test/in3.test

# 2007 November 29
#
# 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 tests the optimisations made in November 2007 of expressions 
# of the following form:
#
#     <value> IN (SELECT <column> FROM <table>)
#
# $Id: in3.test,v 1.5 2008/08/04 03:51:24 danielk1977 Exp $

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

ifcapable !subquery {
  finish_test
  return
}

# Return the number of OpenEphemeral instructions used in the
# implementation of the sql statement passed as a an argument.
#
proc nEphemeral {sql} {
  set nEph 0
  foreach op [execsql "EXPLAIN $sql"] {
    if {$op eq "OpenEphemeral"} {incr nEph}
  }
  set nEph
}

# This proc works the same way as execsql, except that the number
# of OpenEphemeral instructions used in the implementation of the
# statement is inserted into the start of the returned list.
#
proc exec_neph {sql} {
  return [concat [nEphemeral $sql] [execsql $sql]]
}

do_test in3-1.1 {
  execsql {
    CREATE TABLE t1(a PRIMARY KEY, b);
    INSERT INTO t1 VALUES(1, 2);
    INSERT INTO t1 VALUES(3, 4);
    INSERT INTO t1 VALUES(5, 6);
  }
} {}

# All of these queries should avoid using a temp-table:
#
do_test in3-1.2 {
  exec_neph { SELECT rowid FROM t1 WHERE rowid IN (SELECT rowid FROM t1); }
} {0 1 2 3}
do_test in3-1.3 {
  exec_neph { SELECT a FROM t1 WHERE a IN (SELECT a FROM t1); }
} {0 1 3 5}
do_test in3-1.4 {
  exec_neph { SELECT rowid FROM t1 WHERE rowid+0 IN (SELECT rowid FROM t1); }
} {0 1 2 3}
do_test in3-1.5 {
  exec_neph { SELECT a FROM t1 WHERE a+0 IN (SELECT a FROM t1); }
} {0 1 3 5}

# Because none of the sub-select queries in the following statements
# match the pattern ("SELECT <column> FROM <table>"), the following do 
# require a temp table.
#
do_test in3-1.6 {
  exec_neph { SELECT rowid FROM t1 WHERE rowid IN (SELECT rowid+0 FROM t1); }
} {1 1 2 3}
do_test in3-1.7 {
  exec_neph { SELECT a FROM t1 WHERE a IN (SELECT a+0 FROM t1); }
} {1 1 3 5}
do_test in3-1.8 {
  exec_neph { SELECT a FROM t1 WHERE a IN (SELECT a FROM t1 WHERE 1); }
} {1 1 3 5}
do_test in3-1.9 {
  exec_neph { SELECT a FROM t1 WHERE a IN (SELECT a FROM t1 GROUP BY a); }
} {1 1 3 5}

# This should not use a temp-table. Even though the sub-select does
# not exactly match the pattern "SELECT <column> FROM <table>", in
# this case the ORDER BY is a no-op and can be ignored.
do_test in3-1.10 {
  exec_neph { SELECT a FROM t1 WHERE a IN (SELECT a FROM t1 ORDER BY a); }
} {0 1 3 5}

# These do use the temp-table. Adding the LIMIT clause means the 
# ORDER BY cannot be ignored.
do_test in3-1.11 {
  exec_neph {SELECT a FROM t1 WHERE a IN (SELECT a FROM t1 ORDER BY a LIMIT 1)}
} {1 1}
do_test in3-1.12 {
  exec_neph {
    SELECT a FROM t1 WHERE a IN (SELECT a FROM t1 ORDER BY a LIMIT 1 OFFSET 1)
  }
} {1 3}

# Has to use a temp-table because of the compound sub-select.
#
ifcapable compound {
  do_test in3-1.13 {
    exec_neph {
      SELECT a FROM t1 WHERE a IN (
        SELECT a FROM t1 UNION ALL SELECT a FROM t1
      )
    }
  } {1 1 3 5}
}

# The first of these queries has to use the temp-table, because the 
# collation sequence used for the index on "t1.a" does not match the
# collation sequence used by the "IN" comparison. The second does not
# require a temp-table, because the collation sequences match.
#
do_test in3-1.14 {
  exec_neph { SELECT a FROM t1 WHERE a COLLATE nocase IN (SELECT a FROM t1) }
} {1 1 3 5}
do_test in3-1.15 {
  exec_neph { SELECT a FROM t1 WHERE a COLLATE binary IN (SELECT a FROM t1) }
} {0 1 3 5}

# Neither of these queries require a temp-table. The collation sequence
# makes no difference when using a rowid.
#
do_test in3-1.16 {
  exec_neph {SELECT a FROM t1 WHERE a COLLATE nocase IN (SELECT rowid FROM t1)}
} {0 1 3}
do_test in3-1.17 {
  exec_neph {SELECT a FROM t1 WHERE a COLLATE binary IN (SELECT rowid FROM t1)}
} {0 1 3}

# The following tests - in3.2.* - test a bug that was difficult to track
# down during development. They are not particularly well focused.
#
do_test in3-2.1 {
  execsql {
    DROP TABLE IF EXISTS t1;
    CREATE TABLE t1(w int, x int, y int);
    CREATE TABLE t2(p int, q int, r int, s int);
  }
  for {set i 1} {$i<=100} {incr i} {
    set w $i
    set x [expr {int(log($i)/log(2))}]
    set y [expr {$i*$i + 2*$i + 1}]
    execsql "INSERT INTO t1 VALUES($w,$x,$y)"
  }
  set maxy [execsql {select max(y) from t1}]
  db eval { INSERT INTO t2 SELECT 101-w, x, $maxy+1-y, y FROM t1 }
} {}
do_test in3-2.2 {
  execsql {
    SELECT rowid 
    FROM t1 
    WHERE rowid IN (SELECT rowid FROM t1 WHERE rowid IN (1, 2));
  }
} {1 2}
do_test in3-2.3 {
  execsql {
    select rowid from t1 where rowid IN (-1,2,4)
  }
} {2 4}
do_test in3-2.4 {
  execsql {
    SELECT rowid FROM t1 WHERE rowid IN 
       (select rowid from t1 where rowid IN (-1,2,4))
  }
} {2 4}

#-------------------------------------------------------------------------
# This next block of tests - in3-3.* - verify that column affinity is
# correctly handled in cases where an index might be used to optimise
# an IN (SELECT) expression.
#
do_test in3-3.1 {
  catch {execsql {
    DROP TABLE t1;
    DROP TABLE t2;
  }}

  execsql {

    CREATE TABLE t1(a BLOB, b NUMBER ,c TEXT);
    CREATE UNIQUE INDEX t1_i1 ON t1(a);        /* no affinity */
    CREATE UNIQUE INDEX t1_i2 ON t1(b);        /* numeric affinity */
    CREATE UNIQUE INDEX t1_i3 ON t1(c);        /* text affinity */

    CREATE TABLE t2(x BLOB, y NUMBER, z TEXT);
    CREATE UNIQUE INDEX t2_i1 ON t2(x);        /* no affinity */
    CREATE UNIQUE INDEX t2_i2 ON t2(y);        /* numeric affinity */
    CREATE UNIQUE INDEX t2_i3 ON t2(z);        /* text affinity */

    INSERT INTO t1 VALUES(1, 1, 1);
    INSERT INTO t2 VALUES('1', '1', '1');
  }
} {}

do_test in3-3.2 {
  # No affinity is applied before comparing "x" and "a". Therefore
  # the index can be used (the comparison is false, text!=number).
  exec_neph { SELECT x IN (SELECT a FROM t1) FROM t2 }
} {0 0}
do_test in3-3.3 {
  # Logically, numeric affinity is applied to both sides before 
  # the comparison.  Therefore it is possible to use index t1_i2.
  exec_neph { SELECT x IN (SELECT b FROM t1) FROM t2 }
} {0 1}
do_test in3-3.4 {
  # No affinity is applied before the comparison takes place. Making
  # it possible to use index t1_i3.
  exec_neph { SELECT x IN (SELECT c FROM t1) FROM t2 }
} {0 1}

do_test in3-3.5 {
  # Numeric affinity should be applied to each side before the comparison
  # takes place. Therefore we cannot use index t1_i1, which has no affinity.
  exec_neph { SELECT y IN (SELECT a FROM t1) FROM t2 }
} {1 1}
do_test in3-3.6 {
  # Numeric affinity is applied to both sides before 
  # the comparison.  Therefore it is possible to use index t1_i2.
  exec_neph { SELECT y IN (SELECT b FROM t1) FROM t2 }
} {0 1}
do_test in3-3.7 {
  # Numeric affinity is applied before the comparison takes place. 
  # Making it impossible to use index t1_i3.
  exec_neph { SELECT y IN (SELECT c FROM t1) FROM t2 }
} {1 1}

#---------------------------------------------------------------------
#
# Test using a multi-column index.
#
do_test in3-4.1 {
  execsql {
    CREATE TABLE t3(a, b, c);
    CREATE UNIQUE INDEX t3_i ON t3(b, a);
  }

  execsql {
    INSERT INTO t3 VALUES(1, 'numeric', 2);
    INSERT INTO t3 VALUES(2, 'text', 2);
    INSERT INTO t3 VALUES(3, 'real', 2);
    INSERT INTO t3 VALUES(4, 'none', 2);
  }
} {}
do_test in3-4.2 {
  exec_neph { SELECT 'text' IN (SELECT b FROM t3) }
} {0 1}
do_test in3-4.3 {
  exec_neph { SELECT 'TEXT' COLLATE nocase IN (SELECT b FROM t3) }
} {1 1}
do_test in3-4.4 {
  # A temp table must be used because t3_i.b is not guaranteed to be unique.
  exec_neph { SELECT b FROM t3 WHERE b IN (SELECT b FROM t3) }
} {1 none numeric real text}
do_test in3-4.5 {
  execsql { CREATE UNIQUE INDEX t3_i2 ON t3(b) }
  exec_neph { SELECT b FROM t3 WHERE b IN (SELECT b FROM t3) }
} {0 none numeric real text}
do_test in3-4.6 {
  execsql { DROP INDEX t3_i2 }
} {}

# The following two test cases verify that ticket #2991 has been fixed.
#
do_test in3-5.1 {
  execsql {
    CREATE TABLE Folders(
      folderid INTEGER PRIMARY KEY, 
      parentid INTEGER, 
      rootid INTEGER, 
      path VARCHAR(255)
    );
  }
} {}
do_test in3-5.2 {
  catchsql {
    DELETE FROM Folders WHERE folderid IN
    (SELECT folderid FROM Folder WHERE path LIKE 'C:\MP3\Albums\' || '%');
  }
} {1 {no such table: Folder}}

finish_test