/ Check-in [684013ce]
Login

Many hyperlinks are disabled.
Use anonymous login to enable hyperlinks.

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.
Downloads: Tarball | ZIP archive | SQL archive
Timelines: family | ancestors | descendants | both | trunk
Files: files | file ages | folders
SHA3-256: 684013cef6bfcfd920a4aec645df9f5d41ace8b34e75fca61759c1b4f82cc89e
User & Date: drh 2018-11-16 13:56:15
Context
2018-11-16
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: d584a0cb 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: 684013ce user: drh tags: trunk
13:06
Fix comments and make magic numbers into #defines in the fsdir implementation. check-in: c537c9c3 user: drh tags: trunk
Changes
Hide Diffs Unified Diffs Ignore Whitespace Patch

Changes to ext/misc/fileio.c.

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
**  (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 idx4 = -1;         /* Index in pIdxInfo->aConstraint of PATH= */
  int idx5 = -1;         /* Index in pIdxInfo->aConstraint of DIR= */


  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;


    if( pConstraint->iColumn==4 && pConstraint->usable ) idx4 = i;








    if( pConstraint->iColumn==5 ) idx5 = i;




  }


  if( idx4<0 || (idx5>=0 && pIdxInfo->aConstraint[idx5].usable==0) ){








    pIdxInfo->idxNum = 0;


    pIdxInfo->estimatedCost = (double)(((sqlite3_int64)1) << 60);
  }else{
    pIdxInfo->aConstraintUsage[idx4].omit = 1;
    pIdxInfo->aConstraintUsage[idx4].argvIndex = 1;
    if( idx5>=0 ){
      pIdxInfo->aConstraintUsage[idx5].omit = 1;
      pIdxInfo->aConstraintUsage[idx5].argvIndex = 2;
      pIdxInfo->idxNum = 2;
      pIdxInfo->estimatedCost = 10.0;
    }else{
      pIdxInfo->idxNum = 1;
      pIdxInfo->estimatedCost = 100.0;
    }
  }







|
|
>
>






>
>
|
>
>
>
>
>
>
>
>
|
>
>
>
>
|
>
|
<
>
>
>
>
>
>
>
>

>
>
|

|
|
|
|
|







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;
    }
  }

Changes to src/where.c.

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
1072

1073
1074
1075
1076
1077
1078
1079
1080
....
3139
3140
3141
3142
3143
3144
3145








3146

3147
3148
3149
3150
3151
3152
3153

/*
** 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 a
** non-zero value is returned. Otherwise, 0 is returned and the output
** part of the sqlite3_index_info structure is left populated.


**
** 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 ){
    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;

#if 0
  /* This error is now caught by the caller.
  ** Search for "xBestIndex malfunction" below */
  for(i=0; i<p->nConstraint; i++){
    if( !p->aConstraint[i].usable && p->aConstraintUsage[i].argvIndex>0 ){
      sqlite3ErrorMsg(pParse, 
          "table %s: xBestIndex returned an invalid plan", pTab->zName);
    }
  }
#endif


  return pParse->nErr;
}
#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:
................................................................................
  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 ) 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++){







|
|
|
>
>













|










<
<
<
<
<
<
<
<
<
<
<
<
>
|







 







>
>
>
>
>
>
>
>
|
>







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
....
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153

/*
** 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:
................................................................................
  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++){

Changes to test/bestindex4.test.

151
152
153
154
155
156
157
158
159
160

161
162
163
164
165
166
167

168
169
170
171
172
173
}

do_execsql_test 2.0 {
  CREATE VIRTUAL TABLE x1 USING tcl(vtab_command);
  CREATE TABLE t1 (x INT PRIMARY KEY);
} {}

do_execsql_test 2.1 {
  EXPLAIN QUERY PLAN SELECT * FROM t1, x1 WHERE x1.d=t1.x;
} {

  3 0 0 {SCAN TABLE x1 VIRTUAL TABLE INDEX 0:}
  7 0 0 {SEARCH TABLE t1 USING COVERING INDEX sqlite_autoindex_t1_1 (x=?)}
}

do_execsql_test 2.2 {
  EXPLAIN QUERY PLAN SELECT * FROM t1, x1(t1.x)
} {

  3 0 0 {SCAN TABLE t1} 
  5 0 0 {SCAN TABLE x1 VIRTUAL TABLE INDEX 555:}
}


finish_test







|
|

>
|
|


|
|

>
|
|




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