third_party/sqlite/sqlite-src-3080704/test/autoindex3.test

# 2014-06-17
#
# 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.  The
# focus of this script is testing automatic index creation logic,
# and specifically that an automatic index will not be created that
# shadows a declared index.
#

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

# The t1b and t2d indexes are not very selective.  It used to be that
# the autoindex mechanism would create automatic indexes on t1(b) or
# t2(d), make assumptions that they were reasonably selective, and use
# them instead of t1b or t2d.  But that would be cheating, because the
# automatic index cannot be any more selective than the real index.
#
# This test verifies that the cheat is no longer allowed.
#
do_execsql_test autoindex3-100 {
  CREATE TABLE t1(a,b,x);
  CREATE TABLE t2(c,d,y);
  CREATE INDEX t1b ON t1(b);
  CREATE INDEX t2d ON t2(d);
  ANALYZE sqlite_master;
  INSERT INTO sqlite_stat1 VALUES('t1','t1b','10000 500');
  INSERT INTO sqlite_stat1 VALUES('t2','t2d','10000 500');
  ANALYZE sqlite_master;
  EXPLAIN QUERY PLAN SELECT * FROM t1, t2 WHERE d=b;
} {~/AUTO/}

# Automatic indexes can still be used if existing indexes do not
# participate in == constraints.
#
do_execsql_test autoindex3-110 {
  EXPLAIN QUERY PLAN SELECT * FROM t1, t2 WHERE d>b AND x=y;
} {/AUTO/}
do_execsql_test autoindex3-120 {
  EXPLAIN QUERY PLAN SELECT * FROM t1, t2 WHERE d<b AND x=y;
} {/AUTO/}
do_execsql_test autoindex3-130 {
  EXPLAIN QUERY PLAN SELECT * FROM t1, t2 WHERE d IS NULL AND x=y;
} {/AUTO/}
do_execsql_test autoindex3-140 {
  EXPLAIN QUERY PLAN SELECT * FROM t1, t2 WHERE d IN (5,b) AND x=y;
} {/AUTO/}


finish_test