Re: Problem with PITR recovery

On Tue, Apr 19, 2005 at 11:05:32AM -0400, Bruce Momjian wrote:
> Simon Riggs wrote:

> > The disk would only fill if the archiver doesn't keep up with
> > transmitting xlog files to the archive. The archive can fill up if it is
> > not correctly sized, even now. Switching log files every N seconds would
> > at least give a very predictable archive sizing calculation which should
> > actually work against users sizing their archives poorly.
>
> I was thinking of the archiver filling because of lots of almost-empty
> 16mb files. If you archive every five seconds, it is 11 Gigs/hour,
> which is not too bad, I guess, but I would bet compression would save
> space and I/O load too.

I suggested back then that some command to replace an archive could be
provided. So some people could use rsync to update the older version of
the XLog file to the new state. Non-rsync enabled people could use a
temporary file to copy the new file, and then rename to the original
XLog name, substituting the older version. And as a third way, maybe we
can come up with a sort-of-xdelta that would only update the yet-unused
portion of the old xlog file to the new content. (Maybe this could be
made to work with tape.)

Everyone here said that there was no need for such a thing because it
would complicate matters.

--
Alvaro Herrera (<alvherre[(at)]dcc(dot)uchile(dot)cl>)
"Hay quien adquiere la mala costumbre de ser infeliz" (M. A. Evans)