Peter Eisentraut <peter.eisentr...@2ndquadrant.com> writes: > On 9/20/17 12:06, Tom Lane wrote: >> I'm tempted to propose that we invent some kind of "unknown" >> collation, which the planner would have to be taught to not equate to any >> other column collation (not even other instances of "unknown"), and that >> postgres_fdw's IMPORT ought to label remote columns with that collation >> unless specifically told to do otherwise. Then it's on the user's head >> if he tells us to do the wrong thing; but we won't produce incorrect >> plans by default.
> OID 0 might already work that way, depending on the details. No, OID 0 means "column is not collatable". I'm pretty sure there are some asserts that will trip if we use that collation OID for a column of a collatable data type --- and even if there are not, I think conflating the two cases would be a bad idea. regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers