XDO2: A deductive object-oriented query language for XML

Abstract

In the past decade, researchers have combined deductive and object-oriented features to produce systems that are powerful and have excellent modeling capabilities. More recently, an XML query language XTree was proposed. Queries written in XTree are more compact, more convenient to write and easier to understand than queries written in XPath. In this paper, we introduce a novel XML query language XDO2 that extends XTree, with deductive features such as deductive rules and negation, and object-oriented features such as inheritance and methods. Our XDO2 language is more compact, and convenient to use than current query languages for XML such as XQuery and XPath because it is based on XTree, supports (recursive) deductive rules and the not-predicate. An XDO2 database example is given to motivate the usefulness of the language. The formal treatment of language syntax and semantics are presented in the appendices. © Springer-Verlag Berlin Heidelberg 2005.