Applying Intensional Query Processing Techniques to Object-Oriented Database Systems

Conventional database systems generate a set of facts (extensional answers) as an answer for a given query. This also applies to object-oriented databases where a set of objects will be returned. However, deductive database systems give an opportunity to obtain the answer ofa query as a set offormulas @tensional answers). Intensional answers provide users additional insight to the nature ofextensional answers and can be computed only using the rules without accessing the database. So, they can be computed much faster and more cheaply than extensional answers. In this paper, by introducing rules for abstract expression in the object-oriented database systems and by applying the intensional query processing techniques of deductive database systems to the object-oriented database systems, we make it possible not only to answer incomplete queries which are not able to be answered in conventional object-oriented database systems, but also to express the answer-set abstractly as the names of classes.