ViewJoin: Efficient view-based evaluation of tree pattern queries

There is a lot of recent interest in applying views to optimize the processing of tree pattern queries (TPQs). However, existing work in this area has focused predominantly on logical optimization issues, namely, view selection and query rewriting. With the exception of the recent work on InterJoin (which is primarily focused on path queries and views), there is very little work that has examined the important physical optimization issue of how to efficiently evaluate TPQs using materialized views. In this paper, we present a new storage scheme for materialized TPQ views and a novel evaluation algorithm for processing general TPQ queries using materialized TPQ views. Our experimental results demonstrate that our proposed method outperforms the state-of-the-art approaches.