Categorical Semantics for Object-Oriented Data-Specifications

Abstract

Semantic data-specifications have been used for many years in the early stages of database design. The most influential example is undoubtedly the Entity Relationship specification method ([Chen, 1976]), in which aspects of a certain reality are expressed in terms of entities, relations and attributes. The paradigm of object-oriented software development stimulated new research in the area of data-specifications. Indeed, the major goal of object-oriented analysis ([Coad and Yourdon, 1990, Van Baelen et al., 1991]), is to develop a specification of the external world. Since then, many extensions to ER-like data-specifications have been suggested, either to enhance the expressiveness, or to suit them more to the needs of software engineering. However, most of the data-specification mechanisms used in practice are of an informal nature.