Re: 1GB Tables as Classes, or Tables as Types, and all that refuted
Date: Wed, 24 Nov 2004 16:56:14 GMT
Message-ID: <41a4bcf4.21479484_at_news.wanadoo.es>
On Wed, 24 Nov 2004 16:26:18 +0100, "Ja Lar" <ingen_at_mail.her> wrote:
>> An attribute of a relation can not have another relation as its
No, you are missing the point. Relation valued attributes don't have a
relation value as their type (domain), they have a relation type as
>> domain. This is an absurd.
>
>I recommend you Date's Intro ...(8th ed), Part II/The Relational Model p.
>152: Relation-Valued Attributes.
>You might want to inform him about the absurdity :-)
For instance:
var CandidateKeys real relation { RelVar Char, Attributes relation { Attribute Char } } key { RelVar, Attributes };
Here "relation { Attribute Char }" is a relation type generator that generates a relation type for the "Attributes" attribute.
Regards Received on Wed Nov 24 2004 - 17:56:14 CET