Efficient Query Optimization : A novel approach for generating optimal query plans using Iterative Improvement and Simulated Annealing

The collection of various sites, distributed over a computer network is called Distributed Database whereas the technique of finding the optimal processing method to answer a query is called Query Optimization. In Distributed Database, the sites communicate with each other through networks. There are various issues arise during evaluation of query cost, among which the processing cost and a transmission cost are the important. There are several algorithm developed to find the best possible solution for a particular query, but they all have their certain limitations. The primary objective of distributed query plan is to generate the query plan that reduces the quantity of data transfer between sites and also the distributed query response time. In distributed database system the data is scattered over various multiple sites and a single relation may be present in more than one sites. In such case the cost of query processing is effected by various cost involved such as optimization cost, communication cost, local processing cost, query localization cost etc .The optimizer is mainly concern on the cost model, search space, and the search strategy. It primarily focuses on these three factors. The query cost depends on the order of evaluation of the operators, for the same query we can have different cost if the order is changed. Hence, to find the optimal cost for a particular query is emerging as an open challenge for many researchers. Therefore the cost-based query optimization technique has emerged as an important concept for dealing with the query optimization. In this paper, the optimal query plan is generated by applying the concept of iterative improvement algorithm and simulated annealing algorithm and then the comparative study of both results are done using same heuristic to generate the optimal query plans. Keyword : Distributed Query Optimization, Simulated Annealing, Iterative Improvement, Distributed Database, Cost based Optimization. Efficient Query Optimization : A novel approach for generating optimal query plans using Iterative Improvement and Simulated Annealing Pramod Kumar Yadav* SAM Rizvi** IJCTA, 9(21), 2016, pp. 243-249 © International Science Press * KIET Group of Institutions, Ghaziabad, UP, India [email protected] ** Jamia Millia Islamia, New Delhi, India [email protected]