#
# show the global and session values;
#
select @@global.old;
select @@session.old;
show global variables like 'old';
show session variables like 'old';
select * from information_schema.global_variables where variable_name='old';
select * from information_schema.session_variables where variable_name='old';

set global old=1;
set session old=1;
select @@global.old;
select @@session.old;
set @@global.old=DEFAULT;