FLUSH [NO_WRITE_TO_BINLOG | LOCAL]
FLUSH statements are
written to the binary log so that they will be replicated to
replication slaves. Logging can be suppressed with the optional
NO_WRITE_TO_BINLOG keyword or its alias
flush_option can be any of the
Reloads the DES keys from the file that was specified with
--des-key-file option at
server startup time.
Empties the host cache tables. You should flush the host
tables if some of your hosts change IP number or if you get
the error message
When more than
host_name' is blocked
occur successively for a given host while connecting to the
MySQL server, MySQL assumes that something is wrong and
blocks the host from further connection requests. Flushing
the host tables enables further connection attempts from the
host. See Section B.5.2.6, “
Host '”. You can start
to avoid this error message.
Closes and reopens all log files. If binary logging is
enabled, the sequence number of the binary log file is
incremented by one relative to the previous file. On Unix,
this is the same thing as sending a
SIGHUP signal to the
mysqld server (except on some Mac OS X
10.3 versions where mysqld ignores
If the server is writing error output to a named file (for
example, if it was started with the
causes it to rename the current error log file with a suffix
-old and create a new empty log file.
No renaming occurs if the server is not writing to a named
file (for example, if it is writing errors to the console).
Deletes all binary logs, resets the binary log index file
and creates a new binary log.
MASTER is deprecated in favor of
RESET MASTER, and is
supported for backward compatibility only. See
Section 188.8.131.52, “
RESET MASTER Syntax”.
Reloads the privileges from the grant tables in the
mysql database. On Unix, this also occurs
if the server receives a
The server caches information in memory as a result of
CREATE SERVER, and
INSTALL PLUGIN statements.
This memory is not released by the corresponding
DROP SERVER, and
UNINSTALL PLUGIN statements,
so for a server that executes many instances of the
statements that cause caching, there will be an increase in
memory use. This cached memory can be freed with
Resets all replication slave parameters, including relay log
files and replication position in the master's binary logs.
is deprecated in favor of
SLAVE, and is supported for backward compatibility
only. See Section 184.108.40.206, “
RESET SLAVE Syntax”.
This option adds the current thread's session status
variable values to the global values and resets the session
values to zero. It also resets the counters for key caches
(default and named) to zero and sets
the current number of open connections. This is something
you should use only when debugging a query. See
Section 1.7, “How to Report Bugs or Problems”.
Closes all open tables, forces all tables in use to be
closed, and flushes the query cache.
TABLES also removes all query results from the
query cache, like the
With a list of one or more comma-separated table names,
this is like
TABLES with no names except that the server
flushes only the named tables. No error occurs if a
named table does not exist.
FLUSH TABLES WITH READ LOCK
Closes all open tables and locks all tables for all
databases with a global read lock until you explicitly
release the lock by executing
TABLES. This is a very convenient way to get
backups if you have a file system such as Veritas or ZFS
that can take snapshots in time.
FLUSH TABLES WITH
READ LOCK acquires a global read lock and not
table locks, so it is not subject to the same behavior
LOCK TABLES and
TABLES with respect to table locking and
TABLES implicitly commits any active
transaction only if any tables currently have been
TABLES. The commit does not occur for
WITH READ LOCK because the latter
statement does not acquire table locks.
Beginning a transaction causes table locks acquired
LOCK TABLES to
be released, as though you had executed
TABLES. Beginning a transaction does not
release a global read lock acquired with
WITH READ LOCK.
FLUSH TABLES WITH
READ LOCK does not prevent the server from
inserting rows into the log tables (see
Section 5.2.1, “Selecting General Query and Slow Query Log Output Destinations”).
Resets all per-hour user resources to zero. This enables
clients that have reached their hourly connection, query, or
update limits to resume activity immediately.
USER_RESOURCES does not apply to the limit on
maximum simultaneous connections. See
Section 5.5.4, “Setting Account Resource Limits”.
The mysqladmin utility provides a
command-line interface to some flush operations, via command
It is not possible in MySQL 5.1 to issue
FLUSH statements within stored
functions or triggers. However, you may use
FLUSH in stored procedures, so
long as these are not called from stored functions or
triggers. See Section D.1, “Restrictions on Stored Routines, Triggers, and Events”.