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Index vs. Navigation in XPath Evaluation

  • Norman May
  • Matthias Brantner
  • Alexander Böhm
  • Carl-Christian Kanne
  • Guido Moerkotte
Part of the Lecture Notes in Computer Science book series (LNCS, volume 4156)

Abstract

A well-known rule of thumb claims, it is better to scan than to use an index when more than 10% of the data are accessed. This rule was formulated for relational databases. But is it still valid for XML queries? In this paper we develop similar rules of thumb for XML queries by experimentally comparing different execution strategies, e.g. using navigation or indices. These rules can be used immediately for heuristic optimization of XML queries, and in the long run, they may serve as a foundation for cost-based query optimization in XQuery.

Keywords

Query Evaluation Candidate Node Structural Join XPath Query XPath Expression 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer-Verlag Berlin Heidelberg 2006

Authors and Affiliations

  • Norman May
    • 1
  • Matthias Brantner
    • 1
  • Alexander Böhm
    • 1
  • Carl-Christian Kanne
    • 1
  • Guido Moerkotte
    • 1
  1. 1.University of MannheimMannheimGermany

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