tens of GB is tiny though. most production systems are at least a few hundred gb, and the previously mentioned scaling problems from foreign keys and constrain

tens of GB is tiny though. most production systems are at least a few hundred gb, and the previously mentioned scaling problems from foreign keys and constraints are pretty nonexistent unless you're starting to push the boundaries of normal ACID DBs. i.e. a few TB of data with at least thousands of queries per second and lots of writes/updates