It's pretty awful, generally best avoided unless you have a specific reason for doing so (e.g. encrypting the full SQLite DB per customer). It also introduces you to some pretty bad risks (what if there is a bug in a migration which only affects certain tenants?).

That being said it can be done and it's pretty normal for mobile apps, desktop apps etc. You just have to make sure the migrations are run when the tenant connects/unlocks/runs the app - and make sure that you minimise the risk of it going wrong!

We do it on Postgres with schemas but we have a very fixed amount of tenants so it works.

I don't think it scales when you have unbounded amounts of tenants.