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 17 set testdir [file dirname $argv0] 18 source $testdir/tester.tcl 19 20 # Evaluate SQL. Return the result set followed by the 21 # and the number of full-scan steps. 22 # 23 proc 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 # 30 do_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 # 50 do_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 60 finish_test 61
