Oracle Error Codes

System triggers cannot have INSERT- UPDATE- or DELETE as triggering events

System triggers cannot have a REFERENCING clause

System triggers cannot have a FOR EACH ROW clause

System triggers should not reference a column in a WHEN clause

System triggers cannot be based on tables or views

Normal triggers cannot be based on a schema or a database

Client logon triggers cannot have BEFORE type

Client logoff triggers cannot have AFTER type

System triggers cannot be defined on the schema of SYS user

Invalid DDL operation in system triggers