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An extended preorder index for optimising XPath expressions

O'Connor, Martin F. and Bellahsène, Zohra and Roantree, Mark (2005) An extended preorder index for optimising XPath expressions. In: XSym 2005 - Third International XML Database Symposium, 28-29 August, 2005, Trondheim, Norway. ISBN 978-3-540-28583-0

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Many of the problems with native XML databases relate to query performance and subsequently, it can be difficult to convince traditional database users of the benefits of using semi- or unstructured databases. Presently, there still lacks an index structure providing efficient support for structural queries and the traditional data-centric and content queries. This paper presents an extended index structure based on the preorder traversal rank and the level (or depth) rank of each node in a document tree. The extended index fully supports the navigation of all XPath axes while efficiently supporting data-centric queries. The ability to start path traversals from arbitrary nodes in a document tree also enables the extended index to support the evaluation of path traversals embedded in XQuery expressions. Furthermore, an encoding technique is presented where properties of the level ranking may be exploited to provide efficient and optimised level-based XPath evaluations.

Item Type:Conference or Workshop Item (Paper)
Event Type:Conference
Additional Information:The original publication is available at
Uncontrolled Keywords:XML; database; index; query; preorder;
Subjects:Computer Science > Information storage and retrieval systems
Computer Science > Algorithms
DCU Faculties and Centres:DCU Faculties and Schools > Faculty of Engineering and Computing > School of Computing
Published in:Proceedings of the Third International XML Database Symposium, XSym 2005. Lecture Notes in Computer Science 3671. Springer Berlin / Heidelberg. ISBN 978-3-540-28583-0
Publisher:Springer Berlin / Heidelberg
Official URL:
Copyright Information:© 2005 Springer
Use License:This item is licensed under a Creative Commons Attribution-NonCommercial-Share Alike 3.0 License. View License
ID Code:4561
Deposited On:08 May 2009 17:16 by Martin F. O'Connor. Last Modified 08 May 2009 17:16

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