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Overview
Comment: | Enhance the xBestIndex interface of virtual table so that if the xBestIndex method returns SQLITE_CONSTRAINT then that particular combination of constraints is considered unusable and does not participate further in query planning. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA3-256: |
684013cef6bfcfd920a4aec645df9f5d |
User & Date: | drh 2018-11-16 13:56:15.713 |
Context
2018-11-16
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14:36 | In order to avoid exporting a symbol, use a macro instead of a function to replace sqlite3_complete() in the shell code when SQLITE_OMIT_COMPLETE is defined. (check-in: d584a0cb51 user: dan tags: trunk) | |
13:56 | Enhance the xBestIndex interface of virtual table so that if the xBestIndex method returns SQLITE_CONSTRAINT then that particular combination of constraints is considered unusable and does not participate further in query planning. (check-in: 684013cef6 user: drh tags: trunk) | |
13:06 | Fix comments and make magic numbers into #defines in the fsdir implementation. (check-in: c537c9c363 user: drh tags: trunk) | |
Changes
Changes to ext/misc/fileio.c.
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842 843 844 845 846 847 848 | ** (2) Path is in argv[0] and dir is in argv[1] */ static int fsdirBestIndex( sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo ){ int i; /* Loop over constraints */ | | | > > > > | > > > > > > > > | > > > > | > | > > > > > > | > > > | | | | | | | 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 | ** (2) Path is in argv[0] and dir is in argv[1] */ static int fsdirBestIndex( sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo ){ int i; /* Loop over constraints */ int idxPath = -1; /* Index in pIdxInfo->aConstraint of PATH= */ int idxDir = -1; /* Index in pIdxInfo->aConstraint of DIR= */ int seenPath = 0; /* True if an unusable PATH= constraint is seen */ int seenDir = 0; /* True if an unusable DIR= constraint is seen */ const struct sqlite3_index_constraint *pConstraint; (void)tab; pConstraint = pIdxInfo->aConstraint; for(i=0; i<pIdxInfo->nConstraint; i++, pConstraint++){ if( pConstraint->op!=SQLITE_INDEX_CONSTRAINT_EQ ) continue; switch( pConstraint->iColumn ){ case FSDIR_COLUMN_PATH: { if( pConstraint->usable ){ idxPath = i; seenPath = 0; }else if( idxPath<0 ){ seenPath = 1; } break; } case FSDIR_COLUMN_DIR: { if( pConstraint->usable ){ idxDir = i; seenDir = 0; }else if( idxDir<0 ){ seenDir = 1; } break; } } } if( seenPath || seenDir ){ /* If input parameters are unusable, disallow this plan */ return SQLITE_CONSTRAINT; } if( idxPath<0 ){ pIdxInfo->idxNum = 0; /* The pIdxInfo->estimatedCost should have been initialized to a huge ** number. Leave it unchanged. */ pIdxInfo->estimatedRows = 0x7fffffff; }else{ pIdxInfo->aConstraintUsage[idxPath].omit = 1; pIdxInfo->aConstraintUsage[idxPath].argvIndex = 1; if( idxDir>=0 ){ pIdxInfo->aConstraintUsage[idxDir].omit = 1; pIdxInfo->aConstraintUsage[idxDir].argvIndex = 2; pIdxInfo->idxNum = 2; pIdxInfo->estimatedCost = 10.0; }else{ pIdxInfo->idxNum = 1; pIdxInfo->estimatedCost = 100.0; } } |
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Changes to src/where.c.
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1027 1028 1029 1030 1031 1032 1033 | /* ** The table object reference passed as the second argument to this function ** must represent a virtual table. This function invokes the xBestIndex() ** method of the virtual table with the sqlite3_index_info object that ** comes in as the 3rd argument to this function. ** | | | > | > | | < < < < < < < < < < < | | 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 | /* ** The table object reference passed as the second argument to this function ** must represent a virtual table. This function invokes the xBestIndex() ** method of the virtual table with the sqlite3_index_info object that ** comes in as the 3rd argument to this function. ** ** If an error occurs, pParse is populated with an error message and an ** appropriate error code is returned. A return of SQLITE_CONSTRAINT from ** xBestIndex is not considered an error. SQLITE_CONSTRAINT indicates that ** the current configuration of "unusable" flags in sqlite3_index_info can ** not result in a valid plan. ** ** Whether or not an error is returned, it is the responsibility of the ** caller to eventually free p->idxStr if p->needToFreeIdxStr indicates ** that this is required. */ static int vtabBestIndex(Parse *pParse, Table *pTab, sqlite3_index_info *p){ sqlite3_vtab *pVtab = sqlite3GetVTable(pParse->db, pTab)->pVtab; int rc; TRACE_IDX_INPUTS(p); rc = pVtab->pModule->xBestIndex(pVtab, p); TRACE_IDX_OUTPUTS(p); if( rc!=SQLITE_OK && rc!=SQLITE_CONSTRAINT ){ if( rc==SQLITE_NOMEM ){ sqlite3OomFault(pParse->db); }else if( !pVtab->zErrMsg ){ sqlite3ErrorMsg(pParse, "%s", sqlite3ErrStr(rc)); }else{ sqlite3ErrorMsg(pParse, "%s", pVtab->zErrMsg); } } sqlite3_free(pVtab->zErrMsg); pVtab->zErrMsg = 0; // assert( pParse->nErr==0 || (rc!=SQLITE_OK && rc!=SQLITE_CONSTRAINT) ); return rc; } #endif /* !defined(SQLITE_OMIT_VIRTUALTABLE) */ #ifdef SQLITE_ENABLE_STAT3_OR_STAT4 /* ** Estimate the location of a particular key among all keys in an ** index. Store the results in aStat as follows: |
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3139 3140 3141 3142 3143 3144 3145 | pIdxInfo->estimatedCost = SQLITE_BIG_DBL / (double)2; pIdxInfo->estimatedRows = 25; pIdxInfo->idxFlags = 0; pIdxInfo->colUsed = (sqlite3_int64)pSrc->colUsed; /* Invoke the virtual table xBestIndex() method */ rc = vtabBestIndex(pParse, pSrc->pTab, pIdxInfo); | | > > > > > > > > > | 3130 3131 3132 3133 3134 3135 3136 3137 3138 3139 3140 3141 3142 3143 3144 3145 3146 3147 3148 3149 3150 3151 3152 3153 | pIdxInfo->estimatedCost = SQLITE_BIG_DBL / (double)2; pIdxInfo->estimatedRows = 25; pIdxInfo->idxFlags = 0; pIdxInfo->colUsed = (sqlite3_int64)pSrc->colUsed; /* Invoke the virtual table xBestIndex() method */ rc = vtabBestIndex(pParse, pSrc->pTab, pIdxInfo); if( rc ){ if( rc==SQLITE_CONSTRAINT ){ /* If the xBestIndex method returns SQLITE_CONSTRAINT, that means ** that the particular combination of parameters provided is unusable. ** Make no entries in the loop table. */ return SQLITE_OK; } return rc; } mxTerm = -1; assert( pNew->nLSlot>=nConstraint ); for(i=0; i<nConstraint; i++) pNew->aLTerm[i] = 0; pNew->u.vtab.omitMask = 0; pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint; for(i=0; i<nConstraint; i++, pIdxCons++){ |
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Changes to test/bestindex4.test.
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151 152 153 154 155 156 157 | } do_execsql_test 2.0 { CREATE VIRTUAL TABLE x1 USING tcl(vtab_command); CREATE TABLE t1 (x INT PRIMARY KEY); } {} | | | > | | | | > | | | 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 | } do_execsql_test 2.0 { CREATE VIRTUAL TABLE x1 USING tcl(vtab_command); CREATE TABLE t1 (x INT PRIMARY KEY); } {} do_eqp_test 2.1 { SELECT * FROM t1, x1 WHERE x1.d=t1.x; } { QUERY PLAN |--SCAN TABLE x1 VIRTUAL TABLE INDEX 0: `--SEARCH TABLE t1 USING COVERING INDEX sqlite_autoindex_t1_1 (x=?) } do_eqp_test 2.2 { SELECT * FROM t1, x1(t1.x) } { QUERY PLAN |--SCAN TABLE t1 `--SCAN TABLE x1 VIRTUAL TABLE INDEX 555: } finish_test |