From: Michael Stone <mstone+postgres@mathom.us>
To: pgsql-performance@postgresql.org
Subject: Re: 1 TB of memory
Date: Fri, 17 Mar 2006 07:31:23 -0500
Message-ID: <20060317123121.GO15140@mathom.us> (raw)
In-Reply-To: <C03F9AC9.1F5EE%llonergan@greenplum.com>
References: <8B16F5C8-DFC8-4694-902C-AE584E490530@pervasive.com>
<C03F9AC9.1F5EE%llonergan@greenplum.com>
On Thu, Mar 16, 2006 at 10:44:25PM -0800, Luke Lonergan wrote:
>You'd be better off with 4 x $10K servers that do 800MB/s from disk each and
>a Bizgres MPP - then you'd do 3.2GB/s (faster than the SSD) at a price 1/10
>of the SSD, and you'd have 24TB of RAID5 disk under you.
Except, of course, that your solution doesn't have a seek time of zero.
That approach is great for applications that are limited by their
sequential scan speed, not so good for applications with random access.
At 3.2 GB/s it would still take over 5 minutes to seqscan a TB, so you'd
probably want some indices--and you're not going to be getting 800MB/s
per system doing random index scans from rotating disk (but you might
with SSD). Try not to beat your product drum quite so loud...
Mike Stone
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To: pgsql-performance@postgresql.org
Cc: mstone+postgres@mathom.us
Subject: Re: 1 TB of memory
In-Reply-To: <20060317123121.GO15140@mathom.us>
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