This article examines data base description problems from the point of view of logic programming, and presents an experimental deductive data base system implemented in PROLOG. We first discuss the advantages of logic for describing data bases, in a general manner, and then its application to our particular data base system. The incidence of natural language consultation capabilities upon the system's characteristics is briefly considered, and then we formally define our concept of a data base. Next we delimit which part of a data base's description is system-controlled, and which part is defined by the-user, entering into the details where the user's description is concerned. Finally, we show some examples of a data base consultation that were tested in our system.