Forschungsprojekte

BaseX - Processing and Visualizing large XML instances

As XML has been proven to be successful as a standardized format for textual data exchange, it is increasingly used as a representation format for large databases, stretching over several gigabytes. Yet, most XML processors are still specialized on storing and querying pretty small XML documents. In the scope of our research, we analyze the storage, query, update and visualization of large XML instances. BaseX is our native XML database prototype. It features compact storage structures, a very efficient XPath implementation and a graphical user interface, facilitating visual access to large XML documents. more...

...get personal info from Christian Grün

DeepFS - Implementing filesystems using semi-structured database technology

DeepFS provides means to query the data stored in filesystems using standardized database query languages, namely XPath/XQuery. more...

...get personal info from Alexander Holupirek

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. more...

...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. more...

...get personal info from Svetlana Mansmann

Former Projects

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.

Pastel

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.

CROQUE

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.