| From: | Scott Marlowe <smarlowe(at)g2switchworks(dot)com> |
|---|---|
| To: | Stephane Bortzmeyer <bortzmeyer(at)nic(dot)fr> |
| Cc: | Guy Rouillier <guyr(at)masergy(dot)com>, pgsql-general(at)postgresql(dot)org |
| Subject: | Re: PRIMARY KEY on a *group* of columns imply that each column is |
| Date: | 2005-04-27 13:46:11 |
| Message-ID: | 1114609571.13303.1280.camel@state.g2switchworks.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-general |
On Wed, 2005-04-27 at 02:12, Stephane Bortzmeyer wrote:
> On Tue, Apr 26, 2005 at 03:48:44PM -0500,
> Scott Marlowe <smarlowe(at)g2switchworks(dot)com> wrote
> a message of 26 lines which said:
>
> > Here's a quote from the SQL1992 spec that's VERY clear:
>
> Yes, PostgreSQL is right and implement the standard. Now, what's the
> rationale for the standard? I understand it for a single column but,
> for several columns, it should be still possible to have different
> tuples, such as (3, NULL) and (5, NULL) for instance.
Since NULL <> NULL, that means you could then have
(5,NULL) and (5,NULL) since the two NULLS aren't equal.
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Stephan Szabo | 2005-04-27 13:54:57 | Re: PRIMARY KEY on a *group* of columns imply that each |
| Previous Message | deepak | 2005-04-27 12:56:02 | BUG #1633: about transactions and row level locking |