SET @start_global_value = @@global.innodb_old_blocks_time;
SELECT @start_global_value;
@start_global_value
1000
Valid values are zero or above
select @@global.innodb_old_blocks_time >=0;
@@global.innodb_old_blocks_time >=0
1
select @@global.innodb_old_blocks_time;
@@global.innodb_old_blocks_time
1000
select @@session.innodb_old_blocks_time;
ERROR HY000: Variable 'innodb_old_blocks_time' is a GLOBAL variable
show global variables like 'innodb_old_blocks_time';
Variable_name	Value
innodb_old_blocks_time	1000
show session variables like 'innodb_old_blocks_time';
Variable_name	Value
innodb_old_blocks_time	1000
select * from information_schema.global_variables where variable_name='innodb_old_blocks_time';
VARIABLE_NAME	VARIABLE_VALUE
INNODB_OLD_BLOCKS_TIME	1000
select * from information_schema.session_variables where variable_name='innodb_old_blocks_time';
VARIABLE_NAME	VARIABLE_VALUE
INNODB_OLD_BLOCKS_TIME	1000
set global innodb_old_blocks_time=10;
select @@global.innodb_old_blocks_time;
@@global.innodb_old_blocks_time
10
select * from information_schema.global_variables where variable_name='innodb_old_blocks_time';
VARIABLE_NAME	VARIABLE_VALUE
INNODB_OLD_BLOCKS_TIME	10
select * from information_schema.session_variables where variable_name='innodb_old_blocks_time';
VARIABLE_NAME	VARIABLE_VALUE
INNODB_OLD_BLOCKS_TIME	10
set session innodb_old_blocks_time=1;
ERROR HY000: Variable 'innodb_old_blocks_time' is a GLOBAL variable and should be set with SET GLOBAL
set global innodb_old_blocks_time=1.1;
ERROR 42000: Incorrect argument type to variable 'innodb_old_blocks_time'
set global innodb_old_blocks_time=1e1;
ERROR 42000: Incorrect argument type to variable 'innodb_old_blocks_time'
set global innodb_old_blocks_time="foo";
ERROR 42000: Incorrect argument type to variable 'innodb_old_blocks_time'
set global innodb_old_blocks_time=-7;
Warnings:
Warning	1292	Truncated incorrect innodb_old_blocks_time value: '-7'
select @@global.innodb_old_blocks_time;
@@global.innodb_old_blocks_time
0
select * from information_schema.global_variables where variable_name='innodb_old_blocks_time';
VARIABLE_NAME	VARIABLE_VALUE
INNODB_OLD_BLOCKS_TIME	0
SET @@global.innodb_old_blocks_time = @start_global_value;
SELECT @@global.innodb_old_blocks_time;
@@global.innodb_old_blocks_time
1000
