MySQL:
RESET PERSIST
Syntax:
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.
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The privileges required for RESET PERSIST depend on the type of system
variable to be removed:
o For dynamic system variables, this statement requires the
SYSTEM_VARIABLES_ADMIN privilege (or the deprecated SUPER privilege).
o For read-only system variables, this statement requires the
SYSTEM_VARIABLES_ADMIN and PERSIST_RO_VARIABLES_ADMIN privileges.
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Depending on whether the variable name and IF EXISTS clauses are
present, the RESET PERSIST statement has these forms:
o 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.
o 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.
o 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;
Example