On Structural Features of Global Transactions in Multidatabase Systems

Supporting the isolation and atomicity of global transactions in multidatabase systems has become an increasingly difficult task. Local autonomy requires that the maintenance of isolation and atomicity as an execution condition of global transactions must also hold when such execution is interleaved with local transactions. This paper proposes the utilization of both the syntactic and semantic knowledge of global transactions to formulate such a condition. An enriched combination of two theories, hybrid serializability and global committability, is presented as a vehicle for the maintenance of the isolation and semantic atomicity of global transactions. We then explore the structural features of global transactions which provide the necessary conditions for supporting this theory. As a result, we raise a new research issue for the management of global transactions. Instead of seeking restrictions on local transaction management systems, we have shown that placing conditions on global transactions to accommodate the autonomous local environment is a valid approach to preserving local autonomy.