Sami, You can use the concept of an IOT if your query is against one table. Simply put all of the columns from your query into an index. A simple test would answer whether it is good for you or not. Tom -----Original Message----- From: Sami Seerangan [mailto:dba.orcl@xxxxxxxxx] Sent: Thursday, March 31, 2005 9:48 PM To: thomas.mercadante@xxxxxxxxxxxxxxxxx Cc: Igor Neyman; sjaffarhussain@xxxxxxxxx; oracle-l@xxxxxxxxxxxxx Subject: Re: reducing LIO's Thomas, I have a similar situation(query) and needs performance improvement. My understanding is that IOT is good for lookup tables. Can I use IOT for transaction tables(gets updated every few mins). Did anyone try clustering the tables involved in joins to improve the performance? On Thu, 31 Mar 2005 09:42:30 -0500, Mercadante, Thomas F <thomas.mercadante@xxxxxxxxxxxxxxxxx> wrote: > I agree. I reduced a very slow OLTP summary query from 3 minutes to 5 > seconds using an IOT. This query was used every time a user hit their home > page. -- //www.freelists.org/webpage/oracle-l