Re: A pk is *both* a physical and a logical object.
Date: Fri, 13 Jul 2007 09:03:40 -0000
On 13 jul, 06:00, Jonathan Leffler <jleff..._at_earthlink.net> wrote:
> Jan Hidders wrote:
> > On 11 jul, 22:25, Cimode <cim..._at_hotmail.com> wrote:
> >> Furthermore...
> >> <<Technically a PK is *only* a physical implementation device, not a
> >> logical concept at all.>>
> > `When I use a word,' Humpty Dumpty said, in rather a scornful tone,
> > `it means just what I choose it to mean -- neither more nor less.'
> > `The question is,' said Alice, `whether you can make words mean so
> > many different things.'
> > `The question is,' said Humpty Dumpty, `which is to be master --
> > that's all.'
> > ;-)
> > To answer the question, I think that is quite simple. As defined in
> > the relational model it is a logical concept. As far as I know the SQL
> > standard does not state that a PK implies an index
> The SQL standard doesn't mention indexes.
Thanks for confirming that. So also there it is a purely logical concept. Problem solved.
- Jan Hidders