Re: HowTo find out used (useful) and unused (usesless) indexes?

From: DA Morgan <damorgan_at_psoug.org>
Date: Sat, 19 Apr 2008 10:09:08 -0700
Message-ID: <1208624947.696580@bubbleator.drizzle.com>


Shakespeare wrote:

> But an index may become useful over time, true?
>
> Shakespeare

On that basis alone one could justify putting an index on every column of every table so I will respectfully disagree unless you write a very broad definition of "may."

You need to understand your data and how it is being accessed. The extra overhead of an unused index is not value added.

My recommendation would be to use the DBMS_STATS.SET.... procedures to see how queries will react to the expected future growth of both tables and indexes.

-- 
Daniel A. Morgan
Oracle Ace Director & Instructor
University of Washington
damorgan_at_x.washington.edu (replace x with u to respond)
Puget Sound Oracle Users Group
www.psoug.org
Received on Sat Apr 19 2008 - 12:09:08 CDT

Original text of this message