Abstract
Proper data allocation is a key performance factor for an efficient functionality of Distributed Database Systems (DDBSs). Therefore, if data allocation across sites is performed accurately while preserving the issues of communication and site constraints, an optimal solution for DDBS performance in a dynamic distributed environment will be achieved.
In this paper, a new dynamic data allocation algorithm for non-replicated DDBS is presented, the proposed Performance Optimality Enhancement Algorithm (POEA) explores and improves some concepts used in previously developed algorithms to reallocates fragments to different sites given the changing data access patterns, time and sites constraints of the DDBS. Moreover, the POEA adopts the shortest path between the old location and the new anticipated location for the transferred fragments when migration decision is made. Experimental results show that POEA has efficiently reduced the transmission cost subsequently minimizing the frequency and the time spent on fragment migration over the network sites resulting to a great improvement in the overall DDBS performance. (C) 2013 Elsevier Ltd. All rights reserved.