Hangdong Zhao PhD’25 Wins 2026 ACM SIGMOD Jim Gray Doctoral Dissertation Award, a First for UW-Madison
The Department of Computer Sciences is proud to announce that Hangdong Zhao PhD ’25, advised by Professor Paris Koutris, has been selected as a winner of the 2026 ACM SIGMOD Jim Gray Doctoral Dissertation Award for his dissertation Advancing Join Algorithms for Real-world Queries. This marks the first time a graduate of UW-Madison has received this honor, one of the most prestigious dissertation awards in the field of database research.
Presented annually by the Association for Computing Machinery’s Special Interest Group on Management of Data (ACM SIGMOD), the Jim Gray Doctoral Dissertation Award recognizes outstanding doctoral research in the database field worldwide. Established in 2006 and renamed in 2008 in honor of Turing Award winner Jim Gray, the award highlights exceptional dissertations that advance the foundations and practice of data management.
Zhao’s dissertation addresses one of the central challenges in databases: how to evaluate join queries efficiently on real-world data. His work develops new algorithmic techniques for query optimization, bridging deep theoretical ideas with practical systems concerns. During his PhD, Zhao’s research received multiple recognitions at top database theory venues, including a Best Paper Award at PODS 2025, a SIGMOD Research Highlight Award, and multiple distinguished paper awards at PODS 2024 and PODS 2023.
Zhao completed his PhD at UW-Madison in 2025 and is now a Senior Researcher at Microsoft’s Gray Systems Lab. His achievement highlights the department’s strength in foundational and systems-oriented data management research.
Congratulations, Hangdong!
The Department of Computer Sciences is proud to announce that Hangdong Zhao PhD ’25, advised by Professor Paris Koutris, has been selected as a winner of the 2026 ACM SIGMOD Jim Gray Doctoral Dissertation Award for his dissertation Advancing Join Algorithms for Real-world Queries. This marks the first time a graduate of UW-Madison has received this honor, one of the most prestigious dissertation awards in the field of database research.
Presented annually by the Association for Computing Machinery’s Special Interest Group on Management of Data (ACM SIGMOD), the Jim Gray Doctoral Dissertation Award recognizes outstanding doctoral research in the database field worldwide. Established in 2006 and renamed in 2008 in honor of Turing Award winner Jim Gray, the award highlights exceptional dissertations that advance the foundations and practice of data management.
Zhao’s dissertation addresses one of the central challenges in databases: how to evaluate join queries efficiently on real-world data. His work develops new algorithmic techniques for query optimization, bridging deep theoretical ideas with practical systems concerns. During his PhD, Zhao’s research received multiple recognitions at top database theory venues, including a Best Paper Award at PODS 2025, a SIGMOD Research Highlight Award, and multiple distinguished paper awards at PODS 2024 and PODS 2023.
Zhao completed his PhD at UW-Madison in 2025 and is now a Senior Researcher at Microsoft’s Gray Systems Lab. His achievement highlights the department’s strength in foundational and systems-oriented data management research.
Congratulations, Hangdong!