An Entity-Relationship Model Extended To Describe Historical Information

The entity-relationship (ER) model has proved a successful conceptual capture and modelling tool for the relational data model. Much effort has recently been made to extend the relational data model to describe historical information, but as yet little corresponding development in ER modelling has been made. We describe in detail the various temporal behaviours that entities and relationships may exhibit, and apply the results to enhance a binary ER model with temporal semantics. The resultant ERT may be used to fully model historical relational database schemata.