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Re: Strange problems with more memory.

From: Mark Kirkwood <markir(at)coretech(dot)co(dot)nz>
To: Stef <svb(at)ucs(dot)co(dot)za>
Cc: pgsql-performance(at)postgresql(dot)org
Subject: Re: Strange problems with more memory.
Date: 2004-08-17 06:26:15
Message-ID: 4121A507.1000704@coretech.co.nz (view raw or flat)
Thread:
Lists: pgsql-performance
If your nightly process is heavily read-only, then raid5 is probably 
fine. If however, there is a significant write component then it would 
perhaps be worth getting another disk and converting to raid10 
(alternatively - see previous postings about raid cards with on-board 
cache). Are you seeing a lot of write activity?

Note that it is possible for a SELECT only workload to generate 
significant write activity - if the resulting datasets are too large for 
memory sorting or hashing. I'm *guessing* that with an 11G database and 
1G (or was that 2G?) of ram that it is possible to overflow whatever 
your sort_mem is set to.


cheers

Mark

Stef wrote:

>Got 3 10000 rpm SCSI raid5 on here. I doubt I will get much better than that
>without losing both arms and legs... 
>
>  
>

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