Use this statement with caution to ensure you do not lose any wanted binary log file data and GTID execution history.
For a server where binary logging is enabled
RESET MASTER deletes
all existing binary log files and resets the binary log index
file, resetting the server to its state before binary logging
was started. A new empty binary log file is created so that
binary logging can be restarted.
For a server where GTIDs are in use
resets the GTID execution history. The value of the
gtid_purged system variable is
set to an empty string (
''), the global value
(but not the session value) of the
gtid_executed system variable
is set to an empty string, and the
mysql.gtid_executed table is cleared (see
mysql.gtid_executed Table). If the
GTID-enabled server has binary logging enabled,
RESET MASTER also resets the
binary log as described above. Note that
RESET MASTER is the method to
reset the GTID execution history even if the GTID-enabled server
is a replication slave where binary logging is disabled;
RESET SLAVE has no effect on the
GTID execution history. For more information on resetting the
GTID execution history, see
Resetting the GTID Execution History.
RESET MASTERremoves all binary log files that are listed in the index file, leaving only a single, empty binary log file with a numeric suffix of
.000001, whereas the numbering is not reset by
PURGE BINARY LOGS.
RESET MASTERis not intended to be used while any replication slaves are running. The behavior of
RESET MASTERwhen used while slaves are running is undefined (and thus unsupported), whereas
PURGE BINARY LOGSmay be safely used while replication slaves are running.
RESET MASTER can prove useful
when you first set up the master and the slave, so that you can
verify the setup as follows:
Start the master and slave, and start replication (see Section 16.1.2, “Setting Up Binary Log File Position Based Replication”).
Execute a few test queries on the master.
Check that the queries were replicated to the slave.
RESET MASTERon the master to clean up the test queries.
After verifying the setup, resetting the master and slave and ensuring that no unwanted data or binary log files generated by testing remain on master or slave, you can start the slave and begin replicating.