/trunk/test/tkt3757.test |
@@ -0,0 +1,60 @@ |
# 2009 March 28 |
# |
# 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. |
# |
#*********************************************************************** |
# |
# Ticket #3757: The cost functions on the query optimizer for the |
# IN operator can be improved. |
# |
# $Id: tkt3757.test,v 1.1 2009/03/29 00:13:04 drh Exp $ |
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set testdir [file dirname $argv0] |
source $testdir/tester.tcl |
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# Evaluate SQL. Return the result set followed by the |
# and the number of full-scan steps. |
# |
proc count_steps {sql} { |
set r [db eval $sql] |
lappend r scan [db status step] sort [db status sort] |
} |
|
# Construct tables |
# |
do_test tkt3757-1.1 { |
db eval { |
CREATE TABLE t1(x INTEGER, y INTEGER, z TEXT); |
CREATE INDEX t1i1 ON t1(y,z); |
INSERT INTO t1 VALUES(1,2,'three'); |
CREATE TABLE t2(a INTEGER, b TEXT); |
INSERT INTO t2 VALUES(2, 'two'); |
ANALYZE; |
SELECT * FROM sqlite_stat1 ORDER BY 1, 2; |
} |
} {t1 t1i1 {1 1 1} t2 {} 1} |
|
# Modify statistics in order to make the optimizer then that: |
# |
# (1) Table T1 has about 250K entries |
# (2) There are only about 5 distinct values of T1. |
# |
# Then run a query with "t1.y IN (SELECT ..)" in the WHERE clause. |
# Make sure the index is used. |
# |
do_test tkt3757-1.2 { |
db eval { |
DELETE FROM sqlite_stat1; |
INSERT INTO sqlite_stat1 VALUES('t1','t1i1','250000 50000 30'); |
} |
count_steps { |
SELECT * FROM t1 WHERE y IN (SELECT a FROM t2) |
} |
} {1 2 three scan 0 sort 0} |
|
finish_test |