By Chris Malek | 03 February 2011
Unique Constraint Error on PS_MESSAGE_LOG
If you are getting a unique constraint error on PS_MESSAGE_LOG in the process monitor like this:
ORA-00001: unique constraint (SYSADM.PS_MESSAGE_LOG) violated
The cause is generally a locked user account that has a scheduled job. Clear all their errors and recurrences or unlock the account. You will see this error on un-related jobs for other users and not the locked user so it is confusing.
For additional information see the Oracle Support article 640200.1