Indian Institute of Management Calcutta

Among various models like TSQL2, XML and SQL:2003 for temporal databases, TSQL2 is perhaps the most comprehensive one and introduces new constructs for temporal query support. However, these constructs mask the user from the underlying conceptual model and essentially provides a “black box” flavour. Further, the temporal attributes are not directly accessible. In this paper, we propose a “chronon” based conceptual (relational) model, which works on a tuple timestamping paradigm. Here, the time attribute is treated in similar fashion as any other attribute and is available to the user for inclusion in SQL statements, making the model easy to understand and use. A corresponding efficient physical model based on the attribute versioning format akin to XML/SQL:2003 has also been proposed and the mapping between the proposed conceptual and physical models has been described. We evaluate the model by comparing with TSQL2 and SQL:2003, and show its equivalence to Allen’s algebra.