Dynamic systems specifications using versions and time

A temporal data model can be used to specify not only static but also dynamic aspects of an application, allowing us to record the evolution of its objects. Conventional applications commonly use the concept of transaction to update information, while unconventional applications require managing many database states to keep the update history. To fulfil this request, the concept of version is presented. The main purpose of the work is to present an alternative for the union of temporal data and a version model. The result, the Temporal Versions Model, is able to store the object versions and for each version, the history of its dynamic properties and relationship values. One of the most interesting features of our model is the possibility of having two different time orders, branched time for the object and linear time for each version. The model still supports integration with existing databases by allowing the modeling of normal classes among the temporal versioned classes.