Lule Ahmedi
ABSTRACT
Opting for link semantics in XML is almost like hyperlinks for HTML documents. XLink describes a standard way to add hyperlinks to an XML document. The current XPath technologies are restricted to follow ID/IDREF(S) links for intra-document navigation only. We investigate the Lightweight Directory Access Protocol (LDAP) that offers a rich collection of primitives to express links among distributed data collections in the network, and facilities to follow links when searching. In virtue of querying the underlying LDAP model by referrals, we developed an extended XPath processor that is capable of addressing links of any type (IDREF(S), XLink) embedded in XML data on the Web. Links may be inter-document, or even traverse across different local or remote servers. We describe the internal LDAP data representation and query model used by the processor for the storage and querying in XPath of XML documents based on links, and provide examples to illustrate them. We complement the discussion with experimental analyses that prove the efficiency of our query evaluation techniques. The latter confirms the relevance of our approach for applications that need to interact with interlinked XML document networks in an XPath-like fashion.
- XSL Transformations (XSLT) Version 1.0. W3C Recommendation, November 1999. http://www.w3.org/TR/xslt.]]Google Scholar
- XML Linking Language (XLink) Version 1.0. W3C Recommendation, June 2001. http://www.w3.org/TR/xlink/.]]Google Scholar
- XML Pointer Language (XPointer). W3C Working Draft, August 2002. http://www.w3.org/TR/xptr/.]]Google Scholar
- XQuery 1.0: An XML Query Language. W3C Working Draft, November 2003. http://www.w3.org/XML/Query/.]]Google Scholar
- S. Amer-Yahia, D. Srivastava, and D. Suciu. Distributed query evaluation in LDAP directories. IEEE Transactions on Knowledge and Data Engineering (TKDE), 15(4), July/August 2003. IEEE Computer Society Press.]]Google Scholar
- T. Berners-Lee, R. Fielding, and L. Masinter. RFC 2396: Uniform Resource Identifiers (URI): Generic syntax, Aug. 1998. Status: Draft Standard.]] Google ScholarDigital Library
- T. Berners-Lee, L. Masinter, and M. McCahill. RFC 1738: Uniform resource locators (URL), Dec. 1994. Status: Proposed Standard.]] Google ScholarDigital Library
- J. Clark and S. DeRose. XML Path Language (XPath) Version 1.0. W3C Recommendation, November 1999. http://www.w3c.org/TR/xpath.]]Google Scholar
- T. Howes and M. Smith. RFC 2255: The LDAP URL format, ftp://ftp.isi.edu/in-notes/rfc2255. txt, Dec. 1997. Status: Proposed Standard.]] Google ScholarDigital Library
- T. A. Howes, M. C. Smith, and G. S. Good. Understanding and deploying LDAP directory services. Macmillan Technical Publishing, 1999.]] Google ScholarDigital Library
- Innosoft International Inc. LDAP world implementation survey, http://www.innosoft.com/ldap_survey/lisurvey.html, February 1997.]]Google Scholar
- A. Malhorta, J. Melton, and N. Walsh. XQuery 1.0 and XPath 2.0 Functions and Operators. W3C Working Draft, November 2003. http://www.w3.org/TR/xpath-functions/.]]Google Scholar
- P. J. Marrón and G. Lausen. On processing XML in LDAP. In Proceedings of the 27th Intl. Conference on Very Large Data Bases (VLDB), September, 2001, Roma, Italy, pages 601--610, Los Altos, USA, 2001. Morgan Kaufmann Publishers.]] Google ScholarDigital Library
- W. May. Mondial database. http://www.informatik.uni-freiburg.de/~may/Mondial, 2000.]]Google Scholar
- W. May. Linking the semantic web with existing sources. In DEXA Workshop on Web Semantics (WebS), pages 93--97, Aix-en-Provence, France, September 2002. IEEE Computer Society Press.]] Google ScholarDigital Library
- W. May. Querying linked XML document networks in the Web. In The 11th Intl. World Wide Web Conference (WWW), Honolulu, USA, May 2002.]]Google Scholar
- OpenLDAP Group. OpenLDAP server. LDAP implementation available at http://www.openldap.org/.]]Google Scholar
- D. Veillard. Libxml - The Gnome/W3C XML library. http://www.xmlsoft.org.]]Google Scholar
- W3C DOM Working Group. Document object model specification. http://www.w3.org/DOM/, December 1997.]]Google Scholar
- W3C Implementation Chart. XML Linking implementations survey. http://www.w3.org/XML/2000/09/LinkingImplementations.html.]]Google Scholar
- M. Wahl, T. Howes, and S. Kille. RFC 2251: Lightweight Directory Access Protocol (v3), Dec. 1997.]] Google ScholarDigital Library
Index Terms
- Making XPath reach for the web-wide links
Recommendations
Filtering XPath expressions for XML access control
XPath is a standard for specifying parts of XML documents and a suitable language for both query processing and access control of XML. In this paper, we use the XPath expression for representing user queries and access control for XML. And we propose an ...
Visual Evaluation of XPath Queries
ICCIS '13: Proceedings of the 2013 International Conference on Computational and Information SciencesOver the past one decade, due to its simplicity and flexibility, Extensible Markup Language (XML) is rapidly gaining in popularity as a universal data format for data exchange and integration on the web. In this paper, we present a novel framework to ...
Efficient Cache Answerability for XPath Queries
Proceedings of the VLDB 2002 Workshop EEXTT and CAiSE 2002 Workshop DTWeb on Efficiency and Effectiveness of XML Tools and Techniques and Data Integration over the Web-Revised PapersThe problem of cache answerability has traditionally been studied over conjunctive queries performed on top of a relational database system. However, with the proliferation of semistructured data and, in particular, of XML as the de facto standard for ...
Comments