Efficient Processing of XML Tree Pattern Queries
Yangjun Chen* and Dunren Che**
*Department of Applied Computer Science, University of Winnipeg, 515 Portage Avenue, Winnipeg, Manitoba R3B 2E9, Canada
**Department of Computer Science, Southern Illinois University, Carbondale, IL 62901, USA
In this paper, we present a polynomial-time algorithm for TPQ (tree pattern queries) minimization without XML constraints involved. The main idea of the algorithm is a dynamic programming strategy to find all the matching subtrees within a TPQ. A matching subtree implies a redundancy and should be removed in such a way that the semantics of the original TPQ is not damaged. Our algorithm consists of two parts: one for subtree recognization and the other for subtree deletion. Both of them needs only O(n2) time, where n is the number of nodes in a TPQ.
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