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Capturing Abstraction Relationships' Semantics for Concurrency Control in KBMSs

Fernando de Ferreira Rezende and Theo Härder

Department of Computer Science - University of Kaiserslautern
P.O.Box 3049 - 67653 Kaiserslautern - Germany
Phone: +49 (0631) 205 3274/4031 - Fax: +49 (0631) 205 3558
E-Mail: {rezende/haerder}@informatik.uni-kl.de

Full paper (postscript version, compressed by gzip or PDF version )

Abstract

Knowledge Base Management Systems (KBMSs) are a growing research area finding applicability in several different domains. On behalf of this increasing applicability, the demand for ever-larger knowledge bases (KBs) is growing more and more. Inside this context, knowledge sharing turns out to be a crucial point to be supported by KBMSs. In this paper, we propose a way of controlling knowledge sharing, i.e., we present a concurrency control (CC) technique tailored for the KBMS environment. We show how we obtain serializability of transactions providing many different locking granules, which are based on the semantics of the abstraction relationships. We discuss the main challenges to be coped with by a CC technique for KBs and expose our solution to them. The main benefit of our technique is the higher degree of potential concurrency, which may be obtained by means of a logical partitioning of the KB graph and the provision of many lock types to be used on the basis of each one of the partitions. By this way, we capture more of the semantics contained in a KB graph, through an interpretation of its edges grounded in the abstraction relationships, and make feasible a full exploitation of all inherent parallelism in a knowledge representation approach.

in: ZRI-Bericht 6/94, University Kaiserslautern, 1994.