MySQL – How to Delete Slow Query Log File

MySQLmysql-workbenchperformanceslow-log

I was logging slow queries of my system. Now I have few queries to be optimized and reset the global slow_query_log variable to 0. Now I want to delete slow query log file mysqld-slow.log. can anyone tell me what is the standard way to do this ?

I am using Cent OS and do not want to delete or affect other log files (i.e. general log or binary log)
Thanks.

Best Answer

As of 5.5.3, FLUSH LOGS will close and reopen the slowlog. (In old versions, FLUSH had no effect on the slowlog.)

So, on *nix OS, this should work without restarting the server:

  1. rm (to delete) or mv the slowlog to another name. (Note: mysqld will continue to write to the file, even though you changed the name.)
  2. FLUSH LOGS;. As of 5.5.3, you can limit the effect via FLUSH SLOW LOGS;

See http://bugs.mysql.com/bug.php?id=14104 and http://bugs.mysql.com/bug.php?id=60878

I would not turn off the slowlog -- next month someone will add a naughty query and you will want to know about it.

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