#
# 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');