The following bug has been logged online:
Bug reference: 1996
Logged by: Ludmil Tinkov
Email address: ludmil(at)fyrex(dot)com
PostgreSQL version: 7.3.2
Operating system: RedHat 9.0
Description: DISTINCT fails with national character varying
Details:
create table depression(ID int, name national character varying(50))
insert into depression values(1, '');
insert into depression values(2, '');
insert into depression values(3, '');
insert into depression values(4, '');
select distinct name from depression
--the last statement returns only a single row
--namely:
--it should return 4 rows!