Re: foreign key constraint versus referential integrity constraint
Date: Wed, 28 Oct 2009 13:17:19 -0700 (PDT)
> If I recall it
> wasn't until his second paper that he introduced the pair of attribute
> and domain name, he was adjusting his theory to meet practice.
As for the headers being less relevant in the context of domain analysis, I meant that domain analysis clearly focuses on the body of each un-ary relation being primarily a domain subset (*before* relation level constraints are applied; I use the term with great caution !) to be considered an attribute of a specific relation. It is only once domain requirements are met that the assignment of a specific header defines the attribute (then the header set defining the relation).
My observation is that a lot of work has been done into defining
relations in order to algebrically operate them as relations but very
little has been done to use domains to clarify relational algebra.
My conclusion is that the relational consensus that constraint specialization through domain analysis could be in any way orthogonal to relation structural definitions restricts the possibility of clarifying further relational model operations and implementations.
But that is only my opinion.
Regards... Received on Wed Oct 28 2009 - 21:17:19 CET