FLUSH [NO_WRITE_TO_BINLOG | LOCAL]
By default, the server writes
FLUSH statements to the binary
log so that they replicate to replication slaves. To suppress
logging, specify the optional
NO_WRITE_TO_BINLOG keyword or its alias
FLUSH statement causes an
implicit commit. See Section 13.3.3, “Statements That Cause an Implicit Commit”.
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. You should flush the host cache if
some of your hosts change IP address or if the error message
Host ' occurs. (See
Section B.5.2.6, “Host 'host_name' is blocked”.) When more than
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 cache enables further connection attempts from the
host. The default value of
max_connect_errors is 10.
To avoid this error message, start the server with
max_connect_errors set to a
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.
If you execute
LOGS and mysqld is writing the
error log to a file (for example, if it was started with the
--log-error option), log file
renaming occurs as described in Section 5.2.1, “The Error Log”.
Deletes all binary logs, resets the binary log index file
and creates a new binary log.
MASTER is deprecated in favor of
MASTER is still accepted in MySQL 5.0
for backward compatibility, but is removed in MySQL 5.6. See
Section 188.8.131.52, “RESET MASTER Syntax”.
Reloads the privileges from the grant tables in the
The server caches information in memory as a result of
CREATE USER statements. This
memory is not released by the corresponding
DROP USER 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
is still accepted in MySQL 5.0 for backward
compatibility, but is removed in MySQL 5.6. 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. Some global variables may be reset to zero
as well. 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”.
TABLES flushes tables, and, depending on the
variant used, acquires locks. The permitted syntax is
discussed later in this section.
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 6.3.4, “Setting Account Resource Limits”.
The mysqladmin utility provides a
command-line interface to some flush operations, using commands
Section 4.5.2, “mysqladmin — Client for Administering a MySQL Server”.
It is not possible 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 Programs”.
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
RESET QUERY CACHE
With a list of one or more comma-separated table names, this
statement 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. 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. Use
TABLES to release the lock.
FLUSH TABLES WITH
READ LOCK acquires a global read lock and not
table locks, so it is not subject to the same behavior as
LOCK TABLES and
TABLES with respect to table locking and implicit
TABLES implicitly commits any active
transaction only if any tables currently have been
The commit does not occur for
FLUSH TABLES WITH
READ LOCK because the latter statement does
not acquire table locks.
Beginning a transaction causes table locks acquired with
LOCK TABLES to be
released, as though you had executed
TABLES. Beginning a transaction does not
release a global read lock acquired with
FLUSH TABLES WITH