SET @start_global_value = @@global.flush_time;
select @@global.flush_time;
@@global.flush_time
0
select @@session.flush_time;
ERROR HY000: Variable 'flush_time' is a GLOBAL variable
show global variables like 'flush_time';
Variable_name	Value
flush_time	0
show session variables like 'flush_time';
Variable_name	Value
flush_time	0
select * from information_schema.global_variables where variable_name='flush_time';
VARIABLE_NAME	VARIABLE_VALUE
FLUSH_TIME	0
select * from information_schema.session_variables where variable_name='flush_time';
VARIABLE_NAME	VARIABLE_VALUE
FLUSH_TIME	0
set global flush_time=1;
select @@global.flush_time;
@@global.flush_time
1
set session flush_time=1;
ERROR HY000: Variable 'flush_time' is a GLOBAL variable and should be set with SET GLOBAL
set global flush_time=1.1;
ERROR 42000: Incorrect argument type to variable 'flush_time'
set global flush_time=1e1;
ERROR 42000: Incorrect argument type to variable 'flush_time'
set global flush_time="foo";
ERROR 42000: Incorrect argument type to variable 'flush_time'
set global flush_time=0;
select @@global.flush_time;
@@global.flush_time
0
set global flush_time=cast(-1 as unsigned int);
Warnings:
Note	1105	Cast to unsigned converted negative integer to it's positive complement
Warning	1292	Truncated incorrect flush_time value: '18446744073709551615'
select @@global.flush_time;
@@global.flush_time
31536000
SET @@global.flush_time = @start_global_value;