Liat Peterfreund ליאת פטרפרוינד

I am a CNRS researcher (chargée de recherche) at LIGM, Paris-Est University.

My research focuses on the foundations of data management. I am interested in studying real-life problems through the lens of well-defined and elegant mathematical formulations.

I am currently working on various aspects of graph query languages, and novel approaches for handling incomplete information.

I have completed my Ph.D. in August 2019 under the supervision of Prof. Benny Kimelfeld at the Computer Science Department, Technion. My Ph.D. dissertation deals with the complexity of queries for information extraction -- relational queries on data that is extracted from text. After my Ph.D., I was a postdoc at IRIF (Paris Diderot University) and in the Valda team at École Normale Supérieure Paris, hosted by Prof. Leonid Libkin, and funded also by DIM Math Innov and FSMP.

My complete and updated publication list can be found in my dblp entry. In addition, I have a page on google scholar.

If you are interested in my research or looking for an academic advisor, please contact me!

Contact: name.surmame "at"

Université Paris EST, Marne-la-Vallée

LIGM, Bât Copernic, 5 Bd Descartes. 77454 Marne-la-Vallée.

Cover photo: Haifa, my hometown. My photo was taken by Jean-Charles Caslot.

News (Winter 2022/3)

  • I will serve as a PC member of PODS 2024

  • I have three new papers that were accepted to PODS 2023 and will be presented in Seattle on June

    • SQL Nulls and Two-Valued Logic written with Leonid Libkin, questions the choice of SQL to use three-valued Kleene's logic to handle nulls, and shows it could have been avoided and replaced by standard Boolean logic, hence resolving a source of confusion for programmers and researchers.

    • Querying Incomplete Numerical Data: Between Certain and Possible Answers written with Marco Console and Leonid Libkin, studies queries over numerical data (i.e., queries that include aggregates, comparisons, function applications, etc.) on incomplete databases. It presents and studies a novel intermediate notion that lies between possible and certain answers (which are often meaningless when it gets to such expressive queries) based on assumed prior knowledge given as probability distributions.

    • GPC: A Pattern Calculus for Property Graphs written with Nadime Francis, Amelie Gheerbrant, Paolo Guagliardo, Leonid Libkin, Victor Marsault, Wim Martens, Filip Murlak, Alexandra Rogova, and Domagoj Vrgoc is the result of a long-term effort to standardize GQL, a new standard for graph query languages. The paper presents pattern calculus for the property graph model (in which edges and nodes are enriched with labels and properties), defines its typing system and formal semantics, and presents some preliminary complexity results.

  • In the upcoming academic year, I will be teaching the course Web Data Management in the MPRI program.

  • I presented our paper Revisiting Semiring Provenance for Datalog in KR 2022, with Camille Bourgaux, Pierre Bourhis, and Michaël Thomazo.

  • I was invited to give a talk in the FloC 2022 Mentoring Workshop. My talk was about logic-based approaches in data management (or, less formally, how to find the balance between our curiosity and practical needs).

Publications My DBLP and Google Scholar pages

GPC: A Pattern Calculus for Property Graphs

with N.Francis, A.Gheerbrant, P.Guagliardo, L.Libkin, V.Marsault, W.Martens, F.Murlak, A.Rogova, D.Vrgoc


Querying Incomplete Numerical Data: Between Certain and Possible Answers

with Marco Console, Leonid Libkin.


SQL Nulls and Two-Valued Logic

with Leonid Libkin.


with Camille Bourgaux, Pierre Bourhis, and Michaël Thomazo.


with Ami Paz.

INVITED TO Theoretical Computer Science SPECIAL ISSUE


with Dominik D. Freydenberger.


INVITED TO Discrete Applied Mathematics SPECIAL ISSUE


with Benny Kimelfeld, Ester Livshits.


with Johannes Doleschal, Benny Kimelfeld, Wim Martens.

INVITED TO Logical Methods in Computer Science SPECIAL ISSUE



with Dominik D. Freydenberger, Benny Kimelfeld, Markus Kröll.


with Balder ten Cate, Ronald Fagin, Benny Kimelfeld.


with Dominik D. Freydenberger, Benny Kimelfeld.



with Benny Kimelfeld, Ester Livshits.


with Yoav Nahshon Stijn Vansummeren.





While at the Technion, I was a TA in several courses:

  • Automata and Formal Languages

  • Logic and Set Theory

  • Database Management Systems

Academic Activity

  • PC Member of the 43rd Symposium on Principles of Database Systems (PODS) 2024.

  • PC Member of the 26th International Conference on Database Theory (ICDT) 2023.

  • PC Member of the 4th International Workshop on the Resurgence of Datalog in Academia and Industry (Datalog 2.0) 2022.

  • PC Member of the 38th French conference on Data Management BDA 2022.

  • PC Member of the 25th International Conference on Database Theory (ICDT) 2022.

  • PC Member of the 30th annual EACSL Conference on Computer Science Logic (CSL) 2022.

  • PC Member of the 40th Symposium on Principles of Database Systems (PODS) 2021.

  • Reviewing ICDT, IPEC, Acta Informatica, and Mathematical Reviews.

Other Activity

Scholarships and Awards

  • L'Oréal-UNESCO Prize for Young Talents, 2020.

  • FSMP Postdoctoral Scholarship, 2020 and 2021.

  • DIM Math Innov Postdoctoral Fellowship, 2019.

  • Zuckerman Postdoctoral Scholarship (declined), 2019.

  • Eric and Wendy Schmidt Postdoctoral Fellowship, 2018.

  • Hiroshi Fujiwara Cyber Security Research Grant, 2018.

  • IBM PhD Fellowship, 2017.

  • CS Excellence Scholarship (Computer Science Department, Technion), 2016.

  • Best Paper Award, WebDB16, 2016.

  • Excellence in Teaching Award (Technion), 2014.


Writing a Curriculum Vita

by Wislawa Szymborska (translated from Polish by Grazyna Drabik and Austin Flint)