segment monitoring, stats, histograms

From: Jeremiah Wilton <jeremiah_at_ora-600.net>
Date: Fri, 04 Feb 2005 00:08:40 +0000
Message-ID: <W750972317140761107475720@webmail4>

What is the current state of the art WRT CBO best practices?

I'm working on 9.2.0.4 and considering the 'automated statistics gatherin=
g' approach.  This involves turning on monitoring for any and all tables =
that need to ever have stats updated, then periodically running dbms_stat=

s in gather_stale mode.

How is this working for people? Does monitoring impact DML operations, a= nd if so, how much?

Does this approach make any kind of intelligent decisions about sample si= zes and block sampling?

When histograms are present, does this approach always/never/sometimes re= generate the histogram with the correct number of buckets?

Does it seem to reliably choose the correct tables to analyze?

--

Jeremiah Wilton
ORA-600 Consulting
http://www.ora-600.net

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http://www.freelists.org/webpage/oracle-l Received on Thu Feb 03 2005 - 19:11:36 CST