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Re: Cost vs Rule

From: Suzy Vordos <lvordos_at_qwest.com>
Date: Thu, 07 Mar 2002 12:43:53 -0800
Message-ID: <F001.00422844.20020307124353@fatcity.com>

Tim Gorman wrote a good paper about using these parameters: http://www.evdbt.com/SearchIntelligenceCBO.doc

Shaw John-P55297 wrote:
>
> have you tried adjusting optimzer_index_caching and
> optimizer_index_cost_adj?
>
> -----Original Message-----
> Sent: Thursday, March 07, 2002 1:23 PM
> To: Multiple recipients of list ORACLE-L
>
> I work in a dev shop - most of the sql is canned and pretty basic. We've
> been running CBO in all of our dev environments, but we have a few long txns
> that just take forever. At the request of some savvy developers, I turned
> on RBO, and it brought down execution times dramatically.
>
> I've been analyzing affected tables often (we do a lot of bulk load/unload
> for testing), and have played with partitioning and clustering, particularly
> on one table that's just a dog. CBO will always do a FTS where RBO uses the
> PK to retrieve data.
>
> Where to go next? I've been unable to alter the costs dramatically enough
> to make any real difference in execution time.
>
> thx
>
> --
> Please see the official ORACLE-L FAQ: http://www.orafaq.com
> --
> Author: Magaliff, Bill
> INET: Bill.Magaliff_at_lendware.com
>
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> Author: Shaw John-P55297
> INET: P55297_at_motorola.com
>
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-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.com
-- 
Author: Suzy Vordos
  INET: lvordos_at_qwest.com

Fat City Network Services    -- (858) 538-5051  FAX: (858) 538-5051
San Diego, California        -- Public Internet access / Mailing Lists
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Received on Thu Mar 07 2002 - 14:43:53 CST

Original text of this message

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