SQLite

      }else{
        /* Note: this call could be optimized away - since the same values must 
        ** have been requested when testing key $P in whereEqualScanEst().  */
        whereKeyStats(pParse, p, pRec, 0, a);
        iLower = a[0];
        iUpper = a[0] + a[1];
      }

      assert( pLower==0 || (pLower->eOperator & (WO_GT|WO_GE))!=0 );
      assert( pUpper==0 || (pUpper->eOperator & (WO_LT|WO_LE))!=0 );
      if( p->pKeyInfo && p->pKeyInfo->aSortOrder[nEq] ){
        /* The roles of pLower and pUpper are swapped for a DESC index */
        SWAP(WhereTerm*, pLower, pUpper);
      }

      /* If possible, improve on the iLower estimate using ($P:$L). */
      if( pLower ){
        int bOk;                    /* True if value is extracted from pExpr */
        Expr *pExpr = pLower->pExpr->pRight;
        assert( (pLower->eOperator & (WO_GT|WO_GE))!=0 );
        rc = sqlite3Stat4ProbeSetValue(pParse, p, &pRec, pExpr, aff, nEq, &bOk);
        if( rc==SQLITE_OK && bOk ){
          tRowcnt iNew;
          whereKeyStats(pParse, p, pRec, 0, a);
          iNew = a[0] + ((pLower->eOperator & WO_GT) ? a[1] : 0);
          iNew = a[0] + ((pLower->eOperator & (WO_GT|WO_LE)) ? a[1] : 0);
          if( iNew>iLower ) iLower = iNew;
          nOut--;
          pLower = 0;
        }
      }

      /* If possible, improve on the iUpper estimate using ($P:$U). */
      if( pUpper ){
        int bOk;                    /* True if value is extracted from pExpr */
        Expr *pExpr = pUpper->pExpr->pRight;
        assert( (pUpper->eOperator & (WO_LT|WO_LE))!=0 );
        rc = sqlite3Stat4ProbeSetValue(pParse, p, &pRec, pExpr, aff, nEq, &bOk);
        if( rc==SQLITE_OK && bOk ){
          tRowcnt iNew;
          whereKeyStats(pParse, p, pRec, 1, a);
          iNew = a[0] + ((pUpper->eOperator & WO_LE) ? a[1] : 0);
          iNew = a[0] + ((pUpper->eOperator & (WO_GT|WO_LE)) ? a[1] : 0);
          if( iNew<iUpper ) iUpper = iNew;
          nOut--;
          pUpper = 0;
        }
      }

      pBuilder->pRec = pRec;

# 2014-10-08
#
# 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 tests for using STAT4 information
# on a descending index in a range query.
#

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

ifcapable {!stat4} {
  finish_test
  return
}

# Verify that range queries on an ASCENDING index will use the
# index only if the range covers only a small fraction of the
# entries.
#
do_execsql_test analyzeE-1.0 {
  CREATE TABLE t1(a,b);
  WITH RECURSIVE
    cnt(x) AS (VALUES(1000) UNION ALL SELECT x+1 FROM cnt WHERE x<2000)
  INSERT INTO t1(a,b) SELECT x, x FROM cnt;
  CREATE INDEX t1a ON t1(a);
  ANALYZE;
} {}
do_execsql_test analyzeE-1.1 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t1 WHERE a BETWEEN 500 AND 2500;
} {/SCAN TABLE t1/}
do_execsql_test analyzeE-1.2 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t1 WHERE a BETWEEN 2900 AND 3000;
} {/SEARCH TABLE t1 USING INDEX t1a/}
do_execsql_test analyzeE-1.3 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t1 WHERE a BETWEEN 1700 AND 1750;
} {/SEARCH TABLE t1 USING INDEX t1a/}
do_execsql_test analyzeE-1.4 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t1 WHERE a BETWEEN 1 AND 500
} {/SEARCH TABLE t1 USING INDEX t1a/}
do_execsql_test analyzeE-1.5 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t1 WHERE a BETWEEN 3000 AND 3000000
} {/SEARCH TABLE t1 USING INDEX t1a/}
do_execsql_test analyzeE-1.6 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t1 WHERE a<500
} {/SEARCH TABLE t1 USING INDEX t1a/}
do_execsql_test analyzeE-1.7 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t1 WHERE a>2500
} {/SEARCH TABLE t1 USING INDEX t1a/}
do_execsql_test analyzeE-1.8 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t1 WHERE a>1900
} {/SEARCH TABLE t1 USING INDEX t1a/}
do_execsql_test analyzeE-1.9 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t1 WHERE a>1100
} {/SCAN TABLE t1/}
do_execsql_test analyzeE-1.10 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t1 WHERE a<1100
} {/SEARCH TABLE t1 USING INDEX t1a/}
do_execsql_test analyzeE-1.11 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t1 WHERE a<1900
} {/SCAN TABLE t1/}

# Verify that everything works the same on a DESCENDING index.
#
do_execsql_test analyzeE-2.0 {
  DROP INDEX t1a;
  CREATE INDEX t1a ON t1(a DESC);
  ANALYZE;
} {}
do_execsql_test analyzeE-2.1 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t1 WHERE a BETWEEN 500 AND 2500;
} {/SCAN TABLE t1/}
do_execsql_test analyzeE-2.2 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t1 WHERE a BETWEEN 2900 AND 3000;
} {/SEARCH TABLE t1 USING INDEX t1a/}
do_execsql_test analyzeE-2.3 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t1 WHERE a BETWEEN 1700 AND 1750;
} {/SEARCH TABLE t1 USING INDEX t1a/}
do_execsql_test analyzeE-2.4 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t1 WHERE a BETWEEN 1 AND 500
} {/SEARCH TABLE t1 USING INDEX t1a/}
do_execsql_test analyzeE-2.5 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t1 WHERE a BETWEEN 3000 AND 3000000
} {/SEARCH TABLE t1 USING INDEX t1a/}
do_execsql_test analyzeE-2.6 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t1 WHERE a<500
} {/SEARCH TABLE t1 USING INDEX t1a/}
do_execsql_test analyzeE-2.7 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t1 WHERE a>2500
} {/SEARCH TABLE t1 USING INDEX t1a/}
do_execsql_test analyzeE-2.8 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t1 WHERE a>1900
} {/SEARCH TABLE t1 USING INDEX t1a/}
do_execsql_test analyzeE-2.9 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t1 WHERE a>1100
} {/SCAN TABLE t1/}
do_execsql_test analyzeE-2.10 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t1 WHERE a<1100
} {/SEARCH TABLE t1 USING INDEX t1a/}
do_execsql_test analyzeE-2.11 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t1 WHERE a<1900
} {/SCAN TABLE t1/}

# Now do a range query on the second term of an ASCENDING index
# where the first term is constrained by equality.
#
do_execsql_test analyzeE-3.0 {
  DROP TABLE t1;
  CREATE TABLE t1(a,b,c);
  WITH RECURSIVE
    cnt(x) AS (VALUES(1000) UNION ALL SELECT x+1 FROM cnt WHERE x<2000)
  INSERT INTO t1(a,b,c) SELECT x, x, 123 FROM cnt;
  CREATE INDEX t1ca ON t1(c,a);
  ANALYZE;
} {}
do_execsql_test analyzeE-3.1 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t1 WHERE a BETWEEN 500 AND 2500 AND c=123;
} {/SCAN TABLE t1/}
do_execsql_test analyzeE-3.2 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t1 WHERE a BETWEEN 2900 AND 3000 AND c=123;
} {/SEARCH TABLE t1 USING INDEX t1ca/}
do_execsql_test analyzeE-3.3 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t1 WHERE a BETWEEN 1700 AND 1750 AND c=123;
} {/SEARCH TABLE t1 USING INDEX t1ca/}
do_execsql_test analyzeE-3.4 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t1 WHERE a BETWEEN 1 AND 500 AND c=123
} {/SEARCH TABLE t1 USING INDEX t1ca/}
do_execsql_test analyzeE-3.5 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t1 WHERE a BETWEEN 3000 AND 3000000 AND c=123
} {/SEARCH TABLE t1 USING INDEX t1ca/}
do_execsql_test analyzeE-3.6 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t1 WHERE a<500 AND c=123
} {/SEARCH TABLE t1 USING INDEX t1ca/}
do_execsql_test analyzeE-3.7 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t1 WHERE a>2500 AND c=123
} {/SEARCH TABLE t1 USING INDEX t1ca/}
do_execsql_test analyzeE-3.8 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t1 WHERE a>1900 AND c=123
} {/SEARCH TABLE t1 USING INDEX t1ca/}
do_execsql_test analyzeE-3.9 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t1 WHERE a>1100 AND c=123
} {/SCAN TABLE t1/}
do_execsql_test analyzeE-3.10 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t1 WHERE a<1100 AND c=123
} {/SEARCH TABLE t1 USING INDEX t1ca/}
do_execsql_test analyzeE-3.11 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t1 WHERE a<1900 AND c=123
} {/SCAN TABLE t1/}

# Repeat the 3.x tests using a DESCENDING index
#
do_execsql_test analyzeE-4.0 {
  DROP INDEX t1ca;
  CREATE INDEX t1ca ON t1(c ASC,a DESC);
  ANALYZE;
} {}
do_execsql_test analyzeE-4.1 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t1 WHERE a BETWEEN 500 AND 2500 AND c=123;
} {/SCAN TABLE t1/}
do_execsql_test analyzeE-4.2 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t1 WHERE a BETWEEN 2900 AND 3000 AND c=123;
} {/SEARCH TABLE t1 USING INDEX t1ca/}
do_execsql_test analyzeE-4.3 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t1 WHERE a BETWEEN 1700 AND 1750 AND c=123;
} {/SEARCH TABLE t1 USING INDEX t1ca/}
do_execsql_test analyzeE-4.4 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t1 WHERE a BETWEEN 1 AND 500 AND c=123
} {/SEARCH TABLE t1 USING INDEX t1ca/}
do_execsql_test analyzeE-4.5 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t1 WHERE a BETWEEN 3000 AND 3000000 AND c=123
} {/SEARCH TABLE t1 USING INDEX t1ca/}
do_execsql_test analyzeE-4.6 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t1 WHERE a<500 AND c=123
} {/SEARCH TABLE t1 USING INDEX t1ca/}
do_execsql_test analyzeE-4.7 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t1 WHERE a>2500 AND c=123
} {/SEARCH TABLE t1 USING INDEX t1ca/}
do_execsql_test analyzeE-4.8 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t1 WHERE a>1900 AND c=123
} {/SEARCH TABLE t1 USING INDEX t1ca/}
do_execsql_test analyzeE-4.9 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t1 WHERE a>1100 AND c=123
} {/SCAN TABLE t1/}
do_execsql_test analyzeE-4.10 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t1 WHERE a<1100 AND c=123
} {/SEARCH TABLE t1 USING INDEX t1ca/}
do_execsql_test analyzeE-4.11 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t1 WHERE a<1900 AND c=123
} {/SCAN TABLE t1/}

finish_test