Database Theory and Engineering Lab

Welcome to the Database Theory and Engineering Lab (DT&E lab) at the Department of Computing and Software, McMaster University. The DTELab is focused on innovative database research on foundational technologies for future databases, with a strong combined focus on the intersection of theoretical and engineering challenges in the areas of data management and transaction processing.

Our current research projects focus on distributed data management (with a particular focus on resilience and trust), on graph data (with a particular focus on graph query optimization), and, in general, high-performance data management.

News

2025

June 2: Celine was awarded an Ontario Graduate Scholarship (OGS) to support her PhD studies in the 2025-2026 academic year.
May 27: Celine successfully defended her Comprehensive Exam II.
May 13: Jelle received a Best Program Committee Member Award award for his work in the program committee of the 41th IEEE International Conference on Data Engineering (ICDE 2025), 🇭🇰.
May 2: Nancy successfully defended her Comprehensive Exam II.
April 3: Jelle was granted a generous cloud allocation to support the research in this lab from the Digital Research Alliance of Canada as part of the Resources for Research Groups 2025 competition.

2024

December 12: Nancy presented our work on eliminating the primary bottleneck in primary-backup consensus at the second Ontario DataBase Day (OnDBD 2024), 🇨🇦 Canada.
December 12: Celine presented our work on alternatives for consensus at the second Ontario DataBase Day (OnDBD 2024), 🇨🇦 Canada.
October 9: Our paper Explaining results of path queries on graphs: Single-path results for context-free path queries (DOI: 10.1016/j.is.2024.102475, author copy, project page) was accepted for publication in Information Systems (Elsevier).
September 25: Ning successfully completed her Master Project.
August 7: Nancy successfully defended her Comprehensive Exam I.
June 30: Celine was awarded an Ontario Graduate Scholarship (OGS) to support her PhD studies in the 2024-2025 academic year.
May 15: Our paper SpotLess: Concurrent Rotational Consensus Made Practical through Rapid View Synchronization (DOI: 10.1109/ICDE60146.2024.00157) in collaboration with the Exploratory Systems Lab was accepted at the the 40th IEEE International Conference on Data Engineering, Utrecht, 🇳🇱 the Netherlands.
April 25: Jelle presented a Lighting Talk at McMaster University titled Do Programming Languages need Query Languages? (slides).
April 8: Our research group celebrated the 2024 Solar Eclipse outside our office!
April 7: Jelle received a Research Track Best Reviewers award for his work in the research program committee of the 39th IEEE International Conference on Data Engineering (ICDE 2023), 🇺🇸 USA.
February 22: Celine successfully defended her Comprehensive Exam I.
February 20: Jelle presented an invited talk at The ODIn Lab at the University at Buffalo, 🇺🇸 USA, mtitled Do Programming Languages need Query Languages? (slides)
February 13: Maryam successfully defended her Comprehensive Exam I.

2023

December 12: Jelle presented (slides) his work on the integration of high-level query capabilities in low-level programming languages at the first Ontario DataBase Day (OnDBD 2023), 🇨🇦 Canada.
June 30: Celine was awarded an Ontario Graduate Scholarship (OGS) to support her PhD studies in the 2023-2024 academic year.
April 25: Jelle presented a seminar in the DSG Seminar Series at Waterloo University titled Resilient Data Management Systems: Challenges and Opportunities (slides).
June 27: Jelle presented our paper Expressive Completeness of Two-Variable First-Order Logic with Counting for First-Order Logic Queries on Rooted Unranked Trees (DOI: 10.1109/LICS56636.2023.10175828, author copy, slides, poster) at the the 38th Annual ACM/IEEE Symposium on Logic in Computer Science (LICS 2023), Boston, 🇺🇸 USA.
April 27: Our paper Byzantine Cluster-Sending in Expected Constant Cost and Constant Time (DOI: 10.5070/SR33161345, author copy, project page) was accepted for publication in the Journal of Systems Research (eScholarship).
April 27: Our paper Cerberus: Minimalistic Multi-shard Byzantine-resilient Transaction Processing (DOI: 10.5070/SR33161314, author copy) was accepted for publication in the Journal of Systems Research (eScholarship).
April 13: Jelle was granted an NSERC Discovery Grant for our proposal titled Toward simple, performant resilient data management. This grant will support our ongoing and future research toward the development of high-performance resilient data management systems.
March 21: Our paper ByShard: sharding in a Byzantine environment (DOI: 10.1007/s00778-023-00794-0, author copy, project page) was accepted for publication in The VLDB Journal (Springer).
March 9: Our lab contributes to a project to build a digital community for global entrepreneurs. We refer to the news article for more information on the project.
January 19: Our 🇺🇸 Patent Application Multi-Shard transactions in a Byzantine Computing Environment of Mohammad Sadoghi, Jelle Hellings, Suyash Gupta, and Sajjad Rahnama has been published. See US-20230019637-A1 for more details.

2022

June 21: Jelle presented our paper The fault-tolerant cluster-sending problem (DOI: 10.1007/978-3-031-11321-5_10, author copy, slides) at the 12th International Symposium on Foundations of Information and Knowledge Systems (FoIKS 2022), Helsinki, 🇫🇮 Finland.
June 20: Jelle presented our paper Optimizing multiset relational algebra queries using weak-equivalent rewrite rules (DOI: 10.1007/978-3-031-11321-5_11, author copy, slides) at the 12th International Symposium on Foundations of Information and Knowledge Systems (FoIKS 2022), Helsinki, 🇫🇮 Finland.
January 4: Our paper The power of Tarski's relation algebra on trees (DOI: 10.1016/j.jlamp.2022.100748, author copy, project page) was accepted for publication in the Journal of Logical and Algebraic Methods in Programming (Elsevier).

Current Members

	Jelle Hellings Lead Investigator Personal Website.
	Celine Sana PhD Student (September 2022-present) Personal Website, LinkedIn. Celine is a PhD student in Computer Science at McMaster University working on novel alternatives to Byzantine fault-tolerant consensus.
	Nancy Kansal PhD Student (January 2023-present) Personal Website. Nancy is a PhD student in Computer Science at McMaster University working on improving primary-backup consensus.
	Mingzhe Wang MSc Student (May 2023-present) LinkedIn. Mingzhe is a MSc student in Computer Science at McMaster University working on automated tooling to objectively compare query plans generated by multiple relational database management products.
	Yuchen You Undergraduate Researcher (July 2023-May 2024) and MSc Student (September 2024-present) Yuchen is a MSc student in Computer Science at McMaster University working on efficient algorithms to evaluate and explain the results of complex Datalog queries.

Former Members

	Ning Wang MEng Student (July 2023-September 2024). Ning completed her work on the parallelization of temporal joins.
	Maryam Valian PhD Student (September 2022-November 2024). Maryam worked on novel practical techniques to produce high-quality query plans.