Middleware transaction manager in multidatabase management systems

In this paper, we describe a new transaction management scheme, MTM, for incorporating existing applications of local database systems into multidatabase applications. By capitalizing on the structural semantics of a global transaction, which can be specified in terms of intra-transaction dependencies, global transactions are modeled and executed as open-nested transactions. We design and implement a middleware facility to address issues related to managing transactions when they are described only with high-level operations which are explicitly exported by local database systems. We also describe a group checkpointing scheme to maintain MTM architecture tolerable from failures.