Re: Re: Index freelists

From: <ryan.gaffuri_at_cox.net>
Date: Thu, 29 Apr 2004 7:39:50 -0400
Message-Id: <20040429113950.DFDP10595.lakermmtao08.cox.net@smtp.central.cox.net>

what type of wait tells you that you have contention for freelists? =

> =

> From: "Nuno Souto" <dbvision_at_optusnet.com.au>
> Date: 2004/04/29 Thu AM 07:29:15 EDT
> To: <oracle-l_at_freelists.org>
> Subject: Re: Index freelists
> =

> ----- Original Message ----- =

> From: "Tanel P=F5der" <tanel.poder.003_at_mail.ee>
> =

> > snip
> > But if you have contention on index segment's header block because of=

> block
> > splits/freelist operations, then either partition the index or have
> multiple
> > freelist groups, adding freelists again won't help here. Note that ad=
ding
> > freelist groups require segment rebuild.
> =

> Very interesting points, Tanel. I've discussed a similar situation wit=
h
> one of the local Oracle consultants here when 10G and ASSM/ASM were
> announced
> (re-announced?) early last year.
> =

> We both reached the conclusion the best approach to contention problems=
in
> situations like these (header block contention) is to hash partition as=
much
> as we can (and dare) and forget about fine-tuning segment-headers, free=
lists
> and all that jazz. Much better bang-for-buck of our time. Same applie=
s to
> RAC and clustered situations where there may be block (or row) contenti=
on.
> =

> Just hash partition the table + indexes over 50 or so splits and be don=
e
> with it. 99 times out of 100 it's all you need to do, the remaining 1%=

> you ask a guru to sort it out. Would you agree?
> =

> =

> Cheers
> Nuno Souto
> in sunny Sydney, Australia
> dbvision_at_optusnet.com.au
> =

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Received on Thu Apr 29 2004 - 06:36:55 CDT