select @@global.innodb_ft_total_cache_size;
@@global.innodb_ft_total_cache_size
640000000
select @@session.innodb_ft_total_cache_size;
ERROR HY000: Variable 'innodb_ft_total_cache_size' is a GLOBAL variable
show global variables like 'innodb_ft_total_cache_size';
Variable_name	Value
innodb_ft_total_cache_size	640000000
show session variables like 'innodb_ft_total_cache_size';
Variable_name	Value
innodb_ft_total_cache_size	640000000
select * from information_schema.global_variables where variable_name='innodb_ft_total_cache_size';
VARIABLE_NAME	VARIABLE_VALUE
INNODB_FT_TOTAL_CACHE_SIZE	640000000
select * from information_schema.session_variables where variable_name='innodb_ft_total_cache_size';
VARIABLE_NAME	VARIABLE_VALUE
INNODB_FT_TOTAL_CACHE_SIZE	640000000
set global innodb_ft_total_cache_size=1;
ERROR HY000: Variable 'innodb_ft_total_cache_size' is a read only variable
set session innodb_ft_total_cache_size=1;
ERROR HY000: Variable 'innodb_ft_total_cache_size' is a read only variable
