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Fixed bug mdev-4349.

Range analysis of the condition for a non-indexed column may
return an impossible range. This must be taken into account.
This commit is contained in:
Igor Babaev
2013-04-03 00:54:24 -07:00
parent 70badba5e0
commit 915a8ae42c
5 changed files with 171 additions and 21 deletions

View File

@@ -681,6 +681,47 @@ DROP VIEW v1;
DROP TABLE t1,t2;
set optimizer_use_condition_selectivity=@save_optimizer_use_condition_selectivity;
set use_stat_tables=@tmp_use_stat_tables;
#
# Bug mdev-4349: impossible range for non-indexed column
#
set optimizer_use_condition_selectivity=3;
create table t1 (a int);
insert into t1 values
(3), (7), (2), (5), (7), (1), (2), (2);
set optimizer_use_condition_selectivity=1;
explain extended
select * from t1 where a < 1 and a > 7;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 8 100.00 Using where
Warnings:
Note 1003 select `test`.`t1`.`a` AS `a` from `test`.`t1` where ((`test`.`t1`.`a` < 1) and (`test`.`t1`.`a` > 7))
select * from t1 where a < 1 and a > 7;
a
set optimizer_use_condition_selectivity=3;
explain extended
select * from t1 where a < 1 and a > 7;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE NULL NULL NULL NULL NULL NULL NULL NULL Impossible WHERE noticed after reading const tables
Warnings:
Note 1003 select `test`.`t1`.`a` AS `a` from `test`.`t1` where 0
select * from t1 where a < 1 and a > 7;
a
drop table t1;
create table t1 (a int);
insert into t1 values (1);
create table t2 (b int);
insert into t2 values (2),(3);
explain extended
select * from t1 where a in ( select b from t2 ) AND ( a > 3 );
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t1 ALL NULL NULL NULL NULL 1 0.00 Using where
1 PRIMARY t2 ALL NULL NULL NULL NULL 2 0 Using where; FirstMatch(t1); Using join buffer (flat, BNL join)
Warnings:
Note 1003 select `test`.`t1`.`a` AS `a` from `test`.`t1` semi join (`test`.`t2`) where ((`test`.`t2`.`b` = `test`.`t1`.`a`) and (`test`.`t1`.`a` > 3))
select * from t1 where a in ( select b from t2 ) AND ( a > 3 );
a
drop table t1,t2;
set optimizer_use_condition_selectivity=@save_optimizer_use_condition_selectivity;
set use_stat_tables=@save_use_stat_tables;
set optimizer_switch=@save_optimizer_switch_for_selectivity_test;
SET SESSION STORAGE_ENGINE=DEFAULT;