Advertisement

Hidden Conditioned Homomorphism for XPath Fragment Containment

  • Yuguo Liao
  • Jianhua Feng
  • Yong Zhang
  • Lizhu Zhou
Part of the Lecture Notes in Computer Science book series (LNCS, volume 3882)

Abstract

As a query language for navigating XML trees and selecting a set of element nodes, XPath is ubiquitous in XML applications. One important issue of XPath queries is checking containment. In particular, we investigate a frequently used fragment of XPath that consists of node tests, the child axis (/), the descendant axis (//), branches ([]) and label wildcards (*). For special classes of pattern trees, the homomorphism algorithm returns false negatives. In order to address this problem, we propose two containment techniques, conditioned homomorphism and hidden conditioned homomorphism, and then present sound algorithms to check containment. The analytical result is given with an experiment.

Keywords

Tree Pattern Conjunctive Query Tree Automaton 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.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    Amer-Yahia, S., Cho, S., Lakshmanan, L.V.S., Srivastava, D.: Minimi-zation of tree pattern queries. In: Proc of the 2001 ACM SIGMOD Conf. on Management of Data (2001)Google Scholar
  2. 2.
    Amer-Yahia, S., Cho, S., Laksshmanan, L.V.S., Srivastava, D.: Tree pattern query minimization. The VLDB Journal 11(4), 315–331 (2002)CrossRefMATHGoogle Scholar
  3. 3.
    Benedikt, M., Fan, W., Kuper, G.M.: Structural properties of XPath fragments. In: Calvanese, D., Lenzerini, M., Motwani, R. (eds.) ICDT 2003. LNCS, vol. 2572, Springer, Heidelberg (2002)Google Scholar
  4. 4.
    Boag, S., Chamberlin, D., Fernández, M.F., Florescu, D., Robie, J., Siméon, J.: XQuery 1.0: An XML Query Language, http://www.w3.org/TR/xquery.W3CWorkingdraft
  5. 5.
    Buneman, P., Davidson, S., Fan, W., Hara, C., Tan, W.: Reasoning about keys for xml (2000)Google Scholar
  6. 6.
    Calvanese, D., DeGiacomo, G., Vadi, M.: Decidable containment of recursive queries. In: Calvanese, D., Lenzerini, M., Motwani, R. (eds.) ICDT 2003. LNCS, vol. 2572, pp. 330–345. Springer, Heidelberg (2002)CrossRefGoogle Scholar
  7. 7.
    Chandra, A., Merlin, P.: Optimal implementation of conjunctive queries in relational data bases. In: Proceedings of 9th ACM Symposium on Theory of Computing, pp. 77–90 (1977)Google Scholar
  8. 8.
    Clark, J.: XSL Transformations (XSLT), http://www.w3.org/TR/xslt.W3CWorkingdraft
  9. 9.
    Clark, J., DeRose, S.: XML Path Language (XPath) Version 1.0. W3C Working draft, http://www.w3.org/TR/xpath
  10. 10.
    DeRose, S., Maler, E., Orchard, D.: XML Linking Language (XLink) Version 1.0. W3C Working draft, http://www.w3.org/TR/xpath
  11. 11.
    DeRose, S., Jr., R.D., Grosso, P., Maler, E., Marsh, J., Walsh, N.: XML Pointer Language (XPointer). W3C Working draft, http://www.w3.org/TR/xptr
  12. 12.
    Miklau, G., Suciu, D.: Containment and equivalence for a fragment of XPath. Journal of the ACM 51(1), 2–45 (2004)MathSciNetCrossRefMATHGoogle Scholar
  13. 13.
    Milo, T., Suciu, D.: Index structures for path expressions. In: Beeri, C., Bruneman, P. (eds.) ICDT 1999. LNCS, vol. 1540, pp. 277–295. Springer, Heidelberg (1998)CrossRefGoogle Scholar
  14. 14.
    Neven, F.: Automata Theory for XML researchers. SIGMOD Record 31(3), 39–46 (2002)CrossRefGoogle Scholar
  15. 15.
    Neven, F.,, T.: XPath containment in the presence of disjunction, DTDs, and variables. In: Proc. 9th Int. Conf. on Database Theory (ICDT), Siena, pp. 315–329 (2003)Google Scholar
  16. 16.
    Schwentick, T.: XPath query containment. ACM SIGMOD Database priciples Column (2004)Google Scholar
  17. 17.
    Shmueli, O.: Equivalence of datalog queries is undecidable. The Journal of Logic Programming 15(3), 231–242 (1993)MathSciNetCrossRefMATHGoogle Scholar
  18. 18.
    Wood, P.T.: Containment for XPath fragments under DTD constraints. In: Calvanese, D., Lenzerini, M., Motwani, R. (eds.) ICDT 2003. LNCS, vol. 2572, pp. 300–314. Springer, Heidelberg (2002)CrossRefGoogle Scholar
  19. 19.
    Wood, P.T.: Minimizing simple xpath expressions. In: Fourth International Workshop on the Web and Databases (WebDB 2001) (2001)Google Scholar
  20. 20.
    Wood, P.T.: On the equivalence of xml patterns. In: International Conference on Deductive and Object-Oriented Databases (DOOD), pp. 1152–1166 (2000)Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2006

Authors and Affiliations

  • Yuguo Liao
    • 1
  • Jianhua Feng
    • 1
  • Yong Zhang
    • 1
  • Lizhu Zhou
    • 1
  1. 1.Department of Computer Science and TechnologyTsinghua UniversityBeijingP.R. China

Personalised recommendations