Advertisement

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)

Abstract

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.

Keywords

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.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    Segoufin, L., Vianu, V.: Validating streaming XML documents. In: ACM PODS, pp. 53–64 (2002)Google Scholar
  2. 2.
    Martens, W., Neven, F., Schwentick, T., Bex, G.J.: Expressiveness and complexity of XML schema. ACM Transactions of Database Systems 31(3), 770–813 (2006)CrossRefGoogle Scholar
  3. 3.
    Gupta, A.K., Suciu, D.: Stream processing of XPath queries with predicates. In: ACM SIGMOD, pp. 419–430 (2003)Google Scholar
  4. 4.
    Fernandez, M., Michiels, P., Siméon, J., Stark, M.: XQuery streaming á la carte. In: 23nd International Conference on Data Engineering, pp. 256–265 (2007)Google Scholar
  5. 5.
    Benedikt, M., Jeffrey, A.: Efficient and expressive tree filters. In: Arvind, V., Prasad, S. (eds.) FSTTCS 2007. LNCS, vol. 4855, pp. 461–472. Springer, Heidelberg (2007)CrossRefGoogle Scholar
  6. 6.
    Bar-Yossef, Z., Fontoura, M., Josifovski, V.: Buffering in query evaluation over XML streams. In: ACM PODS, pp. 216–227 (2005)Google Scholar
  7. 7.
    Olteanu, D.: SPEX: Streamed and progressive evaluation of XPath. IEEE Trans. on Know. Data Eng. 19(7), 934–949 (2007)CrossRefGoogle Scholar
  8. 8.
    Gou, G., Chirkova, R.: Efficient algorithms for evaluating XPath over streams. In: ACM SIGMOD, pp. 269–280 (2007)Google Scholar
  9. 9.
    Berlea, A.: Online evaluation of regular tree queries. Nordic Journal of Computing 13(4), 1–26 (2006)MathSciNetzbMATHGoogle Scholar
  10. 10.
    Gauwin, O., Niehren, J., Tison, S.: Earliest query answering for deterministic streaming tree automata and a fragment of XPath (2009)Google Scholar
  11. 11.
    Gauwin, O., Niehren, J., Roos, Y.: Streaming tree automata. Information Processing Letters 109(1), 13–17 (2008)MathSciNetCrossRefzbMATHGoogle Scholar
  12. 12.
    Alur, R.: Marrying words and trees. In: ACM PODS, pp. 233–242 (2007)Google Scholar
  13. 13.
    Alur, R., Madhusudan, P.: Visibly pushdown languages. In: 36th ACM Symposium on Theory of Computing, pp. 202–211 (2004)Google Scholar
  14. 14.
    Neumann, A., Seidl, H.: Locating matches of tree patterns in forests. In: Arvind, V., Ramanujam, R. (eds.) FST TCS 1998. LNCS, vol. 1530, pp. 134–146. Springer, Heidelberg (1998)CrossRefGoogle Scholar
  15. 15.
    Comon, H., Dauchet, M., Gilleron, R., Löding, C., Jacquemard, F., Lugiez, D., Tison, S., Tommasi, M.: (1997) (revised October 12th, 2007), http://tata.gforge.inria.fr
  16. 16.
    Carme, J., Niehren, J., Tommasi, M.: Querying unranked trees with stepwise tree automata. In: van Oostrom, V. (ed.) RTA 2004. LNCS, vol. 3091, pp. 105–118. Springer, Heidelberg (2004)CrossRefGoogle Scholar
  17. 17.
    Seidl, H.: Single-valuedness of tree transducers is decidable in polynomial time. Theoretical Computer Science 106, 135–181 (1992)MathSciNetCrossRefzbMATHGoogle Scholar
  18. 18.
    Stearns, R.E., Hunt III, H.B.: On the equivalence and containment problems for unambiguous regular expressions, regular grammars and finite automata. SIAM Journal on Computing 14(3), 598–611 (1985)MathSciNetCrossRefzbMATHGoogle Scholar
  19. 19.
    Weber, A., Seidl, H.: On the degree of ambiguity of finite automata. In: Wiedermann, J., Gruska, J., Rovan, B. (eds.) MFCS 1986. LNCS, vol. 233, pp. 620–629. Springer, Heidelberg (1986)CrossRefGoogle Scholar
  20. 20.
    Allauzen, C., Mohri, M., Rastogi, A.: General algorithms for testing the ambiguity of finite automata. In: Ito, M., Toyama, M. (eds.) DLT 2008. LNCS, vol. 5257, pp. 108–120. Springer, Heidelberg (2008)CrossRefGoogle Scholar
  21. 21.
    Carme, J., Lemay, A., Niehren, J.: Learning node selecting tree transducer from completely annotated examples. In: Paliouras, G., Sakakibara, Y. (eds.) ICGI 2004. LNCS (LNAI), vol. 3264, pp. 91–102. Springer, Heidelberg (2004)CrossRefGoogle Scholar
  22. 22.
    Seidl, H.: Ambiguity, valuedness and costs, Habilitation Thesis (1992)Google Scholar
  23. 23.
    Sakarovitch, J., de Souza, R.: Decidability of bounded valuedness for transducers. In: Mathematical Foundations of Computer Science (2008)Google Scholar

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

Personalised recommendations