Re: Status of 8.3 patches - Mailing list pgsql-hackers

From Alvaro Herrera
Subject Re: Status of 8.3 patches
Date
Msg-id 20070820204422.GW27916@alvh.no-ip.org
Whole thread Raw
In response to Re: Status of 8.3 patches  ("Joshua D. Drake" <jd@commandprompt.com>)
Responses Re: Status of 8.3 patches  ("Joshua D. Drake" <jd@commandprompt.com>)
List pgsql-hackers
Joshua D. Drake wrote:
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> Heikki Linnakangas wrote:
> > Joshua D. Drake wrote:
> >> Heikki Linnakangas wrote:
> >>> Bruce Momjian wrote:
> >>>>   o  Automatic adjustment of bgwriter_lru_maxpages 
> >>>>
> >>>>      We show this as waiting for performance results.  I am thinking we
> >>>>      should hold this for 8.4.
> >>> Agreed. I spent close to a week trying different benchmarks and
> >>> configurations and simple test cases on a test server and my laptop, and
> >>> couldn't demonstrate bgwriter making a positive impact in any
> >>> configuration I tried. The theory behind the patch is sound, but it
> >>> looks like a lot more testing and analysis is needed.
> >> Wouldn't real world testing be needed to actually gain insight to this
> >> patch?
> > 
> > I would expect a fairly static benchmark workload to benefit from having
> > a bgwriter, more so than more unpredictable real world applications.
> 
> Hmmm, I find that real world applications are quite predictable over
> time. Certainly you have spikes (good pr, whatever) but in general with
> a little bit of monitoring it is quite possible to evaluate a generally
> expected result.
> 
> I guess my point is, if the patch looks good and does not appear to hurt
> anything, why not apply it? At least that way we can start to review the
> progress of the feature itself as it starts to see use.

Yeah, you mean like commit_delay.  It really worked great, that
reviewing of a feature, you know.  It only took 3 years until someone
realized that it didn't work as advertised.

-- 
Alvaro Herrera                  http://www.amazon.com/gp/registry/5ZYLFMCVHXC
"En las profundidades de nuestro inconsciente hay una obsesiva necesidad
de un universo lógico y coherente. Pero el universo real se halla siempre
un paso más allá de la lógica" (Irulan)


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