ORA-30502: system triggers cannot have INSERT, UPDATE, or DELETE as triggering events

ORA-30502: system triggers cannot have INSERT, UPDATE, or DELETE as triggering events

Cause: An attempt was made to create a system trigger with INSERT, UPDATE, or DELETE triggering events, but this type of trigger is not supported because a system trigger does not have a base table.

Action: Do not attempt to create a system trigger with INSERT, UPDATE, or DELETE triggering events.