Re: Query tuning exercise: what to look for in a 10053 trace

From: Alex Gorbachev <gorbyx_at_gmail.com>
Date: Tue, 25 Jul 2006 20:41:09 +0200
Message-ID: <c2213f680607251141p697b45efw493c5b60afe843d4@mail.gmail.com>

The first thing is to verify that cardinality of datasets that CBO estimates is correct. Only after that you can look at cost estimation for each access path and only than at join order and join cardinalities.

Sorry, I don't have a straight answer for you becuase there are probaly no such thing. At least, based on so little info you provided.

2006/7/25, Schultz, Charles <sac_at_uillinois.edu>:
> From an academic standpoint, I am trying to figure out why the CBO is using
> a different join order - perhaps this is a vain and useless endeavor, but I
> am curious.

-- 
Best regards,
Alex Gorbachev

http://blog.oracloid.com
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Received on Tue Jul 25 2006 - 13:41:09 CDT