Updating intensional predicates in deductive databases

摘要

We present an approach to updating deductive databases in which every insertion or deletion of a fact (atomic formula without variables) can be performed in a deterministic way. The main features of our approach are the following: (i) the inserted and deleted facts may concern any predicate of the underlying alphabet—not just extensional predicates, and (ii) deleted facts are explicitly stored in the database. We show that logic programs in our approach can be associated with well-founded semantics. Moreover, as the explicit storage of deleted facts introduces a significant overhead, we also study the problem of storage optimization.