Re: Readme of Buffer Management seems to have wrong sentence

>>I don't think there is a clear picture yet of what benchmark to use for
testing changes here.
I will first try to generate such a scenario(benchmark). I have still not
thought completely.
However the idea in my mind is that scenario where buffer list is heavily
operated upon.
Operations where shared buffers are much less compare to the data in disk
and the operations are distributed such that
they require to access most of the data in disk randomly.

>> Proving that a) a new policy helps on some workloads
I thought to prove, I should write a proof of concept code and then test it
by having appropriate test, or do you think that it needs to be proved some
other way.

>>and b) it doesn't harm any important workload, those are the hard parts
here
Do you have something in mind which needs to be taken care or thought about
before attempting the idea.

-----Original Message-----
From: Greg Smith [mailto:greg(at)2ndQuadrant(dot)com]
Sent: Wednesday, May 23, 2012 10:35 PM
To: pgsql-hackers(at)postgresql(dot)org; amit(dot)kapila(at)huawei(dot)com
Subject: Re: [HACKERS] Readme of Buffer Management seems to have wrong
sentence

On 05/23/2012 11:36 AM, Amit Kapila wrote:

> Do you feel I can attempt to address this problem with some prototypes and
> discuss here after few days when I have some results ready.

I don't think there is a clear picture yet of what benchmark to use for
testing changes here. Items like "Consider adding buffers the
background writer finds reusable to the free list" have been on the TODO
list since 2007; neither ideas nor code are the problem here. Proving
that a) a new policy helps on some workloads and b) it doesn't harm any
important workload, those are the hard parts here.

--
Greg Smith 2ndQuadrant US greg(at)2ndQuadrant(dot)com Baltimore, MD
PostgreSQL Training, Services, and 24x7 Support www.2ndQuadrant.com