You might try this: Alter system set optimizer_features_enable=8.1.7 -----Original Message----- From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Peter McLarty Sent: Tuesday, June 12, 2007 12:34 AM To: ujang.jaenudin@xxxxxxxxx; oracle-l@xxxxxxxxxxxxx Subject: RE: 10g vs 9i Hi Ujang I have seen this behaviour. It happens going from 9 to 10 at any level. In the case I had was due to things doing joins whose performance changed due to the effects of the optimiser. You will have to take each case by itself and analyse it. I would consult with your business users for their worst performer and isolate the cause of that and then work back from there removing the most expensive issues It is likely as you take it apart you may fix a number of issues at the same time Look out for joins to v$ views as these performed badly Cheers Peter -----Original Message----- From: Ujang Jaenudin [mailto:ujang.jaenudin@xxxxxxxxx] Sent: Tuesday, 12 June 2007 03:14 PM To: oracle-l@xxxxxxxxxxxxx Subject: 10g vs 9i all, recently i have a dev machine 10g on itanium ia-64 another linux is itanium ia-64 with 9i the performance on 10g (10.2.0.3) is dropped for almost 1/3 from the 9i, if someone has the same experiences, pls share.... all these parameters doesn't help either... alter system set optimizer_features_enable='9.2.0' scope=both; alter system set "_optimizer_cost_based_transformation" =on scope=both; alter system set "_gby_hash_aggregation_enabled" = TRUE scope=both; -- regards ujang -- //www.freelists.org/webpage/oracle-l -- //www.freelists.org/webpage/oracle-l ------------------------------------------------------------------------------ NOTICE: This electronic mail message and any attached files are confidential. The information is exclusively for the use of the individual or entity intended as the recipient. If you are not the intended recipient, any use, copying, printing, reviewing, retention, disclosure, distribution or forwarding of the message or any attached file is not authorized and is strictly prohibited. If you have received this electronic mail message in error, please advise the sender by reply electronic mail immediately and permanently delete the original transmission, any attachments and any copies of this message from your computer system. Thank you. ============================================================================== -- //www.freelists.org/webpage/oracle-l