Thanks Jhonatan and every one I'm in 9.2, and as in a previous post, and in
Tom kyte's book
I can use system statics, I had ask to Tom Kyte his opinion about "don't
touch them".
Once he giveme an answer I'll continue this post, becaues is very confusing,
their usage, it seem to be a hidden parameter only used when needed.
:)
----- Original Message -----
From: "Jonathan Lewis" <jonathan_at_jlcomp.demon.co.uk>
To: <oracle-l_at_freelists.org>
Sent: Thursday, March 25, 2004 12:51 PM
Subject: Re: how to set optimizer_index_cost_adj and cache parameters?
>
> Just in case you haven't come across it, the following
> article of mine has just been published on DBAZine:
>
> www.dbazine.com/jlewis18.shtml
>
> OICA is a bit of a threat because it's often treated
> as a standalone solution, when it's really part of
> a strategy for getting the truth into the optimizer.
>
> It's also a bit of a bodge job in 8.1 anyway, because
> it tries to fix two issues simultaneously (caching and
> relative read speeds). It is also easy to set it to an
> inappropriate value because of the impact that bad
> SQL can have on your attempts to work out a
> reasonable value.
>
> Just to add to the confusion - whatever you do in
> 8.1 should be reconsidered for 9.2 anyway, where
> system statistics can be used to set relative I/O speeds
> and OICA can be used as an indicator of caching benefits
> on tables.
>
> Regards
>
> Jonathan Lewis
> http://www.jlcomp.demon.co.uk
>
> The Co-operative Oracle Users' FAQ
> http://www.jlcomp.demon.co.uk/faq/ind_faq.html
>
> April 2004 Iceland http://www.index.is/oracleday.php
> June 2004 UK - Optimising Oracle Seminar
>
>
> ----- Original Message -----
> From: "Juan Cachito Reyes Pacheco" <jreyes_at_dazasoftware.com>
> To: <oracle-l_at_freelists.org>
> Sent: Thursday, March 25, 2004 1:23 PM
> Subject: how to set optimizer_index_cost_adj and cache parameters?
>
>
> : Hi,
> :
> : After reading a lot about this, this is my conclusion, do you agree?
> :
> : the conclusion seems to be gather system statics from every distinct
> process
> : or group of process, and set manually this values in every one of them.
> :
> : If this process is by time, for example night and day, you can use alter
> : system parameter,
> : if this is only for ap articular process you will have to set alter
> session.
> :
> : And set the value.
> : This seems to be a hard work.
> :
> : regards,
> :
>
>
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Received on Thu Mar 25 2004 - 12:57:37 CST
