# 2005 July 22 # # 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. # #*********************************************************************** # This file implements regression tests for SQLite library. # This file implements tests for the ANALYZE command. # # $Id: analyze.test,v 1.9 2008/08/11 18:44:58 drh Exp $ set testdir [file dirname $argv0] source $testdir/tester.tcl set ::testprefix analyzeD ifcapable {!stat4} { finish_test return } # Set up a table with the following properties: # # * Contains 1000 rows. # * Column a contains even integers between 0 and 18, inclusive (so that # a=? for any such integer matches 100 rows). # * Column b contains integers between 0 and 9, inclusive. # * Column c contains integers between 0 and 199, inclusive (so that # for any such integer, c=? matches 5 rows). # * Then add 7 rows with a new value for "a" - 3001. The stat4 table will # not contain any samples with a=3001. # do_execsql_test 1.0 { CREATE TABLE t1(a, b, c); } do_test 1.1 { for {set i 1} {$i < 1000} {incr i} { set c [expr $i % 200] execsql { INSERT INTO t1(a, b, c) VALUES( 2*($i/100), $i%10, $c ) } } execsql { INSERT INTO t1 VALUES(3001, 3001, 3001); INSERT INTO t1 VALUES(3001, 3001, 3002); INSERT INTO t1 VALUES(3001, 3001, 3003); INSERT INTO t1 VALUES(3001, 3001, 3004); INSERT INTO t1 VALUES(3001, 3001, 3005); INSERT INTO t1 VALUES(3001, 3001, 3006); INSERT INTO t1 VALUES(3001, 3001, 3007); CREATE INDEX t1_ab ON t1(a, b); CREATE INDEX t1_c ON t1(c); ANALYZE; } } {} # With full ANALYZE data, SQLite sees that c=150 (5 rows) is better than # a=3001 (7 rows). # do_eqp_test 1.2 { SELECT * FROM t1 WHERE a=3001 AND c=150; } { 0 0 0 {SEARCH TABLE t1 USING INDEX t1_c (c=?)} } do_test 1.3 { execsql { DELETE FROM sqlite_stat1 } db close sqlite3 db test.db } {} # Without stat1, because 3001 is larger than all samples in the stat4 # table, SQLite things that a=3001 matches just 1 row. So it (incorrectly) # chooses it over the c=150 index (5 rows). Even with stat1 data, things # worked this way before commit [e6f7f97dbc]. # do_eqp_test 1.4 { SELECT * FROM t1 WHERE a=3001 AND c=150; } { 0 0 0 {SEARCH TABLE t1 USING INDEX t1_ab (a=?)} } do_test 1.5 { execsql { UPDATE t1 SET a=13 WHERE a = 3001; ANALYZE; } } {} do_eqp_test 1.6 { SELECT * FROM t1 WHERE a=13 AND c=150; } { 0 0 0 {SEARCH TABLE t1 USING INDEX t1_c (c=?)} } do_test 1.7 { execsql { DELETE FROM sqlite_stat1 } db close sqlite3 db test.db } {} # Same test as 1.4, except this time the 7 rows that match the a=? condition # do not feature larger values than all rows in the stat4 table. So SQLite # gets this right, even without stat1 data. do_eqp_test 1.8 { SELECT * FROM t1 WHERE a=13 AND c=150; } { 0 0 0 {SEARCH TABLE t1 USING INDEX t1_c (c=?)} } finish_test