Performance Analysis of Degree of Redundancy for Replication in Distributed Database System

Allocation, and replication of fragments at sites is a challenging task. After fragmentation, allocation should be done in an efficient way, such that the transmission cost, and global access is reduced. Availability of fragment is an important issue to reduce the cost. Replication of fragments is necessary whenever another site is also frequently accessing the fragment. Finding the suitable amount of replication or degree of redundancy is required to increase the availability. This paper provides a way to ascertain the number of copies of fragment (benefit of degree of replication) that should be placed on different sites. With the increase in the degree of redundancy, there is no progressive increase in the benefit of degree of replication. If the number of replicas is between two to four, then the benefit of replication is increasing progressively. This increases the availability of data, reliability of system, reduced network load, and supports parallelism. Beyond this, increasing the number of replicas is proportionally less beneficial.