Picture of Olaf Hartig Olaf Hartig
Associate Professor (Universitetslektor, docent)
Division for Database and Information Techniques
Department of Computer and Information Science (IDA)
Linköping University

View Olaf Hartig's profile on Google Scholar   View Olaf Hartig's profile on DBLP   Olaf Hartig's Blog   View Olaf Hartig's profile on Github   View Olaf Hartig's profile on Twitter   View Olaf Hartig's profile on Slideshare   View Olaf Hartig's profile on videolectures.net

Research Interests

I am interested in problems related to the management of databases and knowledge. My focus in this broad context is on data on the Web (Semantic Web and Linked Data, in particular) and on graph data, as well as on problems in which the data is distributed over multiple, autonomous and/or heterogeneous sources (keywords: federated data management, federated knowledge graphs). Other keywords that appear in some of my work are data provenance and data quality. Regarding all of these topics, my interests range from theoretical foundations (e.g., complexity and expressive power of query languages) all the way to systems-building related research (e.g., efficient storage of datasets and databases, query processing, and query optimization).

News

March 30, 2021: I have been invited to present the RDF-star approach in the upcoming Knowledge Graph Conference.

March 26, 2021: Together with Pierre-Antoine Champin, we presented the RDF-star approach in a Lotico event. A recording of the presentation can be found on the event page.

February 18, 2021: We have published the first draft of the RDF-star spec.

December 23, 2020: In the RDF* community we are making progress towards an RDF*/SPARQL* community report that provides a specification of the approach.

December 1, 2020: Sijin and I have won the best paper award for our paper "FedQPL: A Language for Logical Query Plans over Heterogeneous Federations of RDF Data Sources" PDF file at the 22nd International Conference on Information Integration and Web-based Applications & Services (iiWAS)!!!

November 9, 2020: I will serve as Doctoral Consortium co-chair of the 25th European Conference on Advances in Databases and Information Systems (ADBIS), which will take place in August 2021 in Tartu, Estonia.

October 2, 2020: New paper: Our research paper "FedQPL: A Language for Logical Query Plans over Heterogeneous Federations of RDF Data Sources" has been accepted to the 22nd International Conference on Information Integration and Web-based Applications & Services (iiWAS). We have made available a PDF file preprint of the paper.

September 24, 2020: I have become working group leader of a newly established COST action about Distributed Knowledge Graphs.

August 28, 2020: The 18th European Semantic Web Conference, ESWC 2021 will feature a new track for replication studies and I will gladly serve as a co-chair of this track.

August 14, 2020: New paper: With Robin Keskisärkkä, Eva Blomqvist, and Leili Lind (all Linköping University) we have a paper titled "Capturing and Querying Uncertainty in RDF Stream Processing" at EKAW 2020. This is the first research work that looks into approaches to consider uncertainty during RDF stream processing. We have made available a PDF file preprint of this paper.

August 6, 2020: Native support for RDF* and SPARQL* has found its way into the following RDF-related programming libraries: Eclipse RDF4J, Apache Jena, RDF.rb, and N3.js.

April 23, 2020: Two more commercial RDF triple store vendors have announced that their systems support the RDF*/SPARQL* approach now; these systems are Stardog and GraphDB. Other RDF graph database systems that have support for RDF* and SPARQL* since a while now are Blazegraph and AnzoGraph.

CV

Here is my academic CV: PDF file

Selected Publications

This following list contains selected publications. There is also a complete list of all my publications.