Hop-Constrained Subgraph Query and Summarization on Large Graphs.

We study the problem of hop-constrained relation discovery in a graph, i.e., finding the structural relation between a source node s and a target node t within k hops. Previously studied s - t graph problems, such as distance query and path enumeration, fail to reveal the s - t relation as a big picture. In this paper, we propose the k-hop s - t subgraph query, which returns the subgraph containing all paths from s to t within k hops. Since the subgraph may be too large to be well understood by the users, we further present a graph summarization method to uncover the key structure of the subgraph. Experiments show the efficiency of our algorithms against the existing path enumeration based method, and the effectiveness of the summarization.