Partial Database Replication and Group Communication Primitives (Extended Abstract)

) Gustavo Alonso Database research Group Institute for Information Systems ETH Zentrum, Zurich CH-8092, Switzerland E-mail: falonsog@inf.ethz.ch January 17, 1997 1 Introduction Existing research on replication is generally based on synchronous replication (all copies are kept consistent at all times) and update everywhere (any replica can be updated) approaches. There is a strong belief among database designers, however, that synchronous, update everywhere replication is simply not feasible in a database environment [GBH + 96, Gol94, Sta94]. Some of the arguments behind this belief is the high probability of deadlocks that replication introduces and the problems to scale any replication approach beyond a few sites. As a result, most current database replication solutions are asynchronous (copies are not kept consistent at all times) and based on a primary-copy approach 1 (only one master copy can be updated, all other replicas are read-only) [Gol94, Sta94]. An additional argument..