Closure-Tree: An Index Structure for Graph Queries

Graphs have become popular for modeling structured data. As a result, graph queries are becoming common and graph indexing has come to play an essential role in query processing. We introduce the concept of a graph closure, a generalized graph that represents a number of graphs. Our indexing technique, called Closure-tree, organizes graphs hierarchically where each node summarizes its descendants by a graph closure. Closure-tree can efficiently support both subgraph queries and similarity queries. Subgraph queries find graphs that contain a specific subgraph, whereas similarity queries find graphs that are similar to a query graph. For subgraph queries, we propose a technique called pseudo subgraph isomorphism which approximates subgraph isomorphism with high accuracy. For similarity queries, we measure graph similarity through edit distance using heuristic graph mapping methods. We implement two kinds of similarity queries: K-NN query and range query. Our experiments on chemical comp...

• Type: Conference
• Year: 2006
• Where: ICDE
• Authors: Huahai He, Ambuj K. Singh
• Keywords: Database, ICDE 2006, Pseudo Subgraph Isomorphism, Similarity Queries, Subgraph Queries