Re: In praise of auto space management

From: Jonathan Lewis <jonathan_at_jlcomp.demon.co.uk>
Date: Thu, 11 Jul 2002 13:12:46 +0100
Message-ID: <1026389514.15595.0.nnrp-12.9e984b29@news.demon.co.uk>

!!!

Have you really got 5,141 truly concurrent insert processes running at high speed ? Your figures seem a bit extreme - especially for an index cluster.

Can you tell us a little more ?

Is this OPS/RAC by the way - the comment about half-empty extents suggests it may be.

--
Jonathan Lewis
http://www.jlcomp.demon.co.uk

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Andrew Mobbs wrote in message ...


>Jonathan Lewis <jonathan_at_jlcomp.demon.co.uk> wrote:

>>

>>One thought, have you noticed that in a fairly

>>recent version of Oracle, (possibly 8.1.7) you

>>can modify freelists online without having to

>>rebuild the table ?

>

>Yes, I had noticed that, and it's a very good thing. Freelist groups

>are still static though.

>

>For large system benchmarks, I've been using up to 53 freelist groups

>and 97 freelists on one particular table (single-table index cluster

>actually). I really try not to think about how much space is being wasted

>in partially full extents.

>

>Thanks for the comments though. I'm now considering the whole thing

>much more carefully before recommending ASSM as a panacea for insert

>contention. Shame, I was very enthusiastic about the thought of never

>again having to trawl through a performance problem report to find that

>it was a simple lack of freelists (or worse, FL groups).

>

>--

>Andrew Mobbs - http://www.chiark.greenend.org.uk/~andrewm/

Received on Thu Jul 11 2002 - 07:12:46 CDT