1# 2009 March 28 2# 3# The author disclaims copyright to this source code. In place of 4# a legal notice, here is a blessing: 5# 6# May you do good and not evil. 7# May you find forgiveness for yourself and forgive others. 8# May you share freely, never taking more than you give. 9# 10#*********************************************************************** 11# 12# Ticket #3757: The cost functions on the query optimizer for the 13# IN operator can be improved. 14# 15# $Id: tkt3757.test,v 1.1 2009/03/29 00:13:04 drh Exp $ 16 17set testdir [file dirname $argv0] 18source $testdir/tester.tcl 19 20# Evaluate SQL. Return the result set followed by the 21# and the number of full-scan steps. 22# 23proc count_steps {sql} { 24 set r [db eval $sql] 25 lappend r scan [db status step] sort [db status sort] 26} 27 28# Construct tables 29# 30do_test tkt3757-1.1 { 31 db eval { 32 CREATE TABLE t1(x INTEGER, y INTEGER, z TEXT); 33 CREATE INDEX t1i1 ON t1(y,z); 34 INSERT INTO t1 VALUES(1,2,'three'); 35 CREATE TABLE t2(a INTEGER, b TEXT); 36 INSERT INTO t2 VALUES(2, 'two'); 37 ANALYZE; 38 SELECT * FROM sqlite_stat1 ORDER BY 1, 2; 39 } 40} {t1 t1i1 {1 1 1} t2 {} 1} 41 42# Modify statistics in order to make the optimizer then that: 43# 44# (1) Table T1 has about 250K entries 45# (2) There are only about 5 distinct values of T1. 46# 47# Then run a query with "t1.y IN (SELECT ..)" in the WHERE clause. 48# Make sure the index is used. 49# 50do_test tkt3757-1.2 { 51 db eval { 52 DELETE FROM sqlite_stat1; 53 INSERT INTO sqlite_stat1 VALUES('t1','t1i1','250000 50000 30'); 54 } 55 count_steps { 56 SELECT * FROM t1 WHERE y IN (SELECT a FROM t2) 57 } 58} {1 2 three scan 0 sort 0} 59 60finish_test 61