Validity of Tree Pattern Queries with Respect to Schema Information

  • Henrik Björklund
  • Wim Martens
  • Thomas Schwentick
Part of the Lecture Notes in Computer Science book series (LNCS, volume 8087)


We prove that various containment and validity problems for tree pattern queries with respect to a schema are EXPTIME-complete. When one does not require the root of a tree pattern query to match the root of a tree, validity of a non-branching tree pattern query with respect to a Relax NG schema or W3C XML Schema is already EXPTIME-hard when the query does not branch and uses only child axes. These hardness results already hold when the alphabet size is fixed. Validity with respect to a DTD is proved to be EXPTIME-hard already when the query only uses child axes and is allowed to branch only once.


Regular Expression Tiling System Winning Strategy Conjunctive Query Tree Automaton 
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Copyright information

© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  • Henrik Björklund
    • 1
  • Wim Martens
    • 2
  • Thomas Schwentick
    • 3
  1. 1.Umeå UniversitySweden
  2. 2.University of BayreuthGermany
  3. 3.TU Dortmund UniversityGermany

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