An improved methodology for fragment re-allocation in Peer-to-Peer Distributed Databases

The process of allocating fragments into the appropriate sites is a crucial step in the design of Peerto- Peer Distributed Databases. Accessibility of data influences the Quality of Service for requests. This paper proposes a methodology for fragment reallocation by using Hungarian Assignment algorithm of optimization principle. The objective of the work is to reduce the number of un-successful queries that are forwarded to other sites of the network. The results show that re-allocation of fragments to suitable sites cause significant part in the communication cost while transaction.