From 9861a9f0656bc7d0e38dc440892416e33fa662a7 Mon Sep 17 00:00:00 2001
From: drh <drh@noemail.net>
Date: Tue, 27 Jun 2006 02:33:40 +0000
Subject: [PATCH] Cleanup and refactor parts of the optimizer. (CVS 3301)

FossilOrigin-Name: 6609c25fbfa5ad7f55c356936abb1721686c47ca
---
 manifest      | 12 ++++++------
 manifest.uuid |  2 +-
 src/where.c   | 32 +++++++++++++++-----------------
 3 files changed, 22 insertions(+), 24 deletions(-)

diff --git a/manifest b/manifest
index e41efea03a..7bb211cfd3 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Cache\sand\sreuse\svirtual\stable\sindex\sinformation\sin\sthe\soptimizer.\nImproved\sdiagnostics\sfor\svirtual\stable\sindex\sselection.\s(CVS\s3300)
-D 2006-06-27T01:54:26
+C Cleanup\sand\srefactor\sparts\sof\sthe\soptimizer.\s(CVS\s3301)
+D 2006-06-27T02:33:40
 F Makefile.in f839b470345d3cb4b0644068474623fe2464b5d3
 F Makefile.linux-gcc 2d8574d1ba75f129aba2019f0b959db380a90935
 F README 9c4e2d6706bdcc3efdd773ce752a8cdab4f90028
@@ -105,7 +105,7 @@ F src/vdbeaux.c bb0a7b800a7167f2e49702a2bfc971919c0b99d1
 F src/vdbefifo.c 9efb94c8c3f4c979ebd0028219483f88e57584f5
 F src/vdbemem.c 5f0afe3b92bb2c037f8d5d697f7c151fa50783a3
 F src/vtab.c 4751954e26e9caa6ce3ea5ad9468bd34f07d1de7
-F src/where.c 676105f882af3e58fd4cf75fb51746f8e9f70bdc
+F src/where.c f794d15f5f0503b7b5cdb3fa49fd1f76c015e80d
 F tclinstaller.tcl 046e3624671962dc50f0481d7c25b38ef803eb42
 F test/aggerror.test a867e273ef9e3d7919f03ef4f0e8c0d2767944f2
 F test/all.test 5df90d015ca63fcef2a4b62c24f7316b66c4bfd4
@@ -374,7 +374,7 @@ F www/tclsqlite.tcl bb0d1357328a42b1993d78573e587c6dcbc964b9
 F www/vdbe.tcl 87a31ace769f20d3627a64fa1fade7fed47b90d0
 F www/version3.tcl 890248cf7b70e60c383b0e84d77d5132b3ead42b
 F www/whentouse.tcl 97e2b5cd296f7d8057e11f44427dea8a4c2db513
-P 1ca385bb39514cb73f506bfbbe38aabb6b70816c
-R 68db026572948c11690ddd8e3fadf452
+P 28413cf2b3f0e6f294e1f3c59fcce135b65c294f
+R 241cba895df62f4aae2eec3dd91bf438
 U drh
-Z b6129eea235de4e5615a497f90bd0807
+Z e0a333826629d40e18f9e44a948284ff
diff --git a/manifest.uuid b/manifest.uuid
index 6e627fb2a2..145605a475 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-28413cf2b3f0e6f294e1f3c59fcce135b65c294f
\ No newline at end of file
+6609c25fbfa5ad7f55c356936abb1721686c47ca
\ No newline at end of file
diff --git a/src/where.c b/src/where.c
index 02b751e82d..0493f71527 100644
--- a/src/where.c
+++ b/src/where.c
@@ -16,7 +16,7 @@
 ** so is applicable.  Because this module is responsible for selecting
 ** indices, you might also think of this module as the "query optimizer".
 **
-** $Id: where.c,v 1.224 2006/06/27 01:54:26 drh Exp $
+** $Id: where.c,v 1.225 2006/06/27 02:33:40 drh Exp $
 */
 #include "sqliteInt.h"
 
@@ -1856,7 +1856,6 @@ WhereInfo *sqlite3WhereBegin(
       }
       assert( pTabItem->pTab );
 #ifndef SQLITE_OMIT_VIRTUALTABLE
-      pIndex = 0;
       if( IsVirtual(pTabItem->pTab) ){
         sqlite3_index_info **ppIdxInfo = &pWInfo->a[j].pIdxInfo;
         cost = bestVirtualIndex(pParse, &wc, pTabItem, notReady,
@@ -1875,6 +1874,7 @@ WhereInfo *sqlite3WhereBegin(
         cost = bestIndex(pParse, &wc, pTabItem, notReady,
                          (i==0 && ppOrderBy) ? *ppOrderBy : 0,
                          &pIdx, &flags, &nEq);
+        pIndex = 0;
       }
       if( cost<lowestCost ){
         once = 1;
@@ -1883,9 +1883,7 @@ WhereInfo *sqlite3WhereBegin(
         bestFlags = flags;
         bestNEq = nEq;
         bestJ = j;
-#ifndef SQLITE_OMIT_VIRTUALTABLE
         pLevel->pBestIdx = pIndex;
-#endif
       }
       if( doNotReorder ) break;
     }
@@ -1921,7 +1919,6 @@ WhereInfo *sqlite3WhereBegin(
   ** searching those tables.
   */
   sqlite3CodeVerifySchema(pParse, -1); /* Insert the cookie verifier Goto */
-  pLevel = pWInfo->a;
   for(i=0, pLevel=pWInfo->a; i<pTabList->nSrc; i++, pLevel++){
     Table *pTab;     /* Table to open */
     Index *pIx;      /* Index used to access pTab (if any) */
@@ -2036,7 +2033,7 @@ WhereInfo *sqlite3WhereBegin(
       /* Case 0:  The table is a virtual-table.  Use the VFilter and VNext
       **          to access the data.
       */
-      int ii;
+      int j;
       sqlite3_index_info *pBestIdx = pLevel->pBestIdx;
       int nConstraint = pBestIdx->nConstraint;
       struct sqlite3_index_constraint_usage *aUsage =
@@ -2044,25 +2041,26 @@ WhereInfo *sqlite3WhereBegin(
       const struct sqlite3_index_constraint *aConstraint =
                                                   pBestIdx->aConstraint;
 
-      for(ii=1; ii<=nConstraint; ii++){
-        int j;
-        for(j=0; j<nConstraint; j++){
-          if( aUsage[j].argvIndex==ii ){
-            int k = aConstraint[j].iTermOffset;
-            sqlite3ExprCode(pParse, wc.a[k].pExpr->pRight);
+      for(j=1; j<=nConstraint; j++){
+        int k;
+        for(k=0; k<nConstraint; k++){
+          if( aUsage[k].argvIndex==j ){
+            int iTerm = aConstraint[j-1].iTermOffset;
+            sqlite3ExprCode(pParse, wc.a[iTerm].pExpr->pRight);
             break;
           }
         }
-        if( j==nConstraint ) break;
+        if( k==nConstraint ) break;
       }
-      sqlite3VdbeAddOp(v, OP_Integer, ii-1, 0);
+      sqlite3VdbeAddOp(v, OP_Integer, j-1, 0);
       sqlite3VdbeAddOp(v, OP_Integer, pBestIdx->idxNum, 0);
       sqlite3VdbeOp3(v, OP_VFilter, iCur, brk, pBestIdx->idxStr,
                       pBestIdx->needToFreeIdxStr ? P3_MPRINTF : P3_STATIC);
       pBestIdx->needToFreeIdxStr = 0;
-      for(ii=0; ii<pBestIdx->nConstraint; ii++){
-        if( pBestIdx->aConstraintUsage[ii].omit ){
-          disableTerm(pLevel, &wc.a[ii]);
+      for(j=0; j<pBestIdx->nConstraint; j++){
+        if( aUsage[j].omit ){
+          int iTerm = aConstraint[j].iTermOffset;
+          disableTerm(pLevel, &wc.a[iTerm]);
         }
       }
       pLevel->op = OP_VNext;
-- 
2.47.2