Re: What is that "more" that makes E-R model truly independent ?

From: beginner16 <kaja_love160_at_yahoo.com>
Date: Tue, 24 Jul 2007 08:24:20 -0700
Message-ID: <1185290660.192401.99150_at_22g2000hsm.googlegroups.com>


>>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
>>implementation ?
>It is more vague and more imprecise. Being even more vague we could be
>even more independent, and saying nothing we achieve complete
>independence :-)
>
Are Bachman diagrams less vague than E-R diagrams? Received on Tue Jul 24 2007 - 17:24:20 CEST

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