TimeER plus: A Temporal EER Model Supporting Schema Changes

A wide range of database applications manage information that varies over time. Many of the underlying database schemas of these were designed using one of the several versions, with varying syntax and semantics, of the Entity-Relationship (ER) model. In the research community as well as in industry, it is common knowledge that the temporal aspects of the mini-world are important, but are also difficult to capture using the ER model. Not surprisingly, enhancements to the ER model have been proposed in an attempt to more naturally support the modeling of temporal aspects of information. Common to the existing temporally extended ER models, few or no specific requirements to the models were given by their designers. With the existing proposals, an ontological foundation, and novel requirements as its basis, this paper defines a novel temporally extended ER model satisfying an array of properties not satisfied by any single previously proposed model.