diff options
Diffstat (limited to 'src/wherecode.c')
| -rw-r--r-- | src/wherecode.c | 25 |
1 files changed, 24 insertions, 1 deletions
diff --git a/src/wherecode.c b/src/wherecode.c index d95eae279..a895d3935 100644 --- a/src/wherecode.c +++ b/src/wherecode.c @@ -1338,6 +1338,27 @@ static SQLITE_NOINLINE void filterPullDown( } /* +** Loop pLoop is a WHERE_INDEXED level that uses at least one IN(...) +** operator. Return true if level pLoop is guaranteed to visit only one +** row for each key generated for the index. +*/ +static int whereLoopIsOneRow(WhereLoop *pLoop){ + if( pLoop->u.btree.pIndex->onError + && pLoop->nSkip==0 + && pLoop->u.btree.nEq==pLoop->u.btree.pIndex->nKeyCol + ){ + int ii; + for(ii=0; ii<pLoop->u.btree.nEq; ii++){ + if( pLoop->aLTerm[ii]->eOperator & (WO_IS|WO_ISNULL) ){ + return 0; + } + } + return 1; + } + return 0; +} + +/* ** Generate code for the start of the iLevel-th loop in the WHERE clause ** implementation described by pWInfo. */ @@ -2084,7 +2105,9 @@ Bitmask sqlite3WhereCodeOneLoopStart( } /* Record the instruction used to terminate the loop. */ - if( pLoop->wsFlags & WHERE_ONEROW ){ + if( (pLoop->wsFlags & WHERE_ONEROW) + || (pLevel->u.in.nIn && whereLoopIsOneRow(pLoop)) + ){ pLevel->op = OP_Noop; }else if( bRev ){ pLevel->op = OP_Prev; |