Re: Seems like a large amount of xlog files

On Wed, May 25, 2011 at 8:19 AM, Michael Holt <michael(at)aers(dot)ca> wrote:
>
> We're trying to do some performance tuning on a couple of postgres boxes and I've noticed there seems to be a lot of activity in the pg_xlog folder. There seems to consitently be 132 files with many being written almost every minute. Looking just now I see 40 written in the last minute and 48 in the minute before that. I'm having some difficulty determining why there are so many WAL files being written so frequently as this is normally a low-write/high read server. There are some things causing implicit transactions in some old code, but they do not actually write to any tables. So i have two questions: 1) Does simply running a transaction (implicit or explicit) cause writing to the WAL? 2) Is there any simple way to track what may be causing WAL writes?

Is archive_timeout more than zero in your setting?
If yes, that setting might have caused such a large number of
WAL files.

Regards,

--
Fujii Masao
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center