I came across the following problem when migrating from 7.3.4 to 7.4b4.
Query #4 does not fail under version 7.3.4. But it does under version
7.4b4. It seems that in some situations the implicit cast fails. It
would not be a problem if I had the opportunity to manually cast these
queries. But I don't. I am using a client package (Hibernate) which
generates statements automatically based on an O/R mapping.=20=20
CREATE DOMAIN foo_varchardomain AS varchar(10);
CREATE DOMAIN foo_intdomain AS int4;
CREATE TABLE foo_table (i foo_intdomain, c foo_varchardomain);
INSERT INTO foo_table VALUES (1, 'x');
SELECT * FROM foo_table WHERE i =3D '1'::text;
SELECT * FROM foo_table WHERE i::int4 =3D '1'; -- query #1 ok
SELECT * FROM foo_table WHERE i =3D 1; -- query #2 ok
SELECT * FROM foo_table WHERE c =3D 'x'; -- query #3 ok
SELECT * FROM foo_table WHERE i =3D '1'; -- query #4 ERROR
ERROR: operator is not unique: foo_intdomain =3D "unknown"
HINT: Could not choose a best candidate operator. You may need to add
explicit type casts.
TIA
David