The tests passed. The plan didn't.

RegreSQL 2.0 improves over its predecessor by testing database query plans alongside output accuracy, ensuring that performance regressions can be identified even when query results remain unchanged. It leverages real production statistics to better simulate actual database behavior, addresses the hidden issue of plan drift, and ultimately helps developers catch potential problems before they reach production. The post also outlines how RegreSQL measures various plan metrics, ensuring queries run optimally and offering a more accurate testing method for database queries.