Monadic Queries over Tree-Structured Data

Monadic query languages over trees currently receive considerable interest in the database community, as the problem of selecting nodes from a tree is the most basic and widespread database query problem in the context of XML. Partly a survey of recent work done by the authors and their group on logical query languages for this problem and their expressiveness, this paper provides a number of new results related to the complexity of such languages over so-called axis relations (such as “child” or “descendant”) which are motivated by their presence in the XPath standard or by their utility for data extraction (wrapping).

• Type: Conference
• Year: 2002
• Where: LICS
• Authors: Georg Gottlob, Christoph Koch
• Keywords: Automated Reasoning, Database Query Problem, LICS 2002, Monadic Query Languages, Query Languages