Rewriting queries using views

Abstract

In this paper we consider the problem of answering queries using materialized views in the presence of negative goals. The solution is carried out by 'inverting' views and deriving both positive and negative knowledge. In order to derive negative knowledge we invert conjunctive views with negation into a set of (extended) views which may also have, in addition to negation-as-failure, a different form of negation called classical (or strong) negation. Finally, we analyze the problem of inferring knowledge from views based on relations with functional dependencies.