From: drh <drh@noemail.net>
Date: Wed, 5 Jun 2013 12:47:59 +0000 (+0000)
Subject: Performance tweak to whereLoopInsert().
X-Git-Tag: version-3.8.0~130^2~25
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=cd0f407c3f9ab27cfac6be88e53ce0036d2208b2;p=thirdparty%2Fsqlite.git

Performance tweak to whereLoopInsert().

FossilOrigin-Name: 1c4a78807b7a28c9976ca8c5722ff4e2e8755b7e
---

diff --git a/manifest b/manifest
index ed506f992c..ae6211e19d 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Add\sa\stest\scase\scontributed\son\sthe\smailing\slist\nthat\sworks\sin\sNGQP\sbut\sfails\sin\slegacy.
-D 2013-06-05T12:18:15.188
+C Performance\stweak\sto\swhereLoopInsert().
+D 2013-06-05T12:47:59.358
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 5e41da95d92656a5004b03d3576e8b226858a28e
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -289,7 +289,7 @@ F src/vtab.c b05e5f1f4902461ba9f5fc49bb7eb7c3a0741a83
 F src/wal.c 436bfceb141b9423c45119e68e444358ee0ed35d
 F src/wal.h df01efe09c5cb8c8e391ff1715cca294f89668a4
 F src/walker.c 4fa43583d0a84b48f93b1e88f11adf2065be4e73
-F src/where.c 0b8fd61de3c71df0ba084d13177c384bb50e4d22
+F src/where.c 3b175d731c15e30bd8893b0309f9e7e8d0f11121
 F test/8_3_names.test ebbb5cd36741350040fd28b432ceadf495be25b2
 F test/aggerror.test a867e273ef9e3d7919f03ef4f0e8c0d2767944f2
 F test/aggnested.test 45c0201e28045ad38a530b5a144b73cd4aa2cfd6
@@ -1094,7 +1094,7 @@ F tool/vdbe-compress.tcl f12c884766bd14277f4fcedcae07078011717381
 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh fbc018d67fd7395f440c28f33ef0f94420226381
 F tool/win/sqlite.vsix 97894c2790eda7b5bce3cc79cb2a8ec2fde9b3ac
-P cf96eb5945a9bab71104cb1581ee13ab30022566
-R 373c05c6780cec478b9924edf49e0658
+P 96afe50866a08ed14e911c3c955030f7ab83a3ed
+R 70441548922262718992448fc2500d0d
 U drh
-Z c785a25f44da51b36475ec1e8ccfb14e
+Z 415f390706a3e5c8723b2ce592b50c3b
diff --git a/manifest.uuid b/manifest.uuid
index bafc3efa21..ce1f9dfb25 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-96afe50866a08ed14e911c3c955030f7ab83a3ed
\ No newline at end of file
+1c4a78807b7a28c9976ca8c5722ff4e2e8755b7e
\ No newline at end of file
diff --git a/src/where.c b/src/where.c
index d9dccf7541..3af73198e8 100644
--- a/src/where.c
+++ b/src/where.c
@@ -3859,25 +3859,27 @@ static int whereLoopInsert(WhereLoopBuilder *pBuilder, WhereLoop *pTemplate){
   */
   for(ppPrev=&pWInfo->pLoops, p=*ppPrev; p; ppPrev=&p->pNextLoop, p=*ppPrev){
     if( p->iTab!=pTemplate->iTab || p->iSortIdx!=pTemplate->iSortIdx ) continue;
-    if( p->nTerm<pTemplate->nTerm
-     && (p->wsFlags & WHERE_INDEXED)!=0
-     && (pTemplate->wsFlags & WHERE_INDEXED)!=0
-     && p->u.btree.pIndex==pTemplate->u.btree.pIndex
-     && p->prereq==pTemplate->prereq
-    ){
-      /* Overwrite an existing WhereLoop with an similar one that uses
-      ** more terms of the index */
-      pNext = p->pNextLoop;
-      whereLoopClear(db, p);
-      break;
-    }
     if( (p->prereq & pTemplate->prereq)==p->prereq
      && p->rSetup<=pTemplate->rSetup
      && p->rRun<=pTemplate->rRun
     ){
-      /* Already holding an equal or better WhereLoop.
-      ** Return without changing or adding anything */
-      goto whereLoopInsert_noop;
+      /* p is equal or better than pTemplate */
+      if( p->nTerm<pTemplate->nTerm
+       && (p->wsFlags & WHERE_INDEXED)!=0
+       && (pTemplate->wsFlags & WHERE_INDEXED)!=0
+       && p->u.btree.pIndex==pTemplate->u.btree.pIndex
+       && p->prereq==pTemplate->prereq
+      ){
+        /* Overwrite an existing WhereLoop with an similar one that uses
+        ** more terms of the index */
+        pNext = p->pNextLoop;
+        whereLoopClear(db, p);
+        break;
+      }else{
+        /* pTemplate is not helpful.
+        ** Return without changing or adding anything */
+        goto whereLoopInsert_noop;
+      }
     }
     if( (p->prereq & pTemplate->prereq)==pTemplate->prereq
      && p->rSetup>=pTemplate->rSetup