Keynote: Can We Finally Query Decentralized Knowledge Graphs?
Pascal Molli
Abstract:
The original idea of the Semantic Web was not only to publish structured data on the Web, but to make decentralized knowledge usable by machines. Linked Data gave this vision a concrete form, and knowledge graphs have since become a major abstraction for organizing, integrating, and exploiting data. However, getting here took a long time, and the resulting Web of Knowledge Graphs is still not a coherent queryable ecosystem. Many datasets, identifiers, vocabularies, and endpoints exist, but discovering, querying, combining, trusting, and governing them across autonomous sources remains difficult.
The rise of LLMs may help users and agents access, organize, and query ecosystems of knowledge graphs, but it does not remove the need for reliable data-management infrastructures underneath.
This talk focuses on the major bottlenecks and opportunities for making decentralized knowledge graphs queryable as a robust ecosystem. Such an ecosystem requires the combination of symbolic queries, approximate discovery, federation, provenance, access control, and LLM-assisted interfaces.
About the speaker: Pascal Molli received his PhD in Computer Science from Nancy University in 1996. He is now Full Professor at University of Nantes and is head of GDD Team. He is working on distributed collaborative systems and more precisely on distributed data management and queries for federated systems. His current research topics are: distributed algorithms for distributed collaborative systems, distributed collaborative systems, federated query processing in Linked Dara.
Workshop Program
DMKG 2026 is a full-day workshop, taking place at October 25, 2026, co-hosted at ISWC 2026 in Bari, Italy. The full workshop schedule is as follows:
| Timing | Content |
|---|---|
| Session 1: Decentralization and Governance | |
| 09:00-09:15 | Welcome and opening |
| 09:15-10:00 | Keynote and Q&A on Can We Finally Query Decentralized Knowledge Graphs?. Pascal Molli |
| 10:00-10:20 | Privacy-Preserving Family Media Profiles in Decentralized Data Ecosystems. Els de Vleeschauwer, Maarten Vandenbrande, Karim Dahdah, Pieter Bonte, Femke Ongenae, Ben De Meester and Pieter Colpaert |
| 10:20-10:40 | A Policy-Aware Data Sharing System Using Solid, Semantic Provenance, and IDS-Inspired Data Governance. Muhammad Raza Naqvi, Antoine Zimmermann and Christoph Braun |
| 10:40-11:10 | Coffee Break |
| Session 2: Federated and Distributed Querying | |
| 11:10-11:30 | Strengthening LargeRDFBench for Interoperable Federated SPARQL Evaluation. Bryan-Elliott Tam, Muhammad Saleem and Ruben Taelman |
| 11:30-11:50 | Cost Characterization of Vertically Partitioned Federated Knowledge Graphs. Md Saikat Islam Khan Bappy and Oshani Seneviratne |
| 11:50-12:10 | Janus: Querying RDF Streams Across Past and Present. Kushagra Singh Bisen, Femke Ongenae and Pieter Bonte |
| 12:10-12:30 | Entry Point Control for Path-Safe Knowledge Graph Exploration. Shuya Higuchi and Natthawut Kertkeidkachorn |
| 12:30-12:50 | Knowledge Graph Consumption Layers. Lars Heling, Munir Abobaker, Richard Detlefs, Hassan el Hajj, Mulang Onando and Felix Sasaki |
| 12:50-14:10 | Lunch |
| Session 3: RDF 1.2, Property Graphs and Integration | |
| 14:10-14:30 | GQL Datatypes as an RDF Vocabulary. Dominik Tomaszuk and Daniel Szałaj |
| 14:30-14:50 | RML 1.2: Aligning RML with RDF 1.2 Triple Terms and Reifying Triples. Julián Arenas-Guerrero, Sebastián Ferrada, Sebastián Vergara and Olaf Hartig |
| 14:50-15:10 | Translating RDF 1.2 Graphs to Property Graphs. Maxime Jakubowski, Dominik Tomaszuk, Daniel Fernandez Alvarez, Jose Emilio Labra Gayo, Ruben Taelman, Ruben Dedecker and Katja Hose |
| 15:10-15:30 | Configuration and Optimization of Knowledge Graph Integration Pipelines. Marvin Hofer, Erhard Rahm and Victor Christen |
| 15:30-15:50 | A Requirement Interpretation Agent for Formalizing Quality Requirements in Enterprise Knowledge Graphs. Narciso Arruda Jr, Valéria Magalhães Pequeno, Flávio Verissimo Lima, Frederico Ribeiro, Vania Maria Ponte Vidal and Marco Antonio Casanova |
| 15:50-16:20 | Coffee Break |
| Session 4: Validation and Quality | |
| 16:20-16:40 | Extending and Optimizing the rudof SHACL validator. Álvaro García-Fernández, Samuel Bustamante-Larriet, Jose Emilio Labra-Gayo and Oscar Corcho-García |
| 16:40-17:00 | Toward a Comparison Score for the Open Research Knowledge Graph: Modeling Guideline and Metrics. Lena John, Sören Auer and Oliver Karras |
| 17:00-17:20 | sheval: An RDF data shapes evaluation tool and test-suite for recursive shapes. Shqiponja Ahmetaj, Iovka Boneva, Jan Hidders, Maxime Jakubowski, Jose Emilio Labra Gayo, Wim Martens, Filip Murlak, Cem Okulmus, Ognjen Savkovic, Mantas Simkus and Dominik Tomaszuk |
| 17:20-17:40 | From fragmentation to federation: bridging heterogeneous SSH knowledge graphs through query mediation in GRAPHIA. Julien Homo, Kévin Darty, Luca De Santis, Silvio Peroni, Matteo Romanello, Tomasz Hoffmann, Arkadiusz Margraf, Sy Holsinger, Maxim Kupreyev, Ursula Rabar, Florian Lemoine, Yann Le Franc, Jan Wiebelitz and Benjamin Zapilko |
| 17:40-18:00 | Closing and open discussion |
Important Dates
July 10, 2026
July 17, 2026
Abstract deadline
July 17, 2026
July 24, 2026
Paper submission deadline
August 21, 2026
Notification of acceptance
September 11, 2026
Camera-ready version due
October 25 / 26, 2026
Workshop date
Call for Papers
The rapid increase in the adoption of knowledge graphs over the past years, both in the open data domain as well as the industry, means that data management solutions for knowledge graphs today have to support ever increasing amounts of data.
The continously growing KGs resulting from the increasing popularity of semantic technologies highlight the necessity for scalable and efficient solutions for management of knowledge graphs in distributed, federated, and centralized environments.
The DMKG workshop therefore invites novel research and advances in scalable data management solutions for large-scale knowledge graphs. Such data management solutions include techniques for storage and indexing, partitioning for decentralized/centralized systems, archiving and versioning, validation with SHACL/shEx, or federated data management. We welcome a broad range of papers including full research papers, vision papers, negative results, and system demonstrations.
The main goal of the workshop is to bring together both early-stage and established researchers as well as industrial partners in order to facilitate communication and collaboration between partners in different domains on the issues relating to scalable data management techniques for large-scale knowledge graphs.
We seek contributions covering all aspects of data management for knowledge graphs, including, but not limited to, the following topics:
Storage and Management
- Storing and indexing knowledge graphs
- Partitioning knowledge graphs
- Decentralized, distributed and federated knowledge graph storage
- Graph databases and NoSQL
- Archiving and versioning
- Representing knowledge graphs using RDF 1.2
Analytics and Exploration
- Knowledge graph validation (SHACL/shEx)
- Graph schema discovery and exploration
- Large-scale knowledge graph analytics (GraphX, Giraph, Pergel, ...)
Querying and Benchmarking
- Efficient query processing
- Distributed and federated querying over knowledge graphs
- Querying over streaming graphs
- Benchmarking data management systems for knowledge graphs
- Querying knowledge graphs using SPARQL 1.2
Submission Instructions
We welcome a broad range of papers to the DMKG workshop. All papers must be original and not simultaneously submitted to another journal, conference, or workshop. We welcome the following paper categories (page limits include references):
- Research papers (up to 12 pages): Papers presenting significant scientific research pertaining to the topics specified above, incl. vision papers.
- Short papers (up to 6 pages): Position papers, negative results and papers describing systems, libraries, APIs and datasets.
- Demo/poster papers (up to 4 pages): Papers demonstrating systems or scientific results not significant enough for a full research paper.
Submission must be in English and formatted in the style of CEURART by CEUR-WS. For more information on using the CEURART style (single column), please visit the author guidelines. We accept PDF submissions.
Papers must be submitted via the following EasyChair link no later than July 24th at 23:59 Anywhere on Earth (UTC-12). All submissions will be reviewed by members of the program committee. Papers will be evaluated according to their significance, novelty, originality, technical contributions, writing style, clarity, and relevance the the topics of the workshop.
Organizing Committee
The workshop is organized by the following people.
Assistant Professor, Ghent University
Ruben is an Assistant Professor at IDLab, imec, Ghent University with a focus on investigating decentralized Web querying and publication techniques for Linked Data. He leads a team of researchers that focuses on querying over Decentralized Knowledge Graphs on the Web, and investigating the trade-offs that exist between server and client.
@rubensworks
Senior Associate Professor, Linköping University
Olaf is a Senior Associate Professor in Computer Science at Linköping University, Sweden. Additionally, he is an Amazon Scholar working with the Neptune graph database team at Amazon Web Services. He is interested in problems related to the management of databases and knowledge, with a focus 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.
@olafhartig
Professor, TU Wien
Katja is a professor in the Institute of Logic and Computation at TU Wien, Austria. She has been a professor in the Department of Computer Science at Aalborg University, Denmark, leading the Data, Knowledge, and Web Engineering group. Prior to joining Aalborg University, she was a postdoc at the Max Planck Institute for Informatics in Saarbrücken, Germany, and earned her PhD in Computer Science from Ilmenau University of Technology, Germany. Her work is rooted in databases and graph technologies and spans theory, algorithms, and applications of data science and knowledge engineering including knowledge graph management, querying, and analytics.
@HoseKatja@katjahose@mastodon.social
Program Committee
The program committee consists of the following people.
| PC Members |
|---|
| Aidan Hogan, DCC, Universidad de Chile |
| Beatriz Esteves, Universidad Politécnica de Madrid |
| Hala Skaf-Molli, University of Nantes - LS2N |
| Maria-Esther Vidal, Technical Information Library Leibniz (TIB) |
| Jesse Wright, Oxford University |
| Maribel Acosta, TU Munich |
| Pascal Molli, University of Nantes - LS2N |
| Pierre-Antoine Champin, W3C |
| Jose Emilio Labra, University of Oviedo, Spain |
| Sebastián Ferrada, DCC, Universidad de Chile |
| Luis Galarraga, INRIA/IRISA |
| Ruben Eschauzier, Ghent University - imec |
| Robin Keskisärkkä, Linköping University |
| Philipp D. Rohde, Leibniz Universität Hannover |
| Andreas Harth, University of Erlangen-Nuremberg and Fraunhofer IIS |
| Carlos Buil Aranda, Philip Morris |
| Andreas Schwarte, metaphacts |
| Dominik Tomaszuk, University of Białystok |
| Pieter Bonte, KU Leuven |
| Oscar Corcho, Universidad Politécnica de Madrid |
| Julián Arenas-Guerrero, Universidad Politécnica de Madrid |
| Daniel Fernandez Alvarez, University of Oviedo |
| Maxime Jakubowski, TU Wien |
| Olivier Curé, Université Gustave Eiffel |
| Anisa Rula, University of Brescia |
| Bryan-Elliott Tam, Ghent University - imec |
