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