Syntax
------ 
PURGE { BINARY | MASTER } LOGS
 { TO 'log_name' | BEFORE datetime_expr }
 
Description
----------- 
The PURGE BINARY LOGS statement deletes all the binary log
files listed in the log index file prior to the specified
log file name or
date. BINARY and MASTER are synonyms.
Deleted log files also are removed from the list recorded in
the index file, so
that the given log file becomes the first in the list.
 
The datetime expression is in the format 'YYYY-MM-DD
hh:mm:ss'. 
 
If a slave is active but has yet to read from a binary log
file you attempt to delete, the statement will fail with an
error. However, if the slave is not connected and has yet to
read from a log file you delete, the file will be deleted,
but the slave will be unable to continue replicating once it
connects again.
 
This statement has no effect if the server was not started
with the
--log-bin option to enable binary logging.
 
To list the binary log files on the server, use SHOW BINARY
LOGS. To see which files they are reading, use SHOW SLAVE
STATUS. You can only delete the files that are older than
the oldest file that is used by the slaves.
 
To delete all binary log files, use RESET MASTER.
To move to a new log file (for example if you want to remove
the current log file), use FLUSH LOGS before you execute
PURGE LOGS.
 
If the expire_logs_days server system variable is not set to
0, the server automatically deletes binary log files after
the given number of days.
 
Examples
-------- 
PURGE BINARY LOGS TO 'mariadb-bin.000063';
 
PURGE BINARY LOGS BEFORE '2013-04-21';
 
PURGE BINARY LOGS BEFORE '2013-04-22 09:55:22';
 


URL: https://mariadb.com/kb/en/purge-binary-logs/