Date: Sat, 19 Nov 2005 15:27:49 +1300
From: Mark Kirkwood <markir@paradise.net.nz>
Subject: Re: Hardware/OS recommendations for large databases (
In-reply-to: <BFA3AC67.14125%llonergan@greenplum.com>
To: Luke Lonergan <llonergan@greenplum.com>
Cc: Dave Cramer <pg@fastcrypt.com>, Greg Stark <gsstark@mit.edu>,
	Joshua Marsh <icub3d@gmail.com>, pgsql-performance@postgresql.org
Message-id: <437E8DA5.1050703@paradise.net.nz>
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References: <BFA3AC67.14125%llonergan@greenplum.com>

Luke Lonergan wrote:
> Mark,
> 
> On 11/18/05 3:46 PM, "Mark Kirkwood" <markir@paradise.net.nz> wrote:
> 
>     If you alter this to involve more complex joins (e.g 4. way star) and
>     (maybe add a small number of concurrent executors too) - is it still the
>     case?
> 
> 
> I may not have listened to you - are you asking about whether the 
> readahead works for these cases?
> 
> I’ll be running some massive TPC-H benchmarks on these machines soon – 
> we’ll see then.


That too, meaning the business of 1 executor random reading a given 
relation file whilst another is sequentially scanning (some other) part 
of it....

Cheers

Mark