Re: Has E/R had a negative impact on db?
From: Bob Badour <bbadour_at_pei.sympatico.ca>
Date: Sun, 23 Apr 2006 04:57:01 GMT
Message-ID: <xOD2g.64518$VV4.1215646_at_ursa-nb00s0.nbnet.nb.ca>
>
> There is nothing in the RM called "entity."
> There is nothing in the RM called "relationship."
Date: Sun, 23 Apr 2006 04:57:01 GMT
Message-ID: <xOD2g.64518$VV4.1215646_at_ursa-nb00s0.nbnet.nb.ca>
> Neo wrote:
>
>>>>> Just a thought. I don't like entities. In fact I despise entities, >>>>> as the enemy of good information philosophy. >>>> >>>> What is your definition of an entity? What steps would one go through >>>> to verify something is an entity? >>> >>> I refer to them as they are specified by Chen. I've already pointed out >>> I believe their specification is impossible above simply being >>> arbitrary so your second question makes no sense to me. >> >> Ok, I just wanted to make sure there isn't anything in RM that would be >> considered an entity.
>
> There is nothing in the RM called "entity."
> There is nothing in the RM called "relationship."
Technically, the latter statement is untrue. Codd distinguishes relations and relationships in his early papers, but most folks don't any longer. Similarly, Date and Darwen have dropped the term 'domain' in favour of 'type', which decision certainly eliminates a lot of explaining.
Regardless, Neo is incapable of understanding any of it. Received on Sun Apr 23 2006 - 06:57:01 CEST