Re: Two relations with the same attributes

From: mAsterdam <mAsterdam_at_vrijdag.org>
Date: Mon, 18 Sep 2006 01:08:21 +0200
Message-ID: <450dd4f2$0$4524$e4fe514c@news.xs4all.nl>

Cimode wrote:
> mAsterdam wrote:

>> Cimode wrote:
>>>  If 2 relations have the same attributes then they should be one
>>> relation.
>> No. As long as the name of the relation and the meaning of the
>> propositions differ it is ok to have two relations with the same
>> attributes. The meaning of the propositions depends on the external
>> predicate.

>
> I see your point...
> Thank your for pointing that out but such definition is valid only for
> SQL systems. I should have stated that the proposed definition assumes
> an implementation that supports domain derivability (in a word, forget
> SQL)
SQL has nothing to do with it.

Is it ok to have two different relations with the same attributes?

No, you say, and you build on that.
Yes, I say, so IMO the rest of your building is irrelevant.

[snip] Received on Sun Sep 17 2006 - 18:08:21 CDT