SQLite

Check-in [4902015d]
Login

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

Overview
Comment:As evidenced by forum post f3f546025a, the new RIGHT JOIN related restriction on the push-down optimization implemented by [da3fba18742b6e0b] also needs to apply to the automatic index (a.k.a. hash-join) optimization and to the Bloom filter optimization. Computation of the restriction is now moved into the sqlite3ExprIsSingleTableConstraint() routine.
Downloads: Tarball | ZIP archive | SQL archive
Timelines: family | ancestors | descendants | both | trunk
Files: files | file ages | folders
SHA3-256: 4902015dcf3869f08d9986e422faa231d9218a5e0fc59ba8df0f407e4eb3d605
User & Date: drh 2023-05-15 02:06:35
Context
2023-05-15
03:48
Make generate_series() correct on ones complement ALUs and acceptable to UBSAN. (check-in: 4c5cd3e6 user: larrybr tags: trunk)
02:06
As evidenced by forum post f3f546025a, the new RIGHT JOIN related restriction on the push-down optimization implemented by [da3fba18742b6e0b] also needs to apply to the automatic index (a.k.a. hash-join) optimization and to the Bloom filter optimization. Computation of the restriction is now moved into the sqlite3ExprIsSingleTableConstraint() routine. (check-in: 4902015d user: drh tags: trunk)
01:02
Simplify the interface to constructAutomaticIndex(). (check-in: c5da1655 user: drh tags: trunk)
Changes
Hide Diffs Unified Diffs Ignore Whitespace Patch

Changes to src/expr.c.

2374
2375
2376
2377
2378
2379
2380
2381
2382

2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405













2406
2407





2408
2409
2410
2411
2412
2413
2414
2415













2416
2417
2418
2419
2420
2421
2422
** table other than iCur.
*/
int sqlite3ExprIsTableConstant(Expr *p, int iCur){
  return exprIsConst(p, 3, iCur);
}

/*
** Check pExpr to see if it is an constraint on the single data source pSrc.
** In other words, check to see if pExpr constrains pSrc but does not depend

** on any other tables or data sources anywhere else in the query.  Return
** true (non-zero) if pExpr is a constraint on pSrc only.
**
** This is an optimization.  False negatives will perhaps cause slower
** queries, but false positives will yield incorrect answers.  So when in
** doubt, return 0.
**
** To be an single-source constraint, the following must be true:
**
**   (1)  pExpr cannot refer to any table other than pSrc->iCursor.
**
**   (2)  pExpr cannot use subqueries or non-deterministic functions.
**
**   (3)  pSrc cannot be part of the left operand for a RIGHT JOIN.
**        (Is there some way to relax this constraint?)
**
**   (4)  If pSrc is the right operand of a LEFT JOIN, then...
**         (4a)  pExpr must come from an ON clause..
           (4b)  and specifically the ON clause associated with the LEFT JOIN.
**
**   (5)  If pSrc is not the right operand of a LEFT JOIN or the left
**        operand of a RIGHT JOIN, then pExpr must be from the WHERE
**        clause, not an ON clause.













*/
int sqlite3ExprIsSingleTableConstraint(Expr *pExpr, const SrcItem *pSrc){





  if( pSrc->fg.jointype & JT_LTORJ ){
    return 0;  /* rule (3) */
  }
  if( pSrc->fg.jointype & JT_LEFT ){
    if( !ExprHasProperty(pExpr, EP_OuterON) ) return 0;   /* rule (4a) */
    if( pExpr->w.iJoin!=pSrc->iCursor ) return 0;         /* rule (4b) */
  }else{
    if( ExprHasProperty(pExpr, EP_OuterON) ) return 0;    /* rule (5) */













  }
  return sqlite3ExprIsTableConstant(pExpr, pSrc->iCursor); /* rules (1), (2) */
}


/*
** sqlite3WalkExpr() callback used by sqlite3ExprIsConstantOrGroupBy().







|
|
>
|
|
















|




>
>
>
>
>
>
>
>
>
>
>
>
>

|
>
>
>
>
>








>
>
>
>
>
>
>
>
>
>
>
>
>







2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
** table other than iCur.
*/
int sqlite3ExprIsTableConstant(Expr *p, int iCur){
  return exprIsConst(p, 3, iCur);
}

/*
** Check pExpr to see if it is an constraint on the single data source
** pSrc = &pSrcList->a[iSrc].  In other words, check to see if pExpr
** constrains pSrc but does not depend on any other tables or data
** sources anywhere else in the query.  Return true (non-zero) if pExpr
** is a constraint on pSrc only.
**
** This is an optimization.  False negatives will perhaps cause slower
** queries, but false positives will yield incorrect answers.  So when in
** doubt, return 0.
**
** To be an single-source constraint, the following must be true:
**
**   (1)  pExpr cannot refer to any table other than pSrc->iCursor.
**
**   (2)  pExpr cannot use subqueries or non-deterministic functions.
**
**   (3)  pSrc cannot be part of the left operand for a RIGHT JOIN.
**        (Is there some way to relax this constraint?)
**
**   (4)  If pSrc is the right operand of a LEFT JOIN, then...
**         (4a)  pExpr must come from an ON clause..
**         (4b)  and specifically the ON clause associated with the LEFT JOIN.
**
**   (5)  If pSrc is not the right operand of a LEFT JOIN or the left
**        operand of a RIGHT JOIN, then pExpr must be from the WHERE
**        clause, not an ON clause.
**
**   (6) Either:
**
**       (6a) pExpr does not originate in an ON or USING clause, or
**
**       (6b) The ON or USING clause from which pExpr is derived is
**            not to the left of a RIGHT JOIN (or FULL JOIN).
**
**       Without this restriction, accepting pExpr as a single-table
**       constraint might move the the ON/USING filter expression
**       from the left side of a RIGHT JOIN over to the right side,
**       which leads to incorrect answers.  See also restriction (9)
**       on push-down.
*/
int sqlite3ExprIsSingleTableConstraint(
  Expr *pExpr,                 /* The constraint */
  const SrcList *pSrcList,     /* Complete FROM clause */
  int iSrc                     /* Which element of pSrcList to use */
){
  const SrcItem *pSrc = &pSrcList->a[iSrc];
  if( pSrc->fg.jointype & JT_LTORJ ){
    return 0;  /* rule (3) */
  }
  if( pSrc->fg.jointype & JT_LEFT ){
    if( !ExprHasProperty(pExpr, EP_OuterON) ) return 0;   /* rule (4a) */
    if( pExpr->w.iJoin!=pSrc->iCursor ) return 0;         /* rule (4b) */
  }else{
    if( ExprHasProperty(pExpr, EP_OuterON) ) return 0;    /* rule (5) */
  }
  if( ExprHasProperty(pExpr, EP_OuterON|EP_InnerON)  /* (6a) */
   && (pSrcList->a[0].fg.jointype & JT_LTORJ)!=0     /* Fast pre-test of (6b) */
  ){
    int jj;
    for(jj=0; jj<iSrc; jj++){
      if( pExpr->w.iJoin==pSrcList->a[jj].iCursor ){
        if( (pSrcList->a[jj].fg.jointype & JT_LTORJ)!=0 ){
          return 0;  /* restriction (6) */
        }
        break;
      }
    }
  }
  return sqlite3ExprIsTableConstant(pExpr, pSrc->iCursor); /* rules (1), (2) */
}


/*
** sqlite3WalkExpr() callback used by sqlite3ExprIsConstantOrGroupBy().

Changes to src/select.c.

5115
5116
5117
5118
5119
5120
5121
5122

5123
5124
5125
5126
5127
5128
5129
**       (9b) The subquery is to the right of the ON/USING clause
**
**       (9c) There is a RIGHT JOIN (or FULL JOIN) in between the ON/USING
**            clause and the subquery.
**
**       Without this restriction, the push-down optimization might move
**       the ON/USING filter expression from the left side of a RIGHT JOIN
**       over to the right side, which leads to incorrect answers.

**
**  (10) The inner query is not the right-hand table of a RIGHT JOIN.
**
**  (11) The subquery is not a VALUES clause
**
** Return 0 if no changes are made and non-zero if one or more WHERE clause
** terms are duplicated into the subquery.







|
>







5115
5116
5117
5118
5119
5120
5121
5122
5123
5124
5125
5126
5127
5128
5129
5130
**       (9b) The subquery is to the right of the ON/USING clause
**
**       (9c) There is a RIGHT JOIN (or FULL JOIN) in between the ON/USING
**            clause and the subquery.
**
**       Without this restriction, the push-down optimization might move
**       the ON/USING filter expression from the left side of a RIGHT JOIN
**       over to the right side, which leads to incorrect answers.  See
**       also restriction (6) in sqlite3ExprIsSingleTableConstraint().
**
**  (10) The inner query is not the right-hand table of a RIGHT JOIN.
**
**  (11) The subquery is not a VALUES clause
**
** Return 0 if no changes are made and non-zero if one or more WHERE clause
** terms are duplicated into the subquery.
5200
5201
5202
5203
5204
5205
5206

5207
5208
5209
5210
5211
5212
5213
5214
5215
5216
5217
5218
5219
5220
5221
5222
5223
5224
5225
5226
5227
5228
5229
5230
5231
5232
5233
5234
5235
5236
5237
5238
5239
5240
5241
5242
5243
5244
5245
5246
    return 0; /* restriction (3) */
  }
  while( pWhere->op==TK_AND ){
    nChng += pushDownWhereTerms(pParse, pSubq, pWhere->pRight, pSrcList, iSrc);
    pWhere = pWhere->pLeft;
  }


  if( ExprHasProperty(pWhere, EP_OuterON|EP_InnerON) /* (9a) */
   && (pSrcList->a[0].fg.jointype & JT_LTORJ)!=0     /* Fast pre-test of (9c) */
  ){
    int jj;
    for(jj=0; jj<iSrc; jj++){
      if( pWhere->w.iJoin==pSrcList->a[jj].iCursor ){
        /* If we reach this point, both (9a) and (9b) are satisfied.
        ** The following loop checks (9c):
        */
        for(jj++; jj<iSrc; jj++){
          if( (pSrcList->a[jj].fg.jointype & JT_RIGHT)!=0 ){
            return 0;  /* restriction (9) */
          }
        }
      }
    }
  }

#if 0 /* These checks now done by sqlite3ExprIsSingleTableConstraint() */
  if( isLeftJoin
   && (ExprHasProperty(pWhere,EP_OuterON)==0
         || pWhere->w.iJoin!=iCursor)
  ){
    return 0; /* restriction (4) */
  }
  if( ExprHasProperty(pWhere,EP_OuterON)
   && pWhere->w.iJoin!=iCursor 
  ){
    return 0; /* restriction (5) */
  }
#endif

  if( sqlite3ExprIsSingleTableConstraint(pWhere, pSrc) ){
    nChng++;
    pSubq->selFlags |= SF_PushDown;
    while( pSubq ){
      SubstContext x;
      pNew = sqlite3ExprDup(pParse->db, pWhere, 0);
      unsetJoinExpr(pNew, -1, 1);
      x.pParse = pParse;







>

















<
<













|







5201
5202
5203
5204
5205
5206
5207
5208
5209
5210
5211
5212
5213
5214
5215
5216
5217
5218
5219
5220
5221
5222
5223
5224
5225


5226
5227
5228
5229
5230
5231
5232
5233
5234
5235
5236
5237
5238
5239
5240
5241
5242
5243
5244
5245
5246
    return 0; /* restriction (3) */
  }
  while( pWhere->op==TK_AND ){
    nChng += pushDownWhereTerms(pParse, pSubq, pWhere->pRight, pSrcList, iSrc);
    pWhere = pWhere->pLeft;
  }

#if 0 /* These checks now done by sqlite3ExprIsSingleTableConstraint() */
  if( ExprHasProperty(pWhere, EP_OuterON|EP_InnerON) /* (9a) */
   && (pSrcList->a[0].fg.jointype & JT_LTORJ)!=0     /* Fast pre-test of (9c) */
  ){
    int jj;
    for(jj=0; jj<iSrc; jj++){
      if( pWhere->w.iJoin==pSrcList->a[jj].iCursor ){
        /* If we reach this point, both (9a) and (9b) are satisfied.
        ** The following loop checks (9c):
        */
        for(jj++; jj<iSrc; jj++){
          if( (pSrcList->a[jj].fg.jointype & JT_RIGHT)!=0 ){
            return 0;  /* restriction (9) */
          }
        }
      }
    }
  }


  if( isLeftJoin
   && (ExprHasProperty(pWhere,EP_OuterON)==0
         || pWhere->w.iJoin!=iCursor)
  ){
    return 0; /* restriction (4) */
  }
  if( ExprHasProperty(pWhere,EP_OuterON)
   && pWhere->w.iJoin!=iCursor 
  ){
    return 0; /* restriction (5) */
  }
#endif

  if( sqlite3ExprIsSingleTableConstraint(pWhere, pSrcList, iSrc) ){
    nChng++;
    pSubq->selFlags |= SF_PushDown;
    while( pSubq ){
      SubstContext x;
      pNew = sqlite3ExprDup(pParse->db, pWhere, 0);
      unsetJoinExpr(pNew, -1, 1);
      x.pParse = pParse;

Changes to src/sqliteInt.h.

4902
4903
4904
4905
4906
4907
4908
4909
4910
4911
4912
4913
4914
4915
4916
int sqlite3ExprIdToTrueFalse(Expr*);
int sqlite3ExprTruthValue(const Expr*);
int sqlite3ExprIsConstant(Expr*);
int sqlite3ExprIsConstantNotJoin(Expr*);
int sqlite3ExprIsConstantOrFunction(Expr*, u8);
int sqlite3ExprIsConstantOrGroupBy(Parse*, Expr*, ExprList*);
int sqlite3ExprIsTableConstant(Expr*,int);
int sqlite3ExprIsSingleTableConstraint(Expr*,const SrcItem*);
#ifdef SQLITE_ENABLE_CURSOR_HINTS
int sqlite3ExprContainsSubquery(Expr*);
#endif
int sqlite3ExprIsInteger(const Expr*, int*);
int sqlite3ExprCanBeNull(const Expr*);
int sqlite3ExprNeedsNoAffinityChange(const Expr*, char);
int sqlite3IsRowid(const char*);







|







4902
4903
4904
4905
4906
4907
4908
4909
4910
4911
4912
4913
4914
4915
4916
int sqlite3ExprIdToTrueFalse(Expr*);
int sqlite3ExprTruthValue(const Expr*);
int sqlite3ExprIsConstant(Expr*);
int sqlite3ExprIsConstantNotJoin(Expr*);
int sqlite3ExprIsConstantOrFunction(Expr*, u8);
int sqlite3ExprIsConstantOrGroupBy(Parse*, Expr*, ExprList*);
int sqlite3ExprIsTableConstant(Expr*,int);
int sqlite3ExprIsSingleTableConstraint(Expr*,const SrcList*,int);
#ifdef SQLITE_ENABLE_CURSOR_HINTS
int sqlite3ExprContainsSubquery(Expr*);
#endif
int sqlite3ExprIsInteger(const Expr*, int*);
int sqlite3ExprCanBeNull(const Expr*);
int sqlite3ExprNeedsNoAffinityChange(const Expr*, char);
int sqlite3IsRowid(const char*);

Changes to src/where.c.

891
892
893
894
895
896
897

898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913

914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
  char *zNotUsed;             /* Extra space on the end of pIdx */
  Bitmask idxCols;            /* Bitmap of columns used for indexing */
  Bitmask extraCols;          /* Bitmap of additional columns */
  u8 sentWarning = 0;         /* True if a warning has been issued */
  u8 useBloomFilter = 0;      /* True to also add a Bloom filter */
  Expr *pPartial = 0;         /* Partial Index Expression */
  int iContinue = 0;          /* Jump here to skip excluded rows */

  SrcItem *pSrc;              /* The FROM clause term to get the next index */
  int addrCounter = 0;        /* Address where integer counter is initialized */
  int regBase;                /* Array of registers where record is assembled */
#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
  int addrExp = 0;            /* Address of OP_Explain */
#endif

  /* Generate code to skip over the creation and initialization of the
  ** transient index on 2nd and subsequent iterations of the loop. */
  v = pParse->pVdbe;
  assert( v!=0 );
  addrInit = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);

  /* Count the number of columns that will be added to the index
  ** and used to match WHERE clause constraints */
  nKeyCol = 0;

  pSrc = &pWC->pWInfo->pTabList->a[pLevel->iFrom];
  pTable = pSrc->pTab;
  pWCEnd = &pWC->a[pWC->nTerm];
  pLoop = pLevel->pWLoop;
  idxCols = 0;
  for(pTerm=pWC->a; pTerm<pWCEnd; pTerm++){
    Expr *pExpr = pTerm->pExpr;
    /* Make the automatic index a partial index if there are terms in the
    ** WHERE clause (or the ON clause of a LEFT join) that constrain which
    ** rows of the target table (pSrc) that can be used. */
    if( (pTerm->wtFlags & TERM_VIRTUAL)==0
     && sqlite3ExprIsSingleTableConstraint(pExpr, pSrc)
    ){
      pPartial = sqlite3ExprAnd(pParse, pPartial,
                                sqlite3ExprDup(pParse->db, pExpr, 0));
    }
    if( termCanDriveIndex(pTerm, pSrc, notReady) ){
      int iCol;
      Bitmask cMask;







>
















>
|










|







891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
  char *zNotUsed;             /* Extra space on the end of pIdx */
  Bitmask idxCols;            /* Bitmap of columns used for indexing */
  Bitmask extraCols;          /* Bitmap of additional columns */
  u8 sentWarning = 0;         /* True if a warning has been issued */
  u8 useBloomFilter = 0;      /* True to also add a Bloom filter */
  Expr *pPartial = 0;         /* Partial Index Expression */
  int iContinue = 0;          /* Jump here to skip excluded rows */
  SrcList *pTabList;          /* The complete FROM clause */
  SrcItem *pSrc;              /* The FROM clause term to get the next index */
  int addrCounter = 0;        /* Address where integer counter is initialized */
  int regBase;                /* Array of registers where record is assembled */
#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
  int addrExp = 0;            /* Address of OP_Explain */
#endif

  /* Generate code to skip over the creation and initialization of the
  ** transient index on 2nd and subsequent iterations of the loop. */
  v = pParse->pVdbe;
  assert( v!=0 );
  addrInit = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);

  /* Count the number of columns that will be added to the index
  ** and used to match WHERE clause constraints */
  nKeyCol = 0;
  pTabList = pWC->pWInfo->pTabList;
  pSrc = &pTabList->a[pLevel->iFrom];
  pTable = pSrc->pTab;
  pWCEnd = &pWC->a[pWC->nTerm];
  pLoop = pLevel->pWLoop;
  idxCols = 0;
  for(pTerm=pWC->a; pTerm<pWCEnd; pTerm++){
    Expr *pExpr = pTerm->pExpr;
    /* Make the automatic index a partial index if there are terms in the
    ** WHERE clause (or the ON clause of a LEFT join) that constrain which
    ** rows of the target table (pSrc) that can be used. */
    if( (pTerm->wtFlags & TERM_VIRTUAL)==0
     && sqlite3ExprIsSingleTableConstraint(pExpr, pTabList, pLevel->iFrom)
    ){
      pPartial = sqlite3ExprAnd(pParse, pPartial,
                                sqlite3ExprDup(pParse->db, pExpr, 0));
    }
    if( termCanDriveIndex(pTerm, pSrc, notReady) ){
      int iCol;
      Bitmask cMask;
1146
1147
1148
1149
1150
1151
1152

1153
1154
1155

1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169


1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193

  assert( pLoop!=0 );
  assert( v!=0 );
  assert( pLoop->wsFlags & WHERE_BLOOMFILTER );

  addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
  do{

    const SrcItem *pItem;
    const Table *pTab;
    u64 sz;

    sqlite3WhereExplainBloomFilter(pParse, pWInfo, pLevel);
    addrCont = sqlite3VdbeMakeLabel(pParse);
    iCur = pLevel->iTabCur;
    pLevel->regFilter = ++pParse->nMem;

    /* The Bloom filter is a Blob held in a register.  Initialize it
    ** to zero-filled blob of at least 80K bits, but maybe more if the
    ** estimated size of the table is larger.  We could actually
    ** measure the size of the table at run-time using OP_Count with
    ** P3==1 and use that value to initialize the blob.  But that makes
    ** testing complicated.  By basing the blob size on the value in the
    ** sqlite_stat1 table, testing is much easier.
    */
    pItem = &pWInfo->pTabList->a[pLevel->iFrom];


    assert( pItem!=0 );
    pTab = pItem->pTab;
    assert( pTab!=0 );
    sz = sqlite3LogEstToInt(pTab->nRowLogEst);
    if( sz<10000 ){
      sz = 10000;
    }else if( sz>10000000 ){
      sz = 10000000;
    }
    sqlite3VdbeAddOp2(v, OP_Blob, (int)sz, pLevel->regFilter);

    addrTop = sqlite3VdbeAddOp1(v, OP_Rewind, iCur); VdbeCoverage(v);
    pWCEnd = &pWInfo->sWC.a[pWInfo->sWC.nTerm];
    for(pTerm=pWInfo->sWC.a; pTerm<pWCEnd; pTerm++){
      Expr *pExpr = pTerm->pExpr;
      if( (pTerm->wtFlags & TERM_VIRTUAL)==0
       && sqlite3ExprIsSingleTableConstraint(pExpr, pItem)
      ){
        sqlite3ExprIfFalse(pParse, pTerm->pExpr, addrCont, SQLITE_JUMPIFNULL);
      }
    }
    if( pLoop->wsFlags & WHERE_IPK ){
      int r1 = sqlite3GetTempReg(pParse);
      sqlite3VdbeAddOp2(v, OP_Rowid, iCur, r1);







>



>













|
>
>
















|







1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199

  assert( pLoop!=0 );
  assert( v!=0 );
  assert( pLoop->wsFlags & WHERE_BLOOMFILTER );

  addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
  do{
    const SrcList *pTabList;
    const SrcItem *pItem;
    const Table *pTab;
    u64 sz;
    int iSrc;
    sqlite3WhereExplainBloomFilter(pParse, pWInfo, pLevel);
    addrCont = sqlite3VdbeMakeLabel(pParse);
    iCur = pLevel->iTabCur;
    pLevel->regFilter = ++pParse->nMem;

    /* The Bloom filter is a Blob held in a register.  Initialize it
    ** to zero-filled blob of at least 80K bits, but maybe more if the
    ** estimated size of the table is larger.  We could actually
    ** measure the size of the table at run-time using OP_Count with
    ** P3==1 and use that value to initialize the blob.  But that makes
    ** testing complicated.  By basing the blob size on the value in the
    ** sqlite_stat1 table, testing is much easier.
    */
    pTabList = pWInfo->pTabList;
    iSrc = pLevel->iFrom;
    pItem = &pTabList->a[iSrc];
    assert( pItem!=0 );
    pTab = pItem->pTab;
    assert( pTab!=0 );
    sz = sqlite3LogEstToInt(pTab->nRowLogEst);
    if( sz<10000 ){
      sz = 10000;
    }else if( sz>10000000 ){
      sz = 10000000;
    }
    sqlite3VdbeAddOp2(v, OP_Blob, (int)sz, pLevel->regFilter);

    addrTop = sqlite3VdbeAddOp1(v, OP_Rewind, iCur); VdbeCoverage(v);
    pWCEnd = &pWInfo->sWC.a[pWInfo->sWC.nTerm];
    for(pTerm=pWInfo->sWC.a; pTerm<pWCEnd; pTerm++){
      Expr *pExpr = pTerm->pExpr;
      if( (pTerm->wtFlags & TERM_VIRTUAL)==0
       && sqlite3ExprIsSingleTableConstraint(pExpr, pTabList, iSrc)
      ){
        sqlite3ExprIfFalse(pParse, pTerm->pExpr, addrCont, SQLITE_JUMPIFNULL);
      }
    }
    if( pLoop->wsFlags & WHERE_IPK ){
      int r1 = sqlite3GetTempReg(pParse);
      sqlite3VdbeAddOp2(v, OP_Rowid, iCur, r1);

Changes to test/pushdown.test.

202
203
204
205
206
207
208




















209
210
} {- - 3 - 5}
do_execsql_test 4.2 {
  SELECT * FROM v6 JOIN t5 ON false RIGHT JOIN t3 ON true;
} {- - - 3}
do_execsql_test 4.3 {
  SELECT * FROM t1 JOIN t2 ON false JOIN v6 ON true RIGHT JOIN t3 ON true;
} {- - - - 3}





















finish_test







>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>


202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
} {- - 3 - 5}
do_execsql_test 4.2 {
  SELECT * FROM v6 JOIN t5 ON false RIGHT JOIN t3 ON true;
} {- - - 3}
do_execsql_test 4.3 {
  SELECT * FROM t1 JOIN t2 ON false JOIN v6 ON true RIGHT JOIN t3 ON true;
} {- - - - 3}

# 2023-05-15 https://sqlite.org/forum/forumpost/f3f546025a
# This is restriction (6) on sqlite3ExprIsSingleTableConstraint().
# That restriction (now) used to implement restriction (9) on push-down.
# It is used for other things too, so it is not purely a push-down
# restriction.  But it seems convenient to put it here.
#
reset_db
db null -
do_execsql_test 5.0 {
  CREATE TABLE t1(a INT);  INSERT INTO t1 VALUES(1);
  CREATE TABLE t2(b INT);  INSERT INTO t2 VALUES(2);
  CREATE TABLE t3(c INT);  INSERT INTO t3 VALUES(3);
  CREATE TABLE t4(d INT);  INSERT INTO t4 VALUES(4);
  CREATE TABLE t5(e INT);  INSERT INTO t5 VALUES(5);
  SELECT *
    FROM t1 JOIN t2 ON null RIGHT JOIN t3 ON true
          LEFT JOIN (t4 JOIN t5 ON d+1=e) ON d=4
   WHERE e>0;
} {- - 3 4 5}

finish_test