IMFD researchers stand out at SIGMOD/PODS 2025

The Millennium Institute for Foundational Research on Data (IMFD) had a remarkable participation at the 2025 edition of the prestigious international conference ACM SIGMOD/PODS, one of the world’s leading forums for database research.
“The participation of IMFD researchers strengthens the institute’s positioning in the development of theoretical foundations, computational tools, and applications in data management and analysis, consolidating the presence of research conducted in Chile at the frontier of international data science research,” highlights Cristián Riveros, IMFD Researcher and academic at the Department of Computer Science of the Pontificia Universidad Católica de Chile.

Riveros’ team presented the demo paper “CORE+: A Complex Event Recognition Engine in C++”, a tool that shows promising results for tackling one of the most challenging problems in computing today: complex event recognition (CER) in continuous real-time data streams.

“This type of analysis is crucial in sectors such as cybersecurity, logistics, and predictive maintenance, where detecting critical situations immediately can make all the difference. Our proposal is based on a research prototype called CORE that we had already tested, and it adds new capabilities, optimizations, and features that turn it into a mature, production-ready version,” highlights Cristián Riveros. The development of Core+ involved Kyle Bossonney, from Oxford University; Stijn Vansummeren, from the University of Hasselt; and Nicolás Buzeta, Vicente Calisto, and Juan-Eduardo López, all from Universidad Católica de Chile and IMFD.

IMFD Research Presented at SIGMOD/PODS

In “Towards Tractability of the Diversity of Query Answers: Ultrametrics to the Rescue“, another of the papers presented at SIGMOD/PODS, the researchers propose an approach based on ultrametrics to construct diverse query answers. “Given the massive volumes of information handled today, a simple query can have millions of results. The idea is to be able to present the user with a small, representative, and diverse selection of possible answers, reflecting the variety of the full set of possible answers,” explains Riveros. This research involved Timo Merkl and Reinhard Pichler, both from TU Wien; and Cristian Riveros and Marcelo Arenas, both from Universidad Católica de Chile and IMFD researchers.

The paper “Complex Event Recognition meets Hierarchical Conjunctive Queries” by Dante Pinto and Cristian Riveros, both from Pontificia Universidad Católica de Chile, combines two key areas: Complex Event Recognition (CER) and Hierarchical Conjunctive Queries (HCQ). Through a new parallelized automata model (PCEA), the study manages to efficiently express a wide range of sequential patterns with desirable algorithmic properties for real-time processing.

In “Complex Event Recognition under Time Constraints: Towards a Formal Framework for Efficient Query Evaluation” by Cristian Riveros and Julián García, both from Universidad Católica de Chile and IMFD, a formal model is proposed to study how to evaluate queries over event streams with time constraints. The work introduces a logic extended with temporal operators and a clock-based automaton model, achieving efficient evaluation under specific conditions.

Notable recognition

Meanwhile, Pablo Barceló, a faculty member at the Institute of Mathematical and Computational Engineering of Universidad Católica de Chile and IMFD researcher, also received the Distinguished Paper Award for the work, also presented at PODS, “Explaining k-Nearest Neighbors: Counterfactual and Abductive Explanations”, which explores explanatory foundations for widely used machine learning models. The paper was developed together with Alexander Kozachinskiy (Universidad Católica de Chile), Miguel Romero (Universidad Católica de Chile), Bernardo Subsercaseaux (Carnegie Mellon University), and Jose Verschae (Universidad Católica de Chile)