1select @@global.report_host;
2@@global.report_host
3NULL
4select @@session.report_host;
5ERROR HY000: Variable 'report_host' is a GLOBAL variable
6show global variables like 'report_host';
7Variable_name	Value
8report_host
9show session variables like 'report_host';
10Variable_name	Value
11report_host
12select * from information_schema.global_variables where variable_name='report_host';
13VARIABLE_NAME	VARIABLE_VALUE
14REPORT_HOST
15select * from information_schema.session_variables where variable_name='report_host';
16VARIABLE_NAME	VARIABLE_VALUE
17REPORT_HOST
18set global report_host=1;
19ERROR HY000: Variable 'report_host' is a read only variable
20set session report_host=1;
21ERROR HY000: Variable 'report_host' is a read only variable
22