Re: A pk is *both* a physical and a logical object.
From: Jonathan Leffler <jleffler_at_earthlink.net>
Date: Fri, 13 Jul 2007 04:00:22 GMT
Message-ID: <qNCli.7007$tj6.1475_at_newsread4.news.pas.earthlink.net>
>
> `When I use a word,' Humpty Dumpty said, in rather a scornful tone,
> `it means just what I choose it to mean -- neither more nor less.'
>
> `The question is,' said Alice, `whether you can make words mean so
> many different things.'
>
> `The question is,' said Humpty Dumpty, `which is to be master --
> that's all.'
>
> ;-)
>
> To answer the question, I think that is quite simple. As defined in
> the relational model it is a logical concept. As far as I know the SQL
> standard does not state that a PK implies an index
Date: Fri, 13 Jul 2007 04:00:22 GMT
Message-ID: <qNCli.7007$tj6.1475_at_newsread4.news.pas.earthlink.net>
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.
-- Jonathan Leffler #include <disclaimer.h> Email: jleffler_at_earthlink.net, jleffler_at_us.ibm.com Guardian of DBD::Informix v2007.0226 -- http://dbi.perl.org/Received on Fri Jul 13 2007 - 06:00:22 CEST