Object-oriented database systems

This paper describes my vision of the current state of object-oriented database research. I first briefly define this field by its objectives, and relate it to other database subfields. I describe what I consider to be the main characteristics of an object oriented system, i.e. those which are important to integrate in a database system: encapsulation, object identity, classes or types, inheritance, overriding and late binding. I point out the differences between an object oriented system and an object oriented database system. I also point out the advantages and drawbacks of an object oriented database system with respect to a relational system. Finally, I list some research issues.