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RE: Cost vs Rule

From: Shaw John-P55297 <P55297_at_motorola.com>
Date: Thu, 07 Mar 2002 12:03:37 -0800
Message-ID: <F001.004226DE.20020307120337@fatcity.com>


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

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Author: Magaliff, Bill
  INET: Bill.Magaliff_at_lendware.com

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Author: Shaw John-P55297
  INET: P55297_at_motorola.com
Fat City Network Services    -- (858) 538-5051  FAX: (858) 538-5051
San Diego, California        -- Public Internet access / Mailing Lists
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To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). Received on Thu Mar 07 2002 - 14:03:37 CST

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