Controlled cooperation in engineering database systems

Database systems for engineering applications must be particularly efficient in storing and retrieving very complex structures. But they must also be capable of assisting in the project-oriented cooperation of design engineers by supporting the controlled exchange of stored information. The latter aspect has not been given much emphasis in the past; and the few proposals found in the literature all deal with extending the database system´s transaction concept. This paper presents an alternative approach that is orthogonal to transactions and thus is much simpler to understand and to implement.