The collation column is empty here, which means that collation for str* columns is default collation i.e. C. This isn't true, since the default ncollation on the foreign server is different from the default collation of local database. AFAIU, import foreign schema should have set appropriate collation of the foreign table.
That's what we saw. The query inside IMPORT FOREIGN SCHEMA assumes a NULL collation means default, without asking the server what that default is. I was thinking that we could change the select inside postgresImportForeignSchema and replace collname, with something borrowed from information_schema.sql like
coalesce(collname, (SELECT encoding FROM pg_catalog.pg_database WHERE datname = pg_catalog.current_database()))
which itself isn't right because encoding names don't match up perfectly with collation names.
