# MDEV-6289 : Unexpected results when querying information_schema
#
CREATE TABLE t1 (
id int(11) unsigned NOT NULL AUTO_INCREMENT,
db varchar(254) NOT NULL DEFAULT '',
PRIMARY KEY (id),
UNIQUE KEY db (db)
) DEFAULT CHARSET=utf8;
INSERT INTO t1 (db) VALUES ('mysqltest1'),('mysqltest2'),('mysqltest3'),('mysqltest4');
drop database if exists mysqltest1;
drop database if exists mysqltest2;
drop database if exists mysqltest3;
drop database if exists mysqltest4;
create database mysqltest1;
create database mysqltest2;
create database mysqltest3;
create database mysqltest4;
SELECT db FROM t1 WHERE db IN (SELECT SCHEMA_NAME FROM information_schema.schemata) ORDER BY db DESC;
db
mysqltest4
mysqltest3
mysqltest2
mysqltest1
EXPLAIN EXTENDED
SELECT db FROM t1 WHERE db IN (SELECT SCHEMA_NAME FROM information_schema.schemata) ORDER BY db DESC;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY <subquery2> ALL distinct_key NULL NULL NULL 2 100.00 Using temporary; Using filesort
1 PRIMARY t1 eq_ref db db 764 information_schema.schemata.SCHEMA_NAME 1 100.00 Using where; Using index
2 MATERIALIZED schemata ALL NULL NULL NULL NULL NULL NULL
Warnings:
Note 1003 select `test`.`t1`.`db` AS `db` from `test`.`t1` semi join (`information_schema`.`schemata`) where (`test`.`t1`.`db` = `information_schema`.`schemata`.`SCHEMA_NAME`) order by `test`.`t1`.`db` desc
drop table t1;
drop database mysqltest1;
drop database mysqltest2;
drop database mysqltest3;
drop database mysqltest4;
# End of 5.5 tests
set @subselect_mat_test_optimizer_switch_value=null;
set @@optimizer_switch='materialization=on,in_to_exists=off,semijoin=off';
# MDEV-6289 : Unexpected results when querying information_schema
#
CREATE TABLE t1 (
id int(11) unsigned NOT NULL AUTO_INCREMENT,
db varchar(254) NOT NULL DEFAULT '',
PRIMARY KEY (id),
UNIQUE KEY db (db)
) DEFAULT CHARSET=utf8;
INSERT INTO t1 (db) VALUES ('mysqltest1'),('mysqltest2'),('mysqltest3'),('mysqltest4');
drop database if exists mysqltest1;
drop database if exists mysqltest2;
drop database if exists mysqltest3;
drop database if exists mysqltest4;
create database mysqltest1;
create database mysqltest2;
create database mysqltest3;
create database mysqltest4;
SELECT db FROM t1 WHERE db IN (SELECT SCHEMA_NAME FROM information_schema.schemata) ORDER BY db DESC;
db
mysqltest4
mysqltest3
mysqltest2
mysqltest1
EXPLAIN EXTENDED
SELECT db FROM t1 WHERE db IN (SELECT SCHEMA_NAME FROM information_schema.schemata) ORDER BY db DESC;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY <subquery2> ALL distinct_key NULL NULL NULL 2 100.00 Using temporary; Using filesort
1 PRIMARY t1 eq_ref db db 764 information_schema.schemata.SCHEMA_NAME 1 100.00 Using where; Using index
2 MATERIALIZED schemata ALL NULL NULL NULL NULL NULL NULL
Warnings:
Note 1003 select `test`.`t1`.`db` AS `db` from `test`.`t1` semi join (`information_schema`.`schemata`) where (`test`.`t1`.`db` = `information_schema`.`schemata`.`SCHEMA_NAME`) order by `test`.`t1`.`db` desc