Universität Konstanz | Informatik und Informationswissenschaft | dbis | Research

Current Projects

BaseX - Processing and Visualizing large XML instances

BaseX is a light-weight, high-performance and scalable XML Database engine and XPath/XQuery 3.0 Processor, including full support for the W3C Update and Full Text extensions. An interactive and user-friendly GUI frontend gives you insight into your XML documents. more...

...get personal info from Christian Grün, Alexander Holupirek

Integration of Data Mining with Database System

Significant research efforts have been made to enable in-database data mining to take advantage of the DBMS's power of handling large volume of data. The integration of data mining algorithms with a relational Database Management System is a challenging issue. Tight coupling of data mining and database systems, more...

...get personal info from Nafees Ur Rehman

Dynamic Faceted Search Systems

Faceted Search Applications have emerged as a convenient interface for exploring large information spaces, especially web contents. Since the facets of interests may change due to query refinement, it appears feasible to provide a mechanism for automatic adjustment of the facets to the context. We design a generic framework for constructing dynamic faceted search systems using the XML technology and implement it in a prototype Crafts&Arts Pattern Finder. more...

...get personal info from Svetlana Mansmann

Former Projects

DeepFS: XQuery Your Filesystem - Enhancing filesystems using semi-structured database technology

DeepFS wants to find synergies between file system and semi-structured database techniques.
While file systems provide an easy and well-understood interface to the data, they lack important and demanded features like, for example, the ability to query the data. more...

...get personal info from Alexander Holupirek

Pathfinder - Full Text

This project was about the extension of a purely algebraic XQuery compiler (Pathfinder [1]) with an infrastructure for implicit score propagation. This is used to implement a subset of XQuery—Full Text [2], employing the PF/Tijah [3] index for Full Text search more...

...get personal info from Stefan Klinger

DELOS - a Network of Excellence on Digital Libraries

DELOS is a Network of Excellence on Digital Libraries, partially funded by the European Commission's Information Society Technologies Programme (IST). The main objective of DELOS is to coordinate a joint programme of activities of the major European teams working in digital library related areas. http://www.informatik.uni-konstanz.de/arbeitsgruppen/dbis/forschung/delos/more...http://www.informatik.uni-konstanz.de/arbeitsgruppen/dbis/forschung/delos/

...get personal info from Marc H. Scholl

UniVis - OLAP Empowerment for Complex Data

Comprehensive data analysis has become indispensable in a variety of environments. Standard OLAP systems, however, are too rigid for some domains such as medicine, science, or government, where analysts are confronted with complex, imprecise, incomplete, or irregular data. The aim of this research is to identify modeling requirements for supporting complex data found in real-world applications and extend the multidimensional data model accordingly. The ultimate usefulness of the proposed solutions at the conceptual level is determined by their implementability in a visual OLAP interface. We verify our concepts by implementing an OLAP application called UniVis Explorer as a client user interface to an open-source university data warehouse SuperX.

Pathfinder (XQuery Compilation)

XML is the new standard to label semistructured data. It is therefore expected that new XML databases will emerge that natively support XML structured data. This new model of semi-structured data requires a new query language that supports the features of XML documents. The XQuery working group of the W3 Consortium is currently working on a proposal for such a query language, which is called “XQuery”. The new data model opens a broad range of research aspects. In the Pathfinder XQuery implementation we have addressed some of these aspects. more...

Concurrency Control in Mobile Databases

The aim of our research work in the field of mobile databases is the design, analytical analysis, and simulation of efficient concurrency control protocols for read-only transactions that satisfy various data consistency and currency requirements. Our research activity focuses on the development of weaker currency control protocols that incorporate both consistency and currency guarantees. To prevent read-only transactions from interfering with concurrent read-write transactions, our protocols exploit multi-versioning. First results of simulation studies show that weaker protocols such as the Multi-version Concurrency Control Protocol with Strict Forward BOT View Consistency guarantees (MVCC-SFBVC) outperform semantically stronger (serializable) but more restrictive protocols.


The goal of persistent programming is to support the activity of application construction for long-lived, concurrently accessed and potentially large bodies of data and programs, referred to here as Persistent Applications Systems (PASs). The Pastel consortium recognises that the individual components, methods and tools that support PASs have largely been developed independently by different research communities and different kinds of IT companies. The result is that the designers and programmers working to build a PAS have to operate in an environment that is very complex. Pastel has the vision of a consistent and coherent environment which yields a quantum leap in the productivity of PAS software engineers. The Pastel project started in December 1996 for a duration of 36 months.


This project aims at developing optimization techniques for object oriented database management systems (ODBMS). The main focus is to investigate query rewriting technique for rule based and algebraic query languages, evaluation techniques for object oriented queries, as well as the optimization of the physical design of object oriented DBMS, according to a given application. Further details can be found here (german only) or on the CROQUE web of the Database research group at the University of Rostock.