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RE: rm RULE based optimizer != GOOD IDEA

From: Post, Ethan <Ethan.Post_at_ps.net>
Date: Thu, 21 Apr 2005 17:03:32 -0500
Message-ID: <E5D2567DDF0D03428A15664A78CA473C3B5DBC@pscdalpexch02.perotsystems.net>


The problem with that is the environment for the most part is very stable and things run very nice, why go about making changes that are going to effect every query on the system to tweak one query? And again, the argument is why spend time trying to figure this out, no matter how wonderful the CBO becomes, it will occasionally screw up, and if all I need to do is add +RULE and walla! then I think that feature better stay (at the statement level for the very least). Just an argument to keep RULE around, I can't recall what Oracle says the status of this is.

-----Original Message-----
From: Michael Fontana [mailto:mfontana_at_verio.net]=20 Sent: Thursday, April 21, 2005 4:59 PM
To: Post, Ethan; oracle-l_at_freelists.org
Subject: RE: rm RULE based optimizer !=3D GOOD IDEA

If you could post your optimizer settings, I think I can explain this.

For example, in SQLPLUS, enter

Show parameter opt

Sometime you have to tune your optimizer settings to match your query Mix in the real world.

<<Now that ran really slow using the COST optimizer...

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Received on Thu Apr 21 2005 - 18:08:03 CDT

Original text of this message

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