Fruited-Forest: A Reachability Querying Method Based on Spanning Tree Modelling of Reduced DAG

Liu Yang, Tingxuan Chen, Junyu Zhang, Jun Long, Zhigang Hu, Victor S. Sheng

Abstract: A reachability query is a fundamental graph operation in real graph applications, which answers whether a node can reach another node through a path in a graph. However, the increasingly large amounts of real graph data make it more challenging for query efficiency and scalability. In this paper, we propose a Fruited-Forest (FF) approach to accelerate reachability queries in large graphs by constructing four kinds of fruited-forests from a reduced DAG in different traversal orders. We build different binary-label schemes for the four kinds of fruited-forests to cover reachability between nodes as much as possible, and create a corresponding index for the deleted edges which are deleted during the construction of fruited-forests. Our experimental results on 18 large real graph datasets show that our FF approach requires less index construct time and a smaller index size, which is more scalable to answer reachability queries compared with other existing works.