Digress: A Deductive Interface to a Relational Database

Databases with inferencing capabilities have a practical as we;; as a theoretical interest because they have the potential to combine the efficient use of secondary storage and multi-user controls common to databases ,management system with the capabilities of expert system technology. A relational database is a knowledge representation scheme in which detuctive inferences are valid logical consequences of information contained in the database under the closed world assumption, the domain closure assumption, and the unique names assumption. Since the database relational calculus can be expressed as a first order language, it can be utilized to perform deductive reasoning. This paper reviews the theoretical and practical justifications for providing current database technology with inferencing capabilities and reports on a current research project which implements a deductive retrieval in INGRES, using the DBMS data manipulation language QUEL and its interface language EQUEL