changed files with 115 additions and 40 deletions
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78
src/wherecode.c
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@ -1129,6 +1129,7 @@ Bitmask sqlite3WhereCodeOneLoopStart(
int addrCont; /* Jump here to continue with next cycle */
int iRowidReg = 0; /* Rowid is stored in this register, if not zero */
int iReleaseReg = 0; /* Temp register to free before returning */
Index *pIdx = 0; /* Index used by loop (if any) */
pParse = pWInfo->pParse;
v = pParse->pVdbe;
@ -1454,7 +1455,6 @@ Bitmask sqlite3WhereCodeOneLoopStart(
int endEq; /* True if range end uses ==, >= or <= */
int start_constraints; /* Start of range is constrained */
int nConstraint; /* Number of constraint terms */
Index *pIdx; /* The index we will be using */
int iIdxCur; /* The VDBE cursor for the index */
int nExtraReg = 0; /* Number of extra registers needed */
int op; /* Instruction opcode */
@ -1705,6 +1705,7 @@ Bitmask sqlite3WhereCodeOneLoopStart(
}else{
assert( pLevel->p5==0 );
}
if( omitTable ) pIdx = 0;
}else
#ifndef SQLITE_OMIT_OR_OPTIMIZATION
@ -2022,42 +2023,53 @@ Bitmask sqlite3WhereCodeOneLoopStart(
/* Insert code to test every subexpression that can be completely
** computed using the current set of tables.
*/
for(pTerm=pWC->a, j=pWC->nTerm; j>0; j--, pTerm++){
Expr *pE;
int skipLikeAddr = 0;
testcase( pTerm->wtFlags & TERM_VIRTUAL );
testcase( pTerm->wtFlags & TERM_CODED );
if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
if( (pTerm->prereqAll & pLevel->notReady)!=0 ){
testcase( pWInfo->untestedTerms==0
&& (pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE)!=0 );
pWInfo->untestedTerms = 1;
continue;
}
pE = pTerm->pExpr;
assert( pE!=0 );
if( pLevel->iLeftJoin && !ExprHasProperty(pE, EP_FromJoin) ){
continue;
}
if( pTerm->wtFlags & TERM_LIKECOND ){
/* If the TERM_LIKECOND flag is set, that means that the range search
** is sufficient to guarantee that the LIKE operator is true, so we
** can skip the call to the like(A,B) function. But this only works
** for strings. So do not skip the call to the function on the pass
** that compares BLOBs. */
**
** This loop may run either once (pIdx==0) or twice (pIdx!=0). If
** it is run twice, then the first iteration codes those sub-expressions
** that can be computed using columns from pIdx only (without seeking
** the main table cursor). */
while( 1 ){
for(pTerm=pWC->a, j=pWC->nTerm; j>0; j--, pTerm++){
Expr *pE;
int skipLikeAddr = 0;
testcase( pTerm->wtFlags & TERM_VIRTUAL );
testcase( pTerm->wtFlags & TERM_CODED );
if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
if( (pTerm->prereqAll & pLevel->notReady)!=0 ){
testcase( pWInfo->untestedTerms==0
&& (pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE)!=0 );
pWInfo->untestedTerms = 1;
continue;
}
pE = pTerm->pExpr;
assert( pE!=0 );
if( pIdx && !sqlite3ExprCoveredByIndex(pE, pLevel->iTabCur, pIdx) ){
continue;
}
if( pLevel->iLeftJoin && !ExprHasProperty(pE, EP_FromJoin) ){
continue;
}
if( pTerm->wtFlags & TERM_LIKECOND ){
/* If the TERM_LIKECOND flag is set, that means that the range search
** is sufficient to guarantee that the LIKE operator is true, so we
** can skip the call to the like(A,B) function. But this only works
** for strings. So do not skip the call to the function on the pass
** that compares BLOBs. */
#ifdef SQLITE_LIKE_DOESNT_MATCH_BLOBS
continue;
continue;
#else
u32 x = pLevel->iLikeRepCntr;
assert( x>0 );
skipLikeAddr = sqlite3VdbeAddOp1(v, (x&1)? OP_IfNot : OP_If, (int)(x>>1));
VdbeCoverage(v);
u32 x = pLevel->iLikeRepCntr;
assert( x>0 );
skipLikeAddr = sqlite3VdbeAddOp1(v, (x&1)?OP_IfNot:OP_If, (int)(x>>1));
VdbeCoverage(v);
#endif
}
sqlite3ExprIfFalse(pParse, pE, addrCont, SQLITE_JUMPIFNULL);
if( skipLikeAddr ) sqlite3VdbeJumpHere(v, skipLikeAddr);
pTerm->wtFlags |= TERM_CODED;
}
sqlite3ExprIfFalse(pParse, pE, addrCont, SQLITE_JUMPIFNULL);
if( skipLikeAddr ) sqlite3VdbeJumpHere(v, skipLikeAddr);
pTerm->wtFlags |= TERM_CODED;
if( pIdx==0 ) break;
pIdx = 0;
}
/* Insert code to test for implied constraints based on transitivity