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Home -> Community -> Mailing Lists -> Oracle-L -> RE: performance in 10g
If you use alter session and set the optimizer mode to 'rule', how do the queries run? This isn't a proposed solution just a question. RULE has not gone away completely.
Alter session set optimizer_mode=rule;
Will invoke the rule optimizer. I wrote earlier about queries in support of DML such as CTAS or insert into ... Select ... Were horrendously slow, althought the queries when separated from the "create" or insert operations ran quickly. I had tried many other things and setting the optimizer to rule for the session fixed the problem. Although in the end as these Oracle devliered queries having to do with a Peoplesoft upgrade were rewritten by Oracle rewrote. We didn't have to use rule to get us through tghat part of the upgrade.
Ian
-----Original Message-----
From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org] On Behalf Of David Boyd
Sent: Thursday, January 25, 2007 6:10 AM
To: Riazouddine.Rahamathullah_at_brooks.com; oracle-l_at_freelists.org
Subject: RE: performance in 10g
Riaz,
Thanks for your quick response. We do have the latest stats in place.
Dave
>Gather the objects statistics first using DBMS_STATS which will help you
>to improve the performance a lot. Because, no RBO in oracle 10g and the
>optimizer will give you the optimized plan if your db should have the
>latest stats.
-- http://www.freelists.org/webpage/oracle-l -- http://www.freelists.org/webpage/oracle-lReceived on Thu Jan 25 2007 - 09:55:37 CST
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