Discovery of frequent XML query patterns with DTD cardinality constraints

Common query patterns of multiple XML queries can be stored and shared to accelerate the query execution efficiently. We present a new technique for efficiently mining frequent XML query patterns with DTD cardinality constraints. We first introduce a new definition of extended subtree for XML query patterns (EST), which provides a model for supporting special characters of "common" XML query pattern. Then we "push" the DTD cardinality constraints deep into the mining process to prune the search space and still ensure the completeness of the answers. Finally, we propose an algorithm FEST for effectively mining frequent ESTs to improve the query performance for XML data management system.