Re: Weird "could not determine which collation to use for string comparison" with LEAST/GREATEST on PG11 procedure - Mailing list pgsql-bugs

"Voillequin, Jean-Marc" <Jean-Marc.Voillequin@moodys.com> writes:
> SIMPLE=> create or replace procedure same_values_proc(a text, b text) as $body$
> SIMPLE$> begin
> SIMPLE$>        assert a = b;
> SIMPLE$> end;$body$ language plpgsql;
> CREATE PROCEDURE
> SIMPLE=>
> SIMPLE=> call same_values_proc(least('a','b'),'a');
> ERROR:  could not determine which collation to use for string comparison
> HINT:  Use the COLLATE clause to set the collation explicitly.

Yeah, same here.  I think somebody forgot to run assign_expr_collations()
on CALL arguments.

            regards, tom lane