diff options
Diffstat (limited to 'src/where.c')
| -rw-r--r-- | src/where.c | 31 |
1 files changed, 28 insertions, 3 deletions
diff --git a/src/where.c b/src/where.c index 35b9056ff..213df4223 100644 --- a/src/where.c +++ b/src/where.c @@ -2535,7 +2535,7 @@ static WhereLoop **whereLoopFindLesser( /* If pTemplate is always better than p, then cause p to be overwritten ** with pTemplate. pTemplate is better than p if: - ** (1) pTemplate has no more dependences than p, and + ** (1) pTemplate has no more dependencies than p, and ** (2) pTemplate has an equal or lower cost than p. */ if( (p->prereq & pTemplate->prereq)==pTemplate->prereq /* (1) */ @@ -5003,7 +5003,8 @@ static int wherePathSolver(WhereInfo *pWInfo, LogEst nRowEst){ ** For joins of 3 or more tables, track the 10 best paths */ mxChoice = (nLoop<=1) ? 1 : (nLoop==2 ? 5 : 10); assert( nLoop<=pWInfo->pTabList->nSrc ); - WHERETRACE(0x002, ("---- begin solver. (nRowEst=%d)\n", nRowEst)); + WHERETRACE(0x002, ("---- begin solver. (nRowEst=%d, nQueryLoop=%d)\n", + nRowEst, pParse->nQueryLoop)); /* If nRowEst is zero and there is an ORDER BY clause, ignore it. In this ** case the purpose of this call is to estimate the number of rows returned @@ -5758,6 +5759,28 @@ static SQLITE_NOINLINE void whereAddIndexedExpr( } /* +** Set the reverse-scan order mask to one for all tables in the query +** with the exception of MATERIALIZED common table expressions that have +** their own internal ORDER BY clauses. +** +** This implements the PRAGMA reverse_unordered_selects=ON setting. +** (Also SQLITE_DBCONFIG_REVERSE_SCANORDER). +*/ +static SQLITE_NOINLINE void whereReverseScanOrder(WhereInfo *pWInfo){ + int ii; + for(ii=0; ii<pWInfo->pTabList->nSrc; ii++){ + SrcItem *pItem = &pWInfo->pTabList->a[ii]; + if( !pItem->fg.isCte + || pItem->u2.pCteUse->eM10d!=M10d_Yes + || NEVER(pItem->pSelect==0) + || pItem->pSelect->pOrderBy==0 + ){ + pWInfo->revMask |= MASKBIT(ii); + } + } +} + +/* ** Generate the beginning of the loop used for WHERE clause processing. ** The return value is a pointer to an opaque structure that contains ** information needed to terminate the loop. Later, the calling routine @@ -6121,8 +6144,9 @@ WhereInfo *sqlite3WhereBegin( if( db->mallocFailed ) goto whereBeginError; } } + assert( pWInfo->pTabList!=0 ); if( pWInfo->pOrderBy==0 && (db->flags & SQLITE_ReverseOrder)!=0 ){ - pWInfo->revMask = ALLBITS; + whereReverseScanOrder(pWInfo); } if( pParse->nErr ){ goto whereBeginError; @@ -6222,6 +6246,7 @@ WhereInfo *sqlite3WhereBegin( 0!=(wctrlFlags & WHERE_ONEPASS_MULTIROW) && !IsVirtual(pTabList->a[0].pTab) && (0==(wsFlags & WHERE_MULTI_OR) || (wctrlFlags & WHERE_DUPLICATES_OK)) + && OptimizationEnabled(db, SQLITE_OnePass) )){ pWInfo->eOnePass = bOnerow ? ONEPASS_SINGLE : ONEPASS_MULTI; if( HasRowid(pTabList->a[0].pTab) && (wsFlags & WHERE_IDX_ONLY) ){ |