[sknmail@rediffmail.com]

Hi Ian,

Thanks very much for replying to this thread even after long delay. You are 100% correct from the experience you said. Yes our issue too was the database server.
When we had the migrated the TEST environment, we used to do the Volume testing of planning around 2000 orders and 500 orders by pumping the data through JMeter and using another automation tool to select those orders and perform bulk plan. Well we had a so-called benchmark from 5.0 version which was taken around 5-6 months back. Where things were getting planned in 2 hours for 2000 orders whereas in 5.5; around 4 hours to plan these same orders. This caused a moment of panic and started struggling around the servers. Well this hurdle we could solve when we go a dramatic increase in performance of planning by enabling Hyperthreading of CPUs (Not Multhreading in Oracle). After this change, we could plan the same 2000orders in 2 hours 15 minutes. This was very good performance we could analyze on. Based on this performance, we were encouraged to migrate the production that weekend, (the date we originally planned to migrate production).
Well then after the migration of production the same weekend, we had a terrible performance issues with saved queries rendered from OR finder pages..after much monitoring and analysis, we could find some parameters in Oracle which needed a tweak which to some extent resolved the issues of performance we faced. Well the major observation we could find was all the queries were doing a full table scan and not using the index thus causing a heavy load on the CPU and resource. We modified some of the critical saved queries with an index hint, while also changed the database optimizer to back to 9.2.0 which helped us to regain back the performance. Thus I can say now the Oracle Database is still using the 9.2.0 optimizer on 10G.
Anyhow the client is now comfortable to an extent with the environment, however there is a big room of improvement and optimization which we are still undergoing that activity...
I appreciate very much your help by providing the information and experience you had from which we could co-relate and believe to full extent that I was on the right track.

Thanks and Regards,
Suresh