Some constraints assuring serializability in multidatabases

In a multidatabase system, global transactions are executed under the control of the global system, while local transactions are submitted to each local system being outside of the global control. Since the multidatabase system is not aware of the local transactions and the conflicts they may cause, it has difficulty in detecting such conflicts. In [1], the authors gave the following constraints: global transactions should be commit-deferred and local schedules rigorous to assure global serializability of the multidatabase system. In this paper, we define dynamic-serializability and some classes of safe schedules which are recoverable from failure of transactions. Using them we give different, something weaker constraints, while global serializability of the multidatabase system is still achieved.