부분 중복 데이터베이스에서 중복 데이터의 트리를 이용한 일관성 유지

Abstract

The replication of data is used to increase its availability and to improve the performance of a system. The distributed database system has to maintain both the database consistency and the replica consistency. This paper proposes an algorithm which resolves the conflict of the operations by using the mechanism based on the structure that the replicas of each data item are hierarchically organized. Each update is propagated along the tree based on the fact that the root of each data item is the primary replica in partially replicated databases. The use of a hierarchy of data may eliminate useless propagation since the propagation can be done only to sites having the replicas. In consequence, the propagation delay of updates may be reduced. By using the timestamp and a compensating transaction, our algorithm resolves the non-serializability problem caused by the conflict of operations that can happen on the way of the update propagation due to the lazy propagation. This resolution also guarantees the data consistency.