We upgraded from 9i to 10g -- it's a data warehouse database. Since then we are facing a lot of problems with it. First, it's the ORA-00600 error in the alert log file, which refers to trace files.
Besides that the major problem we are facing is the dead slow server response; actually there are many batch jobs that run on it on daily basis and they are our main concern. If you need any further details I can provide you with them.
Oracle support is also trying to help us out but so far no fruitful result has come out, so I need some desperate help.
There are many, many possible reasons for your performance problems. One thing I see that is not done after the upgrade is to ensure the optimizer statistics are up to date. Run the DBMS_STATS.GATHER_DATABASE_STATS procedure. And run the DBMS_STATS.GATHER_SYSTEM_STATS procedure. If you are still having problems, then sign on to the database as SYSTEM and run the ?/rdbms/admin/awrrpt.sql script. It will ask you for a beginning and ending time period. Pick any period that exhibits your poor response time. This script will generate a report. Feel free to email the report to me at and I will look over it and make some recommendations on how to improve performance.