SET @start_global_value = @@global.profiling;
SELECT @start_global_value;
@start_global_value
0
select @@global.profiling;
@@global.profiling
0
select @@session.profiling;
@@session.profiling
0
show global variables like 'profiling';
Variable_name	Value
profiling	OFF
show session variables like 'profiling';
Variable_name	Value
profiling	OFF
select * from information_schema.global_variables where variable_name='profiling';
VARIABLE_NAME	VARIABLE_VALUE
PROFILING	OFF
select * from information_schema.session_variables where variable_name='profiling';
VARIABLE_NAME	VARIABLE_VALUE
PROFILING	OFF
set global profiling=1;
set session profiling=ON;
select @@global.profiling;
@@global.profiling
1
select @@session.profiling;
@@session.profiling
1
show global variables like 'profiling';
Variable_name	Value
profiling	ON
show session variables like 'profiling';
Variable_name	Value
profiling	ON
select * from information_schema.global_variables where variable_name='profiling';
VARIABLE_NAME	VARIABLE_VALUE
PROFILING	ON
select * from information_schema.session_variables where variable_name='profiling';
VARIABLE_NAME	VARIABLE_VALUE
PROFILING	ON
set global profiling=0;
set session profiling=OFF;
select @@global.profiling;
@@global.profiling
0
select @@session.profiling;
@@session.profiling
0
show global variables like 'profiling';
Variable_name	Value
profiling	OFF
show session variables like 'profiling';
Variable_name	Value
profiling	OFF
select * from information_schema.global_variables where variable_name='profiling';
VARIABLE_NAME	VARIABLE_VALUE
PROFILING	OFF
select * from information_schema.session_variables where variable_name='profiling';
VARIABLE_NAME	VARIABLE_VALUE
PROFILING	OFF
set global profiling=1.1;
ERROR 42000: Incorrect argument type to variable 'profiling'
set global profiling=1e1;
ERROR 42000: Incorrect argument type to variable 'profiling'
set global profiling="foo";
ERROR 42000: Variable 'profiling' can't be set to the value of 'foo'
SET @@global.profiling = @start_global_value;
SELECT @@global.profiling;
@@global.profiling
0