15.7.8.7 RESET PERSIST Statement

RESET PERSIST [[IF EXISTS] system_var_name]

RESET PERSIST removes persisted global system variable settings from the mysqld-auto.cnf option file in the data directory. Removing a persisted system variable causes the variable no longer to be initialized from mysqld-auto.cnf at server startup. For more information about persisting system variables and the mysqld-auto.cnf file, see Section 7.1.9.3, “Persisted System Variables”.

Prior to MySQL 8.0.32, this statement did not work with variables whose name contained a dot character (.), such as MyISAM multiple key cache variables and variables registered by components. (Bug #33417357)

The privileges required for RESET PERSIST depend on the type of system variable to be removed:

• For dynamic system variables, this statement requires the SYSTEM_VARIABLES_ADMIN privilege (or the deprecated SUPER privilege).

• For read-only system variables, this statement requires the SYSTEM_VARIABLES_ADMIN and PERSIST_RO_VARIABLES_ADMIN privileges.

See Section 7.1.9.1, “System Variable Privileges”.

Depending on whether the variable name and IF EXISTS clauses are present, the RESET PERSIST statement has these forms:

• To remove all persisted variables from mysqld-auto.cnf, use RESET PERSIST without naming any system variable:

  RESET PERSIST;

  You must have privileges for removing both dynamic and read-only system variables if mysqld-auto.cnf contains both kinds of variables.

• To remove a specific persisted variable from mysqld-auto.cnf, name it in the statement:

  RESET PERSIST system_var_name;

  This includes plugin system variables, even if the plugin is not currently installed. If the variable is not present in the file, an error occurs.

• To remove a specific persisted variable from mysqld-auto.cnf, but produce a warning rather than an error if the variable is not present in the file, add an IF EXISTS clause to the previous syntax:

  RESET PERSIST IF EXISTS system_var_name;

RESET PERSIST is not affected by the value of the persisted_globals_load system variable.

RESET PERSIST affects the contents of the Performance Schema persisted_variables table because the table contents correspond to the contents of the mysqld-auto.cnf file. On the other hand, because RESET PERSIST does not change variable values, it has no effect on the contents of the Performance Schema variables_info table until the server is restarted.

For information about RESET statement variants that clear the state of other server operations, see Section 15.7.8.6, “RESET Statement”.