A Typed Higher-Order Calculus for Querying XML Databases

As the eXtensible Markup Language (XML) is about to emerge as a new standard for databases, the problem of providing solid logical grounds for XML query languages arises. For the relational data model firstorder logic, i.e. the Relational Calculus turned out to be an intuitive basic approach to provide these foundations. For XML, however, it is necessary to deal with ordered trees. In this paper the problem is approached by viewing XML as a data model based on complex objects that are arranged in a class hierarchy. This results in the natural development of a higher-order type system for XML data, and henceforth a higher-order predicate typed logic, the XML calculus (XMLC). The paper presents the basics of the XML object model (XOM), the syntacs and semantics of XMLC, and discusses the expressiveness of the language by means of representative important query samples.

• Type: Conference
• Year: 2008
• Where: ADC
• Authors: Qing Wang, Klaus-Dieter Schewe
• Keywords: ADC 2008, Data Model, Database, XML Object Model, XML Query Languages