Using Finite-Linear Temporal Logic for Specifying Database Dynamics

The specification of a database system consists of the description of its static information structure as well as of its dynamic behaviour. Whereas in classic conceptual database design the main interest was on the static part, specification of database dynamics became an important topic in the last few years. The specification of dynamic database behaviour has to describe the correct evolutions of the stored information. This can be done in terms of allowed user actions, which update database states, or in a descriptive manner by specifying the correct sequences of database states. Here, we concentrate on the latter aspect and present a corresponding logical specification calculus. Starting with [Se80], the use of a temporal logic framework for specifying database dynamics was proposed by several working groups, among them [CF84, Ku84, SFNC84, ELG84, LEG85, KMS85, CS87]. In these approaches, the semantical interpretation of database states by first order logic models is extended in a natural way to the interpretation of database dynamics by sequences of database states. This enables the use of classical first order logic for specifying static databases structure together with a temporal logic description of the desired database behaviour in a single specification framework. Similar to [SFNC84, CS87], we use a layered approach for database specification. A conceptual database schema is described by the following four specification levels :