Efficient processing of continuous min–max distance bounded query with updates in road networks

• We focus on processing the continuous min–max distance bounded query over moving objects in road networks.
• We design several data structures to manage the information of objects and road network.
• We propose two algorithms to efficiently determine the query result at each time instant.
• The experimental results demonstrate the efficiency of the proposed algorithms.

In the last decade, the research community focuses on the design of various methods in support of spatio-temporal queries in road networks. In this paper, we present a novel and important query, named the continuous min–max distance bounded query   (CM2DBQCM2DBQ). Given a moving query object q  , a minimal distance dmdm, and a maximal distance dMdM, a CM2DBQCM2DBQ retrieves the bounded objects whose road distances to q   are within the range [dm,dM][dm,dM] at each time instant. We propose two algorithms, named the Continuous Within Query-based (CWQ-based) algorithm   and the CM2DBQalgorithm, to efficiently determine the bounded objects. In addition, we design a mechanism, named the bounded objects updating mechanism, to rapidly evaluate the new query result when object updates occur. Extensive experiments using real road network dataset demonstrate the efficiency of the proposed algorithms and the usefulness of the bounded objects updating mechanism.