Re: Weird WAL problem - 9.0.3

On Wednesday, April 13, 2011 6:09:25 am Rafael Martinez wrote:
> Hello
>
> Yesterday we had a weird problem with the pg_xlog partition in one of
> our servers:
>
> - The amount of WAL files was much higher than (2*checkpoint_segments)+1
> (over 360 WAL files)
>

Might want to take a look at:
http://www.postgresql.org/docs/9.0/interactive/wal-configuration.html
In particular:

"There will always be at least one WAL segment file, and will normally not be
more files than the higher of wal_keep_segments or (2 +
checkpoint_completion_target) * checkpoint_segments + 1. Each segment file is
normally 16 MB (though this size can be altered when building the server). You
can use this to estimate space requirements for WAL. Ordinarily, when old log
segment files are no longer needed, they are recycled (renamed to become the next
segments in the numbered sequence). If, due to a short-term peak of log output
rate, there are more than 3 * checkpoint_segments + 1 segment files, the unneeded
segment files will be deleted instead of recycled until the system gets back
under this limit."

--
Adrian Klaver
adrian(dot)klaver(at)gmail(dot)com