Oliver Irwin

I am currently a postdoctoral researcher at TU Ilmenau, where I work in the Algorithms team led by Christoph Berkholz.

My research lies at the intersection of database theory, knowledge compilation, and query evaluation. In particular, I am interested in direct access to query answers, worst-case optimal join algorithms, and uniform sampling for database queries.

A recurring theme of my research is the design of algorithmic tools and proofs that are not only efficient, but also simple and readable. I am also interested in extending my current results on direct access and worst-case optimal joins to dynamic databases.

Previously, I completed my PhD in Computer Science at the University of Lille, where I worked primarily with Florent Capelli and Sylvain Salvati in the D-DAL () team. My PhD was part of the KCODA project funded by the French ANR.

If you like ducks (and automata), you can also have a look at Charles Paperman

selected publications

LMCS

Direct Access for Conjunctive Queries with Negations

Florent Capelli, Nofar Carmeli, Oliver Irwin, and Sylvain Salvati

Logical Methods in Computer Science, Mar 2026

arXiv Bib PDF

@article{capelli2026dacqnlong,
  title = {Direct Access for Conjunctive Queries with Negations},
  author = {Capelli, Florent and Carmeli, Nofar and Irwin, Oliver and Salvati, Sylvain},
  url = {https://lmcs.episciences.org/14733},
  doi = {10.46298/lmcs-22(1:24)2026},
  journal = {Logical Methods in Computer Science},
  issn = {1860-5974},
  volume = {Volume 22, Issue 1},
  eid = {24},
  year = {2026},
  month = mar,
  keywords = {Databases},
}

ICDT

A Simple Algorithm for Worst Case Optimal Join and Sampling

Florent Capelli, Oliver Irwin, and Sylvain Salvati

In 28th International Conference on Database Theory (ICDT 2025), March 25 to March 28, 2025, Barcelona, Spain, Mar 2025

Bib PDF Details

@inproceedings{capelli2025sawcojs,
  author = {Capelli, Florent and Irwin, Oliver and Salvati, Sylvain},
  title = {{A Simple Algorithm for Worst Case Optimal Join and Sampling}},
  booktitle = {28th International Conference on Database Theory (ICDT 2025), March 25 to March 28, 2025, Barcelona, Spain},
  pages = {23:1--23:19},
  series = {Leibniz International Proceedings in Informatics (LIPIcs)},
  isbn = {978-3-95977-364-5},
  issn = {1868-8969},
  year = {2025},
  month = mar,
  volume = {328},
  editor = {Roy, Sudeepa and Kara, Ahmet},
  publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address = {Dagstuhl, Germany},
  url = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ICDT.2025.23},
  urn = {urn:nbn:de:0030-drops-229647},
  doi = {10.4230/LIPIcs.ICDT.2025.23},
  annote = {Keywords: join queries, worst-case optimality, uniform sampling},
  details = {wcojs},
}

ICDT

Direct Access for Conjunctive Queries with Negations

Florent Capelli, and Oliver Irwin

In 27th International Conference on Database Theory, ICDT 2024, March 24 to March 28, 2024, Paestum, Italy, Mar 2024

Awarded Bib PDF Details

Best Newcomer Paper

@inproceedings{capelli2024dacqn,
  title = {Direct {{Access}} for {{Conjunctive Queries}} with {{Negations}}},
  author = {Capelli, Florent and Irwin, Oliver},
  editor = {Cormode, Graham and Shekelyan, Michael},
  year = {2024},
  month = mar,
  pages = {13:1--13:20},
  issn = {1868-8969},
  booktitle = {27th International Conference on Database Theory, {ICDT} 2024, March
                24 to March 28, 2024, Paestum, {Italy}},
  publisher = {Schloss Dagstuhl - Leibniz-Zentrum f{\"{u}}r Informatik},
  url = {https://doi.org/10.4230/LIPICS.ICDT.2024.13},
  doi = {10.4230/LIPICS.ICDT.2024.13},
  isbn = {9783959773126},
  langid = {english},
  keywords = {Conjunctive queries,direct access,factorized databases,hypertree decomposition,Information systems → Relational database model},
  details = {dacqn}
}