Discovery of Frequent Query Patterns in XML Pattern Graph with DTD Cardinality Constraints

Common query patterns of multiple XML queries can be stored and shared to accelerate the query execution efficiently. Such common patterns typically arise in many applications. In this paper we present a new technique for efficiently mining frequent XML query patterns in the XML pattern graph with DTD cardinality constraints. First we propose a new method of finding all connected sub-graphs that appear frequently in a large XML query pattern graph. Then we ldquopushrdquo the DTD cardinality constraints deep into the mining process to prune the search space and still ensure the completeness of the answers. At last, we propose an algorithm FESG for effectively mining frequent XML query patterns in the XML pattern graph. We validate the effectiveness and efficiency of the new technique in two ways. The experimental results generated from the real data reveal that the algorithm works well in practice.