3-hop:a high-compression indexing Scheme for reachability Query

Title:3-hop:a high-compression indexing Scheme for reachability Query

Venue:sigmod ' 09

Author:ruoming Jin, Yang Xiang, Ning Ruan, and David Fuhry

Abstract: reachability queries on large directed graphs has attracted much attention recently. The existing work either uses spanning structures, such as chains or trees, to compress the complete transitive closure, O R utilizes the 2-hop strategy to describe the reachability. Almost all of the these approaches work well for very sparse graphs. However, the challenging problem is, and the ratio of the number of edges to the number of vertices increases, the size Of the compressed transitive closure grows very large. In this paper, we propose a new 3-hop indexing scheme for directed graphs with higher density. The basic idea of 3-hop indexing are to use chain structures in combination with hops to minimize the number of structures That's must be indexed. Technically, our goal are to find a 3-hop scheme over dense DAGs (directed acyclic graphs) with minimum index size. We develop an efficient algorithm to discover a transitive closure contour, which yields near optimal index size. EmpiriCal Studies show that we 3-hop scheme has much smaller index size than State-of-the-art reachability query schemes such a S 2-hop and Pathtree when DAGs was not very sparse, while our query time was close to Path-tree, which was considered to be One of the best reachability query schemes.

3-hop:a high-compression indexing Scheme for reachability Query