Enhanced Cache Gird Partitioning Technique for K-NN Queries

Mobile database applications through wireless equipments e.g., PDAs, laptops, cell phones and etc. are growing rapidly. In such environment, clients, servers and object may change their locations. A very applicable class of query is continuous k-NN query which continuously returns the k nearest objects to the current location of the requester. Respect to limitations in mobile environments, it is strongly recommended to minimize number of connections and volume of data transmission from the servers. Caching seems to be very profitable in such situations. In this paper, a enhanced cache grid partitioning technique for continuous k-NN queries in mobile DBSs is proposed. In this, by square grid partitioning the complete search space is divided into such grid areas so that we can impose a piecemeal ordering on the query targets. Simulation results show that the proposed cache grid partitioning schema provides a considerable improvement in response time, number of connections and volume of transferred data from DB server.