Redesign Based Optimization for Distributed Databases

The execution process of the queries in distributed databases require accurate estimations and predictions for performance characteristics. The problems of data allocation and query optimization done by means of mobile agents and evolutionary algorithms are considered. These problems still present a challenge because of the dynamic changes in number of components and architectural complexity of nowadays system topologies. The distributed system is modeled as a graph structure on which is de ned a dynamic cost vector. The cost vector remains consistent, relevant, by use of mobile agents performing cost statistics and vector updates. An evolutionary technique for the re-design phase is proposed. Experimental results prove the e ciency of the proposed technique.