Using positional relations in temporal space

A temporal database is characterized by extending the object identifier by the time dimensions introduced in the Exploring temporal dimensions section in Chapter 11. Typically, the object cannot be directly identified by the ID. Time validity must be applied as well. Thus, there are multiple states for each object. However, each data object tuple characterizes the object’s values at a particular time frame. It must be ensured that each state is defined by no more than one valid state at any time. The uni-temporal model uses a one-time dimension, mostly related to validity. The temporal integrity covers the reliability of the system. Supervision is done by the transaction manager using the positional relationships in the temporal space. The aim is to ensure that each object is characterized by one state, allowing users to sort the states based on the timeline. To do that, the following relationships are used:

• The [intersects...