Dev-Prod Demon Hunters: Finding the Real Cause of Production Slowness

Production is slow. Development is fast. The same query runs in both. Somewhere between the two, a performance demon is hiding—and this session is about hunting it down.

Inspired by Brent Ozar's love of the K-Pop Demon Hunters theme song, this class is delivered almost entirely as live demos, not slides. Brent Ozar will run real queries against two environments labeled “dev” and “prod,” then work through them exactly the way an experienced DBA would in the real world: comparing server settings, analyzing execution plans, and uncovering the subtle differences that led SQL Server to make different decisions. Each “hunt” reveals another demon—statistics, configuration, data distribution, or plan choice—and shows how easily a test environment can lie.

Along the way, Brent will demonstrate practical techniques you can use immediately: running sp_Blitz to surface meaningful environment differences, comparing execution plans to understand *why* SQL Server behaved differently, and making targeted changes to development so it better reflects production reality. By the end, you’ll understand how to stop guessing, stop blaming the engine, and follow the clues that lead to the truth—because when dev and prod finally move in sync, that’s when performance goes golden.

Discover what caused query plans to vary from production Learn how to quickly assess environment differences that would cause query plan changes Understand how to change dev to more closely match prod