Locality Sensitive Hashing for Optimizing Subgraph Query Processing in Parallel Computing Systems.

This paper explores parallel computing systems for efficient subgraph query processing in large graphs. We investigate how to take advantage of the inherent parallelism of parallel computing systems for both intraquery and interquery optimization during subgraph query processing. Rather than relying on widely-used hash-based methods, we utilize and extend locality sensitive hashing methods. For intraquery optimization, we use the structures of both the data graph and subgraph query to design a query-constraint locality sensitive hashing method named QCMH, which can be used to merge multiple tasks during a single subgraph query processing. For interquery optimization, we propose a query locality sensitive hashing method named QMH, which can be used to detect common subgraphs among different subgraph queries, thereby merging multiple subgraph queries. Our proposed methods can reduce the redundant computation among multiple tasks during a single subgraph query processing or multiple queries. Extensive experimental studies on large real and synthetic graphs show that our proposed methods can improve query performance compared to state-of-the-art methods by 10% to 50%.