Introducing negative information in relational databases

Abstract

Traditionally, databases are used in order to deal with positive information such as “John's address is Paris”. We propose here to study another kind of information, called negative information such as “John's address is not Paris”.

We define set-theoretic semantics for relational databases in which negative information may be recorded. We also present an axiomatization for deductive query answering in the presence of positive information, negative information, and functional dependencies. Our model does not make use of the closed world assumption.