On specifying database updates
Document typeConference report
PublisherUniversitat Politècnica de Catalunya. Departament de Llenguatges i Sistemes Informàtics
Rights accessOpen Access
We address the problem of formalizing the evolution of a database under the effect of an arbitrary sequence of update transactions. We do so by appealing to a first order representation language called the situation calculus, which is a standard approach in artificial intelligence to the formalization of planning problems. We formalize database transactions in exactly the same way as actions in the artificial intelligence planning domain. This leads to a database version of the frame problem in artificial intelligence. We provide a solution to the frame problem for a special, but substantial, class of update transactions. Using the axioms corresponding to this solution, we provide procedures for determining whether a given sequence of update transactions is legal, and for query evaluation in an updated database. These procedures have the nice property that they appeal to theorem-proving only with respect to the initial database state. We next address the problem of proving properties true in ali states of the database. It turns out that mathematical induction is required for this task, and we formulate a number of suitable induction principies. Among those properties of database states that we wish to prove are the standard database -notions of static and dynamic integrity constraints. In our setting, these emerge as inductive entailments of the database. Finally, we discuss various possible extensions of the approach of this paper, including transaction logs and historical queries, the complexity of query evaluation, actualized transactions, logic programming approaches to updates, database views and state constraints.
CitationReiter, R. On specifying database updates. A: "Proceedings of the 5th International Workshop on the Deductive Approach to Information Systems and Databases". Universitat Politècnica de Catalunya. Departament de Llenguatges i Sistemes Informàtics, 1994, p. 219-253.