Re: WAL log archive frequency - Mailing list pgsql-admin

From Tom Lane
Subject Re: WAL log archive frequency
Date
Msg-id 17319.1137690111@sss.pgh.pa.us
Whole thread Raw
In response to WAL log archive frequency  (Chris Jewell <c.jewell@lancaster.ac.uk>)
Responses Why psql.exe does not work?  (Sean G <seangaret@yahoo.ca>)
Re: WAL log archive frequency  (Bruce Momjian <pgman@candle.pha.pa.us>)
List pgsql-admin
Chris Jewell <c.jewell@lancaster.ac.uk> writes:
> Further to my question on PITR, I have now implemented it :-)  However,
> I was wondering about the frequency of archiving the WAL.  Does
> postgresql wait until the current WAL file has reached 16MB before
> calling the archive_command?

Yes.  The assumption is the archive_command may be too stupid to deal
with archiving the same file more than once, and/or might have
performance issues with doing that, eg, if it's writing to tape or some
kind of write-once media.

You can do something like saving the newest-by-timestamp file in the
xlog directory every minute or whatever via a cron job.  This ought to
be better integrated though ...

            regards, tom lane

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