I am always getting the following errors:
- ORA-00474:fatal error in background process
- ORA-00474:SMON Process terminated with error.
- ORA-00600:internal error code,arguments 
Once the database is opened, the CPU usage jumps to 100%, and after a few seconds, the database goes down with the above errors. Can you please help me find a solution?
The ORA-600  error indicates that you might have block corruption. You will want to look at the contents of any trace files in your USER_DUMP_DEST location to see if the trace file for the ORA-600 error indicates the table that might be corrupt. Once you've found the table, then validate its structure with a command similar to the following:
ANALYZE TABLE owner.table VALIDATE STRUCTURE CASCADE;
If no errors are reported, then the table is fine. If errors are reported, then you will want to perform a restore from a backup.
If there are no errors, then you will have to contact Oracle Support for additional help on the ORA-600 error.
This was first published in November 2004