August 1 – 6 , 2004, Dagstuhl Seminar 04321

Data Warehousing at the Crossroads


Joachim Hammer (University of Florida – Gainesville, US)
Markus Schneider (University of Florida – Gainesville, US)
Timos Sellis (National Technical University of Athens, GR)

For support, please contact

Dagstuhl Service Team


List of Participants
Dagstuhl's Impact: Documents available


Research in data warehousing and online analytical processing (OLAP) has produced important technologies for the design, management and use of information systems for decision support. Much of the interest and success in this area can be attributed to the need for software and tools to improve data management and analysis given the large amounts of information that are being accumulated in corporate as well as scientific databases. However, despite the continued success and maturing of the field, much work remains to be done across many different areas of data warehousing. As more and more information is managed and stored electronically, data warehouses continue to increase in size at a staggering rate. At the same time, the data that needs to be stored in the warehouse is getting more complex in both structure and semantics while the analysis must keep up with the demands of new applications. For example, customer relationship management, analysis of spatial and spatio-temporal data, OLAP mining, mobile OLAP and more recently applications in life sciences are demanding novel representation and manipulation techniques for non-standard data, efficient algorithms to compute aggregate queries, and new, application-specific index structures.


The goal of this seminar is to bring together researchers, especially from the area of databases and information systems, to review the state-of-the-art in data warehouse technologies for OLAP, discuss recent advances and trends in the field, and identify interesting research problems. An important final outcome will be a research agenda describing opportunities and challenges for what the participants deem to be the most promising new areas in data warehousing research. The write-ups describing the topics will be jointly authored by the organizers and seminar participants and published in the form of an edited book for dissemination to the broader community.

Organization and Contents

The seminar will consist of a mixture of short presentations to the entire group as well as parallel working sessions where specific technical issues will be discussed in greater depth. In order to help the organizers in the planning of the sessions, all participants are asked to prepare and submit a one page position statement identifying one or more research issues that should be addressed in the seminar. In order to achieve maximal success, position papers should focus only on warehousing technologies supporting non-standard or emerging applications such as analysis of spatial, spatio-temporal, Web, semistructured, (bio-)medical, and bioinformatics data just to name a few. Topics include but are not limited to:

  • Conceptual modelling for data warehouses (multidimensional data modelling)
  • Design methods (logical design, physical organization, tuning)
  • New data warehouse architectures such as XML warehouses, Web warehouses, or data warehouse federations
  • Integration of warehouses into the business processes of an enterprise
  • Management of data quality as well as uncertainty, vagueness, and imprecision
  • Organization of meta-data management
  • Multidimensional query languages
  • Query processing and optimization
  • Storage and indexing methods
  • Data warehouse operational processes, including novel Extract-Transform-Load (ETL) tools
  • Data warehouse evolution

The position papers are due on 01/07/2004 and will be used by the organizers to identify a preliminary list of research topics as well as a temporary assignment of participants into working groups. Topics and group assignments will be finalized on the first day of the seminar. We expect there to be approximately 8-10 different groups which will be charged to work out the research agenda for their assigned topic. Morning sessions will be used for status reports by the individual groups and to further cross-fertilization among related topic areas. Group working sessions will be scheduled primarily during the afternoons. To help prepare for the technical discussions, all participants will receive a copy of everybody’s position statement as well as the temporary group assignment prior to their arrival in Dagstuhl.


In the series Dagstuhl Reports each Dagstuhl Seminar and Dagstuhl Perspectives Workshop is documented. The seminar organizers, in cooperation with the collector, prepare a report that includes contributions from the participants' talks together with a summary of the seminar.


Download overview leaflet (PDF).

Dagstuhl's Impact

Please inform us when a publication was published as a result from your seminar. These publications are listed in the category Dagstuhl's Impact and are presented on a special shelf on the ground floor of the library.


Furthermore, a comprehensive peer-reviewed collection of research papers can be published in the series Dagstuhl Follow-Ups.