Friedrich-Schiller-Universität Jena
Lehrstuhl für Datenbanken und Informationssysteme
Prof. Dr. Klaus Küspert

IBM Shared University Research
Grant Proposal


Object-Relational Database Features and Extensions:
Data Model and Physical Aspects

Relational database systems are steadily moving towards so-called object-relational features and extensions. With these, DBMS products like DB2 are not anymore limited to managing only simple types of data; instead, large and complex data can be handled and managed as well. Complex data types are especially needed in new application fields involving multimedia, image, video, text, XML, etc. Object-relational database systems integrate object-oriented techniques and traditional relational features in an evolutionary way.

Object-relational features have been a topic in the research community since the 1980s. From midst of the 1990s, these features have started becoming part of commercial products like DB2, Oracle or Informix, even though in a very heterogenous way. The current standard SQL:1999 is the first standard including some object-relational features as well.

Anyway, further research is needed on various aspects of object-relational technology, the products must still and further move into that direction, and the standard is not yet sufficiently extensive.

In a project with the title

"Object-Relational Database Features and Extensions: Data Model and Physical Aspects"
the Database Group at the University of Jena will contribute to three core aspects of object-relational database technology:
  1. Evolving the data model: Integration of nested collections into the SQL standard.

    Currently, the SQL standard supports collection data types only to some very limited and by no means sufficient extent. Jena wants to contribute to the further development of the standard, supporting and cooperating with IBM. The IBM SQL standard group is one of the major drivers in SQL standardization in order to assure compatibility between DB2 and the standard.

    Major topics are:

  2. Evolving the implementation: Physical storage and handling of complex objects including nested collections.

    The challenge of this implementation aspect is how to integrate complex objects, esp. collections, into ORDBMSs like DB2 with minimal changes to the existing DBMS architecture and code and without hurting the performance of traditional data operations.

    Major topics are:

  3. Evaluation of functional and performance aspects of object-relational extensions to ORDBMS products.

    The University of Jena will look at extensibility features, for instance related to geographic (spatial) data, from a functional and a performance point of view: How do the features in products such as DB2 and Oracle look like, what can be said about the performance of these implementations, etc.

    Major topics are:

The research in the first two areas will comprise the development of a research and evaluation prototype. It will help to evaluate the collection extensions to SQL and to explore the various aspects of collections like physical storage structures and operation support. Another aspect is going to involve the mapping of the developed object-relational SQL extensions to major commercial ORDBMS products like DB2. This will help to understand how to generally integrate these new features into DBMS products.

IBM-University Relationship

IBM has an excellent reputation at the University of Jena and a high visibility to students because of the long standing tradition that IBM researchers are giving curricular courses and talks on several IBM related topics, e.g.

database technology: Prof. A. Blaser IBM Heidelberg
workflow management: Prof. F. Leymann IBM Boeblingen
operating systems,
pervasive computing:
Prof. M. Welsch IBM Boeblingen
information retrieval: H-J. Noack IBM Boeblingen

and many more. And in credit for Dr. Welsch's curricular contributions and the excellent reputation of IBM researchers Dr. Welsch received the honorary professorship of the University of Jena this year.

Previous and current links to IBM include two projects examining DB2 administration aspects (1995-1997) and working on the SQL standard (since 1998). A number of our students have been working at IBM Silicon Valley Lab as interns, serveral graduates are now employed by IBM USA and IBM Germany.

The projects and the high visibility of IBM databse activities at the University of Jena (mainly to the regular use of DB2 for teaching and hands-on training) have resulted in several joint publications as well as diploma and project thesises related to IBM themes.

The project work will be done in close cooperation with IBM Silicon Valley Lab with respect to product-related aspects (DB2) as well as standardization issues (the forthcoming SQL:200x standards). The collaboration will include the German IBM database community (B÷blingen, Ehningen, etc.).

DBIS Web; 2002-06-10