Check my articles about unbalanced indexes rebuilding indexes on www.dbazine.com first, and see if that helps you understand. If you have any specific questions after that, then post them on the list. One guide-line, though - as a one-off exercise after a massive delete from a table, rebuilding the indexes on that table will probably free up some space, and may not cause a performance problem to appear. However, after a massive delete, you need to apply some thought to the issue of whether or not you should rebuilding the table, and what's going to happen the next time you generate statistics even in the absence of a rebuild. Regards Jonathan Lewis http://www.jlcomp.demon.co.uk The educated person is not the person who can answer the questions, but the person who can question the answers -- T. Schick Jr Next public appearances: March 2004 Hotsos Symposium - The Burden of Proof March 2004 Charlotte NC OUG - CBO Tutorial April 2004 Iceland One-day tutorials: http://www.jlcomp.demon.co.uk/tutorial.html Three-day seminar: see http://www.jlcomp.demon.co.uk/seminar.html ____UK___February ____UK___June The Co-operative Oracle Users' FAQ http://www.jlcomp.demon.co.uk/faq/ind_faq.html ----- Original Message ----- From: "vidya kalyanaraman" <vidya.kalyanaraman@xxxxxxxxxx> To: <oracle-l@xxxxxxxxxxxxx> Sent: Friday, February 13, 2004 10:56 AM Subject: Re: Rebuild Indexes Hi Jonathan Thanks for the explanation. Here the customer wants to reclaim the extra space. According to them they had massive deletes and they feel that might have causeed the unbalanced structure and wastage of space. Customer uses mainly B*Tree indexes. what is your suggestion in this situation? Thanks a lot for answering this question. Best Regards Vidya ---------------------------------------------------------------- Please see the official ORACLE-L FAQ: http://www.orafaq.com ---------------------------------------------------------------- To unsubscribe send email to: oracle-l-request@xxxxxxxxxxxxx put 'unsubscribe' in the subject line. -- Archives are at //www.freelists.org/archives/oracle-l/ FAQ is at //www.freelists.org/help/fom-serve/cache/1.html -----------------------------------------------------------------