OLD | NEW |
(Empty) | |
| 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 |
OLD | NEW |