The Database and Information Systems Group at Freie Universität Berlin is working on application-oriented as well as basic research projects. The field of database managment is rapidly changing. Traditional data management tasks are well understood as many application systems today use relational technology. New challenges include unstructured data like text and images and the "information everywhere" paradigm. Data are provided in well structured data bases as well as on the web and more and more in mobile devices.Currently we focus on data management in mobile systems on the one hand and the unstructured-to-structured data area on the other. In both areas applications like eCommerce clients on PDAs or fact extraction tools for natural language text already exist. However, there are many open research problems which urgently need to be solved in order to improve functionality and performance of such applications.As far as mobile data management is concerned, we focus on transactional guarantees of data related computations in unstable infrastructures. Such kind of guarantees are essential for example in electronic commerce and all kinds of service oriented applications in mobile environments.Our focus in the area of unstructured data has been up to now the extraction of facts from texts. However unstructured data is more than text: Answering queries on the web as an enhancement of retrieval techniques, managing personal information, finding similarities in large data sets, sentiment analysis and the integration of such techniques into business processes are promising new fields. An inherent and common theme of these areas is impreciseness and uncertainty of data. Sensor data, e.g. captured in mobile environments, may contain errors, web mining will never result in precise information. The same holds for query results in information retrieval or fact extraction. The emerging field of impreciseness of data is a guiding theme of our research. We also work on more technical aspects of data management. The hardware and net infrastructure has changed radically since the advent of tradidtional relational database systems thirty years ago. It is still unclear how the management of very large data sets can benefit from the technoloy shift. We investigate different directions: Column based data management as opposed to the row based relational storage and the utilitzation of massive parallelisation on commodity hardware guided by the Map-Reduce paradigm. We are in particular interested in improving data management application like time series analysis or business intelligence.
Members of the group are engaged in the Open Street Map (OSM) project. In this context there are several activities contributing to the project like rendering maps on cell phones or classifying GPS traces in order to detect the street topology.
We collaborate closely with Fraunhofer ISST in particular on location based services. Dr. Voisard is department head at ISST and adjunct professor for data base management at our institute.
D. Bößwetter, Sorting in Column Stores, Datenbank Spektrum, Springer Berlin / Heidelberg,
vol. 11, no. 2, (to appear)
D. Bößwetter; Migration im Hintergrund, Data-Warehouse mit MonetDB und MySQL,
iX 03/2011, p.153, heise Verlag
Jürgen Broß and Heiko Ehrig. Generating a Context-Aware Sentiment Sexicon for Aspect-Based Product Review Mining. In Proceedings of 9th Intl. Conference on Web Intelligence (WI2010), to appear, September 2010, Toronto, Canada.
K. Hahn. Transactional Support for ad-hoc Cooperations in Mobile Environments. PhD Thesis, Freie Universität Berlin, Fachbereich Mathematik und Informatik, Berlin 2010.
K. Hahn. Adaptive Workflow Management to Ensure Transactional Service Composition. In Proceedings of 5th Intl. Conference on Digital Information Management (ICDIM). July 2010, Thunder Bay, Canada.
K. Hahn. Transactional Support of ad-hoc Collaborations in Mobile Environments. In Proceedings of 9th Intl. Workshop on Data Engineering for Wireless and Mobile Access (MobiDE) in Conjunction with ACM SIGMOD. June 2010, Indianapolis, USA.
D. Bößwetter; Spaltbare Materie; LucidDB und MonetDB vs. PostgreSQL; iX 10/2009, p. 62
D. Bößwetter. SPAX - PAX with Super-Pages. In J. Grundspenkis, T. Morzy, and G. Vossen (eds.), ADBIS 2009, Volume 5739 of Lecture Notes in Computer Science, pages 362–377. Springer, 2009.
Jürgen Broß and Alan Akbik: 'Wanderlust: Extracting Semantic Relations from Natural Language Text Using Dependency Grammar Patterns'. In Proceedings of the Workshop on Semantic Search in Conjunction with the 18th Int. World Wide Web Conference (WWW2009), April 2009, Madrid, Spain.
Katharina Hahn and Heinz Schweppe: Exploring Transactional Service Properties for Mobile Service Composition. 4. Konferenz Mobilität und Mobile Informationssysteme (MMS 2009), Münster, März 2009.
Katharina Hahn and Heinz Schweppe: Analysis of Non-Functional Service Properties for Transactional Workflow Management. In Proceedings of Workshop on Non-Functional Service Properties and Service Level Agreements in SOC in Conjunction with IEEE European Conference on Web-Services (ECOWS), November 2008, Dublin, Ireland.
Joos-Hendrik Böse and Jürgen Broß: Using a Backup Coordinator to Compensate for Blocking of Atomic Transactions in MANETs. In Proceedings of 1st International Workshop of Ad-Hoc Ambient Computing 2008. Sophia Antipolis, France.
Joos-Hendrik Böse, Jürgen Broß and Heinz Schweppe: A Probabilistic Model for Blocking Risks of Atomic Transactions in P2P Networks. In Proceedings of 6th International Workshop on Databases, Information Systems and Peer-to-Peer Computing (DBISP2P 2008). Auckland, Neuseeland.
Joos-Hendrik Böse and Jürgen Broß: Predicting the Blocking Risk of Atomic Transactions in MANETs Induced by Coordinator Failures. In Proceedings of 2nd Internactional Conference on Wireless Applications and Computing (WAC) 2008. Amsterdam, Netherlands.