Re: Little design mistakes that can be easily avoided (2): Listenning to CELKO (and CELKO alikes)
From: Brian Selzer <brian_at_selzer-software.com>
Date: Mon, 28 May 2007 19:16:37 GMT
Message-ID: <pUF6i.10089$2v1.1634_at_newssvr14.news.prodigy.net>
Date: Mon, 28 May 2007 19:16:37 GMT
Message-ID: <pUF6i.10089$2v1.1634_at_newssvr14.news.prodigy.net>
"Gene Wirchenko" <genew_at_ocis.net> wrote in message
news:cc0m53lkdf0os673kfdunubc46dkidq1uo_at_4ax.com...
> Jon Heggland <jon.heggland_at_idi.ntnu.no> wrote:
>
> [snip]
>
>>It is /always/ a superkey. It might be "candidate" (i.e. irreducible) as
>>well; if not, it is a /proper superkey/. (Also, a tuple is not a key,
>>but I'll quibble about that some other time:)
>
> Why can't a tuple be a key? It does uniquely specify a tuple.
>
Because a tuple is a value and a key is a constraint.
> Sincerely,
>
> Gene Wirchenko
>
> Computerese Irregular Verb Conjugation:
> I have preferences.
> You have biases.
> He/She has prejudices.
Received on Mon May 28 2007 - 21:16:37 CEST