Re: Dbms_stats Analyze Data Dictionay ?

From: Jack Silvey <depifster_at_yahoo.com>
Date: 25 May 2003 11:49:26 -0700
Message-ID: <25c7944d.0305251049.4b6064fc@posting.google.com>

Ryan,

Without stats on the DD, your recursive data dictionary queries run under rule based optimization, which is the intent in earlier versions of Oracle (<9i).

If you analyze the DD, the optimizer will try to use cost based optimization in dictionary queries. This can be a disaster since the dictionary was designed long ago to run under rule. The CBO could start making very bad choices about execution plans and this can really slow down all your users (sort segment allocation, query parsing, space allocation, stats gathering, etc.)

A good thing might be to test on your dev/qa systems.

hth,

Jack Silvey
warehouse DBA somewhere in Texas

> acceptable? does it help at all or its just not a bad thing?
Received on Sun May 25 2003 - 13:49:26 CDT