Re: doubt in sql

From: HansF <News.Hans_at_telus.net>
Date: Fri, 25 Mar 2005 15:29:57 GMT
Message-Id: <pan.2005.03.25.16.31.27.144834@telus.net>

On Fri, 25 Mar 2005 05:28:08 -0500, rasukutty wrote:

> I want to know the difference between IN and NOT IN with regard to
> performance.If Both are going to do full scan on the table then how is one
> going to perform over the other?

You seem to be falling into the trap of thinking that one method may be better than another in general - this is the basis of many Oracle myths.

The answer is: there is a difference, and that difference will show one OR the other being better in specific circumstances.

To determine the circumstances, you want to use evaluation tools such as those described by Mr. Kyte in "Effective Oracle By Design" and Mr. Lewis in "Practical Oracle8i". And remember, even changing number of rows in a table could be enough to change the circumstances.

/Hans Received on Fri Mar 25 2005 - 09:29:57 CST