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From: Nuno Souto <nsouto@optushome.com.au.nospam>
Newsgroups: comp.databases.oracle.server
Subject: Re: SAN revisited
Date: Thu, 6 Jun 2002 21:48:04 +1000
References: <3cfe711b.88492845@ausnews.austin.ibm.com>
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In article <3cfe711b.88492845@ausnews.austin.ibm.com>, you said (and I 
quote):
> 
> What I'm thinking here is that perhaps local drive access will be somewhat
> faster than the SAN and so might be a better location for rollbacks and temp
> space.
> 

Hmmm, not really.  Most SANs have huge caches that can flatten the access 
speed compared to a normal disk. 

In fact, one of the things you can do in some SANs is to allocate 
specific cache to logical volumes that handle uniquely the redo logs, for 
example.  

This allows you to have write performance (on the redo logs) similar to 
memory access speed!  Fast as it can be.  

If you trust your SAN.  If not then still do it, but be ready for the 
occasional recovery.  It is an experience worth it to see a 500Mb write 
finish in a few seconds...

-- 
Cheers
Nuno Souto
nsouto@optushome.com.au.nospam