From: Jeffrey W. Baker <jwbaker@acm.org>
To: Guy Thornley <guy@esphion.com>
Cc: Josh Berkus <josh@agliodbs.com>
Cc: pgsql-performance@postgresql.org, Steve Poe <spoe@sfnet.cc>
Cc: Chris Browne <cbbrowne@acm.org>
Subject: Re: Read/Write block sizes
Date: Tue, 23 Aug 2005 22:25:21 -0700
Message-ID: <1124861121.11270.1.camel@noodles> (raw)
In-Reply-To: <20050824052023.GB31806@conker.esphion.com>
References: <d4b67d7c2b.d7c2bd4b67@bur-mail1.east.sun.com>
<60k6icpapm.fsf@dba2.int.libertyrms.com>
<1124846743.12045.94.camel@amd64-laptop-spoe>
<200508231931.29682.josh@agliodbs.com>
<1124852854.11147.5.camel@noodles>
<20050824052023.GB31806@conker.esphion.com>
On Wed, 2005-08-24 at 17:20 +1200, Guy Thornley wrote:
> As for the async IO, sure you might think 'oh async IO would be so cool!!'
> and I did, once, too. But then I sat down and _thought_ about it, and
> decided well, no, actually, theres _very_ few areas it could actually help,
> and in most cases it just make it easier to drive your box into lseek()
> induced IO collapse.
>
> Dont forget that already in postgres, you have a process per connection, and
> all the processes take care of their own I/O.
That's the problem. Instead you want 1 or 4 or 10 i/o slaves
coordinating the I/O of all the backends optimally. For instance, with
synchronous scanning.
-jwb
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To: pgsql-performance@postgresql.org
Cc: jwbaker@acm.org, guy@esphion.com, josh@agliodbs.com, spoe@sfnet.cc, cbbrowne@acm.org
Subject: Re: Read/Write block sizes
In-Reply-To: <1124861121.11270.1.camel@noodles>
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