When Good Queries Go Bad: Fixing Performance with Query Store

Have you ever had a query that performed well one day and suddenly slowed down the next, with no obvious reason? When queries generate multiple execution plans, relying only on the plan cache makes it difficult to understand what changed, when it changed, or which plan is truly optimal. Performance troubleshooting quickly turns into guesswork.

Query Store removes that uncertainty by capturing a history of queries and execution plans over time. It allows you to identify performance regressions, understand plan changes, and take targeted action to stabilize performance.

This session is designed for developers, DBAs, and anyone who works with SQL Server or Azure SQL Database and wants better insight into query performance. Whether you are new to Query Store or looking to use it more effectively, this session will help you gain confidence in using it.

What will be covered:
1. Query Store fundamentals and key benefits
2. Tracking query and execution plan history
3. Identifying and resolving performance regressions
4. Monitoring performance with built-in reports
5. Forcing and unforcing execution plans
6. Automatic plan correction and best practices

Live demos will show how Query Store helps move from performance guesswork to confidence.

1. Understand how Query Store captures query and execution plan history to identify performance regressions 2. Learn how to analyze, force, and manage execution plans to stabilize query performance 3. Gain practical experience using Query Store features to troubleshoot and optimize SQL Server workloads