A Logical Foundation for XML

  • Mengchi Liu
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 2348)


XML is fast emerging as the dominant standard for data representation and exchange on the World Wide Web. How to view an XML document, i.e., XML data model, and how to query XML documents are two primary research issues for XML. The purpose of this paper is twofold. First, we propose a novel data model for XML that allows us to view XML data in a way similar to complex object data models. Based on this data model, we then investigate how rule-based paradigm can be used to query XML documents and what benefits it brings over existing XML query languages. To this end, we present a rule-based query language called XML-RL, in which we treat existing XML documents as extensional databases, and the queries and functions expressed in rules as intensional databases as in deductive databases. We show that the querying part and result constructing part in XML-RL are strictly separated, the rule body is used to query XML documents and bind variables while the rule head is used to construct the resulting XML document. As several rules can be used for the same query, complex queries can be expressed in XML-RL in a simple and natural way as in logic programming. Also, rules provide a uniform framework for both functions/methods and queries and support recursion in a natural way. Finally, rule-based framework has a formal logic foundation that is lacking in other query languages.


Query Language Logical Foundation Book Element Intensional Database Query Rule 
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 2002

Authors and Affiliations

  • Mengchi Liu
    • 1
  1. 1.School of Computer ScienceCarleton UniversityOttawa

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