Speaker:

Hangdong Zhao

Date:

Tue Mar 10, 2026 @ 12:00pm EDT

Date:

Tue Mar 10, 2026

Time:

12:00pm EDT

Location:

GHC 9115

Title:

Bringing Theory to Industry: Early-Career Lessons in Query Optimization

System:

Microsoft SQL Server

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Talk Info:

What does it really take to bring new ideas into a production system? In this talk, I will share some experiences from my first year working on query optimization at Microsoft Azure. I will recount the story of how we discovered that Microsoft SQL Server had, in effect, been executing the Yannakakis algorithm for decades—despite its only recent resurgence in academia. This unexpected alignment between theory and practice became the foundation of our CIDR’26 paper, where we dissect how this classic join algorithm quietly manifested inside industrial engines.

At the same time, industry is undergoing profound changes by AI agents. For the second part of the talk, I will share some latest experiences working on the frontline of production level query optimization, and how agents are rapidly reshaping my workflows. This talk is part technical deep dive and part early-career—perhaps inevitably biased—reflection.

Bio:

Hangdong Zhao is a Senior Researcher at Microsoft Gray Systems Lab, working on production-grade database optimizations. He received his Ph.D. in May 2025 at the University of Wisconsin–Madison, advised by Paris Koutris. Hangdong’s doctoral work is on novel join algorithms of strong theoretical foundations, and how these insights translate into practice; from 2023 to 2025, his work received multiple PODS Best/Distinguished Paper awards. At Microsoft Azure, Hangdong focuses on translating principled theoretical ideas into production. A central theme of his work is narrowing the gap between theory and practice—designing techniques that not only come with formal efficiency guarantees but also integrate robustly into high-performance database engines at cloud scale.