In this paper a net model for decentralized control of user accesses to a distributed database is proposed and devel oped in detail for a restricted case. Predicate/transition-nets, a first-order extension of Petri nets, are shown to provide suitable means for concise representa tion of complex decentralized systems and for their rigorous formal analysis. It will be demonstrated in the present paper how these net models can be constructed and in terpreted in a quite natural manner and how they can be analyzed by linear algebraic methods. by this, it will be shown that the modelled distributed database system is deadlockfree and guarantees a consistent database as well as a fair and effective service to the users.
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