While this is generally true I doubt there’s many cases if at all where joining distinct data as separate rows over joining as separate columns will yield a performance boost. That’s something I’d only start touching as one of the later options once a query in question was proven to be a hotspot. Foreign keys on primary keys of other tables are hella fast, because the primary key is the the primary way to look up information on that table. It’s afaik always indexed and basically the first thing any db engine will make sure is fast.
