From: Simon Riggs <simon@2ndQuadrant.com>
To: Jignesh K. Shah <J.K.Shah@Sun.COM>
Cc: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Kevin Grittner <Kevin.Grittner@wicourts.gov>
Cc: pgsql-performance@postgresql.org
Subject: Re: Proposal of tunable fix for scalability of 8.4
Date: Wed, 18 Mar 2009 00:43:23 +0000
Message-ID: <1237337003.3953.157.camel@ebony.2ndQuadrant> (raw)
In-Reply-To: <49C0384E.2020707@sun.com>
References: <49B824DD.7090302@sun.com>
<49B7F470.EE98.0025.0@wicourts.gov>
<29080.1236821556@sss.pgh.pa.us>
<49B87161.10201@sun.com>
<1237225198.3963.60.camel@ebony.2ndQuadrant>
<49C01900.5030406@sun.com>
<1237330778.3953.139.camel@ebony.2ndQuadrant>
<49C0384E.2020707@sun.com>
On Tue, 2009-03-17 at 19:54 -0400, Jignesh K. Shah wrote:
>
> Simon Riggs wrote:
> > On Tue, 2009-03-17 at 17:41 -0400, Jignesh K. Shah wrote:
> >
> >
> >> I did a quick test with patch. Unfortunately it improves my number
> >> even with default setting 0 (not sure whether I should be pleased or
> >> sad - Definitely no overhead infact seems to help performance a bit.
> >> NOTE: Logic is same, implementation is slightly different for default
> >> set)
> >>
> >
> > OK, I bite. 25% gain from doing nothing??? You're stretching my... err,
> > credulity.
> >
> > I like the train of thought for setting 1 and it is worth investigating,
> > but something feels wrong somewhere.
> >
> >
> Actually I think I am hurting my credibility here since I cannot
> explain the improvement with the patch but still using default logic
> (thought different way I compare sequential using fields from the
> previous proc structure instead of comparing with constant boolean)
> But the change was necessary to allow it to handle multiple algorithms
> and yet be sleek and not bloated.
>
> In next couple of weeks I plan to test the patch on a different x64
> based system to do a sanity testing on lower number of cores and also
> try out other workloads ...
Good plan. I'm behind your ideas and will be happy to wait.
--
Simon Riggs www.2ndQuadrant.com
PostgreSQL Training, Services and Support
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To: pgsql-performance@postgresql.org
Cc: simon@2ndQuadrant.com, J.K.Shah@Sun.COM, tgl@sss.pgh.pa.us, Kevin.Grittner@wicourts.gov
Subject: Re: Proposal of tunable fix for scalability of 8.4
In-Reply-To: <1237337003.3953.157.camel@ebony.2ndQuadrant>
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