Senior Lecturer in Database and Semantic Technologies

I am an Associate Professor (Universitetslektor, Docent) at the Department of Computer and Information Science of Linköping University.

I hold a Ph.D. in Computer Science from the Humboldt-Universität zu Berlin, and worked previously as a postdoctoral research fellow at the Cheriton School of Computer Science at the University of Waterloo and, thereafter, at the Hasso Plattner Institute, Potsdam.

I am interested in problems related to the management of data and databases. My focus in this broad context is on data on the Web and on graph data, as well as on problems in which the data is distributed over multiple, autonomous and/or heterogeneous sources. Regarding these topics, my interests range from systems-building related research (e.g., efficient storage of data, query processing, and query optimization) all the way to theoretical foundations (e.g., complexity and expressive power of query languages).

I was honored with the SWSA Distinguished Dissertation Award in 2015 for my Ph.D. dissertation "Querying a Web of Linked Data: Foundations and Query Execution," and with the 2019 SWSA Ten-Year Award for my paper "Executing SPARQL Queries over the Web of Linked Data" which pioneered the idea of traversal-based query execution as well as querying Linked Data on the Web in general. Additionally, I have received five best research paper awards (ESWC 2009, ESWC 2015, ISWC 2017,SEMANTiCS 2018, SEMANTiCS 2019).

I am leader or contributor of several open source projects, most notably SQUIN, which is a novel query processing system for the Semantic Web. I co-organized international research workshops, served on multiple program committees, and participated as an invited expert in the provenance incubator group and the provenance working group of the World Wide Web Consortium.

For more detailed information on research, teaching, and services, please see

Research groups

The Database and Web Information Systems Group (of ADIT at IDA)

Semantic Web Research Group (at IDA)

Sports Analytics Research Group (at IDA)

PublicationsShow/Hide content



Olaf Hartig (2019) Foundations to Query Labeled Property Graphs using SPARQL Joint Proceedings of the 1st International Workshop On Semantics For Transport and the 1st International Workshop on Approaches for Making Data Interoperable co-located with 15th Semantics Conference (SEMANTiCS 2019), Karlsruhe, Germany, September 9, 2019

TeachingShow/Hide content

I am course leader and sole lecturer of the basic database technology courses;

Additionally, I am teaching some lectures in a number of other courses;

Advanced Data Models and Databases (TDDD43)
Information Security (TDDD17)
Perspectives in Computer and Software Technology (TDDE25)

Curriculum vitaeShow/Hide content

Selected PublicationsShow/Hide content

Olaf Hartig, Jorge Pérez (2017)

Proceedings of the 11th Alberto Mendelzon International Workshop on Foundations of Data Management and the Web. Continue to DOI

Olaf Hartig, Jorge Perez (2016)

Journal of Web Semantics , Vol.41 Continue to DOI

Olaf Hartig, M. Tamer Ozsu (2016)

SEMANTIC WEB - ISWC 2016, PT I , s.305-324 Continue to DOI

About the divisionShow/Hide content

About the departmentShow/Hide content