Research that stands the test of time is rare. This year, Mahmoud Abo Khamis, Hung Q. Ngo, and Atri Rudra received the 2026 Alberto O. Mendelzon Test-of-Time Award at PODS 2026 in Bengaluru, India, recognizing work whose influence has only grown over the past decade.

Presented annually, the Alberto O. Mendelzon Test-of-Time Award honors a paper published in the ACM Symposium on Principles of Database Systems (PODS) proceedings ten years earlier that has had the greatest impact over the intervening decade—through research, methodology, or transfer into practice. The 2026 selection committee—Wang-Chiew Tan of Google (chair), George Fletcher of Eindhoven University of Technology, and Frank Neven of Hasselt University—selected a single paper for this year's award.

Abo Khamis, Ngo, and Rudra were recognized for FAQ: Questions Asked Frequently (PODS 2016), which introduced the Functional Aggregate Query (FAQ) framework. Rather than treating relational query processing, constraint satisfaction, probabilistic graphical models, and algebraic computation as separate disciplines, the paper revealed a common mathematical structure underlying them all. That unifying perspective gave researchers across multiple communities a shared language—and a foundation for exchanging ideas that had previously evolved in isolation.

The paper also introduced InsideOut, an algorithmic framework for efficiently evaluating Functional Aggregate Queries. Together, FAQ and InsideOut have shaped a decade of research in query optimization and computational reasoning. At RelationalAI, the FAQ framework forms the foundation of a key component of the company's query optimizer.

In its citation, the committee describes the paper as "a quintessential example" of research whose importance has increased over time. Rather than solving only a timely technical challenge, the committee notes, FAQ established a way of thinking that continues to guide the field. Its lasting influence is reflected in extensive follow-on research, continued citations, and its enduring relevance to modern database systems—an impact first recognized with the PODS 2016 Best Paper Award.

Hung Q. Ngo is VP of Research at RelationalAI, where he works on the company's query optimizer.

Mahmoud Abo Khamis is a professor at the University of Oxford and a former researcher at RelationalAI.

Atri Rudra is a professor of computer science at the University at Buffalo, SUNY.

Congratulations to Mahmoud, Hung, and Atri on this well-deserved recognition.

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As of August 11, 2026, the full content of the paper could be found here. All rights reserved.