Capturing Temporal Constraints in Temporal ER Models

A wide range of database applications manage information that varies over time. The conceptual modeling of databases is frequently based on one of the several versions of the ER model. As this model does not provide built-in means for capturing temporal aspects of data, the resulting diagrams are unnecessarily obscure and inadequate for documentation purposes. The TimeER model extends the ER model with suitable constructs for modeling time-varying information, easing the design process, and leading to easy-to-understand diagrams. In a temporal ER model, support for the specification of advanced temporal constraints would be desiderable, allowing the designer to specify, e.g., that the value of an attribute must not change over time. This paper extends the TimeER model by introducing the notation, and the associated semantics, for the specification of new temporal constraints.