MySQL in a Nutshell, 2nd Edition

Name

FLUSH

Synopsis

FLUSH [LOCAL|NO_WRITE_TO_BINLOG] option[, ...]

Options:

DES_KEY_FILE, HOSTS, LOGS, MASTER, PRIVILEGES, QUERY_CACHE,
STATUS, TABLE, TABLES, TABLES WITHOUT READ LOCK, USER_RESOURCES

Use this statement to clear and reload temporary caches in MySQL. It requires RELOAD privileges. To prevent this statement from writing to the binary log file, the NO_WRITE_TO_BINLOG flag or its LOCAL alias may be given. A particular cache to flush may be given as an option. Multiple options (see Table 4-1) may be given in a comma-separated list.

As of version 5.1 of MySQL, FLUSH cannot be used in stored functions and triggers, but can be used in stored procedures. As an alternative to the FLUSH statement, you can use the mysqladmin command (see Chapter 16).

Table 4-1. Options for FLUSH statement

Option	Explanation
DES_KEY_FILE	Reloads the DES encryption file, which is given with the --des-key-file option at startup or in the options file.
HOSTS	Clears the hosts cache, which is used to minimize host/IP address lookups. The hosts cache may need to be flushed if a host has been blocked from accessing the server.
LOGS	Used to close all of the log files and reopen them. If the server has binary logging enabled, it will change the binary log file to the next in numeric sequence. If the error log was enabled, it will rename the error log to the same name, but with the ending -old, and start a new error log. This option is not logged.
MASTER	This option is not logged and has been deprecated. Use the RESET ...