Short Bio

I am a computer-scientist and full-time professor at the Software Languages Lab of the Vrije Universiteit Brussel (VUB). My research primarily focuses on fundamental questions in the area of data systems and query languages, with a particular interest in the formal underpinnings of data management at scale. The latter incudes systems and applications for data management and data-intensive computations that make use of parallelization and data-partitioning, or involve machines with a high degree of autonomy.
Specific research topics include:

  • Concurrency theory for database transactions
  • Optimal query evaluation in distributed systems
  • Coordination needs of algorithms in asynchronous systems

Bio: I obtained a Ph.D. from Hasselt University in 2017 under the advice of Frank Neven and was a postdoctoral researcher at the Swiss Federal Institute of Technology in Lausanne (EPFL) where I worked with Christoph Koch. I did internships at the University of Washington in Seattle, the University of Wisconsin in Madison, and the technical University of Dortmund.

More: Institutional Page · LinkedIn · X · ResearchGate · ORCID · Math Genealogy

Interested in collaborating, or in doing a PhD/postdoc in our group? Send an E-mail! Internships and research visits are also possible.

News

  • Two of our papers got accepted at ICDT26
  • Two new researchers joined our team: Welcome Avi and Sampriti!
  • Tim Baccaert recently got the chance to visit the university of California - Berkeley for several months, to work with prof. Hellerstein. He also obtained an FWO travelgrant for this research stay.
  • Dr. Heba Mohamed obtained a prestigious FWO postdoctoral fellowship.

Awards

Recent Publications

  • (to appear)
    Heba Mohamed, Xiao Hu, Bas Ketsman. Neither Cover nor Pack: Distributed WCO of Degree-2 Joins. In: 28th International Conference on Database Theory. 2026.
  • (to appear)
    Tim Baccaert, Brecht Vandevoort, Bas Ketsman. Bounding the Makespan of Transaction Schedules. In: 28th International Conference on Database Theory. 2026.
  • IS 2026
    Tim Baccaert, Bas Ketsman. A Generalized CALM Theorem for Non-Deterministic Computation in Asynchronous Distributed Systems. In: Information Systems. 2026. Volume 138 No 102691. DOI:10.1016/j.is.2026.102691.
  • PVLDB 2025
    Brecht Vandevoort, Alan D. Fekete, Bas Ketsman, Frank Neven, Stijn Vansummeren. Using Read Promotion and Mixed Isolation Levels for Performant Yet Serializable Execution of Transaction Programs. In: Proceedings of the VLDB Endownment. 2025. Volume 18 No 9. DOI:10.14778/3746405.3746412.
  • TOCL 2025
    Bas Ketsman, Frank Neven, Brecht Vandevoort. Parallel-Correctness and Transferability for Conjunctive Queries under Bag Semantics. In: ACM Transactions on Computational Logic. 2025. Volume 26 No 2. DOI:10.1145/3712291.
More: Full list of publications · List of talks

Teaching Activities

  • Databases / Databanken

    An introduction to relational databases, SQL, RA, ER modeling, normalization, and the basics of data storage, security, cost-based query optimization and access methods.

  • Data and Information Management

    A database-theory course on formal foundations of query languages including expressive power and computational complexity of query evaluation and containment.

  • Scalable Data Management Systems

    A course on scalability aspects of data management, including database concurrency theory, query evaluation in parallel and distributed systems, data partitioning and replication, coordination and synchronization, etc.

  • Advanced Topics in Big Data

    A seminar-style course where students read and present recent research papers on topics from the broad domain of big data, including data management systems, data visualization, and data analytics.

Services

VUB

  • Chair of the exam commission Bachelor in Computer Sciences
  • Department representative in the faculty's commission for follow-up of PhDs (CDO)
  • Research group representative on Open Sciences and Data management
  • Member of the education councils for the Bachelor in Computer Sciences, Bachelor in AI, Master in Computer Sciences, and Master in Applied Computer Sciences

External