Re: 11G Statistics Collection

From: Mladen Gogala <gogala.mladen_at_gmail.com>
Date: Mon, 16 Apr 2012 12:43:30 +0000 (UTC)
Message-ID: <pan.2012.04.16.12.43.30_at_gmail.com>

On Mon, 16 Apr 2012 09:32:02 +0200, Robert Klemme wrote:

> If it is the nature of the application that data distribution changes
> frequently then what other approach than frequent statistics collection
> on affected tables would be your solution for a "properly written
> application"?

You can rely on sort of rule based optimizer that CBO turns into when you use baselines. You set the "fixed" attribute and, voila, your plan never changes. If my SQL is functioning well, I don't want the plans to change, until I say so. SQL also observes the 90:10 rule: it's 10% of SQL statements that will create 90% of the problems. You tune those, nail them to the wall, so they don't move and have a wonderful and happy life as a cereal killer.

-- 
http://mgogala.byethost5.com

Received on Mon Apr 16 2012 - 07:43:30 CDT