SQLite

Check-in [a0bdb58468]
Login

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

Overview
Comment:Attempt to fix the SQLite core so that no floating point operations are used anywhere if SQLITE_OMIT_FLOATING_POINT is defined at compile-time. This is useful to people who use SQLite on embedded processors that lack floating point support. (CVS 2749)
Downloads: Tarball | ZIP archive
Timelines: family | ancestors | descendants | both | trunk
Files: files | file ages | folders
SHA1: a0bdb584680ce6400d9e8c57db9d91197cc7b776
User & Date: drh 2005-10-13 02:09:50.000
Context
2005-10-20
07:28
Changes to prevent various compiler warnings. (CVS 2750) (check-in: e261b8b09a user: drh tags: trunk)
2005-10-13
02:09
Attempt to fix the SQLite core so that no floating point operations are used anywhere if SQLITE_OMIT_FLOATING_POINT is defined at compile-time. This is useful to people who use SQLite on embedded processors that lack floating point support. (CVS 2749) (check-in: a0bdb58468 user: drh tags: trunk)
2005-10-10
00:05
Make the default TEMP_STORE=1 (TEMP tables stored on disk) in the configure script. (CVS 2748) (check-in: 9753af5349 user: drh tags: trunk)
Changes
Side-by-Side Diff Ignore Whitespace Patch
Changes to src/func.c.
12
13
14
15
16
17
18
19

20
21
22
23

24
25
26
27
28
29
30
12
13
14
15
16
17
18

19
20
21
22

23
24
25
26
27
28
29
30







-
+



-
+







** This file contains the C functions that implement various SQL
** functions of SQLite.  
**
** There is only one exported symbol in this file - the function
** sqliteRegisterBuildinFunctions() found at the bottom of the file.
** All other code has file scope.
**
** $Id: func.c,v 1.110 2005/09/08 20:37:43 drh Exp $
** $Id: func.c,v 1.111 2005/10/13 02:09:50 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
#include <math.h>
/* #include <math.h> */
#include <stdlib.h>
#include <assert.h>
#include "vdbeInt.h"
#include "os.h"

/*
** Return the collating function associated with a function.
Changes to src/printf.c.
116
117
118
119
120
121
122

123
124
125
126

127
128
129
130
131
132
133
134
135
136
137

138
139
140

141
142
143
144
145
146
147
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138

139
140
141

142
143
144
145
146
147
148
149







+




+










-
+


-
+







  {  'q',  0, 4, etSQLESCAPE,  0,  0 },
  {  'Q',  0, 4, etSQLESCAPE2, 0,  0 },
  {  'c',  0, 0, etCHARX,      0,  0 },
  {  'o',  8, 0, etRADIX,      0,  2 },
  {  'u', 10, 0, etRADIX,      0,  0 },
  {  'x', 16, 0, etRADIX,      16, 1 },
  {  'X', 16, 0, etRADIX,      0,  4 },
#ifndef SQLITE_OMIT_FLOATING_POINT
  {  'f',  0, 1, etFLOAT,      0,  0 },
  {  'e',  0, 1, etEXP,        30, 0 },
  {  'E',  0, 1, etEXP,        14, 0 },
  {  'G',  0, 1, etGENERIC,    14, 0 },
#endif
  {  'i', 10, 1, etRADIX,      0,  0 },
  {  'n',  0, 0, etSIZE,       0,  0 },
  {  '%',  0, 0, etPERCENT,    0,  0 },
  {  'p', 16, 0, etPOINTER,    0,  1 },
  {  'T',  0, 2, etTOKEN,      0,  0 },
  {  'S',  0, 2, etSRCLIST,    0,  0 },
};
#define etNINFO  (sizeof(fmtinfo)/sizeof(fmtinfo[0]))

/*
** If NOFLOATINGPOINT is defined, then none of the floating point
** If SQLITE_OMIT_FLOATING_POINT is defined, then none of the floating point
** conversions will work.
*/
#ifndef etNOFLOATINGPOINT
#ifndef SQLITE_OMIT_FLOATING_POINT
/*
** "*val" is a double such that 0.1 <= *val < 10.0
** Return the ascii code for the leading digit of *val, then
** multiply "*val" by 10.0 to renormalize.
**
** Example:
**     input:     *val = 3.14159
157
158
159
160
161
162
163
164

165
166
167
168
169
170
171
159
160
161
162
163
164
165

166
167
168
169
170
171
172
173







-
+







  if( (*cnt)++ >= 16 ) return '0';
  digit = (int)*val;
  d = digit;
  digit += '0';
  *val = (*val - d)*10.0;
  return digit;
}
#endif
#endif /* SQLITE_OMIT_FLOATING_POINT */

/*
** On machines with a small stack size, you can redefine the
** SQLITE_PRINT_BUF_SIZE to be less than 350.  But beware - for
** smaller values some %f conversions may go into an infinite loop.
*/
#ifndef SQLITE_PRINT_BUF_SIZE
230
231
232
233
234
235
236
237

238
239
240
241
242
243
244
232
233
234
235
236
237
238

239
240
241
242
243
244
245
246







-
+







  char prefix;               /* Prefix character.  "+" or "-" or " " or '\0'. */
  etByte errorflag = 0;      /* True if an error is encountered */
  etByte xtype;              /* Conversion paradigm */
  char *zExtra;              /* Extra memory used for etTCLESCAPE conversions */
  static const char spaces[] =
   "                                                                         ";
#define etSPACESIZE (sizeof(spaces)-1)
#ifndef etNOFLOATINGPOINT
#ifndef SQLITE_OMIT_FLOATING_POINT
  int  exp, e2;              /* exponent of real numbers */
  double rounder;            /* Used for rounding floating point values */
  etByte flag_dp;            /* True if decimal point should be shown */
  etByte flag_rtz;           /* True if trailing zeros should be removed */
  etByte flag_exp;           /* True to force display of the exponent */
  int nsd;                   /* Number of significant digits returned */
#endif
421
422
423
424
425
426
427
428

429
430
431
432
433
434
435
423
424
425
426
427
428
429

430
431
432
433
434
435
436
437







-
+







        }
        length = &buf[etBUFSIZE-1]-bufpt;
        break;
      case etFLOAT:
      case etEXP:
      case etGENERIC:
        realvalue = va_arg(ap,double);
#ifndef etNOFLOATINGPOINT
#ifndef SQLITE_OMIT_FLOATING_POINT
        if( precision<0 ) precision = 6;         /* Set default precision */
        if( precision>etBUFSIZE/2-10 ) precision = etBUFSIZE/2-10;
        if( realvalue<0.0 ){
          realvalue = -realvalue;
          prefix = '-';
        }else{
          if( flag_plussign )          prefix = '+';
Changes to src/sqlite.h.in.
8
9
10
11
12
13
14
15

16
17
18
19
20
21
22
8
9
10
11
12
13
14

15
16
17
18
19
20
21
22







-
+







**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This header file defines the interface that the SQLite library
** presents to client programs.
**
** @(#) $Id: sqlite.h.in,v 1.141 2005/09/08 10:58:52 drh Exp $
** @(#) $Id: sqlite.h.in,v 1.142 2005/10/13 02:09:50 drh Exp $
*/
#ifndef _SQLITE3_H_
#define _SQLITE3_H_
#include <stdarg.h>     /* Needed for the definition of va_list */

/*
** Make sure we can call this stuff from C++.
82
83
84
85
86
87
88







89
90
91
92
93
94
95
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102







+
+
+
+
+
+
+







  typedef __int64 sqlite_int64;
  typedef unsigned __int64 sqlite_uint64;
#else
  typedef long long int sqlite_int64;
  typedef unsigned long long int sqlite_uint64;
#endif

/*
** If compiling for a processor that lacks floating point support,
** substitute integer for floating-point
*/
#ifdef SQLITE_OMIT_FLOATING_POINT
# define double sqlite_int64
#endif

/*
** A function to close the database.
**
** Call this function with a pointer to a structure that was previously
** returned from sqlite3_open() and the corresponding database will by closed.
**
1265
1266
1267
1268
1269
1270
1271








1272
1273
1274
1275
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290







+
+
+
+
+
+
+
+




** Return the sqlite3* database handle to which the prepared statement given
** in the argument belongs.  This is the same database handle that was
** the first argument to the sqlite3_prepare() that was used to create
** the statement in the first place.
*/
sqlite3 *sqlite3_db_handle(sqlite3_stmt*);

/*
** Undo the hack that converts floating point types to integer for
** builds on processors without floating point support.
*/
#ifdef SQLITE_OMIT_FLOATING_POINT
# undef double
#endif

#ifdef __cplusplus
}  /* End of the 'extern "C"' block */
#endif
#endif
Changes to src/sqliteInt.h.
1
2
3
4
5
6
7
8
9
10
11
12
13
14

15
16
17
18
19
20
21
1
2
3
4
5
6
7
8
9
10
11
12
13

14
15
16
17
18
19
20
21













-
+







/*
** 2001 September 15
**
** 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.
**
*************************************************************************
** Internal interface definitions for SQLite.
**
** @(#) $Id: sqliteInt.h,v 1.422 2005/10/06 16:53:15 drh Exp $
** @(#) $Id: sqliteInt.h,v 1.423 2005/10/13 02:09:50 drh Exp $
*/
#ifndef _SQLITEINT_H_
#define _SQLITEINT_H_

/*
** Many people are failing to set -DNDEBUG=1 when compiling SQLite.
** Setting NDEBUG makes the code smaller and run faster.  So the following
55
56
57
58
59
60
61












62
63
64
65
66
67
68
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80







+
+
+
+
+
+
+
+
+
+
+
+







#include "parse.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <stddef.h>

/*
** If compiling for a processor that lacks floating point support,
** substitute integer for floating-point
*/
#ifdef SQLITE_OMIT_FLOATING_POINT
# define double sqlite_int64
# define LONGDOUBLE_TYPE sqlite_int64
# define SQLITE_BIG_DBL (0x7fffffffffffffff)
# define SQLITE_OMIT_DATETIME_FUNCS 1
# define SQLITE_OMIT_TRACE 1
#endif

/*
** The maximum number of in-memory pages to use for the main database
** table and for temporary tables. Internally, the MAX_PAGES and 
** TEMP_PAGES macros are used. To override the default values at
** compilation time, the SQLITE_DEFAULT_CACHE_SIZE and 
** SQLITE_DEFAULT_TEMP_CACHE_SIZE macros should be set.
*/
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
136
137
138
139
140
141
142














143
144
145
146
147
148
149







-
-
-
-
-
-
-
-
-
-
-
-
-
-







#define MAX_ATTACHED 10

/*
** The maximum value of a ?nnn wildcard that the parser will accept.
*/
#define SQLITE_MAX_VARIABLE_NUMBER 999

/*
** When building SQLite for embedded systems where memory is scarce,
** you can define one or more of the following macros to omit extra
** features of the library and thus keep the size of the library to
** a minimum.
*/
/* #define SQLITE_OMIT_AUTHORIZATION  1 */
/* #define SQLITE_OMIT_MEMORYDB     1 */
/* #define SQLITE_OMIT_VACUUM         1 */
/* #define SQLITE_OMIT_DATETIME_FUNCS 1 */
/* #define SQLITE_OMIT_PROGRESS_CALLBACK 1 */
/* #define SQLITE_OMIT_AUTOVACUUM */
/* #define SQLITE_OMIT_ALTERTABLE */

/*
** Provide a default value for TEMP_STORE in case it is not specified
** on the command-line
*/
#ifndef TEMP_STORE
# define TEMP_STORE 1
#endif
Changes to src/util.c.
10
11
12
13
14
15
16
17

18
19
20
21
22
23
24
10
11
12
13
14
15
16

17
18
19
20
21
22
23
24







-
+







**
*************************************************************************
** Utility functions used throughout sqlite.
**
** This file contains functions for allocating memory, comparing
** strings, and stuff like that.
**
** $Id: util.c,v 1.146 2005/09/17 18:34:11 drh Exp $
** $Id: util.c,v 1.147 2005/10/13 02:09:50 drh Exp $
*/
#include "sqliteInt.h"
#include <stdarg.h>
#include <ctype.h>

#if SQLITE_MEMDEBUG>2 && defined(__GLIBC__)
#include <execinfo.h>
602
603
604
605
606
607
608

609
610
611
612
613
614
615
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616







+







**
** This routine is used instead of the library atof() function because
** the library atof() might want to use "," as the decimal point instead
** of "." depending on how locale is set.  But that would cause problems
** for SQL.  So this routine always uses "." regardless of locale.
*/
int sqlite3AtoF(const char *z, double *pResult){
#ifndef SQLITE_OMIT_FLOATING_POINT
  int sign = 1;
  const char *zBegin = z;
  LONGDOUBLE_TYPE v1 = 0.0;
  if( *z=='-' ){
    sign = -1;
    z++;
  }else if( *z=='+' ){
652
653
654
655
656
657
658



659
660
661
662
663
664
665
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669







+
+
+







      v1 /= scale;
    }else{
      v1 *= scale;
    }
  }
  *pResult = sign<0 ? -v1 : v1;
  return z - zBegin;
#else
  return sqlite3atoi64(z, pResult);
#endif /* SQLITE_OMIT_FLOATING_POINT */
}

/*
** Return TRUE if zNum is a 64-bit signed integer and write
** the value of the integer into *pNum.  If zNum is not an integer
** or is an integer that is too large to be expressed with 64 bits,
** then return false.  If n>0 and the integer is string is not
Changes to src/where.c.
12
13
14
15
16
17
18
19

20
21
22
23
24
25
26
12
13
14
15
16
17
18

19
20
21
22
23
24
25
26







-
+







** This module contains C code that generates VDBE code used to process
** the WHERE clause of SQL statements.  This module is reponsible for
** generating the code that loops through a table looking for applicable
** rows.  Indices are selected and used to speed the search when doing
** so is applicable.  Because this module is responsible for selecting
** indices, you might also think of this module as the "query optimizer".
**
** $Id: where.c,v 1.179 2005/09/20 17:42:23 drh Exp $
** $Id: where.c,v 1.180 2005/10/13 02:09:50 drh Exp $
*/
#include "sqliteInt.h"

/*
** The number of bits in a Bitmask.  "BMS" means "BitMask Size".
*/
#define BMS  (sizeof(Bitmask)*8)
36
37
38
39
40
41
42










43
44
45
46
47
48
49
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59







+
+
+
+
+
+
+
+
+
+







#if defined(SQLITE_TEST) || defined(SQLITE_DEBUG)
int sqlite3_where_trace = 0;
# define TRACE(X)  if(sqlite3_where_trace) sqlite3DebugPrintf X
#else
# define TRACE(X)
#endif

/*
** A large value which is the maximum cost of using an index.
** By default this is a large floating point value.  When compiling
** SQLite for a processor that lacks floating point support, simply
** redefine this constant to a large integer.
*/
#ifndef SQLITE_BIG_DBL
# define SQLITE_BIG_DBL (1.0e+99)
#endif

/* Forward reference
*/
typedef struct WhereClause WhereClause;

/*
** The query generator uses an array of instances of this structure to
** help it analyze the subexpressions of the WHERE clause.  Each WHERE
850
851
852
853
854
855
856
857
858


859
860

861
862
863
864
865
866
867
860
861
862
863
864
865
866


867
868
869

870
871
872
873
874
875
876
877







-
-
+
+

-
+







** Prepare a crude estimate of the logarithm of the input value.
** The results need not be exact.  This is only used for estimating
** the total cost of performing operatings with O(logN) or O(NlogN)
** complexity.  Because N is just a guess, it is no great tragedy if
** logN is a little off.
*/
static double estLog(double N){
  double logN = 1.0;
  double x = 10.0;
  double logN = 1;
  double x = 10;
  while( N>x ){
    logN += 1.0;
    logN += 1;
    x *= 10;
  }
  return logN;
}

/*
** Find the best index for accessing a particular table.  Return a pointer
889
890
891
892
893
894
895
896

897
898
899
900
901
902
903
904
905
906

907
908
909
910
911
912
913
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







-
+










+







  ExprList *pOrderBy,         /* The order by clause */
  Index **ppIndex,            /* Make *ppIndex point to the best index */
  int *pFlags,                /* Put flags describing this choice in *pFlags */
  int *pnEq                   /* Put the number of == or IN constraints here */
){
  WhereTerm *pTerm;
  Index *bestIdx = 0;         /* Index that gives the lowest cost */
  double lowestCost = 1.0e99; /* The cost of using bestIdx */
  double lowestCost;          /* The cost of using bestIdx */
  int bestFlags = 0;          /* Flags associated with bestIdx */
  int bestNEq = 0;            /* Best value for nEq */
  int iCur = pSrc->iCursor;   /* The cursor of the table to be accessed */
  Index *pProbe;              /* An index we are evaluating */
  int rev;                    /* True to scan in reverse order */
  int flags;                  /* Flags associated with pProbe */
  int nEq;                    /* Number of == or IN constraints */
  double cost;                /* Cost of using pProbe */

  TRACE(("bestIndex: tbl=%s notReady=%x\n", pSrc->pTab->zName, notReady));
  lowestCost = SQLITE_BIG_DBL;

  /* Check for a rowid=EXPR or rowid IN (...) constraints
  */
  pTerm = findTerm(pWC, iCur, -1, notReady, WO_EQ|WO_IN, 0);
  if( pTerm ){
    Expr *pExpr;
    *ppIndex = 0;
924
925
926
927
928
929
930
931

932
933
934
935
936
937
938
939
940

941
942
943
944
945
946
947
948
949
950

951
952
953
954

955
956
957
958
959
960
961
935
936
937
938
939
940
941

942
943
944
945
946
947
948
949
950

951
952
953
954
955
956
957
958
959
960

961
962
963
964

965
966
967
968
969
970
971
972







-
+








-
+









-
+



-
+







      ** elements.  */
      lowestCost = pExpr->pList->nExpr;
      lowestCost *= estLog(lowestCost);
    }else{
      /* Rowid IN (SELECT): cost is NlogN where N is the number of rows
      ** in the result of the inner select.  We have no way to estimate
      ** that value so make a wild guess. */
      lowestCost = 200.0;
      lowestCost = 200;
    }
    TRACE(("... rowid IN cost: %.9g\n", lowestCost));
  }

  /* Estimate the cost of a table scan.  If we do not know how many
  ** entries are in the table, use 1 million as a guess.
  */
  pProbe = pSrc->pTab->pIndex;
  cost = pProbe ? pProbe->aiRowEst[0] : 1000000.0;
  cost = pProbe ? pProbe->aiRowEst[0] : 1000000;
  TRACE(("... table scan base cost: %.9g\n", cost));
  flags = WHERE_ROWID_RANGE;

  /* Check for constraints on a range of rowids in a table scan.
  */
  pTerm = findTerm(pWC, iCur, -1, notReady, WO_LT|WO_LE|WO_GT|WO_GE, 0);
  if( pTerm ){
    if( findTerm(pWC, iCur, -1, notReady, WO_LT|WO_LE, 0) ){
      flags |= WHERE_TOP_LIMIT;
      cost *= 0.333;  /* Guess that rowid<EXPR eliminates two-thirds or rows */
      cost /= 3;  /* Guess that rowid<EXPR eliminates two-thirds or rows */
    }
    if( findTerm(pWC, iCur, -1, notReady, WO_GT|WO_GE, 0) ){
      flags |= WHERE_BTM_LIMIT;
      cost *= 0.333;  /* Guess that rowid>EXPR eliminates two-thirds of rows */
      cost /= 3;  /* Guess that rowid>EXPR eliminates two-thirds of rows */
    }
    TRACE(("... rowid range reduces cost to %.9g\n", cost));
  }else{
    flags = 0;
  }

  /* If the table scan does not satisfy the ORDER BY clause, increase
976
977
978
979
980
981
982
983

984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000

1001
1002

1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023

1024
1025
1026
1027

1028
1029
1030
1031
1032
1033
1034
987
988
989
990
991
992
993

994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010

1011
1012

1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033

1034
1035
1036
1037

1038
1039
1040
1041
1042
1043
1044
1045







-
+
















-
+

-
+




















-
+



-
+







    bestFlags = flags;
  }

  /* Look at each index.
  */
  for(; pProbe; pProbe=pProbe->pNext){
    int i;                       /* Loop counter */
    double inMultiplier = 1.0;
    double inMultiplier = 1;

    TRACE(("... index %s:\n", pProbe->zName));

    /* Count the number of columns in the index that are satisfied
    ** by x=EXPR constraints or x IN (...) constraints.
    */
    flags = 0;
    for(i=0; i<pProbe->nColumn; i++){
      int j = pProbe->aiColumn[i];
      pTerm = findTerm(pWC, iCur, j, notReady, WO_EQ|WO_IN, pProbe);
      if( pTerm==0 ) break;
      flags |= WHERE_COLUMN_EQ;
      if( pTerm->operator & WO_IN ){
        Expr *pExpr = pTerm->pExpr;
        flags |= WHERE_COLUMN_IN;
        if( pExpr->pSelect!=0 ){
          inMultiplier *= 100.0;
          inMultiplier *= 100;
        }else if( pExpr->pList!=0 ){
          inMultiplier *= pExpr->pList->nExpr + 1.0;
          inMultiplier *= pExpr->pList->nExpr + 1;
        }
      }
    }
    cost = pProbe->aiRowEst[i] * inMultiplier * estLog(inMultiplier);
    nEq = i;
    if( pProbe->onError!=OE_None && (flags & WHERE_COLUMN_IN)==0
         && nEq==pProbe->nColumn ){
      flags |= WHERE_UNIQUE;
    }
    TRACE(("...... nEq=%d inMult=%.9g cost=%.9g\n", nEq, inMultiplier, cost));

    /* Look for range constraints
    */
    if( nEq<pProbe->nColumn ){
      int j = pProbe->aiColumn[nEq];
      pTerm = findTerm(pWC, iCur, j, notReady, WO_LT|WO_LE|WO_GT|WO_GE, pProbe);
      if( pTerm ){
        flags |= WHERE_COLUMN_RANGE;
        if( findTerm(pWC, iCur, j, notReady, WO_LT|WO_LE, pProbe) ){
          flags |= WHERE_TOP_LIMIT;
          cost *= 0.333;
          cost /= 3;
        }
        if( findTerm(pWC, iCur, j, notReady, WO_GT|WO_GE, pProbe) ){
          flags |= WHERE_BTM_LIMIT;
          cost *= 0.333;
          cost /= 3;
        }
        TRACE(("...... range reduces cost to %.9g\n", cost));
      }
    }

    /* Add the additional cost of sorting if that is a factor.
    */
1059
1060
1061
1062
1063
1064
1065
1066

1067
1068
1069
1070
1071
1072
1073
1070
1071
1072
1073
1074
1075
1076

1077
1078
1079
1080
1081
1082
1083
1084







-
+







        int x = pProbe->aiColumn[j];
        if( x<BMS-1 ){
          m &= ~(((Bitmask)1)<<x);
        }
      }
      if( m==0 ){
        flags |= WHERE_IDX_ONLY;
        cost *= 0.5;
        cost /= 2;
        TRACE(("...... idx-only reduces cost to %.9g\n", cost));
      }
    }

    /* If this index has achieved the lowest cost so far, then use it.
    */
    if( cost < lowestCost ){
1460
1461
1462
1463
1464
1465
1466
1467

1468
1469
1470

1471
1472
1473
1474
1475
1476
1477
1471
1472
1473
1474
1475
1476
1477

1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489







-
+



+







    int flags;                  /* Flags asssociated with pIdx */
    int nEq;                    /* Number of == or IN constraints */
    double cost;                /* The cost for pIdx */
    int j;                      /* For looping over FROM tables */
    Index *pBest = 0;           /* The best index seen so far */
    int bestFlags = 0;          /* Flags associated with pBest */
    int bestNEq = 0;            /* nEq associated with pBest */
    double lowestCost = 1.0e99; /* Cost of the pBest */
    double lowestCost;          /* Cost of the pBest */
    int bestJ;                  /* The value of j */
    Bitmask m;                  /* Bitmask value for j or bestJ */

    lowestCost = SQLITE_BIG_DBL;
    for(j=iFrom, pTabItem=&pTabList->a[j]; j<pTabList->nSrc; j++, pTabItem++){
      m = getMask(&maskSet, pTabItem->iCursor);
      if( (m & notReady)==0 ){
        if( j==iFrom ) iFrom++;
        continue;
      }
      cost = bestIndex(pParse, &wc, pTabItem, notReady,