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Re: Rule-based optimizer wins big over CBO - why?

From: Jason Buchanan <jason.buchanan_at_gmail.com>
Date: 14 Jul 2004 07:20:47 -0700
Message-ID: <5f258456.0407140620.16560b32@posting.google.com>


Daniel Morgan <damorgan_at_x.washington.edu> wrote in message news:<1089764962.962641_at_yasure>...
> Jason Buchanan wrote:
>
> > I'm faced with a problem that I cannot identify or solve. For a
> > mysterious reason the RBO beats the CBO in stunning ways for the query
> > shown below.

> Oracle version and edition? Unknown!

Solaris 8, E4500.
Oracle9i Enterprise Edition Release 9.0.1.1.0 - 64bit Production

I am planning to upgrade to 9.2.0.4 shortly.

> Current statistics? Unknown!

Freshly gathered via:

   DBMS_STATS.gather_database_stats

                          (gather_sys            => FALSE,
                           method_opt            => 'FOR ALL COLUMNS AUTO',
                           options               => 'GATHER AUTO',
                           estimate_percent      => DBMS_STATS.AUTO_SAMPLE_SIZE,
                           CASCADE               => TRUE
                          );



thanks! Received on Wed Jul 14 2004 - 09:20:47 CDT

Original text of this message

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