Picture of Olaf Hartig Olaf Hartig

Senior Associate Professor (Biträdande professor)
Division for Database and Information Techniques
Department of Computer and Information Science (IDA)
Linköping University

Amazon Scholar
Neptune team at Amazon Web Services

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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).


August 12, 2022: New paper: With my PhD student Sijin Cheng we have a paper titled "LinGBM: A Performance Benchmark for Approaches to Build GraphQL Servers" at WISE 2022. We have made available the PDF file camera-ready version of this paper. Additionally, we have published PDF file an extended version of the paper on arXiv and you may look at PDF file Github repo for LinGBM.

June 17, 2022: I have been promoted to Senior Associate Professor (biträdande professor)!!

June 3, 2022: I received a best reviewer award at ESWC 2022.

May 8, 2022: New paper: With my PhD student Shahrzad Khayatbashi and postdoc Sebastian Ferrada we have a paper titled "Converting Property Graphs to RDF: A Preliminary Study of the Practical Impact of Different Mappings" at GRADES 2022. We have made available a PDF file preprint of this paper.

April 24, 2022: I have been invited to serve as Tutorials co-chair of The Web Conference 2023, which will take place in May 2023 in Texas.

April 23, 2022: I have been invited to give a keynote at the DBpedia Day at SEMANTiCS 2022 in Vienna. The title of the keynote will be: "Towards Querying Heterogeneous Federations of Interlinked Knowledge Graphs."

March 7, 2022: I gave a talk titled "Reflections on Linked Data Querying and Other Related Topics" in the DKG/SWSA talk series. There is a recording of the talk and I have uploaded the slides of the talk.

December 21, 2021: It is done! We have published the final community group report of the RDF-star spec.

October 22, 2021: I will serve as Doctoral Consortium co-chair of the 21st International Semantic Web Conference (ISWC), which will take place in October 2022 in Hangzhou, China.

September 8, 2021: Best paper award!! Robin Keskisärkkä, Eva Blomqvist, and I have won the best paper award at the SEMANTiCS Conference 2021. The title of our paper is "Optimizing RDF Stream Processing for Uncertainty Management" (PDF file download a preprint).

September 6, 2021: I have been selected for the Amazon Scholars program! I am hugely excited about the opportunity to spend some of my time working with the AWS Neptune team to advance the state of the art in graph databases and graph database systems.

August 25, 2021: Our community vision "The Future Is Big Graphs: A Community View on Graph Processing Systems" has appeared in The Communications of the ACM. This vision paper is the result of a Dagstuhl seminar on "Big Graph Processing Systems".


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.

Get in Touch

EMail Address: email address

Office: Building B, Ground floor, Room 2B:478

Postal address: Dept. of Computer and Information Science (IDA), Linköpings universitet, SE-581 83 Linköping, SWEDEN