It’s an interesting idea, but how would such a system handle queries that should cross tenant boundaries? (E.g. system-level reporting)

1. Go around pgcat/pgdog?

2. I have had good luck using pragma comments for that kind of thing: a way to communicate to the infrastructure without the target system seeing it

3. From the "malicious compliance department," I would also accept "include it but in a tautological way" (tenant_id = :ten_id or tenant_id <> :ten_id)

Echoing the comment below (above), since we can fingerprint queries using the Postgres parser, we can create an allow list and a more fine-grained ruleset.