Craig from Citus here. There are a number of issues with one schema per tenant, the biggest one is that at a larger scale Postgres will mostly just not work anymore. Things like pg_dump start to fall over and while this has been improved some, there is still an upper limit somewhere between 1,000 and 10,000 tenants. Further having to then run schema migrations against all of them can be quite painful. There are tools that help on the schema migration front, but what we've seen is that again at scale things start to break. If you'll only ever have 100 customers then by schema can work for you.