Re: different sort order for primary key index

On Wed, Oct 14, 2009 at 3:37 PM, Sam Mason <sam(at)samason(dot)me(dot)uk> wrote:

> On Wed, Oct 14, 2009 at 10:29:56AM -0400, Tom Lane wrote:
> > Paul Hartley <phartley(at)gmail(dot)com> writes:
> > > ... I'm unclear
> > > if PostgreSQL treats primary keys differently from unique, non-null
> > > constraints.
> >
> > The *only* thing that the system does specially with a primary key
> > constraint is that a PK creates a default column target for foreign key
> > references.
>
> It also (silently) overrides any NOT NULL constraint doesn't it? For
> example:
>
> CREATE TABLE x ( id INT NULL PRIMARY KEY );
>
> ends up with "id" being NOT NULL, even though I asked for it to be
> nullable. Not sure if it's useful for this case to be an error, though
> it would be more in line with PG throwing errors when you asked for
> something bad instead of making a best guess.
>
> if that happens, shouldn't it be an error ? after all it could potentially
confuse.

--
GJ