Maintaining and Restoring Database Consistency with Update Rules

Sofian Maabout
University of Antwerp (UIA)

Abstract:

Maintaining database consistency is one of the major applications of active databases. One of the problems encountered in this case is the non termination of rules execution. Then, the general solution is to undo the modifications and roll back to the initial database which is assumed to be consistent. In this paper, we present an algorithm that generates update rule programs from constraints expressions. The semantics of these rules is given by means of a logic program model, namely the well founded model. The derived programs can serve to maintain and restore database consistency. Maintaining database consistency assumes its consistency before user updates are requested while restoring consistency does not consider this hypothesis.