PG Bug reporting form <noreply(at)postgresql(dot)org> writes:
> create TABLE my_table (my_text TEXT);
> create VIEW my_view AS SELECT my_text COLLATE "C" FROM my_table;
> create OR REPLACE view my_view AS SELECT my_text COLLATE "en_US.utf8" FROM
> my_table;
> The COLLATION of "my_view"."my_text" should have been changed to
> "en_US.utf8".
> - OR -
> I should have got an error message telling me that it is not possible.
Yeah, that's a bug, it should have thrown an error.
(Changing the collation is impractical for the same reasons that
changing the output datatype is impractical.)
regards, tom lane