Shifting Predicates to Inner Sub-expressions for XQuery Optimization

  • Sven Groppe
  • Jinghua Groppe
  • Stefan Böttcher
  • Marc-André Vollstedt
Part of the Lecture Notes in Computer Science book series (LNCS, volume 4879)


Besides XPath, XQuery is an XML query language developed by W3C. Within this paper, which is an extended version of [6], we present an approach for the optimization of the execution time of nested XQuery queries based on type information of the input XML document given in XML Schema. The optimization approach deletes unnecessary sub-expressions and shifts predicates to inner sub-expressions wherever possible in order to avoid the generation of unnecessary intermediate data. A performance analysis of our prototype demonstrates the optimization of the execution time of various current XQuery evaluators when using the proposed optimization approach.


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Copyright information

© Springer-Verlag Berlin Heidelberg 2009

Authors and Affiliations

  • Sven Groppe
    • 1
  • Jinghua Groppe
    • 2
  • Stefan Böttcher
    • 3
  • Marc-André Vollstedt
    • 3
  1. 1.Institute of Information SystemsUniversity of LübeckLübeckGermany
  2. 2.LübeckGermany
  3. 3.University of PaderbornPaderbornGermany

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