Dr.-Ing. Christian Mathis

Dept. of Computer Science
University of Kaiserslautern
P.O. Box 3049
D-67653 Kaiserslautern

Research Interests

  • Native XML storage structures
  • XML indexing
  • XML query processing
  • XTC project

Private Interests


Supervised Documents

  • 2008
    • Projektarbeit
      Anwendungsfälle für und Anforderungen an XML-Datenbanksysteme
      Matthias Burkhart
    • Diplomarbeit
      Entwicklung von Pfadoperatoren und deren Integration in eine physische XML-Algebra
      Stefan Hühner
  • 2007
    • Projektarbeit
      Implementierung von indexbasierten Planoperatoren für die Anfrageverarbeitung in nativen XML-Datenbanksystemen
      Stefan Hühner
    • Diplomarbeit
      Effiziente und transaktionsgeschützte Speicherung von Dokument-Kollektionen in XML-Datenbanksystemen
      Thomas Sommer
    • Diplomarbeit
      Plangenerierung zur Anfrageauswertung in nativen XML-Datenbankverwaltunssystemen
      Andreas M Weiner
    • Seminar on Mobile and Context-aware Database Technologies and Applications
      Konsistenzsicherung für mobile Anwendungen
      Volker Hudlet, July 2007
  • 2006
    • Projektarbeit
      Eine graphische Benutzeroberfläche zur transaktionsgeschützten DOM-Navigation
      Juliane Neumann
    • Seminar on Dependable Adaptive Information Systems (DAIS)
      Self-Tuning Databases
      Thomas Sommer, Febuary 2006
    • Seminar on Mastering the Information Explosion – Information Integration and Information Quality
      Grundlagen der Informationsintegration
      Paul Schilling, July 2006
    • Seminar on Information Retrieval
      Boolesches Retrieval und weitere IR-Modelle
      Markus Messner-Chaney, February 2006
    • Seminar on Information Retrieval
      Suchmaschinen im Internet
      Matthias Wolf, February 2006
  • 2005
  • A Glimpse: The XML Query Graph Model (XQGM)

    The XQGM is an extension of the classical Query Graph Model introduced by the relational Starburst system. The model can capture a large fragment of the XQuery language and serves as a basis for rule-based query optimization in XTC. In contrast to algebraic query representations, the graphical XQGM is easy to understand and, therefore, facilitates the development and debugging of XQuery expressions and of our query engine. Details on the XQGM semantics, on XQGM-based query rewriting (especially query unnesting and twig discovery), and on the comprehensive physical XML algebra for the implementation of XQGM-operators in XTC will be published soon.

    Screenshots from the XTC Visual Explain Tool

    XQGM representation of XMark Query 12 (initial)


    XQGM representation of XMark Query 12 (after unnesting and twig discovery)


    Generated Query Evaluation Plan (in XTC's physical XML algebra)