Temporal Entity-relationship Models|a Survey a Timecenter Technical Report Title Temporal Entity-relationship Models|a Survey Individual Participants

The Entity-Relationship (ER) Model, using varying notations and with some semantic variations, is enjoying a remarkable, and increasing, popularity in both the research community, the computer science curriculum, and in industry. In step with the increasing di usion of relational platforms, ER modeling is growing in popularity. It has been widely recognized that temporal aspects of database schemas are prevalent and di cult to model using the ER model. As a result, how to enable the ER model to properly capture time-varying information has for a decade and a half been an active area of the database research community. This has led to the proposal of almost a dozen temporally enhanced ER models. This paper surveys all temporally enhanced ER models known to the authors. It is the rst paper to provide a comprehensive overview of temporal ER modeling, and it thus meets a need for consolidating and providing easy access to the research in temporal ER modeling. In the presentation of each model, the paper examines how the time-varying information is captured in the model and present the new concepts and modeling constructs of the model. A total of 20 di erent design properties for temporally enhanced ER models are de ned, and each model is characterized according the these properties1. Keywords|Conceptual modeling, entity-relationship models, database design, temporal databases, temporal data models, design criteria for temporal ER models, time semantics.