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|  | 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 | 
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