A decentralized deadlock-free concurrency control method for multidatabase transactions

A global concurrency control mechanism for multidatabase systems that preserves the autonomy of local databases and is free from global deadlocks is presented. The mechanism extends the notion of timestamps to a multidatabase environment to enforce the global serialization order through additional data operations on a data item stored in local systems. The main advantage of the mechanism is that it allows a fully distributed architecture, in which concurrency control decisions can be made on the basis of locally available information. Since no centralized information is maintained by the mechanism, it provides a higher degree of fault tolerance and allows incremental growth