Johan Petrini's official web page

I am a Ph.D student at Uppsala Database Laboratory (UDBL) at the Department of Information Technology, Uppsala University.
My supervisor is prof. Tore Risch

The semantic web standard RDF enables web resources to be annotated with properties describing structure and contents.
However, there is a vast amount of additional high quality information in the hidden web stored in databases
accessible from the web but not as web pages. In particular, most organizations use relational database technology and
such databases should also be accessible from semantic web applications.

During my research I have designed and implemented and evaluated a system called SWARD (Semantic Web Abridged Relational Databases)
that enables scalable search over RDF views, or, UPVs (Universal Property Views) of information residing in hidden web relational databases.
The UPVs are generated through the mapping of columns in the relational database to properties in some ontology.
Because ontologies can have many properties and relational databases can be huge it is important that SWARD scales over
the size of a) the query, b) the UPV c) the database.

• I have designed and implemented automatic generation of UPVs over relational databases.

• I have developed, tested and evaluated novel optimization strategies, using a technique called partial evaluation, for efficient and
  scalable processing of complex queries over large UPVs of huge relational databases.

Publications

• J. Petrini and T. Risch: Partial Evaluation of Queries to RDF Views of Relational Databases, To be published.

• T. Risch, W. Litwin, J. Petrini, S. Stefanova, S. Sahri: Semantic Exposition Specification,
  Technical report FP6-IST-2004-26727 D 5.1(M16 ),Advanced eGovernment Information Service Bus eGov-Bus,
  September 2007.

• J. Petrini and T. Risch: SWARD - Semantic Web Abridged Relational Databases,
  6th International Workshop on Web Semantics, WEBS 2007, Regensburg, Germany, September 2007.

• Ph. Thiran, T. Risch, C. Costilla, J. Henrard, Th. Kabisch, J. Petrini, W-J. van den Heuvel, and J-L. Hainaut:
  Report on the Workshop on Wrapper Techniques for Legacy Data Systems
  SIGMOD Record, Vol. 34, No. 3, Sept. 2005, pp. 85-86.

• J.Petrini and T.Risch: Processing queries over RDF views of wrapped relational databases,
  1st International Workshop on Wrapper Techniques for Legacy Systems, WRAP 2004, Delft, Holland, November 2004.

Teaching

Studies

2006

2005

2004