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Incremental Evaluation of a Monotone XPath Fragment

by Hidetaka Matsumura, Keishi Tajima

Abstract

This paper shows a scheme for incremental evaluation of XPath queries. Here, we focus on a monotone fragment of XPath, i.e., when a data is deleted from (or inserted to) the database, only deletion (insertion, resp.) may occur to query answers. For efficiently processing deletions, we store information on partial matchings, i.e., which elements were participating in matchings for which query answers, and also store counters showing how many matchings each query answer had. We use the information on the partial matchings also for skipping a part of computation upon data insertion. We investigate properties of the XPath fragment in order to keep the amount of information we store as small as possible.

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Keywords

XML, XPath, query processing, query optimization, incremental evaluation, materialized view, view maintenance, continuous query
Published in Proc. of ACM CIKM 2005, pp.245-246, Oct.-Nov. 2005, Bremen, Germany

Copyright © 2005 by the Association for Computing Machinery, Inc. Permission to make digital or hard copies of part or all of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page.
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