Senior Associate Professor in Computer Science at Linköping University • Amazon Scholar • research on data management topics related to graph data and data on the Web https://olafhartig.dehttps://bsky.app/profile/olafhartig.bsky.socialhttps://bsky.app/profile/olafhartig.bsky.social/post/3me4rnnu4sk2a📣 Postdoc position on Virtual Knowledge Graph Integration at Linköping University I'm looking for a postdoc to actively lead research in two complementary projects on foundations & techniques for querying federations of KG views of heterogeneous data sources. 👉 Further info: https://liu.se/en/work-at-liu/vacancies/2848705 Feb 2026 16:09 +0000at://did:plc:ysktcpw2jia4e32detppdb7d/app.bsky.feed.post/3me4rnnu4sk2ahttps://bsky.app/profile/olafhartig.bsky.social/post/3m7dvadryt22yFinally, our VLDB paper is out: "Exploring Exploratory Querying." — A research vision related to a new way of querying, including new types of users. https://vldb.org/pvldb/volumes/18/paper/Exploring%20Exploratory%20Querying This paper is the result of discussions we had during a Shonan meeting late last year.06 Dec 2025 20:56 +0000at://did:plc:ysktcpw2jia4e32detppdb7d/app.bsky.feed.post/3m7dvadryt22yhttps://bsky.app/profile/olafhartig.bsky.social/post/3lquralbil22iSuper glad to receive the Best Research Paper Award at #ESWC2025 together with Sitt Min Oo for our work on providing a formal foundation for mapping languages for Knowledge Graph construction.05 Jun 2025 16:42 +0000at://did:plc:ysktcpw2jia4e32detppdb7d/app.bsky.feed.post/3lquralbil22ihttps://bsky.app/profile/olafhartig.bsky.social/post/3lqsmp43zrs2mThe @liu.se Semantic Web gang at the #ESWC2025 conference.04 Jun 2025 20:15 +0000at://did:plc:ysktcpw2jia4e32detppdb7d/app.bsky.feed.post/3lqsmp43zrs2mhttps://bsky.app/profile/olafhartig.bsky.social/post/3lnbgzdmwxs2lRelated to our approach to represent and to query lists as composite values in RDF-based Knowledge Graphs, I developed a tool to convert RDF files in which lists are represented as RDF collections (rdf:List) into files that use our cdt:List approach. Repo and download: https://github.com/hartig/SPARQL-CDT-Tools20 Apr 2025 20:03 +0000at://did:plc:ysktcpw2jia4e32detppdb7d/app.bsky.feed.post/3lnbgzdmwxs2lhttps://bsky.app/profile/olafhartig.bsky.social/post/3llbeoolxds2mSo far, declarative mapping languages for knowledge graph construction (RML and the likes) have lacked a solid formal foundation 😶‍🌫️ ⚡ Our latest work, accepted for #ESWC2025, changes that: We introduce an algebra for mappings, provide a formal semantics for RML, and more. 🔎 arxiv.org/abs/2503.10385 https://arxiv.org/abs/2503.1038526 Mar 2025 08:31 +0000at://did:plc:ysktcpw2jia4e32detppdb7d/app.bsky.feed.post/3llbeoolxds2mhttps://bsky.app/profile/olafhartig.bsky.social/post/3lkpq7sfm522b📣 We are looking to expand the Program Committee for this year's CoopIS conference and are calling for self- nominations. If interested, please nominate yourself: https://forms.gle/CYGYkeqVDBLRwPcRA ✍️ ℹ️ More info about CoopIS'25, the 31st Int. Conf. on Cooperative Information Systems: coopis.scitevents.org https://coopis.scitevents.org/19 Mar 2025 08:09 +0000at://did:plc:ysktcpw2jia4e32detppdb7d/app.bsky.feed.post/3lkpq7sfm522bhttps://bsky.app/profile/olafhartig.bsky.social/post/3lk6u4zpeu222In a recent #Dagstuhl seminar we developed a research roadmap towards Computer-Using Personal Agents (CUPAs), automating complex tasks like today's Computer-Using Agents, but including context via controlled access to personal knowledge graphs. Our vision paper: https://openaccess.city.ac.uk/id/eprint/34788/12 Mar 2025 15:04 +0000at://did:plc:ysktcpw2jia4e32detppdb7d/app.bsky.feed.post/3lk6u4zpeu222https://bsky.app/profile/olafhartig.bsky.social/post/3ljfdxtwv3k2pI just saw that DBLP (@dblp.org) has recently started to provide a public query service for everyone to run SPARQL queries over their database with information about computer science publications. Each author page includes links to relevant example queries. Very nice! https://blog.dblp.org/2024/09/09/introducing-our-public-sparql-query-service/02 Mar 2025 11:38 +0000at://did:plc:ysktcpw2jia4e32detppdb7d/app.bsky.feed.post/3ljfdxtwv3k2phttps://bsky.app/profile/olafhartig.bsky.social/post/3lgnsib7wlk2eArrived at Castle Dagstuhl for a week of discussions around "Trust and Accountability in Knowledge Graph-Based AI for Self Determination" www.dagstuhl.de/2505126 Jan 2025 16:04 +0000at://did:plc:ysktcpw2jia4e32detppdb7d/app.bsky.feed.post/3lgnsib7wlk2ehttps://bsky.app/profile/olafhartig.bsky.social/post/3lbg6bjkaz224Interested in translating from the recently-standardized graph database language GQL to Gremlin ? Next Monday (Nov.25), the Tinkerpop community has a talk for you. https://discord.gg/tinkerpop?event=130812602581254562821 Nov 2024 00:07 +0000at://did:plc:ysktcpw2jia4e32detppdb7d/app.bsky.feed.post/3lbg6bjkaz224https://bsky.app/profile/olafhartig.bsky.social/post/3lbded2uj322gI have heard the waters here are calmer. Ready to start new.19 Nov 2024 21:18 +0000at://did:plc:ysktcpw2jia4e32detppdb7d/app.bsky.feed.post/3lbded2uj322g