-C Disable\sthe\swal64k.test\sscript\sfor\snon-unix\ssystems\ssince\sit\sdepends\son\nunix-only\sfeatures.
-D 2014-03-28T14:41:35.536
+C Experiments\sin\spicking\sbetter\squery\splans,\sespecially\swhen\sthe\susage\sof\sone\nindex\sis\sa\ssubset\sof\sanother.
+D 2014-03-29T21:16:07.103
F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
F Makefile.in 2ef13430cd359f7b361bb863504e227b25cc7f81
F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
F src/wal.c 76e7fc6de229bea8b30bb2539110f03a494dc3a8
F src/wal.h df01efe09c5cb8c8e391ff1715cca294f89668a4
F src/walker.c 11edb74d587bc87b33ca96a5173e3ec1b8389e45
-F src/where.c 7d539cedb1c6a6d6b5d2075b8fea3a48db4838eb
+F src/where.c 26c6f6260b0cc2b0038dcc68ace0d7db20c7dcee
F src/whereInt.h 2564055b440e44ebec8b47f237bbccae6719b7af
F test/8_3_names.test ebbb5cd36741350040fd28b432ceadf495be25b2
F test/aggerror.test a867e273ef9e3d7919f03ef4f0e8c0d2767944f2
F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
F tool/warnings.sh d1a6de74685f360ab718efda6265994b99bbea01
F tool/win/sqlite.vsix 030f3eeaf2cb811a3692ab9c14d021a75ce41fff
-P a4e47150f32b3a4120b1f89ccc66d633d829e3bb
-R 578568415288cd31fe0adba6128329da
+P 27deb6e49bcc76714dbdc61b34748603155ac770
+R 1df7985395668b26c614cc4e641f29c8
+T *branch * query-plan-experiments
+T *sym-query-plan-experiments *
+T -sym-trunk *
U drh
-Z 045e2748905f8bd05ecf1197b97d7f20
+Z 1c5ff3f986da6bbe350c60cf72c963dd
}
/*
-** Insert or replace a WhereLoop entry using the template supplied.
+** Search the list of WhereLoops in *ppPrev looking for one that can be
+** supplanted by pTemplate.
**
-** An existing WhereLoop entry might be overwritten if the new template
-** is better and has fewer dependencies. Or the template will be ignored
-** and no insert will occur if an existing WhereLoop is faster and has
-** fewer dependencies than the template. Otherwise a new WhereLoop is
-** added based on the template.
+** Return NULL if the WhereLoop list contains an entry that can supplant
+** pTemplate, in other words if pTemplate does not belong on the list.
**
-** If pBuilder->pOrSet is not NULL then we only care about only the
-** prerequisites and rRun and nOut costs of the N best loops. That
-** information is gathered in the pBuilder->pOrSet object. This special
-** processing mode is used only for OR clause processing.
+** If pX is a WhereLoop that pTemplate can supplant, then return the
+** link that points to pX.
**
-** When accumulating multiple loops (when pBuilder->pOrSet is NULL) we
-** still might overwrite similar loops with the new template if the
-** template is better. Loops may be overwritten if the following
-** conditions are met:
-**
-** (1) They have the same iTab.
-** (2) They have the same iSortIdx.
-** (3) The template has same or fewer dependencies than the current loop
-** (4) The template has the same or lower cost than the current loop
-** (5) The template uses more terms of the same index but has no additional
-** dependencies
+** If pTemplate cannot supplant any existing element of the list but needs
+** to be added to the list, then return a pointer to the tail of the list.
*/
-static int whereLoopInsert(WhereLoopBuilder *pBuilder, WhereLoop *pTemplate){
- WhereLoop **ppPrev, *p, *pNext = 0;
- WhereInfo *pWInfo = pBuilder->pWInfo;
- sqlite3 *db = pWInfo->pParse->db;
-
- /* If pBuilder->pOrSet is defined, then only keep track of the costs
- ** and prereqs.
- */
- if( pBuilder->pOrSet!=0 ){
-#if WHERETRACE_ENABLED
- u16 n = pBuilder->pOrSet->n;
- int x =
-#endif
- whereOrInsert(pBuilder->pOrSet, pTemplate->prereq, pTemplate->rRun,
- pTemplate->nOut);
-#if WHERETRACE_ENABLED /* 0x8 */
- if( sqlite3WhereTrace & 0x8 ){
- sqlite3DebugPrintf(x?" or-%d: ":" or-X: ", n);
- whereLoopPrint(pTemplate, pBuilder->pWC);
- }
-#endif
- return SQLITE_OK;
- }
-
- /* Search for an existing WhereLoop to overwrite, or which takes
- ** priority over pTemplate.
- */
- for(ppPrev=&pWInfo->pLoops, p=*ppPrev; p; ppPrev=&p->pNextLoop, p=*ppPrev){
+static WhereLoop **whereLoopFindLesser(
+ WhereLoop **ppPrev,
+ const WhereLoop *pTemplate
+){
+ WhereLoop *p;
+ for(p=(*ppPrev); p; ppPrev=&p->pNextLoop, p=*ppPrev){
if( p->iTab!=pTemplate->iTab || p->iSortIdx!=pTemplate->iSortIdx ){
/* If either the iTab or iSortIdx values for two WhereLoop are different
** then those WhereLoops need to be considered separately. Neither is
){
/* Overwrite an existing WhereLoop with an similar one that uses
** more terms of the index */
- pNext = p->pNextLoop;
break;
}else{
- /* pTemplate is not helpful.
- ** Return without changing or adding anything */
- goto whereLoopInsert_noop;
+ /* There is an existing WhereLoop that is better than pTemplate */
+ return 0;
}
}
if( (p->prereq & pTemplate->prereq)==pTemplate->prereq
** or (4) number of output rows, and is no worse in any of those
** categories. */
assert( p->rSetup>=pTemplate->rSetup ); /* SETUP-INVARIANT above */
- pNext = p->pNextLoop;
break;
}
}
+ return ppPrev;
+}
+
+/*
+** Insert or replace a WhereLoop entry using the template supplied.
+**
+** An existing WhereLoop entry might be overwritten if the new template
+** is better and has fewer dependencies. Or the template will be ignored
+** and no insert will occur if an existing WhereLoop is faster and has
+** fewer dependencies than the template. Otherwise a new WhereLoop is
+** added based on the template.
+**
+** If pBuilder->pOrSet is not NULL then we care about only the
+** prerequisites and rRun and nOut costs of the N best loops. That
+** information is gathered in the pBuilder->pOrSet object. This special
+** processing mode is used only for OR clause processing.
+**
+** When accumulating multiple loops (when pBuilder->pOrSet is NULL) we
+** still might overwrite similar loops with the new template if the
+** template is better. Loops may be overwritten if the following
+** conditions are met:
+**
+** (1) They have the same iTab.
+** (2) They have the same iSortIdx.
+** (3) The template has same or fewer dependencies than the current loop
+** (4) The template has the same or lower cost than the current loop
+** (5) The template uses more terms of the same index but has no additional
+** dependencies
+*/
+static int whereLoopInsert(WhereLoopBuilder *pBuilder, WhereLoop *pTemplate){
+ WhereLoop **ppPrev, *p;
+ WhereInfo *pWInfo = pBuilder->pWInfo;
+ sqlite3 *db = pWInfo->pParse->db;
+
+ /* If pBuilder->pOrSet is defined, then only keep track of the costs
+ ** and prereqs.
+ */
+ if( pBuilder->pOrSet!=0 ){
+#if WHERETRACE_ENABLED
+ u16 n = pBuilder->pOrSet->n;
+ int x =
+#endif
+ whereOrInsert(pBuilder->pOrSet, pTemplate->prereq, pTemplate->rRun,
+ pTemplate->nOut);
+#if WHERETRACE_ENABLED /* 0x8 */
+ if( sqlite3WhereTrace & 0x8 ){
+ sqlite3DebugPrintf(x?" or-%d: ":" or-X: ", n);
+ whereLoopPrint(pTemplate, pBuilder->pWC);
+ }
+#endif
+ return SQLITE_OK;
+ }
+
+ /* Look for an existing WhereLoop to replace with pTemplate
+ */
+ ppPrev = whereLoopFindLesser(&pWInfo->pLoops, pTemplate);
+
+ if( ppPrev==0 ){
+ /* There already exists a WhereLoop on the list that is better
+ ** than pTemplate, so just ignore pTemplate */
+#if WHERETRACE_ENABLED /* 0x8 */
+ if( sqlite3WhereTrace & 0x8 ){
+ sqlite3DebugPrintf("ins-noop: ");
+ whereLoopPrint(pTemplate, pBuilder->pWC);
+ }
+#endif
+ return SQLITE_OK;
+ }else{
+ p = *ppPrev;
+ }
/* If we reach this point it means that either p[] should be overwritten
** with pTemplate[] if p[] exists, or if p==NULL then allocate a new
}
#endif
if( p==0 ){
- p = sqlite3DbMallocRaw(db, sizeof(WhereLoop));
+ /* Allocate a new WhereLoop to add to the end of the list */
+ *ppPrev = p = sqlite3DbMallocRaw(db, sizeof(WhereLoop));
if( p==0 ) return SQLITE_NOMEM;
whereLoopInit(p);
+ p->pNextLoop = 0;
+ }else{
+ /* We will be overwriting WhereLoop p[]. But before we do, first
+ ** go through the rest of the list and delete any other entries besides
+ ** p[] that are also supplated by pTemplate */
+ WhereLoop **ppTail = &p->pNextLoop;
+ WhereLoop *pToDel;
+ while( *ppTail ){
+ ppTail = whereLoopFindLesser(ppTail, pTemplate);
+ if( NEVER(ppTail==0) ) break;
+ pToDel = *ppTail;
+ if( pToDel==0 ) break;
+ *ppTail = pToDel->pNextLoop;
+#if WHERETRACE_ENABLED /* 0x8 */
+ if( sqlite3WhereTrace & 0x8 ){
+ sqlite3DebugPrintf("ins-del: ");
+ whereLoopPrint(pToDel, pBuilder->pWC);
+ }
+#endif
+ whereLoopDelete(db, pToDel);
+ }
}
whereLoopXfer(db, p, pTemplate);
- p->pNextLoop = pNext;
- *ppPrev = p;
if( (p->wsFlags & WHERE_VIRTUALTABLE)==0 ){
Index *pIndex = p->u.btree.pIndex;
if( pIndex && pIndex->tnum==0 ){
}
}
return SQLITE_OK;
-
- /* Jump here if the insert is a no-op */
-whereLoopInsert_noop:
-#if WHERETRACE_ENABLED /* 0x8 */
- if( sqlite3WhereTrace & 0x8 ){
- sqlite3DebugPrintf("ins-noop: ");
- whereLoopPrint(pTemplate, pBuilder->pWC);
- }
-#endif
- return SQLITE_OK;
}
/*
projects / thirdparty / sqlite.git / commitdiff
