Distributed Spatial Keyword Querying on Road Networks

Spatial-keyword queries on road networks are receiving increasing attention with the prominence of location-based services. There is a growing need to handle queries on road networks in distributed environments because a large network is typically distributed over multiple machines and it will improve query throughput. However, all the existing work on spatial keyword queries is based on a centralized setting. In this paper, we develop a distributed solution to answering spatial keyword queries on road networks. Example queries include “find locations near a supermarket and a hospital,” and “find Chinese restaurants within 500 meters from my current location.” We define an operation for answering such queries and reduce the problem of answering a query into computing a function of such operations. We propose a new distributed index that enables each machine to independently evaluate the operation on its network fragment in a distributed setting. We theoretically prove the space optimality of the proposed index technique. We conduct experiments with a distributed setting. Experimental results demonstrate the promising performance of our method.