Enhance the plan solver to take into account the number of output rows when

computing the set of paths to retain for the next cycle.

FossilOrigin-Name: 1a46a7242313da96420985fa52e1de3f84533e5b

diff --git a/manifest b/manifest
index c355e4ffe5a7c2b44a3281d686ecc0567ea2ccba..af8be5bcd5399a8c7ea5151776797811ec0fa988 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Initial\simplementation\sof\sthe\sunlikely()\sSQL\sfunction\sused\sas\sa\shint\sto\nthe\squery\splanner.
-D 2013-09-06T15:23:29.191
+C Enhance\sthe\splan\ssolver\sto\stake\sinto\saccount\sthe\snumber\sof\soutput\srows\swhen\ncomputing\sthe\sset\sof\spaths\sto\sretain\sfor\sthe\snext\scycle.
+D 2013-09-06T17:45:42.446
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 5e41da95d92656a5004b03d3576e8b226858a28e
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -214,7 +214,7 @@ F src/pragma.c 3aa3d8c8623b7b71c5b1bfb72dcc31fb0c25665f
 F src/prepare.c fa6988589f39af8504a61731614cd4f6ae71554f
 F src/printf.c da9119eb31a187a4b99f60aa4a225141c0ebb74b
 F src/random.c 0b2dbc37fdfbfa6bd455b091dfcef5bdb32dba68
-F src/resolve.c 748618c3df7f37f2cd33c8834770b1e34f9b1185
+F src/resolve.c 8a2b6b9a6487e6e5a23b8de571131ccce62a1ce0
 F src/rowset.c 64655f1a627c9c212d9ab497899e7424a34222e0
 F src/select.c 9239586282bd146ec5843a2cde7d54cd7816cf78
 F src/shell.c d920a891ca09b8bd262cced7fb0ab9d723f7a747
@@ -290,7 +290,7 @@ F src/vtab.c 5a423b042eb1402ef77697d03d6a67378d97bc8d
 F src/wal.c 7dc3966ef98b74422267e7e6e46e07ff6c6eb1b4
 F src/wal.h df01efe09c5cb8c8e391ff1715cca294f89668a4
 F src/walker.c 4fa43583d0a84b48f93b1e88f11adf2065be4e73
-F src/where.c c9f8ae51797bebfbfa49b9e5bede6fc142b44262
+F src/where.c ce16c689b9a199ffffd63745405214912e941e6f
 F test/8_3_names.test ebbb5cd36741350040fd28b432ceadf495be25b2
 F test/aggerror.test a867e273ef9e3d7919f03ef4f0e8c0d2767944f2
 F test/aggnested.test 45c0201e28045ad38a530b5a144b73cd4aa2cfd6
@@ -1111,10 +1111,7 @@ F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh fbc018d67fd7395f440c28f33ef0f94420226381
 F tool/wherecosttest.c f407dc4c79786982a475261866a161cd007947ae
 F tool/win/sqlite.vsix 97894c2790eda7b5bce3cc79cb2a8ec2fde9b3ac
-P 97b10e66e98e84755aa577f8da017bf1aea2056c
-R fcd7cd29a90a12a870cace66939b8877
-T *branch * unlikely-func
-T *sym-unlikely-func *
-T -sym-trunk *
+P 036fc37a034093a4c6fc190633bd41c2b7230d77
+R 3890bf7553bc1077426fb2f0e0259279
 U drh
-Z 2a30cee668099b5c8e0e2b447ac67feb
+Z 80a7432df4b498524e527dd8f32c240f

diff --git a/manifest.uuid b/manifest.uuid
index b43b68fee1ece9daaa0ace3039bbf6c631cd11fa..b05ebc1a7567a1592e418f7897d4f5587987ed38 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-036fc37a034093a4c6fc190633bd41c2b7230d77
\ No newline at end of file
+1a46a7242313da96420985fa52e1de3f84533e5b
\ No newline at end of file

diff --git a/src/resolve.c b/src/resolve.c
index cb86a83ee0be84475792657a4eaf48aba7b456bd..ec6fe90716df2d66e72c26b270a40e97d7f36cd2 100644 (file)
--- a/src/resolve.c
+++ b/src/resolve.c
@@ -705,7 +705,7 @@ static int resolveExprStep(Walker *pWalker, Expr *pExpr){
               pNC->nErr++;
             }
           }else{
-            pExpr->iTable = 100;
+            pExpr->iTable = 75;
           }             
         }
       }

diff --git a/src/where.c b/src/where.c
index a9905769a410919be5247232f19c33ccad76beb5..e4485ac7d4147acdd06cfbd8c60238b736ac3ce8 100644 (file)
--- a/src/where.c
+++ b/src/where.c
@@ -5306,9 +5306,12 @@ static int wherePathSolver(WhereInfo *pWInfo, WhereCost nRowEst){
   sqlite3 *db;              /* The database connection */
   int iLoop;                /* Loop counter over the terms of the join */
   int ii, jj;               /* Loop counters */
-  WhereCost rCost;             /* Cost of a path */
-  WhereCost mxCost = 0;        /* Maximum cost of a set of paths */
-  WhereCost rSortCost;         /* Cost to do a sort */
+  int mxI = 0;              /* Index of next entry to replace */
+  WhereCost rCost;          /* Cost of a path */
+  WhereCost nOut;           /* Number of outputs */
+  WhereCost mxCost = 0;     /* Maximum cost of a set of paths */
+  WhereCost mxOut = 0;      /* Maximum nOut value on the set of paths */
+  WhereCost rSortCost;      /* Cost to do a sort */
   int nTo, nFrom;           /* Number of valid entries in aTo[] and aFrom[] */
   WherePath *aFrom;         /* All nFrom paths at the previous level */
   WherePath *aTo;           /* The nTo best paths at the current level */
@@ -5377,6 +5380,7 @@ static int wherePathSolver(WhereInfo *pWInfo, WhereCost nRowEst){
         ** Compute its cost */
         rCost = whereCostAdd(pWLoop->rSetup,pWLoop->rRun + pFrom->nRow);
         rCost = whereCostAdd(rCost, pFrom->rCost);
+        nOut = pFrom->nRow + pWLoop->nOut;
         maskNew = pFrom->maskLoop | pWLoop->maskSelf;
         if( !isOrderedValid ){
           switch( wherePathSatisfiesOrderBy(pWInfo,
@@ -5399,17 +5403,23 @@ static int wherePathSolver(WhereInfo *pWInfo, WhereCost nRowEst){
         }
         /* Check to see if pWLoop should be added to the mxChoice best so far */
         for(jj=0, pTo=aTo; jj<nTo; jj++, pTo++){
-          if( pTo->maskLoop==maskNew && pTo->isOrderedValid==isOrderedValid ){
+          if( pTo->maskLoop==maskNew
+           && pTo->isOrderedValid==isOrderedValid
+           && ((pTo->rCost<=rCost && pTo->nRow<=nOut) ||
+                (pTo->rCost>=rCost && pTo->nRow>=nOut))
+          ){
             testcase( jj==nTo-1 );
             break;
           }
         }
         if( jj>=nTo ){
-          if( nTo>=mxChoice && rCost>=mxCost ){
+          if( nTo>=mxChoice 
+           && (rCost>mxCost || (rCost==mxCost && nOut>=mxOut))
+          ){
 #ifdef WHERETRACE_ENABLED
             if( sqlite3WhereTrace&0x4 ){
-              sqlite3DebugPrintf("Skip   %s cost=%3d order=%c\n",
-                  wherePathName(pFrom, iLoop, pWLoop), rCost,
+              sqlite3DebugPrintf("Skip   %s cost=%-3d,%3d order=%c\n",
+                  wherePathName(pFrom, iLoop, pWLoop), rCost, nOut,
                   isOrderedValid ? (isOrdered ? 'Y' : 'N') : '?');
             }
 #endif
@@ -5421,26 +5431,26 @@ static int wherePathSolver(WhereInfo *pWInfo, WhereCost nRowEst){
             jj = nTo++;
           }else{
             /* New path replaces the prior worst to keep count below mxChoice */
-            for(jj=nTo-1; aTo[jj].rCost<mxCost; jj--){ assert(jj>0); }
+            jj = mxI;
           }
           pTo = &aTo[jj];
 #ifdef WHERETRACE_ENABLED
           if( sqlite3WhereTrace&0x4 ){
-            sqlite3DebugPrintf("New    %s cost=%-3d order=%c\n",
-                wherePathName(pFrom, iLoop, pWLoop), rCost,
+            sqlite3DebugPrintf("New    %s cost=%-3d,%3d order=%c\n",
+                wherePathName(pFrom, iLoop, pWLoop), rCost, nOut,
                 isOrderedValid ? (isOrdered ? 'Y' : 'N') : '?');
           }
 #endif
         }else{
-          if( pTo->rCost<=rCost ){
+          if( pTo->rCost<=rCost && pTo->nRow<=nOut ){
 #ifdef WHERETRACE_ENABLED
             if( sqlite3WhereTrace&0x4 ){
               sqlite3DebugPrintf(
-                  "Skip   %s cost=%-3d order=%c",
-                  wherePathName(pFrom, iLoop, pWLoop), rCost,
+                  "Skip   %s cost=%-3d,%3d order=%c",
+                  wherePathName(pFrom, iLoop, pWLoop), rCost, nOut,
                   isOrderedValid ? (isOrdered ? 'Y' : 'N') : '?');
-              sqlite3DebugPrintf("   vs %s cost=%-3d order=%c\n",
-                  wherePathName(pTo, iLoop+1, 0), pTo->rCost,
+              sqlite3DebugPrintf("   vs %s cost=%-3d,%d order=%c\n",
+                  wherePathName(pTo, iLoop+1, 0), pTo->rCost, pTo->nRow,
                   pTo->isOrderedValid ? (pTo->isOrdered ? 'Y' : 'N') : '?');
             }
 #endif
@@ -5452,11 +5462,11 @@ static int wherePathSolver(WhereInfo *pWInfo, WhereCost nRowEst){
 #ifdef WHERETRACE_ENABLED
           if( sqlite3WhereTrace&0x4 ){
             sqlite3DebugPrintf(
-                "Update %s cost=%-3d order=%c",
-                wherePathName(pFrom, iLoop, pWLoop), rCost,
+                "Update %s cost=%-3d,%3d order=%c",
+                wherePathName(pFrom, iLoop, pWLoop), rCost, nOut,
                 isOrderedValid ? (isOrdered ? 'Y' : 'N') : '?');
-            sqlite3DebugPrintf("  was %s cost=%-3d order=%c\n",
-                wherePathName(pTo, iLoop+1, 0), pTo->rCost,
+            sqlite3DebugPrintf("  was %s cost=%-3d,%3d order=%c\n",
+                wherePathName(pTo, iLoop+1, 0), pTo->rCost, pTo->nRow,
                 pTo->isOrderedValid ? (pTo->isOrdered ? 'Y' : 'N') : '?');
           }
 #endif
@@ -5464,16 +5474,22 @@ static int wherePathSolver(WhereInfo *pWInfo, WhereCost nRowEst){
         /* pWLoop is a winner.  Add it to the set of best so far */
         pTo->maskLoop = pFrom->maskLoop | pWLoop->maskSelf;
         pTo->revLoop = revMask;
-        pTo->nRow = pFrom->nRow + pWLoop->nOut;
+        pTo->nRow = nOut;
         pTo->rCost = rCost;
         pTo->isOrderedValid = isOrderedValid;
         pTo->isOrdered = isOrdered;
         memcpy(pTo->aLoop, pFrom->aLoop, sizeof(WhereLoop*)*iLoop);
         pTo->aLoop[iLoop] = pWLoop;
         if( nTo>=mxChoice ){
+          mxI = 0;
           mxCost = aTo[0].rCost;
+          mxOut = aTo[0].nRow;
           for(jj=1, pTo=&aTo[1]; jj<mxChoice; jj++, pTo++){
-            if( pTo->rCost>mxCost ) mxCost = pTo->rCost;
+            if( pTo->rCost>mxCost || (pTo->rCost==mxCost && pTo->nRow>mxOut) ){
+              mxCost = pTo->rCost;
+              mxOut = pTo->nRow;
+              mxI = jj;
+            }
           }
         }
       }
@@ -5510,12 +5526,9 @@ static int wherePathSolver(WhereInfo *pWInfo, WhereCost nRowEst){
   
   /* Find the lowest cost path.  pFrom will be left pointing to that path */
   pFrom = aFrom;
-  assert( nFrom==1 );
-#if 0 /* The following is needed if nFrom is ever more than 1 */
   for(ii=1; ii<nFrom; ii++){
     if( pFrom->rCost>aFrom[ii].rCost ) pFrom = &aFrom[ii];
   }
-#endif
   assert( pWInfo->nLevel==nLoop );
   /* Load the lowest cost path into pWInfo */
   for(iLoop=0; iLoop<nLoop; iLoop++){