Streaming XPath evaluation algorithms must record a potentially exponential number of pattern matches when both predicates and descendant axes are present in queries, and the XML data is recursive. In this paper, we use a compact data structure to encode these pattern matches rather than storing them explicitly. We then propose a polynomial time streaming algorithm to evaluate XPath queries by probing the data structure in a lazy fashion. Extensive experiments show that our approach not only has a good theoretical complexity bound but is also efficient in practice.
Linguistic research and natural language processing employ large repositories of ordered trees. XML, a standard ordered tree model, and XPath, its associated language, are natural choices for linguistic data and queries. However, several important expressive features required for linguistic queries are missing or hard to express in XPath. In this paper, we motivate and illustrate these features with a variety of linguistic queries. Then we propose extensions to XPath to support linguistic queries, and design an efficient query engine based on a novel labeling scheme. Experiments demonstrate that our language is not only sufficiently expressive for linguistic trees but also efficient for practical usage.
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Copyright 2006 IEEE. Reprinted from Proceedings of the 22nd International Conference on Data Engineering (ICDE '06).This material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of the University of Pennsylvania's products or services. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to pubs-permissions@ieee.org. By choosing to view this document, you agree to all provisions of the copyright laws protecting it.This conference paper is available at ScholarlyCommons: http://repository.upenn.edu/cis_papers/281
Designing and Evaluating an XPath Dialect for Linguistic Queries
Simultaneous multiple malignancies of the larynx are rarely reported. In this study, we describe a case with simultaneous laryngeal, moderately differentiated squamous cell carcinoma (SCC) and primary malignant fibrous histiocytoma (MFH) in a patient presenting with progressive hoarseness and without cervical lymphadenopathy. The clinical presentation, intraoperative findings, radiographic images and pathology slides are presented. The diagnosis was confirmed using H&E staining and immunohistochemical testing. A partial laryngectomy with bilateral neck selective dissection was performed. The patient survived for more than 46 months following surgery without recurrence or metastasis. To our knowledge, this is the first report of a case with simultaneous laryngeal SCC and primary MFH in the English literature. The results indicate that the markers used to assess the prognosis of MFH may also be used to assess simultaneous laryngeal SCC and primary MFH, and that laryngectomy to preserve function may be performed in early-stage patients.
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