Logic-oriented object bases

摘要

It is generally accepted that object-based systems provide a simple and elegant paradigm for general-purpose programming that meshes well with data models. Such systems are characterized by three core concepts: object, class, and message. As a consequence we are able to define object types with operations, to structure objects according to their properties, and to have objects that share properties. All these features make them suitable to serve as a basis for the next generation computing systems. However, they have been criticized for the lack of declarative semantics which is an essential feature for knowledge-based applications. For this purpose we propose the framework of logic-oriented object bases, i.e. databases that are constructed based on object model and augmented by mathematical logic. Adopting logic as a formal means for knowledge representation, we have developed both algorithmic and knowledge-based approaches to relate objects, to evaluate declarative queries that involve high level concepts, and to schedule declarative update requests such that changes to objects can be made consistently.