A domain theoretic characterisation of the universal relation

We present a domain theoretic characterisation of the weak instance approach to the universal relation (UR) model. This characterisation gives us a better understanding of the semantics of the UR model. In particular, we show that the representative instance is the least upper bound of a transformation function on the database, which is analogous to the well-known chase procedure. In addition, we show that the representative instance is, in fact, the greatest lower bound of the set of corresponding weak instances for the given database and the set of integrity constraints.