Replicating and allocating data in a distributed database system for workstations

Abstract

In the field of office automation, workstations serving a single user with considerable computing power become more and more important. However, such machines are useful only if they are interconnected and offer, among other possibilities for interaction, ways of sharing information in a structured way, i.e. if some kind of common database service is available. Such environments, characterized by a loosely coupled user community and by complete physical control of users over their workstation, raise novel problems for the data replication and allocation. It is important that a database service for interconnected workstations be attractive for its users, because in most cases they decide themselves whether to use it or not. Particular emphasis must therefore be put onto local autonomy and user control over private data. It is shown in this paper that the concepts well known from symmetrical distributed database Systems have to be revised for this situation. A constructive data replication and allocation method is presented and its consequences for the integrity of data are illustrated.