Fernandez, M.F. and Hidders, Jan and Michiels, P. and Simeon, J. and Vercammen, R. (2005) Optimizing sorting and duplicate elimination in xquery path expressions. In: Viborg Andersen, K. and Debenham, J.K. and Wagner, R.R. (eds.) Database and Expert Systems Applications: 16th International Conference. Lecture Notes in Computer Science 3588. Springer, pp. 554-563. ISBN 9783540285663.
Abstract
XQuery expressions can manipulate two kinds of order: document order and sequence order. While the user can impose or observe the order of items within a sequence, the results of path expressions must always be returned in document order. Correctness can be obtained by inserting explicit (and expensive) operations to sort and remove duplicates after each XPath step. However, many such operations are redundant. In this paper, we present a systematic approach to remove unnecessary sorting and duplicate elimination operations in path expressions in XQuery 1.0. The technique uses an automaton-based algorithm which we have applied successfully to path expressions within a complete XQuery implementation. Experimental results show that the algorithm detects and eliminates most redundant sorting and duplicate elimination operators and is very effective on common XQuery path expressions.
Metadata
Item Type: | Book Section |
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School: | Birkbeck Faculties and Schools > Faculty of Science > School of Computing and Mathematical Sciences |
Depositing User: | Sarah Hall |
Date Deposited: | 13 Apr 2021 17:37 |
Last Modified: | 09 Aug 2023 12:50 |
URI: | https://eprints.bbk.ac.uk/id/eprint/43881 |
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