Adding regular expressions to graph reachability and pattern queries

—It is increasingly common to find graphs in which edges bear different types, indicating a variety of relationships. For such graphs we propose a class of reachability queries and a class of graph patterns, in which an edge is specified with a regular expression of a certain form, expressing the connectivity in a data graph via edges of various types. In addition, we define graph pattern matching based on a revised notion of graph simulation. On graphs in emerging applications such as social networks, we show that these queries are capable of finding more sensible information than their traditional counterparts. Better still, their increased expressive power does not come with extra complexity. Indeed, (1) we investigate their containment and minimization problems, and show that these fundamental problems are in quadratic time for reachability queries and are in cubic time for pattern queries. (2) We develop an algorithm for answering reachability queries, in quadratic time as f...

• Type: Journal
• Year: 2011
• Where: ICDE
• Authors: Wenfei Fan, Jianzhong Li, Shuai Ma, Nan Tang, Yinghui Wu
• Keywords: Database, Graph Pattern, Graph Simulation, ICDE 2011, Reachability Queries