“How did it get late so soon?” Photo by Murray Campbell on Unsplash Performance I recently had a query from a colleague regarding a slow DELETE query on PostgreSQL. On the face of it, it was simple enough. It had no CASCADE, and they were only deleting a few records at a time using a subquery (in the absence of a LIMIT for DELETE). This small batch approach was working, but it was too slow to keep up, resulting in a growing backlog. Before making any changes, I had a look at the performance to r...