diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/wherecode.c | 78 |
1 files changed, 45 insertions, 33 deletions
diff --git a/src/wherecode.c b/src/wherecode.c index d429fbb52..a95889136 100644 --- a/src/wherecode.c +++ b/src/wherecode.c @@ -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 |