Foundations for extensible objects with roles, extended abstract
Giorgio Ghelli, D. Palmerini · 1999
Giorgio Ghelli and Debora Palmerini Abstract Object-oriented database systems are an emerging technology which is very promising, and which lays its foundations on the integration of ideas from object-oriented languages along with the specific needs of database applications. The fundamental reason for using such systems is that any real-world entity can be modelled with one object which matches its structure and behavior. To this end, the standard notion of object has to be augmented so that it can model the fact that an entity may acquire new pieces of structure and behavior during its existence, without changing its identity. To allow this extensibility in a statically typed system, a notion of context-dependent behavior ("role playing") has to be added to the basic features of object-oriented languages. This feature is also a useful modeling device. Languages with role mechanisms have already been proposed. However, their design is full of choices which cannot be easily...