A model for optimizing deductive and object-oriented DB requests

The authors propose a model, called the object request network, for representing the input requests to the optimizer which uniformly captures the main features needed in deductive and object-oriented database management systems (DBMSs). This model allows the recursive definition of derived objects, avoids some rewriting effort when changing the navigation on objects, and supports declarative request languages. The authors consider how the requests are optimized, and show that with the approach adopted it is possible to investigate more general execution plans than in earlier work