Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com> wrote:
> If the system is completely idle, and no WAL is written, we skip
> xlog switches too, even if archive_timeout is set . It would be
> pointless to create a stream of WAL files with no content except
> for the XLOG_SWITCH records.
It's not pointless if you want to monitor that your backup system is
healthy. This was previously mentioned a couple years ago:
http://archives.postgresql.org/pgsql-general/2007-10/msg01448.php
It turns out that it's been working fine under 8.3. Of course, we
can always add a crontab job to do some small bogus update to force
WAL switches, so it's not the end of the world if we lose the 8.3
behavior; but my preference would be that if a WAL switch interval
is specified, the WAL files switch at least that often.
-Kevin