Entity-Relationship Modeling Re-revisited

Abstract

AbstractSince its introduction, the Entity-Relationship (ER) model has been the vehicle of choice in communicating the structure of a database schema in an implementation-independent fashion. Part of its popularity has no doubt been due to the clarity and simplicity of the associated pictorial Entity-Relationship Diagrams (“ERD’s”S) and to the dependable mapping it affords to a relational database schema. Although the model has been extended in different ways over the years, its basic properties have been remarkably stable. Even though the ER model has been seen as pretty well “settled,” some recent papers, notably [4] and [2 (from whose paper our title is derived)], have enumerated what their authors consider serious shortcomings of the ER model. They illustrate these by some interesting examples. We believe, however, that those examples are themselves questionable. In fact, while not claiming that the ER model is perfect, we do believe that the overhauls hinted at are probably not necessary and possibly counterproductive.KeywordsEntity TypeDatabase SchemaCardinality ConstraintAttribute ConstraintInclusion DependencyThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.