A Robust: Protocol For Parallel Join Operation In Distributed Data Bases

Abstract

Fault tolerant distributed databases use replicated data(e.g., record or relation) to handle failures of one or more nodes in a computer network. Efficient and economic access strategies for such data bases have not been investigated. In this paper, the binary hypercube, a popular model for fault tolerant interconnection networks, has been studied. It has been shown that, for a local area network based on a binary hypercube, having 2r nodes where every data is replicated r times, in the absence of faults, any query involving an arbitrary sequence of joins R1 @@@@ R2 @@@@ … @@@@ Rn, n ≤ r, may be performed by repeatedly executing joins in a distributed fashion using n node disjoint paths from n/2 distinct sites of database operations to n arbitrary sites containing a target relation each. This protocol also solves the problem of materialization of relations. In the presence of up to r-2 faults, the protocol still guarantees N node disjoint paths to arbitrary sites. The value of N is determined by the number of faulty nodes.