Re: Configuring PostgreSQL to minimize impact of checkpoints

Jack Orenstein wrote:
> Bruce Momjian wrote:
> > jao@geophile.com wrote:
> >
> >>4. I understand that a "background writer" is being contemplated for
> >>7.5.  Will that replace or augment the checkpoint process?  Any
> >>comments on how that work will apply to my problem would be
> >>appreciated. I wouldn't mind seeing the average performance,
> >>(without the spikes) go up -- let's say -- 10%, in exchange for
> >>more uniform performance. These spikes are a real problem.
> >
> >
> > The background writer is designed to address your specific problem.  We
> > will stil checkpoint, but the spike should be greatly minimized.
> >
>
> Thanks. Do you know when 7.5 is expected to be released?

3-6 months.

> Until then, is a workaround known? Also, are the delays I'm seeing out of the ordinary?
> I'm looking at one case in which two successive transactions, each updating a handful of
> records, take 26 and 18 *seconds* (not msec) to complete. These transactions normally complete
> in under 30 msec.

Wow.  Others might know the answer to that.

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