Can postgresql be deployed with audit trail and data validation capability, to meet compliance with 21 cfr part 11?
IMHO, that sort of audit trail should be higher level in your business logic, not in the database. but that's just my opinion, worth exactly what you paid for it.
I've been through 21 cfr part 11 (successfully) and it has nothing to do with the database vendor and everything to do with how you track changes to the data.