Concurrency Control for Knowledge Bases.
Vinay K. Chaudhri, Vassos Hadzilacos, John Mylopoulos · 1992
As the demand for ever-larger knowledge bases grows, knowledge base management techniques assume paramount importance. In this paper we show that large, multi-user knowledge bases need concurrency control. We discuss known techniques from database concurrency control and explain their inadequacies in the context of knowledge bases. We offer a concurrency control algorithm, called the Dynamic Directed Graph (DDG) policy that addresses the specific needs of knowledge bases. The DDG policy exploits the rich structure of a knowledge base to support the interleaved, concurrent execution of several user requests, thereby improving overall system performance. We give a proof of correctness of the proposed concurrency control algorithm and an analysis of its properties. We demonstrate that these results from concurrency control interact in interesting ways with knowledge base features and highlight the importance of performanceoriented tradeoffs in the design of knowledge...