Change management with roles

Various proposals have been made to extend object-oriented languages and database systems with roles because they allow to weaken strict typing concepts and therefore can provide mechanisms for an object to change its type during its lifetime. This so-called object migration is not the only advantage offered by a suitable role model. This paper studies the possibilities to use roles for a general change management system that also includes support for schema evolution. OPAQUE, as the selected role model, can be extended with schema update mechanisms in a surprisingly clean and straightforward way including the concepts of versions and views as well.