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| author | drh <drh@noemail.net> | 2015-11-05 20:25:09 +0000 |
|---|---|---|
| committer | drh <drh@noemail.net> | 2015-11-05 20:25:09 +0000 |
| commit | 70528d7868e67752833c6bac7b34f4d5d652d130 (patch) | |
| tree | 372b20b32551bbbe108cd161a8e2d93bcd8beea5 /src/wherecode.c | |
| parent | d82211db56f53b2ddf0e62904f3c691d24bd2afb (diff) | |
| download | sqlite-70528d7868e67752833c6bac7b34f4d5d652d130.tar.gz sqlite-70528d7868e67752833c6bac7b34f4d5d652d130.zip | |
The top of an index equality loop normally starts with OP_SeekGE and OP_IdxGT.
This check-in adds a flag to OP_SeekGE such that it fails immediately if
the key is not equal, then jumps over the OP_IdxGT, saving a call to the key
comparison functions. Consider this check-in a proof-of-concept. It needs
improvement before going on trunk. Some tests fail, but only because they
new use fewer key comparisons than expected (which is a good thing!).
FossilOrigin-Name: 32e31b9bc8664afcd326a1ff3892d86dc5202474
Diffstat (limited to 'src/wherecode.c')
| -rw-r--r-- | src/wherecode.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/src/wherecode.c b/src/wherecode.c index 87db0e0a2..644c1aa0a 100644 --- a/src/wherecode.c +++ b/src/wherecode.c @@ -1026,6 +1026,7 @@ Bitmask sqlite3WhereCodeOneLoopStart( WhereTerm *pRangeEnd = 0; /* Inequality constraint at range end */ int startEq; /* True if range start uses ==, >= or <= */ int endEq; /* True if range end uses ==, >= or <= */ + int eqOnly; /* True if uses only == */ int start_constraints; /* Start of range is constrained */ int nConstraint; /* Number of constraint terms */ Index *pIdx; /* The index we will be using */ @@ -1095,6 +1096,8 @@ Bitmask sqlite3WhereCodeOneLoopStart( } } assert( pRangeEnd==0 || (pRangeEnd->wtFlags & TERM_VNULL)==0 ); + eqOnly = nEq>0 && (pLoop->wsFlags & WHERE_COLUMN_RANGE)==0 + && (pWInfo->wctrlFlags&WHERE_ORDERBY_MIN)==0; /* If we are doing a reverse order scan on an ascending index, or ** a forward order scan on a descending index, interchange the @@ -1167,6 +1170,7 @@ Bitmask sqlite3WhereCodeOneLoopStart( VdbeCoverageIf(v, op==OP_SeekGE); testcase( op==OP_SeekGE ); VdbeCoverageIf(v, op==OP_SeekLE); testcase( op==OP_SeekLE ); VdbeCoverageIf(v, op==OP_SeekLT); testcase( op==OP_SeekLT ); + if( eqOnly ) sqlite3VdbeChangeP5(v, OPFLAG_SEEKEQ); /* Load the value for the inequality constraint at the end of the ** range (if any). @@ -1202,6 +1206,11 @@ Bitmask sqlite3WhereCodeOneLoopStart( /* Check if the index cursor is past the end of the range. */ if( nConstraint ){ + if( eqOnly ){ + int bx = sqlite3VdbeCurrentAddr(v); + sqlite3VdbeAddOp2(v, OP_Goto, 0, bx+2); + pLevel->p2 = bx+1; + } op = aEndOp[bRev*2 + endEq]; sqlite3VdbeAddOp4Int(v, op, iIdxCur, addrNxt, regBase, nConstraint); testcase( op==OP_IdxGT ); VdbeCoverageIf(v, op==OP_IdxGT ); |