Is that client ID in those trace files? Check the raw trace files for lines like: *** CLIENT ID:( vvp42660) Are those trace files 10046 traces? The trcsess utility only works on 10046 trace files. ----------------------- Ric Van Dyke Hotsos Enterprises ----------------------- Hotsos Symposium March 7 - 11, 2010 Be there. ________________________________ From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Balakrishna Y Sent: Wednesday, August 05, 2009 8:30 AM To: oracle-l@xxxxxxxxxxxxx Subject: Can someone help using trcsess utility Hi all, I have below trace files in udump as kiran_ora_4714776_vvp42660.trc kiran_ora_1638558_vvp42660.trc kiran_ora_4571498_vvp42660.trc kiran_ora_5574948_vvp42660.trc I am trying to merge all this trace files using trcsess but this generates 0 size output file. Dont really understand why ?? trcsess output=vvp.trc clientid=vvp42660 Regards Bala