# ulong global

SET @start_global_value = @@global.extra_max_connections;

#
# exists as global only
#
select @@global.extra_max_connections;
--error ER_INCORRECT_GLOBAL_LOCAL_VAR
select @@session.extra_max_connections;
show global variables like 'extra_max_connections';
show session variables like 'extra_max_connections';
select * from information_schema.global_variables where variable_name='extra_max_connections';
select * from information_schema.session_variables where variable_name='extra_max_connections';

#
# show that it's writable
#
set global extra_max_connections=1;
select @@global.extra_max_connections;
--error ER_GLOBAL_VARIABLE
set session extra_max_connections=1;

#
# incorrect types
#
--error ER_WRONG_TYPE_FOR_VAR
set global extra_max_connections=1.1;
--error ER_WRONG_TYPE_FOR_VAR
set global extra_max_connections=1e1;
--error ER_WRONG_TYPE_FOR_VAR
set global extra_max_connections="foo";

#
# min/max values
#
set global extra_max_connections=0;
select @@global.extra_max_connections;
set global extra_max_connections=cast(-1 as unsigned int);
select @@global.extra_max_connections;

SET @@global.extra_max_connections = @start_global_value;