#
# MDEV-4029 SELECT on information_schema using a subquery locks up the information_schema table due to incorrect mutexes handling 
#
select variable_name from information_schema.session_status where variable_name =
(select variable_name from information_schema.session_status where variable_name = 'uptime');
select variable_name from information_schema.session_variables where variable_name =
(select variable_name from information_schema.session_variables where variable_name = 'basedir');

#
# MDEV-8796 Delete with sub query with information_schema.TABLES deletes too many rows
#
create table t1 (x int);
create table t2 (x int);
create table t3 (x int);
create table t4 AS select table_name from information_schema.TABLES where table_schema = database() and table_type = 'BASE TABLE' ;
delete from t4 where table_name not in (select table_name from information_schema.TABLES where table_schema = database() and table_type = 'BASE TABLE');
select * from t4;
drop table t1, t2, t3, t4;