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