An Efficient Top-K Query Processing Method for Location Based Services

Continuous monitoring of spatial queries has received significant research attention in the past few years. In this paper, we propose an efficient method for continuous monitoring of the top-k queries. The new top-k queries consider both spatial and non-spatial attributes. We use a grid data structure and propose a novel grid access method. The proposed method (i) quickly identifies the moving objects that enter or exit the grid cells and (ii) reduces the number of unnecessary operations by comparing the bit-vector information of moving objects. Furthemore, we construct an extended index Multiple non-Spatial Grid Index(MnS-BVGI) that reflects various non-spatial attributes of moving objects and we propose a query processing method that can perform fast operation by using it. Experimental simulations demonstrate that the proposed methods are several times faster than the previous methods and use considerably less memory.