Won Bae Kim
The past several years have been the gestation period for a new generation of database technology. There has been a flurry of activities to develop and experiment with database systems that support an object-oriented data model or that extend the relational data model with some object-oriented facilities. These activities have been fueled by the emergence of a broad spectrum of database applications which relational database systems cannot support and the increasing need to achieve another productivity leap in application development. As a result of these efforts, there is now a sufficient body of knowledge for the development of a commercially viable next-generation database system. Such a system should support a unified relational and object-oriented data model; that is, a full object-oriented data model in a way that is completely compatible with the relational model. This article examines motivations for unifying the relational and object-oriented data models in a single database system, and outlines design and implementation issues that must be addressed in building such a system.