Bounded Delay and Concurrency for Earliest Query Answering

  • Olivier Gauwin
  • Joachim Niehren
  • Sophie Tison
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 5457)


Earliest query answering is needed for streaming XML processing with optimal memory management. We study the feasibility of earliest query answering for node selection queries. Tractable queries are distinguished by a bounded number of concurrently alive answer candidates at every time point, and a bounded delay for node selection. We show that both properties are decidable in polynomial time for queries defined by deterministic automata for unranked trees. Our results are obtained by reduction to the bounded valuedness problem for recognizable relations between unranked trees.


Binary Tree Tree Automaton Query Answering Bounded Delay Tree Transducer 
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 2009

Authors and Affiliations

  • Olivier Gauwin
    • 1
    • 2
    • 3
  • Joachim Niehren
    • 1
    • 3
  • Sophie Tison
    • 2
    • 3
  1. 1.INRIA, LilleFrance
  2. 2.University of Lille 1France
  3. 3.Mostrare project, INRIA & LIFL (CNRS UMR8022)France

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