SQLite

    nSample = sqlite3_column_int(pStmt, 1);
    if( nSample>255 ) continue;
    pIdx = sqlite3FindIndex(db, zIndex, zDb);
    if( pIdx==0 ) continue;
    assert( pIdx->nSample==0 );
    pIdx->nSample = (u8)nSample;
    pIdx->aSample = sqlite3MallocZero( nSample*sizeof(IndexSample) );
    pIdx->avgEq = pIdx->aiRowEst[1];
    if( pIdx->aSample==0 ){
      db->mallocFailed = 1;
      sqlite3_finalize(pStmt);
      return SQLITE_NOMEM;
    }
  }
  sqlite3_finalize(pStmt);

  zSql = sqlite3MPrintf(db, 
      "SELECT idx,neq,nlt,ndlt,sample FROM %Q.sqlite_stat3", zDb);
  if( !zSql ){
    return SQLITE_NOMEM;
  }
  rc = sqlite3_prepare(db, zSql, -1, &pStmt, 0);
  sqlite3DbFree(db, zSql);
  if( rc ) return rc;

  while( sqlite3_step(pStmt)==SQLITE_ROW ){
    char *zIndex;   /* Index name */
    Index *pIdx;    /* Pointer to the index object */
    int i;          /* Loop counter */
    tRowcnt sumEq;  /* Sum of the nEq values */

    zIndex = (char *)sqlite3_column_text(pStmt, 0);
    if( zIndex==0 ) continue;
    pIdx = sqlite3FindIndex(db, zIndex, zDb);
    if( pIdx==0 ) continue;
    if( pIdx==pPrevIdx ){
      idx++;
    }else{
      pPrevIdx = pIdx;
      idx = 0;
    }
    assert( idx<pIdx->nSample );
    pSample = &pIdx->aSample[idx];
    pSample->nEq = (tRowcnt)sqlite3_column_int64(pStmt, 1);
    pSample->nLt = (tRowcnt)sqlite3_column_int64(pStmt, 2);
    pSample->nDLt = (tRowcnt)sqlite3_column_int64(pStmt, 3);
    if( idx==pIdx->nSample-1 ){
      if( pSample->nDLt>0 ){
        for(i=0, sumEq=0; i<=idx-1; i++) sumEq += pIdx->aSample[i].nEq;
        pIdx->avgEq = (pSample->nLt - sumEq)/pSample->nDLt;
      }
      if( pIdx->avgEq<=0 ) pIdx->avgEq = 1;
    }
    eType = sqlite3_column_type(pStmt, 4);
    pSample->eType = (u8)eType;
    switch( eType ){
      case SQLITE_INTEGER: {
        pSample->u.i = sqlite3_column_int64(pStmt, 4);
        break;
      }
      case SQLITE_FLOAT: {
        pSample->u.r = sqlite3_column_double(pStmt, 4);
        break;
      }
      case SQLITE_NULL: {
        break;
      }
      default: assert( eType==SQLITE_TEXT || eType==SQLITE_BLOB ); {
        const char *z = (const char *)(
              (eType==SQLITE_BLOB) ?
              sqlite3_column_blob(pStmt, 4):
              sqlite3_column_text(pStmt, 4)
           );
        int n = sqlite3_column_bytes(pStmt, 4);
        if( n>0xffff ) n = 0xffff;
        pSample->nByte = (u16)n;
        if( n < 1){
          pSample->u.z = 0;
        }else{
          pSample->u.z = sqlite3Malloc(n);
          if( pSample->u.z==0 ){

  ** dropped. Triggers are handled seperately because a trigger can be
  ** created in the temp database that refers to a table in another
  ** database.
  */
  sqlite3NestedParse(pParse, 
      "DELETE FROM %Q.%s WHERE tbl_name=%Q and type!='trigger'",
      pDb->zName, SCHEMA_TABLE(iDb), pTab->zName);

  if( !isView && !IsVirtual(pTab) ){
    destroyTable(pParse, pTab);
  }

  /* Remove the table entry from SQLite's internal schema and modify
  ** the schema cookie.
  */

  ** on disk.
  */
  v = sqlite3GetVdbe(pParse);
  if( v ){
    sqlite3BeginWriteOperation(pParse, 1, iDb);
    sqlite3FkDropTable(pParse, pName, pTab);
    sqlite3CodeDropTable(pParse, pTab, iDb, isView);
    sqlite3ClearStatTables(pParse, iDb, "tbl", pTab->zName);
  }

exit_drop_table:
  sqlite3SrcListDelete(db, pName);
}

/*

  u8 nSample;      /* Number of elements in aSample[] */
  char *zColAff;   /* String defining the affinity of each column */
  Index *pNext;    /* The next index associated with the same table */
  Schema *pSchema; /* Schema containing this index */
  u8 *aSortOrder;  /* Array of size Index.nColumn. True==DESC, False==ASC */
  char **azColl;   /* Array of collation sequence names for index */
#ifdef SQLITE_ENABLE_STAT3
  tRowcnt avgEq;           /* Average nEq value for key values not in aSample */
  IndexSample *aSample;    /* Samples of the left-most key */
#endif
};

/*
** Each sample stored in the sqlite_stat2 table is represented in memory 
** using a structure of this type.
*/
struct IndexSample {
  union {
    char *z;        /* Value if eType is SQLITE_TEXT or SQLITE_BLOB */
    double r;       /* Value if eType is SQLITE_FLOAT */
    i64 i;          /* Value if eType is SQLITE_INTEGER */
  } u;
  u8 eType;         /* SQLITE_NULL, SQLITE_INTEGER ... etc. */
  u16 nByte;        /* Size in byte of text or blob. */
  tRowcnt nEq;      /* Est. number of rows where the key equals this sample */
  tRowcnt nLt;      /* Est. number of rows where key is less than this sample */
  tRowcnt nDLt;     /* Est. number of distinct keys less than this sample */
};

/*
** Each token coming out of the lexer is an instance of
** this structure.  Tokens are also used as part of an expression.
**
** Note if Token.z==0 then Token.dyn and Token.n are undefined and

  int roundUp,                /* Round up if true.  Round down if false */
  tRowcnt *aStat              /* OUT: stats written here */
){
  tRowcnt n;
  IndexSample *aSample;
  int i, eType;
  int isEq = 0;
  i64 v;
  double r, rS;

  assert( roundUp==0 || roundUp==1 );
  if( pVal==0 ) return SQLITE_ERROR;
  n = pIdx->aiRowEst[0];
  aSample = pIdx->aSample;
  i = 0;
  eType = sqlite3_value_type(pVal);

  if( eType==SQLITE_INTEGER ){
    v = sqlite3_value_int64(pVal);
    r = (i64)v;
    for(i=0; i<pIdx->nSample; i++){
      if( aSample[i].eType==SQLITE_NULL ) continue;
      if( aSample[i].eType>=SQLITE_TEXT ) break;
      if( aSample[i].eType==SQLITE_INTEGER ){
        if( aSample[i].u.i>=v ){
          isEq = aSample[i].u.i==v;
          break;
        }
      }else{
        assert( aSample[i].eType==SQLITE_FLOAT );
        if( aSample[i].u.r>=r ){
          isEq = aSample[i].u.r==r;
          break;
        }
      }
    }
  }else if( eType==SQLITE_FLOAT ){
    r = sqlite3_value_double(pVal);
    for(i=0; i<pIdx->nSample; i++){
      if( aSample[i].eType==SQLITE_NULL ) continue;
      if( aSample[i].eType>=SQLITE_TEXT ) break;
      if( aSample[i].eType==SQLITE_FLOAT ){
        rS = aSample[i].u.r;
      }else{
        rS = aSample[i].u.i;
      }
      if( rS>=r ){
        isEq = rS==r;
        break;
      }
    }
  }else if( eType==SQLITE_NULL ){
    i = 0;
    if( pIdx->nSample>=1 && aSample[0].eType==SQLITE_NULL ) isEq = 1;
  }else{

    aStat[0] = aSample[i].nLt;
    aStat[1] = aSample[i].nEq;
  }else{
    tRowcnt iLower, iUpper, iGap;
    if( i==0 ){
      iLower = 0;
      iUpper = aSample[0].nLt;



    }else{
      iUpper = i>=pIdx->nSample ? n : aSample[i].nLt;
      iLower = aSample[i-1].nEq + aSample[i-1].nLt;

    }
    aStat[1] = pIdx->avgEq;
    if( iLower>=iUpper ){
      iGap = 0;
    }else{
      iGap = iUpper - iLower;
      if( iGap>=aStat[1]/2 ) iGap -= aStat[1]/2;
    }
    if( roundUp ){

*/
static int whereRangeScanEst(
  Parse *pParse,       /* Parsing & code generating context */
  Index *p,            /* The index containing the range-compared column; "x" */
  int nEq,             /* index into p->aCol[] of the range-compared column */
  WhereTerm *pLower,   /* Lower bound on the range. ex: "x>123" Might be NULL */
  WhereTerm *pUpper,   /* Upper bound on the range. ex: "x<455" Might be NULL */
  double *pRangeDiv   /* OUT: Reduce search space by this divisor */
){
  int rc = SQLITE_OK;

#ifdef SQLITE_ENABLE_STAT3

  if( nEq==0 && p->nSample ){
    sqlite3_value *pRangeVal;

      Expr *pExpr = pUpper->pExpr->pRight;
      rc = valueFromExpr(pParse, pExpr, aff, &pRangeVal);
      assert( pUpper->eOperator==WO_LT || pUpper->eOperator==WO_LE );
      if( rc==SQLITE_OK
       && whereKeyStats(pParse, p, pRangeVal, 1, a)==SQLITE_OK
      ){
        iUpper = a[0];
        if( pUpper->eOperator==WO_LE ) iUpper += a[1];
      }
      sqlite3ValueFree(pRangeVal);
    }
    if( rc==SQLITE_OK ){
      if( iUpper<=iLower ){
        *pRangeDiv = (double)p->aiRowEst[0];
      }else{
        *pRangeDiv = (double)p->aiRowEst[0]/(double)(iUpper - iLower);
      }
      WHERETRACE(("range scan regions: %u..%u  div=%g\n",
                  (u32)iLower, (u32)iUpper, *pRangeDiv));
      return SQLITE_OK;
    }
  }
#else
  UNUSED_PARAMETER(pParse);
  UNUSED_PARAMETER(p);
  UNUSED_PARAMETER(nEq);
#endif
  assert( pLower || pUpper );
  *pRangeDiv = (double)1;
  if( pLower && (pLower->wtFlags & TERM_VNULL)==0 ) *pRangeDiv *= (double)4;
  if( pUpper ) *pRangeDiv *= (double)4;
  return rc;
}

#ifdef SQLITE_ENABLE_STAT3
/*
** Estimate the number of rows that will be returned based on
** an equality constraint x=VALUE and where that VALUE occurs in

    **
    **             SELECT a, b    FROM tbl WHERE a = 1;
    **             SELECT a, b, c FROM tbl WHERE a = 1;
    */
    int nEq;                      /* Number of == or IN terms matching index */
    int bInEst = 0;               /* True if "x IN (SELECT...)" seen */
    int nInMul = 1;               /* Number of distinct equalities to lookup */
    double rangeDiv = (double)1;  /* Estimated reduction in search space */
    int nBound = 0;               /* Number of range constraints seen */
    int bSort = !!pOrderBy;       /* True if external sort required */
    int bDist = !!pDistinct;      /* True if index cannot help with DISTINCT */
    int bLookup = 0;              /* True if not a covering index */
    WhereTerm *pTerm;             /* A single term of the WHERE clause */
#ifdef SQLITE_ENABLE_STAT3
    WhereTerm *pFirstTerm = 0;    /* First term matching the index */

      }
    }
#endif /* SQLITE_ENABLE_STAT3 */

    /* Adjust the number of output rows and downward to reflect rows
    ** that are excluded by range constraints.
    */
    nRow = nRow/rangeDiv;
    if( nRow<1 ) nRow = 1;

    /* Experiments run on real SQLite databases show that the time needed
    ** to do a binary search to locate a row in a table or index is roughly
    ** log10(N) times the time to move from one row to the next row within
    ** a table or index.  The actual times can vary, with the size of
    ** records being an important factor.  Both moves and searches are

  sqlite3 db test.db
  execsql {
    SELECT * FROM t4 WHERE x=1234;
  }
} {}

# Verify that DROP TABLE and DROP INDEX remove entries from the 
# sqlite_stat1 and sqlite_stat3 tables.
#
do_test analyze-5.0 {
  execsql {
    DELETE FROM t3;
    DELETE FROM t4;
    INSERT INTO t3 VALUES(1,2,3,4);
    INSERT INTO t3 VALUES(5,6,7,8);
    INSERT INTO t3 SELECT a+8, b+8, c+8, d+8 FROM t3;
    INSERT INTO t3 SELECT a+16, b+16, c+16, d+16 FROM t3;
    INSERT INTO t3 SELECT a+32, b+32, c+32, d+32 FROM t3;
    INSERT INTO t3 SELECT a+64, b+64, c+64, d+64 FROM t3;
    INSERT INTO t4 SELECT a, b, c FROM t3;
    ANALYZE;
    SELECT DISTINCT idx FROM sqlite_stat1 ORDER BY 1;
    SELECT DISTINCT tbl FROM sqlite_stat1 ORDER BY 1;
  }
} {t3i1 t3i2 t3i3 t4i1 t4i2 t3 t4}
ifcapable stat3 {
  do_test analyze-5.1 {
    execsql {
      SELECT DISTINCT idx FROM sqlite_stat3 ORDER BY 1;
      SELECT DISTINCT tbl FROM sqlite_stat3 ORDER BY 1;
    }
  } {t3i1 t3i2 t3i3 t4i1 t4i2 t3 t4}
}
do_test analyze-5.2 {
  execsql {
    DROP INDEX t3i2;
    SELECT DISTINCT idx FROM sqlite_stat1 ORDER BY 1;
    SELECT DISTINCT tbl FROM sqlite_stat1 ORDER BY 1;
  }
} {t3i1 t3i3 t4i1 t4i2 t3 t4}
ifcapable stat3 {
  do_test analyze-5.3 {
    execsql {
      SELECT DISTINCT idx FROM sqlite_stat3 ORDER BY 1;
      SELECT DISTINCT tbl FROM sqlite_stat3 ORDER BY 1;
    }
  } {t3i1 t3i3 t4i1 t4i2 t3 t4}
}
do_test analyze-5.4 {
  execsql {
    DROP TABLE t3;
    SELECT DISTINCT idx FROM sqlite_stat1 ORDER BY 1;
    SELECT DISTINCT tbl FROM sqlite_stat1 ORDER BY 1;
  }
} {t4i1 t4i2 t4}
ifcapable stat3 {
  do_test analyze-5.5 {
    execsql {
      SELECT DISTINCT idx FROM sqlite_stat3 ORDER BY 1;
      SELECT DISTINCT tbl FROM sqlite_stat3 ORDER BY 1;
    }
  } {t4i1 t4i2 t4}
}

# This test corrupts the database file so it must be the last test
# in the series.
#

    COMMIT;
    ANALYZE;
  }
} {}

do_eqp_test analyze3-1.1.2 {
  SELECT sum(y) FROM t1 WHERE x>200 AND x<300
} {0 0 0 {SEARCH TABLE t1 USING INDEX i1 (x>? AND x<?) (~179 rows)}}
do_eqp_test analyze3-1.1.3 {
  SELECT sum(y) FROM t1 WHERE x>0 AND x<1100 
} {0 0 0 {SEARCH TABLE t1 USING INDEX i1 (x>? and x<?) {~959 rows)}}

do_test analyze3-1.1.4 {
  sf_execsql { SELECT sum(y) FROM t1 WHERE x>200 AND x<300 }
} {199 0 14850}
do_test analyze3-1.1.5 {
  set l [string range "200" 0 end]
  set u [string range "300" 0 end]

      CREATE INDEX i3 ON t3(x);
    COMMIT;
    ANALYZE;
  }
} {}
do_eqp_test analyze3-1.3.2 {
  SELECT sum(y) FROM t3 WHERE x>200 AND x<300
} {0 0 0 {SEARCH TABLE t3 USING INDEX i3 (x>? AND x<?) (~166 rows)}}
do_eqp_test analyze3-1.3.3 {
  SELECT sum(y) FROM t3 WHERE x>0 AND x<1100
} {0 0 0 {SCAN TABLE t3 (~111 rows)}}

do_test analyze3-1.3.4 {
  sf_execsql { SELECT sum(y) FROM t3 WHERE x>200 AND x<300 }
} {199 0 14850}

    append t [lindex {a b c d e f g h i j} [expr ($i%10)]]
    execsql { INSERT INTO t1 VALUES($i, $t) }
  }
  execsql COMMIT
} {}
do_eqp_test analyze3-2.2 {
  SELECT count(a) FROM t1 WHERE b LIKE 'a%'
} {0 0 0 {SEARCH TABLE t1 USING INDEX i1 (b>? AND b<?) (~31250 rows)}}
do_eqp_test analyze3-2.3 {
  SELECT count(a) FROM t1 WHERE b LIKE '%a'
} {0 0 0 {SCAN TABLE t1 (~500000 rows)}}

do_test analyze3-2.4 {
  sf_execsql { SELECT count(*) FROM t1 WHERE b LIKE 'a%' }
} {101 0 100}

# 2011 January 19
#
# 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 tests for SQLite library.  The focus of the tests
# in this file is the use of the sqlite_stat3 histogram data on tables
# with many repeated values and only a few distinct values.
#

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

ifcapable !stat3 {
  finish_test
  return
}

set testprefix analyze5

proc eqp {sql {db db}} {

    CREATE INDEX t1u ON t1(u);  -- text
    CREATE INDEX t1v ON t1(v);  -- mixed case text
    CREATE INDEX t1w ON t1(w);  -- integers 0, 1, 2 and a few NULLs
    CREATE INDEX t1x ON t1(x);  -- integers 1, 2, 3 and many NULLs
    CREATE INDEX t1y ON t1(y);  -- integers 0 and very few 1s
    CREATE INDEX t1z ON t1(z);  -- integers 0, 1, 2, and 3
    ANALYZE;
    SELECT sample FROM sqlite_stat3 WHERE idx='t1u' ORDER BY nlt;
  }
} {alpha bravo charlie delta}




do_test analyze5-1.1 {
  db eval {SELECT DISTINCT lower(sample) FROM sqlite_stat3 WHERE idx='t1v'


             ORDER BY 1}
} {alpha bravo charlie delta}
do_test analyze5-1.2 {
  db eval {SELECT idx, count(*) FROM sqlite_stat3 GROUP BY 1 ORDER BY 1}







} {t1t 4 t1u 4 t1v 4 t1w 4 t1x 4 t1y 2 t1z 4}

# Verify that range queries generate the correct row count estimates
#
foreach {testid where index rows} {
    1  {z>=0 AND z<=0}       t1z  400
    2  {z>=1 AND z<=1}       t1z  300
    3  {z>=2 AND z<=2}       t1z  175
    4  {z>=3 AND z<=3}       t1z  125
    5  {z>=4 AND z<=4}       t1z    1
    6  {z>=-1 AND z<=-1}     t1z    1
    7  {z>1 AND z<3}         t1z  175
    8  {z>0 AND z<100}       t1z  600
    9  {z>=1 AND z<100}      t1z  600
   10  {z>1 AND z<100}       t1z  300
   11  {z>=2 AND z<100}      t1z  300
   12  {z>2 AND z<100}       t1z  125
   13  {z>=3 AND z<100}      t1z  125
   14  {z>3 AND z<100}       t1z    1
   15  {z>=4 AND z<100}      t1z    1
   16  {z>=-100 AND z<=-1}   t1z    1
   17  {z>=-100 AND z<=0}    t1z  400
   18  {z>=-100 AND z<0}     t1z    1
   19  {z>=-100 AND z<=1}    t1z  700
   20  {z>=-100 AND z<2}     t1z  700
   21  {z>=-100 AND z<=2}    t1z  875
   22  {z>=-100 AND z<3}     t1z  875
  
   31  {z>=0.0 AND z<=0.0}   t1z  400
   32  {z>=1.0 AND z<=1.0}   t1z  300
   33  {z>=2.0 AND z<=2.0}   t1z  175
   34  {z>=3.0 AND z<=3.0}   t1z  125
   35  {z>=4.0 AND z<=4.0}   t1z    1
   36  {z>=-1.0 AND z<=-1.0} t1z    1
   37  {z>1.5 AND z<3.0}     t1z  174
   38  {z>0.5 AND z<100}     t1z  599
   39  {z>=1.0 AND z<100}    t1z  600
   40  {z>1.5 AND z<100}     t1z  299
   41  {z>=2.0 AND z<100}    t1z  300
   42  {z>2.1 AND z<100}     t1z  124
   43  {z>=3.0 AND z<100}    t1z  125
   44  {z>3.2 AND z<100}     t1z    1
   45  {z>=4.0 AND z<100}    t1z    1
   46  {z>=-100 AND z<=-1.0} t1z    1
   47  {z>=-100 AND z<=0.0}  t1z  400
   48  {z>=-100 AND z<0.0}   t1z    1
   49  {z>=-100 AND z<=1.0}  t1z  700
   50  {z>=-100 AND z<2.0}   t1z  700
   51  {z>=-100 AND z<=2.0}  t1z  875
   52  {z>=-100 AND z<3.0}   t1z  875
  
  101  {z=-1}                t1z    1
  102  {z=0}                 t1z  400
  103  {z=1}                 t1z  300
  104  {z=2}                 t1z  175
  105  {z=3}                 t1z  125
  106  {z=4}                 t1z    1
  107  {z=-10.0}             t1z    1
  108  {z=0.0}               t1z  400
  109  {z=1.0}               t1z  300
  110  {z=2.0}               t1z  175
  111  {z=3.0}               t1z  125
  112  {z=4.0}               t1z    1
  113  {z=1.5}               t1z    1
  114  {z=2.5}               t1z    1
  
  201  {z IN (-1)}           t1z    1
  202  {z IN (0)}            t1z  400
  203  {z IN (1)}            t1z  300
  204  {z IN (2)}            t1z  175
  205  {z IN (3)}            t1z  125
  206  {z IN (4)}            t1z    1
  207  {z IN (0.5)}          t1z    1
  208  {z IN (0,1)}          t1z  700
  209  {z IN (0,1,2)}        t1z  875
  210  {z IN (0,1,2,3)}      {}   100
  211  {z IN (0,1,2,3,4,5)}  {}   100
  212  {z IN (1,2)}          t1z  475
  213  {z IN (2,3)}          t1z  300
  214  {z=3 OR z=2}          t1z  300
  215  {z IN (-1,3)}         t1z  126
  216  {z=-1 OR z=3}         t1z  126

  300  {y=0}                 t1y  974
  301  {y=1}                 t1y   26
  302  {y=0.1}               t1y    1

  400  {x IS NULL}           t1x  400

} {
  # Verify that the expected index is used with the expected row count
  do_test analyze5-1.${testid}a {
    set x [lindex [eqp "SELECT * FROM t1 WHERE $where"] 3]

    WHERE rowid IN (SELECT rowid FROM t1 ORDER BY random() LIMIT 5);
   ANALYZE;
}

# Verify that range queries generate the correct row count estimates
#
foreach {testid where index rows} {
  500  {x IS NULL AND u='charlie'}         t1u  17
  501  {x=1 AND u='charlie'}               t1x   1
  502  {x IS NULL}                         t1x 995
  503  {x=1}                               t1x   1
  504  {x IS NOT NULL}                     t1x   2
  505  {+x IS NOT NULL}                     {} 500
  506  {upper(x) IS NOT NULL}               {} 500

} {
  # Verify that the expected index is used with the expected row count
if {$testid==50299} {breakpoint; set sqlite_where_trace 1}
  do_test analyze5-1.${testid}a {
    set x [lindex [eqp "SELECT * FROM t1 WHERE $where"] 3]
    set idx {}
    regexp {INDEX (t1.) } $x all idx
    regexp {~([0-9]+) rows} $x all nrow
    list $idx $nrow
  } [list $index $rows]
if {$testid==50299} exit

  # Verify that the same result is achieved regardless of whether or not
  # the index is used
  do_test analyze5-1.${testid}b {
    set w2 [string map {y +y z +z} $where]
    set a1 [db eval "SELECT rowid FROM t1 NOT INDEXED WHERE $w2\
                     ORDER BY +rowid"]

} {0 0 0 {SEARCH TABLE t1 USING INDEX t1a (a=?) (~1 rows)}}
do_test analyze7-3.1 {
  execsql {EXPLAIN QUERY PLAN SELECT * FROM t1 WHERE b=123;}
} {0 0 0 {SEARCH TABLE t1 USING INDEX t1b (b=?) (~10 rows)}}
do_test analyze7-3.2.1 {
  execsql {EXPLAIN QUERY PLAN SELECT * FROM t1 WHERE c=?;}
} {0 0 0 {SEARCH TABLE t1 USING INDEX t1cd (c=?) (~86 rows)}}
ifcapable stat3 {
  # If ENABLE_STAT3 is defined, SQLite comes up with a different estimated
  # row count for (c=2) than it does for (c=?).
  do_test analyze7-3.2.2 {
    execsql {EXPLAIN QUERY PLAN SELECT * FROM t1 WHERE c=2;}
  } {0 0 0 {SEARCH TABLE t1 USING INDEX t1cd (c=?) (~57 rows)}}
} else {
  # If ENABLE_STAT3 is not defined, the expected row count for (c=2) is the
  # same as that for (c=?).
  do_test analyze7-3.2.3 {
    execsql {EXPLAIN QUERY PLAN SELECT * FROM t1 WHERE c=2;}
  } {0 0 0 {SEARCH TABLE t1 USING INDEX t1cd (c=?) (~86 rows)}}
}
do_test analyze7-3.3 {
  execsql {EXPLAIN QUERY PLAN SELECT * FROM t1 WHERE a=123 AND b=123}
} {0 0 0 {SEARCH TABLE t1 USING INDEX t1a (a=?) (~1 rows)}}
ifcapable {!stat3} {
  do_test analyze7-3.4 {
    execsql {EXPLAIN QUERY PLAN SELECT * FROM t1 WHERE c=123 AND b=123}
  } {0 0 0 {SEARCH TABLE t1 USING INDEX t1b (b=?) (~2 rows)}}
  do_test analyze7-3.5 {
    execsql {EXPLAIN QUERY PLAN SELECT * FROM t1 WHERE a=123 AND c=123}
  } {0 0 0 {SEARCH TABLE t1 USING INDEX t1a (a=?) (~1 rows)}}
}
do_test analyze7-3.6 {
  execsql {EXPLAIN QUERY PLAN SELECT * FROM t1 WHERE c=123 AND d=123 AND b=123}
} {0 0 0 {SEARCH TABLE t1 USING INDEX t1cd (c=? AND d=?) (~1 rows)}}

finish_test

proc lookaside {db} {
  expr { $::lookaside_buffer_size *
    [lindex [sqlite3_db_status $db SQLITE_DBSTATUS_LOOKASIDE_USED 0] 1]
  }
}

ifcapable stat3 {
  set STAT3 1
} else {
  set STAT3 0
}

#---------------------------------------------------------------------------
# Run the dbstatus-2 and dbstatus-3 tests with several of different
# lookaside buffer sizes.
#
foreach ::lookaside_buffer_size {0 64 120} {

      END;
    }
    5 {
      CREATE TABLE t1(a, b);
      CREATE TABLE t2(c, d);
      CREATE VIEW v1 AS SELECT * FROM t1 UNION SELECT * FROM t2;
    }
    6y {
      CREATE TABLE t1(a, b);
      CREATE INDEX i1 ON t1(a);
      CREATE INDEX i2 ON t1(a,b);
      CREATE INDEX i3 ON t1(b,b);
      INSERT INTO t1 VALUES(randomblob(20), randomblob(25));
      INSERT INTO t1 SELECT randomblob(20), randomblob(25) FROM t1;
      INSERT INTO t1 SELECT randomblob(20), randomblob(25) FROM t1;

    # for any reason is not counted as "schema memory".
    #
    # Additionally, in auto-vacuum mode, dropping tables and indexes causes
    # the page-cache to shrink. So the amount of memory freed is always
    # much greater than just that reported by DBSTATUS_SCHEMA_USED in this
    # case.
    #
    # Some of the memory used for sqlite_stat3 is unaccounted for by
    # dbstatus.
    #
    if {[string match *x $tn] || $AUTOVACUUM
         || ([string match *y $tn] && $STAT3)} {
      do_test dbstatus-2.$tn.ax { expr {($nSchema1-$nSchema2)<=$nFree} } 1
    } else {
      do_test dbstatus-2.$tn.a { expr {$nSchema1-$nSchema2} } $nFree
    }
  
    do_test dbstatus-2.$tn.b { list $nAlloc1 $nSchema1 } "$nAlloc3 $nSchema3"
    do_test dbstatus-2.$tn.c { list $nAlloc2 $nSchema2 } "$nAlloc4 $nSchema4"

# 2011 August 08
#
# 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 the extra functionality provided by the ANALYZE 
# command when the library is compiled with SQLITE_ENABLE_STAT3 defined.
#

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

set testprefix stat3


# Verify that if not compiled with SQLITE_ENABLE_STAT2 that the ANALYZE
# command will delete the sqlite_stat2 table.  Likewise, if not compiled
# with SQLITE_ENABLE_STAT3, the sqlite_stat3 table is deleted.
#
do_test 1.1 {
  db eval {
    PRAGMA writable_schema=ON;
    CREATE TABLE sqlite_stat2(tbl,idx,sampleno,sample);
    CREATE TABLE sqlite_stat3(tbl,idx,neq,nlt,ndlt,sample);
    SELECT name FROM sqlite_master ORDER BY 1;
  }
} {sqlite_stat2 sqlite_stat3}
do_test 1.2 {
  db close
  sqlite3 db test.db
  db eval {SELECT name FROM sqlite_master ORDER BY 1}

  INSERT INTO t1 SELECT a+16, b FROM t1;
  INSERT INTO t1 SELECT a+32, b FROM t1;
  INSERT INTO t1 SELECT a+64, b FROM t1;
  ANALYZE;
} {}

foreach idxmode {ordered unordered} {
  catchsql { DELETE FROM sqlite_stat2 }
  catchsql { DELETE FROM sqlite_stat3 }
  if {$idxmode == "unordered"} {
    execsql { UPDATE sqlite_stat1 SET stat = stat || ' unordered' }
  }
  db close
  sqlite3 db test.db

  foreach {tn sql r(ordered) r(unordered)} {
    1   "SELECT * FROM t1 ORDER BY a"
        {0 0 0 {SCAN TABLE t1 USING INDEX i1 (~128 rows)}}
        {0 0 0 {SCAN TABLE t1 (~128 rows)} 0 0 0 {USE TEMP B-TREE FOR ORDER BY}}
    2   "SELECT * FROM t1 WHERE a >?"
        {0 0 0 {SEARCH TABLE t1 USING INDEX i1 (a>?) (~32 rows)}}
        {0 0 0 {SCAN TABLE t1 (~42 rows)}}