From: drh <drh@noemail.net>
Date: Thu, 13 Jun 2013 17:28:22 +0000 (+0000)
Subject: Make sure that disabling the covering index scan optimization does not
X-Git-Tag: version-3.8.0~134^2~18
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=53cfbe92d1ca41e6873e7c897023187d656f41c1;p=thirdparty%2Fsqlite.git

Make sure that disabling the covering index scan optimization does not
prevent a covering index from being used to satisfy an ORDER BY clause.

FossilOrigin-Name: e8b7ea8202c443bfc8a978588c7d2cfaa14a8fea
---

diff --git a/manifest b/manifest
index 1780bda7cd..97ae5f18b7 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Restore\sthe\sability\sto\sdo\sa\sBETWEEN\squery\son\sthe\srowid.\s\sAlso\sfix\sa\nnearby\scomment.
-D 2013-06-13T15:50:59.429
+C Make\ssure\sthat\sdisabling\sthe\scovering\sindex\sscan\soptimization\sdoes\snot\nprevent\sa\scovering\sindex\sfrom\sbeing\sused\sto\ssatisfy\san\sORDER\sBY\sclause.
+D 2013-06-13T17:28:22.026
 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 82b519b79e4efc45461f6ce3990292c01b5adfdd
+F src/where.c 700085a8d8e0edf13db11e110577320ec7348edc
 F test/8_3_names.test ebbb5cd36741350040fd28b432ceadf495be25b2
 F test/aggerror.test a867e273ef9e3d7919f03ef4f0e8c0d2767944f2
 F test/aggnested.test 45c0201e28045ad38a530b5a144b73cd4aa2cfd6
@@ -1095,7 +1095,7 @@ F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh fbc018d67fd7395f440c28f33ef0f94420226381
 F tool/wherecosttest.c f407dc4c79786982a475261866a161cd007947ae
 F tool/win/sqlite.vsix 97894c2790eda7b5bce3cc79cb2a8ec2fde9b3ac
-P 3a72af2a95b04b8e195ef17cb3e9d9021a4f0915
-R 1257e951bd26adefbb24e4a4d17e2b37
+P 459a7b9068310b36fed950940d251c4b798ffc58
+R 242dd2338fa025aa7191faa8afaf3ae6
 U drh
-Z e1ac17bd2fbb6e506f40edf419e837ee
+Z 7fc4ebaffcaa0d84212cec77e769d428
diff --git a/manifest.uuid b/manifest.uuid
index fe46658266..10384ea54c 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-459a7b9068310b36fed950940d251c4b798ffc58
\ No newline at end of file
+e8b7ea8202c443bfc8a978588c7d2cfaa14a8fea
\ No newline at end of file
diff --git a/src/where.c b/src/where.c
index 14bbf88a5b..46f741d159 100644
--- a/src/where.c
+++ b/src/where.c
@@ -445,7 +445,6 @@ struct WhereInfo {
 #define WHERE_ONEROW       0x00001000  /* Selects no more than one row */
 #define WHERE_MULTI_OR     0x00002000  /* OR using multiple indices */
 #define WHERE_TEMP_INDEX   0x00004000  /* Uses an ephemeral index */
-#define WHERE_COVER_SCAN   0x00008000  /* Full scan of a covering index */
 
 
 /* Convert a WhereCost value (10 times log2(X)) into its integer value X.
@@ -3614,8 +3613,7 @@ static Bitmask codeOneLoopStart(
       pLevel->op = OP_Next;
     }
     pLevel->p1 = iIdxCur;
-    if( (pLoop->wsFlags & (WHERE_COLUMN_EQ | WHERE_COLUMN_RANGE | 
-                          WHERE_COLUMN_NULL | WHERE_COLUMN_IN))==0 ){
+    if( (pLoop->wsFlags & WHERE_CONSTRAINT)==0 ){
       pLevel->p5 = SQLITE_STMTSTATUS_FULLSCAN_STEP;
     }else{
       assert( pLevel->p5==0 );
@@ -4375,6 +4373,7 @@ static int indexMightHelpWithOrderBy(
   int iCol;
   int ii;
 
+  if( pIndex->bUnordered ) return 0;
   if( (pOB = pBuilder->pWInfo->pOrderBy)==0 ) return 0;
   iCol = pIndex->aiColumn[0];
   for(ii=0; ii<pOB->nExpr; ii++){
@@ -4503,6 +4502,8 @@ static int whereLoopAddBtree(
     pNew->prereq = mExtra;
     pNew->u.btree.pIndex = pProbe;
     b = indexMightHelpWithOrderBy(pBuilder, pProbe, pSrc->iCursor);
+    /* The ONEPASS_DESIRED flags never occurs together with ORDER BY */
+    assert( (pWInfo->wctrlFlags & WHERE_ONEPASS_DESIRED)==0 || b==0 );
     if( pProbe->tnum<=0 ){
       /* Integer primary key index */
       pNew->wsFlags = WHERE_IPK;
@@ -4523,11 +4524,13 @@ static int whereLoopAddBtree(
       pNew->wsFlags = (m==0) ? (WHERE_IDX_ONLY|WHERE_INDEXED) : WHERE_INDEXED;
 
       /* Full scan via index */
-      if( (m==0 || b)
-       && pProbe->bUnordered==0
-       && (pWInfo->wctrlFlags & WHERE_ONEPASS_DESIRED)==0
-       && sqlite3GlobalConfig.bUseCis
-       && OptimizationEnabled(pWInfo->pParse->db, SQLITE_CoverIdxScan)
+      if( b
+       || ( m==0
+         && pProbe->bUnordered==0
+         && (pWInfo->wctrlFlags & WHERE_ONEPASS_DESIRED)==0
+         && sqlite3GlobalConfig.bUseCis
+         && OptimizationEnabled(pWInfo->pParse->db, SQLITE_CoverIdxScan)
+          )
       ){
         pNew->iSortIdx = b ? iSortIdx : 0;
         pNew->nOut = rSize;