Context Modelling and Context-Aware Querying(Can Datalog Be of Help?)

Many interpretations of the notion of context have emerged in various fields and context-aware systems are pervading everyday life, becoming an expanding research field. Context has often a significant impact on the way humans (or machines) act, and on how they interpret things; furthermore, a change in context causes a transformation in the experience that is going to be lived. Accordingly, while the computer science community has initially perceived the context simply as a matter of user time and location, in the last few years this notion has been considered not simply as a state, but as part of a process in which users are involved; thus, sophisticated and general context models and systems have been proposed to support context-aware applications. In this paper we propose a foundational framework for the life-cycle of context-aware system, in which the system design and management activities consider context as an orthogonal, first-class citizen. In doing so, we present a Datalog-based formulation for the definition of context-aware databases.