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Overview
| Comment: | Add the ability to disable the omit-join-table optimization for testing purposes. |
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| Downloads: | Tarball | ZIP archive |
| Timelines: | family | ancestors | descendants | both | omit-join-table-opt |
| Files: | files | file ages | folders |
| SHA1: |
d929df9b1ba214c27d8c437099a53ee9 |
| User & Date: | drh 2013-06-22 15:44:26.893 |
Context
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2013-06-26
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| 11:49 | Omit tables from the FROM clause of a join if their presence makes no difference in the final output. (check-in: 6505e2ab02 user: drh tags: trunk) | |
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2013-06-22
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| 15:44 | Add the ability to disable the omit-join-table optimization for testing purposes. (Closed-Leaf check-in: d929df9b1b user: drh tags: omit-join-table-opt) | |
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2013-06-21
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| 02:15 | Only eliminate inner loops of a JOIN if they are the RHS of a LEFT JOIN and if they give no more than a single result. This appears to give correct answers in all cases. (check-in: d7a25cc797 user: drh tags: omit-join-table-opt) | |
Changes
Changes to src/sqliteInt.h.
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1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 | #define SQLITE_FactorOutConst 0x0008 /* Constant factoring */ #define SQLITE_IdxRealAsInt 0x0010 /* Store REAL as INT in indices */ #define SQLITE_DistinctOpt 0x0020 /* DISTINCT using indexes */ #define SQLITE_CoverIdxScan 0x0040 /* Covering index scans */ #define SQLITE_OrderByIdxJoin 0x0080 /* ORDER BY of joins via index */ #define SQLITE_SubqCoroutine 0x0100 /* Evaluate subqueries as coroutines */ #define SQLITE_Transitive 0x0200 /* Transitive constraints */ #define SQLITE_AllOpts 0xffff /* All optimizations */ /* ** Macros for testing whether or not optimizations are enabled or disabled. */ #ifndef SQLITE_OMIT_BUILTIN_TEST #define OptimizationDisabled(db, mask) (((db)->dbOptFlags&(mask))!=0) | > | 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 | #define SQLITE_FactorOutConst 0x0008 /* Constant factoring */ #define SQLITE_IdxRealAsInt 0x0010 /* Store REAL as INT in indices */ #define SQLITE_DistinctOpt 0x0020 /* DISTINCT using indexes */ #define SQLITE_CoverIdxScan 0x0040 /* Covering index scans */ #define SQLITE_OrderByIdxJoin 0x0080 /* ORDER BY of joins via index */ #define SQLITE_SubqCoroutine 0x0100 /* Evaluate subqueries as coroutines */ #define SQLITE_Transitive 0x0200 /* Transitive constraints */ #define SQLITE_OmitNoopJoin 0x0400 /* Omit unused tables in joins */ #define SQLITE_AllOpts 0xffff /* All optimizations */ /* ** Macros for testing whether or not optimizations are enabled or disabled. */ #ifndef SQLITE_OMIT_BUILTIN_TEST #define OptimizationDisabled(db, mask) (((db)->dbOptFlags&(mask))!=0) |
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Changes to src/where.c.
| ︙ | ︙ | |||
5785 5786 5787 5788 5789 5790 5791 |
sqlite3DebugPrintf("\n");
for(ii=0; ii<pWInfo->nLevel; ii++){
whereLoopPrint(pWInfo->a[ii].pWLoop, pTabList);
}
}
#endif
/* Attempt to omit tables from the join that do not effect the result */
| | > > > | 5785 5786 5787 5788 5789 5790 5791 5792 5793 5794 5795 5796 5797 5798 5799 5800 5801 5802 |
sqlite3DebugPrintf("\n");
for(ii=0; ii<pWInfo->nLevel; ii++){
whereLoopPrint(pWInfo->a[ii].pWLoop, pTabList);
}
}
#endif
/* Attempt to omit tables from the join that do not effect the result */
if( pWInfo->nLevel>=2
&& pResultSet!=0
&& OptimizationEnabled(db, SQLITE_OmitNoopJoin)
){
Bitmask tabUsed = exprListTableUsage(pMaskSet, pResultSet);
if( pOrderBy ) tabUsed |= exprListTableUsage(pMaskSet, pOrderBy);
while( pWInfo->nLevel>=2 ){
pLoop = pWInfo->a[pWInfo->nLevel-1].pWLoop;
if( (pWInfo->pTabList->a[pLoop->iTab].jointype & JT_LEFT)==0 ) break;
if( (wctrlFlags & WHERE_WANT_DISTINCT)==0
&& (pLoop->wsFlags & WHERE_ONEROW)==0
|
| ︙ | ︙ |