select @@global.open_files_limit; @@global.open_files_limit # select @@session.open_files_limit; ERROR HY000: Variable 'open_files_limit' is a GLOBAL variable show global variables like 'open_files_limit'; Variable_name Value open_files_limit # show session variables like 'open_files_limit'; Variable_name Value open_files_limit # select * from information_schema.global_variables where variable_name='open_files_limit'; VARIABLE_NAME VARIABLE_VALUE OPEN_FILES_LIMIT # select * from information_schema.session_variables where variable_name='open_files_limit'; VARIABLE_NAME VARIABLE_VALUE OPEN_FILES_LIMIT # set global open_files_limit=1; ERROR HY000: Variable 'open_files_limit' is a read only variable set session open_files_limit=1; ERROR HY000: Variable 'open_files_limit' is a read only variable