It works on my database - Regression testing of SQL queries
SQL queries often lack systematic testing - they’re treated as “just glue code” that only gets validated in production. Meanwhile, PostgreSQL itself has used robust regression testing for decades to prevent disasters in core development. This talk introduces RegreSQL, a tool that brings the same regression testing methodology to application queries, catching both correctness bugs and performance regressions before deployment.
We’ll explore how RegreSQL tests SQL queries systematically: verifying correctness across schema changes, tracking performance baselines, detecting common query plan issues (sequential scans, missing indexes), and managing reproducible test data. You’ll see live demonstrations of catching real-world issues - from missing indexes that cause production slowdowns to ORM-generated queries that perform sequential scans on millions of rows.
Whether you write raw SQL or use ORMs, whether you’re maintaining legacy systems or building greenfield applications, this talk will show you practical techniques for making your PostgreSQL queries testable, maintainable, and production-ready.
Target Audience:
- Application developers who work with PostgreSQL daily
- Teams struggling with SQL-related production incidents
- DBAs looking to improve query quality from development teams
While the talk introduces RegreSQL as an open source project, it’s meant to open discussion on the wider topics of improving developer experience and stability of production deployments in database applications backed by PostgreSQL.