# ulong global

SET @start_global_value = @@global.key_cache_segments;

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

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

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

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

SET @@global.key_cache_segments = @start_global_value;