SET @start_global_value = @@global.sync_master_info;
SELECT @start_global_value;
@start_global_value
0
select @@global.sync_master_info;
@@global.sync_master_info
0
select @@session.sync_master_info;
ERROR HY000: Variable 'sync_master_info' is a GLOBAL variable
show global variables like 'sync_master_info';
Variable_name	Value
sync_master_info	0
show session variables like 'sync_master_info';
Variable_name	Value
sync_master_info	0
select * from information_schema.global_variables where variable_name='sync_master_info';
VARIABLE_NAME	VARIABLE_VALUE
SYNC_MASTER_INFO	0
select * from information_schema.session_variables where variable_name='sync_master_info';
VARIABLE_NAME	VARIABLE_VALUE
SYNC_MASTER_INFO	0
set global sync_master_info=1;
select @@global.sync_master_info;
@@global.sync_master_info
1
set session sync_master_info=1;
ERROR HY000: Variable 'sync_master_info' is a GLOBAL variable and should be set with SET GLOBAL
set global sync_master_info=1.1;
ERROR 42000: Incorrect argument type to variable 'sync_master_info'
set global sync_master_info=1e1;
ERROR 42000: Incorrect argument type to variable 'sync_master_info'
set global sync_master_info="foo";
ERROR 42000: Incorrect argument type to variable 'sync_master_info'
set global sync_master_info=0;
select @@global.sync_master_info;
@@global.sync_master_info
0
set global sync_master_info=cast(-1 as unsigned int);
Warnings:
Note	1105	Cast to unsigned converted negative integer to it's positive complement
Warning	1292	Truncated incorrect sync_master_info value: '18446744073709551615'
select @@global.sync_master_info;
@@global.sync_master_info
4294967295
SET @@global.sync_master_info = @start_global_value;
SELECT @@global.sync_master_info;
@@global.sync_master_info
0
