Uniquest: Determining the Semantics of Complex Uniqueness Constraints
Th.P. van der Weide, Arthur H. M. ter Hofstede, P. van Bommel · The Computer Journal · 1992
In this article the Uniquest Algorithm (the ‘quest for uniqueness’), defined in the Predicator Model, is discussed in depth. The Predicator Model is a general platform for object-role models. The Uniquest Algorithm is a constructive formal definition of the semantics of uniqueness constraints. As such, it facilitates the implementation in so-called CASE-tools. The Uniquest Algorithm provides a systematic approach for the interpretation of complex uniqueness constraints. This interpretation process is easily traced, using an extra formalism, called the Object Relation Network (ORN). The ORN is a directed graph with labelled edges, representing an object-role information structure. Intermediate results that are outside the scope of the information structure at hand, are represented elegantly as an ORN. A number of theoretical and practical examples prove the power of the Uniquest Algorithm. In these examples we will encounter complex uniqueness constraints, that are missed easily. The Uniquest Algorithm provides a handle for recognition.