Semantic ACID properties in multidatabases using remote procedure calls and update propagations

Global ACID properties (Atomicity, Consistency, Isolation and Durability) may be implemented by using a DDBMS (Distributed Data Base Management System.) However, in this solution data availability is low. Further, data may be blocked, i.e. if some data are locked from a remote location, the data cannot always be unlocked when the connection to the data fails. This is not a problem when client/server technology is used because client/server technology only uses local locks, a reason why multidatabases and client/server technology are widely used in real-life distributed systems. However, the trouble with such systems is that they have no inherent global ACID properties. The objective of this paper is to illustrate how global semantic ACID properties, enforced by the transactions themselves, may be implemented on top of client/server technology. This is done to preserve high data availability. The global atomicity property is implemented by using retriable and compensatable subtransactions. The global consistency property must be implemented by the transactions themselves. The global isolation property is implemented by using countermeasures to isolation anomalies. The global durability property is implemented by using the durability property of the local DBMSs. The largest bank in Denmark, Den Danske Bank, has implemented all its applications using methods described in this paper. © 1998 John Wiley & Sons, Ltd.