Re: What is that "more" that makes E-R model truly independent ?
Date: Tue, 24 Jul 2007 08:24:20 -0700
>>But as I stated before, E-R model diagram would be the same no matter
>>if logical DB implementation is hierarchical or relational. For that
>>reason I assume that ER modeling is more than just using symbols for
>>entity, attributes, relationships
>It is not.
What do you mean by "it is not"?
That E-R modeling is nothing more than just a bunch of symbols or that the structure of E-R model does depend on whether underlying logical structure is relational or hierarchical ( well isn't the whole point of E-R model to be independent, at least for the most part, of underlying logical structure ) ?
>>But what is that "more" that makes E-R model truly independent of logical DB
>It is more vague and more imprecise. Being even more vague we could be
>even more independent, and saying nothing we achieve complete
Are Bachman diagrams less vague than E-R diagrams? Received on Tue Jul 24 2007 - 17:24:20 CEST