CONTINUOUS RANGE QUERY PROCESSING FOR NETWORK CONSTRAINED MOBILE OBJECTS

摘要

In contrast to regular queries that are evaluated only once, a continuous query remains active over a period of time and has to be continuously evaluated to provide up to date results. We propose a method for continuous range query processing for different types of queries, characterized by mobility of objects and/or queries which follow paths in an underlying spatial network. The method assumes an available 2D indexing scheme for indexing spatial network data. An appropriately extended R-tree provides matching of queries and objects according to their locations on the network or their network routes. The method introduces an additional pre-refinement step which generates main memory data structures to support efficient, incremental reevaluation of continuous range queries in periodically performed refinement steps.