[upmostly]

The N+1 problem basically means instead of making one efficient query, you end up making N separate queries inside a loop. For example, fetching a list of tables, then for each table fetching its columns individually — that’s N+1 queries. It works, but it’s slow.

We ran into this while building, funnily enough, a database management app called DB Pro (https://dbpro.app) At first we were doing exactly that: query for all schemas, then for each schema query its tables, and then for each table query its columns. On a database with hundreds of tables it took ~3.8s.

We fixed it by flipping the approach: query all the schemas, then all the tables, then all the columns in one go, and join them in memory. That dropped the load time to ~180ms.

N+1 is one of those things you only really “get” when you hit it in practice.