Requirements specification for a temporal extension to the relational model

A set of properties is identified, which should be satisfied by a temporal extension to the relational model. During the process of identifying these proper ties it is initially shown that certain semantic problems arise if time is treated as a means of stamping data in temporal databases. To overcome the problems encountered, it is next shown that a more general extension to the relational model needs to be made to define a model in which a generic interval is sup ported as a primitive data type. This extension has many practical applications. Furthermore, since a time-interval is the only type of interval which is used in temporal databases, the management of temporal data is shown to be one of the applications of this general model