SQLite

Check-in [3c3ffa901f]
Login

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

Overview
Comment:Further improvements to the processing of nested aggregate queries.
Downloads: Tarball | ZIP archive
Timelines: family | ancestors | descendants | both | nested-agg
Files: files | file ages | folders
SHA1: 3c3ffa901f5ce8a523028ff15563ce3e0f55a641
User & Date: drh 2012-08-23 16:18:10.544
Context
2012-08-23
19:46
Add test cases and fix bugs associated with the previous check-in enhancements to nested aggregate subquery processing. (Closed-Leaf check-in: 00b1dc71be user: drh tags: nested-agg)
16:18
Further improvements to the processing of nested aggregate queries. (check-in: 3c3ffa901f user: drh tags: nested-agg)
2012-08-22
00:39
Modify the MSVC makefile to make it easier to select the heap subsystem to use. (check-in: b1dbf49086 user: mistachkin tags: trunk)
Changes
Unified Diff Ignore Whitespace Patch
Changes to src/expr.c.
3812
3813
3814
3815
3816
3817
3818


3819

3820





3821
3822


3823
3824
3825
3826

3827
3828
3829
3830
3831


3832
3833

3834


3835
3836
3837
3838
3839
3840
3841
3842
3843
3844

3845
3846
3847

3848


3849
3850




















3851
3852
3853
3854
3855
3856
3857
    if( pA->a[i].sortOrder!=pB->a[i].sortOrder ) return 1;
    if( sqlite3ExprCompare(pExprA, pExprB) ) return 1;
  }
  return 0;
}

/*


** This is the expression callback for sqlite3FunctionUsesOtherSrc().

**





** Determine if an expression references any table other than one of the
** tables in pWalker->u.pSrcList and abort if it does.


*/
static int exprUsesOtherSrc(Walker *pWalker, Expr *pExpr){
  if( pExpr->op==TK_COLUMN || pExpr->op==TK_AGG_COLUMN ){
    int i;

    SrcList *pSrc = pWalker->u.pSrcList;
    for(i=0; i<pSrc->nSrc; i++){
      if( pExpr->iTable==pSrc->a[i].iCursor ) return WRC_Continue;
    }
    return WRC_Abort;


  }else{
    return WRC_Continue;

  }


}

/*
** Determine if any of the arguments to the pExpr Function references
** any SrcList other than pSrcList.  Return true if they do.  Return
** false if pExpr has no argument or has only constant arguments or
** only references tables named in pSrcList.
*/
static int sqlite3FunctionUsesOtherSrc(Expr *pExpr, SrcList *pSrcList){
  Walker w;

  assert( pExpr->op==TK_AGG_FUNCTION );
  memset(&w, 0, sizeof(w));
  w.xExprCallback = exprUsesOtherSrc;

  w.u.pSrcList = pSrcList;


  if( sqlite3WalkExprList(&w, pExpr->x.pList)!=WRC_Continue ) return 1;
  return 0;




















}

/*
** Add a new element to the pAggInfo->aCol[] array.  Return the index of
** the new element.  Return a negative number if malloc fails.
*/
static int addAggInfoColumn(sqlite3 *db, AggInfo *pInfo){







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

|


>
|

|

<
>
>
|
<
>
|
>
>










>


|
>
|
>
>
|
|
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>







3812
3813
3814
3815
3816
3817
3818
3819
3820
3821
3822
3823
3824
3825
3826
3827
3828
3829

3830
3831
3832
3833
3834
3835
3836
3837
3838
3839
3840

3841
3842
3843

3844
3845
3846
3847
3848
3849
3850
3851
3852
3853
3854
3855
3856
3857
3858
3859
3860
3861
3862
3863
3864
3865
3866
3867
3868
3869
3870
3871
3872
3873
3874
3875
3876
3877
3878
3879
3880
3881
3882
3883
3884
3885
3886
3887
3888
3889
3890
3891
3892
3893
3894
    if( pA->a[i].sortOrder!=pB->a[i].sortOrder ) return 1;
    if( sqlite3ExprCompare(pExprA, pExprB) ) return 1;
  }
  return 0;
}

/*
** An instance of the following structure is used by the tree walker
** to count references to table columns in the arguments of an 
** aggregate function, in order to implement the sqlite3FunctionUsesOtherSrc()
** and sqlite3FunctionThisSrc() routines.
*/
struct SrcCount {
  SrcList *pSrc;   /* One particular FROM clause in a nested query */
  int nThis;       /* Number of references to columns in pSrcList */
  int nOther;      /* Number of references to columns in other FROM clauses */
};


/*
** Count the number of references to columns.
*/
static int exprSrcCount(Walker *pWalker, Expr *pExpr){
  if( pExpr->op==TK_COLUMN || pExpr->op==TK_AGG_COLUMN ){
    int i;
    struct SrcCount *p = pWalker->u.pSrcCount;
    SrcList *pSrc = p->pSrc;
    for(i=0; i<pSrc->nSrc; i++){
      if( pExpr->iTable==pSrc->a[i].iCursor ) break;
    }

    if( i<pSrc->nSrc ){
      p->nThis++;
    }else{

      p->nOther++;
    }
  }
  return WRC_Continue;
}

/*
** Determine if any of the arguments to the pExpr Function references
** any SrcList other than pSrcList.  Return true if they do.  Return
** false if pExpr has no argument or has only constant arguments or
** only references tables named in pSrcList.
*/
static int sqlite3FunctionUsesOtherSrc(Expr *pExpr, SrcList *pSrcList){
  Walker w;
  struct SrcCount cnt;
  assert( pExpr->op==TK_AGG_FUNCTION );
  memset(&w, 0, sizeof(w));
  w.xExprCallback = exprSrcCount;
  w.u.pSrcCount = &cnt;
  cnt.pSrc = pSrcList;
  cnt.nThis = 0;
  cnt.nOther = 0;
  sqlite3WalkExprList(&w, pExpr->x.pList);
  return cnt.nOther>0;
}

/*
** Determine if any of the arguments to the pExpr Function reference
** pSrcList.  Return true if they do.  Also return true if the function
** has no arguments or has only constant arguments.  Return false if pExpr
** references columns but not columns of tables found in pSrcList.
*/
int sqlite3FunctionUsesThisSrc(Expr *pExpr, SrcList *pSrcList){
  Walker w;
  struct SrcCount cnt;
  assert( pExpr->op==TK_AGG_FUNCTION );
  memset(&w, 0, sizeof(w));
  w.xExprCallback = exprSrcCount;
  w.u.pSrcCount = &cnt;
  cnt.pSrc = pSrcList;
  cnt.nThis = 0;
  cnt.nOther = 0;
  sqlite3WalkExprList(&w, pExpr->x.pList);
  return cnt.nThis>0 || cnt.nOther==0;
}

/*
** Add a new element to the pAggInfo->aCol[] array.  Return the index of
** the new element.  Return a negative number if malloc fails.
*/
static int addAggInfoColumn(sqlite3 *db, AggInfo *pInfo){
Changes to src/resolve.c.
564
565
566
567
568
569
570


571

572



573
574
575
576
577

578
579
580
581
582
583
584
        sqlite3ErrorMsg(pParse, "no such function: %.*s", nId, zId);
        pNC->nErr++;
      }else if( wrong_num_args ){
        sqlite3ErrorMsg(pParse,"wrong number of arguments to function %.*s()",
             nId, zId);
        pNC->nErr++;
      }


      if( is_agg ){

        pExpr->op = TK_AGG_FUNCTION;



        pNC->ncFlags |= NC_HasAgg;
      }
      if( is_agg ) pNC->ncFlags &= ~NC_AllowAgg;
      sqlite3WalkExprList(pWalker, pList);
      if( is_agg ) pNC->ncFlags |= NC_AllowAgg;

      /* FIX ME:  Compute pExpr->affinity based on the expected return
      ** type of the function 
      */
      return WRC_Prune;
    }
#ifndef SQLITE_OMIT_SUBQUERY
    case TK_SELECT:







>
>

>

>
>
>
|
|
|
<
|
>







564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581

582
583
584
585
586
587
588
589
590
        sqlite3ErrorMsg(pParse, "no such function: %.*s", nId, zId);
        pNC->nErr++;
      }else if( wrong_num_args ){
        sqlite3ErrorMsg(pParse,"wrong number of arguments to function %.*s()",
             nId, zId);
        pNC->nErr++;
      }
      if( is_agg ) pNC->ncFlags &= ~NC_AllowAgg;
      sqlite3WalkExprList(pWalker, pList);
      if( is_agg ){
        NameContext *pNC2 = pNC;
        pExpr->op = TK_AGG_FUNCTION;
        pExpr->op2 = 0;
        while( pNC2 && !sqlite3FunctionUsesThisSrc(pExpr, pNC2->pSrcList) ){
          pExpr->op2++;
          pNC2 = pNC2->pNext;
        }
        if( pNC2 ) pNC2->ncFlags |= NC_HasAgg;

        pNC->ncFlags |= NC_AllowAgg;
      }
      /* FIX ME:  Compute pExpr->affinity based on the expected return
      ** type of the function 
      */
      return WRC_Prune;
    }
#ifndef SQLITE_OMIT_SUBQUERY
    case TK_SELECT:
Changes to src/select.c.
3517
3518
3519
3520
3521
3522
3523
3524
3525
3526
3527
3528
3529
3530
3531
  w.pParse = pParse;
  sqlite3WalkSelect(&w, pSelect);
#endif
}


/*
** This routine sets of a SELECT statement for processing.  The
** following is accomplished:
**
**     *  VDBE Cursor numbers are assigned to all FROM-clause terms.
**     *  Ephemeral Table objects are created for all FROM-clause subqueries.
**     *  ON and USING clauses are shifted into WHERE statements
**     *  Wildcards "*" and "TABLE.*" in result sets are expanded.
**     *  Identifiers in expression are matched to tables.







|







3517
3518
3519
3520
3521
3522
3523
3524
3525
3526
3527
3528
3529
3530
3531
  w.pParse = pParse;
  sqlite3WalkSelect(&w, pSelect);
#endif
}


/*
** This routine sets up a SELECT statement for processing.  The
** following is accomplished:
**
**     *  VDBE Cursor numbers are assigned to all FROM-clause terms.
**     *  Ephemeral Table objects are created for all FROM-clause subqueries.
**     *  ON and USING clauses are shifted into WHERE statements
**     *  Wildcards "*" and "TABLE.*" in result sets are expanded.
**     *  Identifiers in expression are matched to tables.
3549
3550
3551
3552
3553
3554
3555
3556

3557
3558
3559
3560
3561
3562
3563
}

/*
** Reset the aggregate accumulator.
**
** The aggregate accumulator is a set of memory cells that hold
** intermediate results while calculating an aggregate.  This
** routine simply stores NULLs in all of those memory cells.

*/
static void resetAccumulator(Parse *pParse, AggInfo *pAggInfo){
  Vdbe *v = pParse->pVdbe;
  int i;
  struct AggInfo_func *pFunc;
  if( pAggInfo->nFunc+pAggInfo->nColumn==0 ){
    return;







|
>







3549
3550
3551
3552
3553
3554
3555
3556
3557
3558
3559
3560
3561
3562
3563
3564
}

/*
** Reset the aggregate accumulator.
**
** The aggregate accumulator is a set of memory cells that hold
** intermediate results while calculating an aggregate.  This
** routine generates code that stores NULLs in all of those memory
** cells.
*/
static void resetAccumulator(Parse *pParse, AggInfo *pAggInfo){
  Vdbe *v = pParse->pVdbe;
  int i;
  struct AggInfo_func *pFunc;
  if( pAggInfo->nFunc+pAggInfo->nColumn==0 ){
    return;
Changes to src/sqliteInt.h.
1686
1687
1688
1689
1690
1691
1692
1693
1694

1695
1696
1697
1698
1699
1700
1701
                         ** TK_REGISTER: register number
                         ** TK_TRIGGER: 1 -> new, 0 -> old */
  ynVar iColumn;         /* TK_COLUMN: column index.  -1 for rowid.
                         ** TK_VARIABLE: variable number (always >= 1). */
  i16 iAgg;              /* Which entry in pAggInfo->aCol[] or ->aFunc[] */
  i16 iRightJoinTable;   /* If EP_FromJoin, the right table of the join */
  u8 flags2;             /* Second set of flags.  EP2_... */
  u8 op2;                /* If a TK_REGISTER, the original value of Expr.op */
                         /* If TK_COLUMN, the value of p5 for OP_Column */

  AggInfo *pAggInfo;     /* Used by TK_AGG_COLUMN and TK_AGG_FUNCTION */
  Table *pTab;           /* Table for TK_COLUMN expressions. */
#if SQLITE_MAX_EXPR_DEPTH>0
  int nHeight;           /* Height of the tree headed by this node */
#endif
};








|
|
>







1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
                         ** TK_REGISTER: register number
                         ** TK_TRIGGER: 1 -> new, 0 -> old */
  ynVar iColumn;         /* TK_COLUMN: column index.  -1 for rowid.
                         ** TK_VARIABLE: variable number (always >= 1). */
  i16 iAgg;              /* Which entry in pAggInfo->aCol[] or ->aFunc[] */
  i16 iRightJoinTable;   /* If EP_FromJoin, the right table of the join */
  u8 flags2;             /* Second set of flags.  EP2_... */
  u8 op2;                /* TK_REGISTER: original value of Expr.op
                         ** TK_COLUMN: the value of p5 for OP_Column
                         ** TK_AGG_FUNCTION: nesting depth */
  AggInfo *pAggInfo;     /* Used by TK_AGG_COLUMN and TK_AGG_FUNCTION */
  Table *pTab;           /* Table for TK_COLUMN expressions. */
#if SQLITE_MAX_EXPR_DEPTH>0
  int nHeight;           /* Height of the tree headed by this node */
#endif
};

2494
2495
2496
2497
2498
2499
2500

2501
2502
2503
2504

2505
2506
2507
2508
2509
2510
2511
/*
** Context pointer passed down through the tree-walk.
*/
struct Walker {
  int (*xExprCallback)(Walker*, Expr*);     /* Callback for expressions */
  int (*xSelectCallback)(Walker*,Select*);  /* Callback for SELECTs */
  Parse *pParse;                            /* Parser context.  */

  union {                                   /* Extra data for callback */
    NameContext *pNC;                          /* Naming context */
    int i;                                     /* Integer value */
    SrcList *pSrcList;                         /* FROM clause */

  } u;
};

/* Forward declarations */
int sqlite3WalkExpr(Walker*, Expr*);
int sqlite3WalkExprList(Walker*, ExprList*);
int sqlite3WalkSelect(Walker*, Select*);







>




>







2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
/*
** Context pointer passed down through the tree-walk.
*/
struct Walker {
  int (*xExprCallback)(Walker*, Expr*);     /* Callback for expressions */
  int (*xSelectCallback)(Walker*,Select*);  /* Callback for SELECTs */
  Parse *pParse;                            /* Parser context.  */
  int walkerDepth;                          /* Number of subqueries */
  union {                                   /* Extra data for callback */
    NameContext *pNC;                          /* Naming context */
    int i;                                     /* Integer value */
    SrcList *pSrcList;                         /* FROM clause */
    struct SrcCount *pSrcCount;                /* Counting column references */
  } u;
};

/* Forward declarations */
int sqlite3WalkExpr(Walker*, Expr*);
int sqlite3WalkExprList(Walker*, ExprList*);
int sqlite3WalkSelect(Walker*, Select*);
2831
2832
2833
2834
2835
2836
2837

2838
2839
2840
2841
2842
2843
2844
void sqlite3Vacuum(Parse*);
int sqlite3RunVacuum(char**, sqlite3*);
char *sqlite3NameFromToken(sqlite3*, Token*);
int sqlite3ExprCompare(Expr*, Expr*);
int sqlite3ExprListCompare(ExprList*, ExprList*);
void sqlite3ExprAnalyzeAggregates(NameContext*, Expr*);
void sqlite3ExprAnalyzeAggList(NameContext*,ExprList*);

Vdbe *sqlite3GetVdbe(Parse*);
void sqlite3PrngSaveState(void);
void sqlite3PrngRestoreState(void);
void sqlite3PrngResetState(void);
void sqlite3RollbackAll(sqlite3*,int);
void sqlite3CodeVerifySchema(Parse*, int);
void sqlite3CodeVerifyNamedSchema(Parse*, const char *zDb);







>







2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
void sqlite3Vacuum(Parse*);
int sqlite3RunVacuum(char**, sqlite3*);
char *sqlite3NameFromToken(sqlite3*, Token*);
int sqlite3ExprCompare(Expr*, Expr*);
int sqlite3ExprListCompare(ExprList*, ExprList*);
void sqlite3ExprAnalyzeAggregates(NameContext*, Expr*);
void sqlite3ExprAnalyzeAggList(NameContext*,ExprList*);
int sqlite3FunctionUsesThisSrc(Expr*, SrcList*);
Vdbe *sqlite3GetVdbe(Parse*);
void sqlite3PrngSaveState(void);
void sqlite3PrngRestoreState(void);
void sqlite3PrngResetState(void);
void sqlite3RollbackAll(sqlite3*,int);
void sqlite3CodeVerifySchema(Parse*, int);
void sqlite3CodeVerifyNamedSchema(Parse*, const char *zDb);
Added test/aggnested.test.












































































>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
# 2012 August 23
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.
#
# This file implements tests for processing aggregate queries with 
# subqueries in which the subqueries hold the aggregate functions
# or in which the subqueries are themselves aggregate queries
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl

do_test aggnested-1.1 {
  db eval {
    CREATE TABLE t1(a1 INTEGER);
    INSERT INTO t1 VALUES(1), (2), (3);
    CREATE TABLE t2(b1 INTEGER);
    INSERT INTO t2 VALUES(4), (5);
    SELECT (SELECT group_concat(a1,'x') FROM t2) FROM t1;
  }
} {1x2x3}
do_test aggnested-1.2 {
  db eval {
    SELECT
     (SELECT group_concat(a1,'x') || '-' || group_concat(b1,'y') FROM t2)
    FROM t1;
  }
} {1x2x3-4y5}

finish_test