  Our aim in this paper is to point out a surprising formal connection, between
two topics which seem on face value to have nothing to do with each other:
relational database theory, and the study of non-locality and contextuality in
the foundations of quantum mechanics. We shall show that there is a remarkably
direct correspondence between central results such as Bell's theorem in the
foundations of quantum mechanics, and questions which arise naturally and have
been well-studied in relational database theory.
