From: Simon Riggs <simon@2ndquadrant.com>
To: Gregory Stark <stark@enterprisedb.com>
Cc: Pg Hackers <pgsql-hackers@postgresql.org>
Subject: Re: Commitfest patches
Date: Fri, 28 Mar 2008 09:44:42 +0000
Message-ID: <1206697482.4285.1518.camel@ebony.site> (raw)
In-Reply-To: <87wsnnz046.fsf@oxford.xeocode.com>
References: <87wsnnz046.fsf@oxford.xeocode.com>
On Fri, 2008-03-28 at 09:08 +0000, Gregory Stark wrote:
> A more invasive form of this patch would be to assign and pin a buffer when
> the preread is done. That would men subsequently we would have a pinned buffer
> ready to go and not need to go back to the buffer manager a second time. We
> would instead just "complete" the i/o by issuing a normal read call.
So if posix_fadvise did nothing or there was a longer than optimal
delay, this would be a net loss.
You'd need reasonable evidence that the posix_fadvise facility was a win
on all platforms and recent release levels before we could agree with
that.
I think we need a more thorough examination of this area before we
commit anything. Maybe you've done this, but I haven't seen the
analysis. Can you say more, please? Or at least say what you don't know,
so other experts listening can fill in the blanks.
--
Simon Riggs
2ndQuadrant http://www.2ndQuadrant.com
PostgreSQL UK 2008 Conference: http://www.postgresql.org.uk
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To: pgsql-hackers@postgresql.org
Cc: simon@2ndquadrant.com, stark@enterprisedb.com
Subject: Re: Commitfest patches
In-Reply-To: <1206697482.4285.1518.camel@ebony.site>
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