The foreign table has a primary key. Ruby on Rails uses a system query to lookup what the primary key on the table is, but it's querying the local database, and not finding anything. In a schema dump of the local database, I don't see a primary key defined, so I'm presuming I need to issue an ADD CONSTRAINT command against the foreign table to reflect what is actually true in the foreign table? Is that correct?
The documentation says doing what you suggest won't work...
