Hello
it is not a bug - see
http://archives.postgresql.org/pgsql-hackers/2009-07/msg01525.php
Regards
Pavel Stehule
2012/6/20 <rikard.pavelic@zg.htnet.hr>:
> The following bug has been logged on the website:
>
> Bug reference: =C2=A0 =C2=A0 =C2=A06701
> Logged by: =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0Rikard Pavelic
> Email address: =C2=A0 =C2=A0 =C2=A0rikard.pavelic@zg.htnet.hr
> PostgreSQL version: 9.1.3
> Operating system: =C2=A0 Windows 7
> Description:
>
> create type t AS (i int);
> create type complex as (t t, i int);
> create table bad(i int, c complex);
>
> insert into bad values(1, null);
> insert into bad values(1, ROW(null, 2));
> insert into bad values(1, ROW(ROW(1), 2));
>
> select * from bad;
> select * from bad where c is null;
>
> --This doesn't work as expected
> select * from bad where c is not null;
>
> --Fortunately a workaround
> select * from bad where NOT c is null;
>
>
>
> --
> Sent via pgsql-bugs mailing list (pgsql-bugs@postgresql.org)
> To make changes to your subscription:
> http://www.postgresql.org/mailpref/pgsql-bugs