Sorry for delayed response.
2011/11/29 Albe Laurenz <laurenz.albe@wien.gv.at>:
> I think that this is not always safe even from PostgreSQL to PostgreSQL.
> If two databases have different collation, "<" on strings will behave
> differently.
Indeed. I think that only the owner of foreign table can keep collation
consistent between foreign and local, like data type of column. We need to
support per-column-collation on foreign tables too, or should deny pushing
down condition which is collation-sensitive...
Regards,--
Shigeru Hanada