Efficient Schemes of Executing Star Operators in XPath Query Expressions

  • Young Chul Park
  • Je Hyun Cho
  • Geum Ji Cha
  • Peter Scheuermann
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 3882)


Upon performing XPath queries on XML documents that are stored in relational databases, the execution of path expressions with steps of the star operator ‘*’, which can be mapped to arbitrary names of either elements or attributes, has not been treated seriously in the literature. This paper presents schemes of acquiring path identifiers of query expressions that have steps of star operators in addition to steps of element names and attribute names. The contribution of this paper can be summarized as follows. First, we show that path identifiers of “/@*” and “//@*” can be obtained from the relation Path that holds path identifiers of path expressions in XML documents; by extending the relation Path, path identifiers of “//*” can be obtained from the extended relation; and some of “/*”s can be handled with the same way as “//*”. Second, to obtain path identifiers of “/*” from the extended relation Path, we propose a new reserved character ‘$’ that extends the string-pattern of the LIKE operator of SQL. The reserved character ‘$’ followed by the restricting character string ‘[^patterns]’ matches arbitrary number of arbitrary characters except for the characters listed in the restricting character string.


Element Node Star Operator Document Type Definition Path Expression Partial Path 
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.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    World Wide Web Consortium. Extensible Markup Language (XML) 1.0, W3C Recommendation (February 1998),
  2. 2.
    Deutsch, A., Fernandez, M., Florescu, D., Levy, A., Suciu, D.: World Wide Web Consortium. XML-QL: A Query Language for XML (August. 1998),
  3. 3.
    Robie, J., Lapp, J., Schach, D.: World Wide Web Consortium. XML Query Language (XQL) (September 1998),
  4. 4.
    World Wide Web Consortium. XML Path Language (XPath), Version 2.0, W3C Working Draft (May 2, 2003), [4-1] World Wide Web Consortium. XML Path Language (XPath), Version 1.0,
  5. 5.
    World Wide Web Consortium. XQuery 1.0: An XML Query Language, W3C Working Draft (November 12, 2003)Google Scholar
  6. 6.
    Grust, T., van Keulen, M.: Tree Awareness for Relational DBMS Kernels: Staircase Join. In: Blanken, H.M., Grabs, T., Schek, H.-J., Schenkel, R., Weikum, G. (eds.) Intelligent Search on XML Data. LNCS, vol. 2818, pp. 231–245. Springer, Heidelberg (2003)CrossRefGoogle Scholar
  7. 7.
    Grust, T., Keulen, M.V., Teubner, J.: Accelerating XPath Evaluation in Any RDBMS. ACM Transactions on Database Systems 29(1), 91–131 (2004)CrossRefGoogle Scholar
  8. 8.
    Fernandez, M.F., Morishima, A., Suciu, D., Tan, W.C.: Publishing Relational Data in XML: The SilkRoute Approach. IEEE Data Engineering Bulletin 24(2), 12–19 (2001)Google Scholar
  9. 9.
    Carey, M., Florescu, D., Ives, Z., Lu, Y., Shanmugasundaram, J., Shekita, E., Subramanian, S.: XPERANTO: Publishing Object-Relational Data as XML. In: Workshop on Web and Databases, WebDB (2000) (Informal Proceedings)Google Scholar
  10. 10.
    Shimura, T., Yoshikawa, M., Uemura, S.: Storage and Retrieval of XML Documents Using Object-Relational Databases. In: Bench-Capon, T.J.M., Soda, G., Tjoa, A.M. (eds.) DEXA 1999. LNCS, vol. 1677, pp. 206–217. Springer, Heidelberg (1999)CrossRefGoogle Scholar
  11. 11.
    Yoshikawa, M., Amagasa, T., Shimura, T., Uemura, S.: XREL: A Path-Based Approach to Storage and Retrieval of XML Documents using Relational Databases. ACM Transactions on Internet Technology 1(1), 110–141 (2001)CrossRefGoogle Scholar
  12. 12.
    Shanmugasundaram, J., Tatarinov, I., Viglas, S.D., Beyer, K., Shekita, E., Zhang, C.: Storing and Querying Ordered XML using a Relational Database System. In: Proc. of ACM SIGMOD International Conference on Management of Data, Madison, Wisconsin, USA, June 2002, pp. 204–215 (2002)Google Scholar
  13. 13.
    World Wide Web Consortium. Document Type Definition (DTD), W3C Recommendation (February 4, 2004),
  14. 14.
    World Wide Web Consortium. XML Schema Part 0: Primer, W3C Recommendation (May 2, 2001),
  15. 15.
  16. 16.
    Fnderburk, J.E., Kiernan, G., Shanmugasundaram, J., Shekita, E., Wei, C.: XTABLES: Bridging Relational Technology and XML. IBM Systems Journal 41(4), 616–641 (2002)CrossRefGoogle Scholar
  17. 17.
    Bosak, J.: The Play of Shakespeare in XML (January 1998),
  18. 18.
    Oracle Enterprise Manager Administrator’s Guide Release 9.0.2, Oracle Corporation (2002)Google Scholar
  19. 19.
    Oracle9i Application Developer’s Guide - XML, Release 1 (9.0.1), Part No. A88894-01 (June 2001)Google Scholar
  20. 20.
    SQL2000 Server, Microsoft Corp,
  21. 21.
    Chan, C.Y., Fan, W., Zeng, Y.: Taming XPath Queries by Minimizing Wildcard Steps. In: Proc. of VLDB Conference, Toronto, Canada, pp. 156–167 (2004)Google Scholar
  22. 22.
    Rao, P., Moon, B.: PRIX: Indexing And Querying XML Using Prufer Sequences. In: Proc. of ICDE, Boston, MA, USA (March 2004)Google Scholar
  23. 23.
    Wang, H., Park, S., Fan, W., Yu, P.S.: ViST: A Dynamic Index Method for Querying XML Data by Tree Structures. In: Proc. of ACM SIGMOD International Conference on Management of Data, San Diego, CA (June 2003)Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2006

Authors and Affiliations

  • Young Chul Park
    • 1
  • Je Hyun Cho
    • 1
  • Geum Ji Cha
    • 1
  • Peter Scheuermann
    • 2
  1. 1.Department of Computer ScienceKyungpook National UniversityDaeguKorea
  2. 2.Department of Electrical and Computer EngineeringNorthwestern UniversityEvanstonUSA

Personalised recommendations