Re: Relational vs network vs hierarchic databases

On Tue, 09 Nov 2004 16:07:08 GMT, "Dan" <guntermann_at_verizon.com> wrote:

>> Yes. You (both) are talking about physical/implementation matters, not
>> about
>> relational model versus hierarchical/network model.
>
>Not really. I could write a set of names on a piece of paper and connect
>them by arrows and traverse any given sequence much quicker than doing a
>sequence of tuple associative value lookups.

This is physical implementation again. It depends on how you distribute the names on the paper and which sequences you want to obtain.

>I can model a hierarchy and a network relationally. Is this what you mean?

No, we mean that it does not make sense to talk about the performance of a data model.

>What does orthogonal mean? Does it mean that the intersecting vectors of
>relational and performance never ever really intersect? No.

It means that they are mutually independent.

It is a rather frequent term in computing science. See this:

http://dictionary.reference.com/search?q=orthogonal%20instruction%20set

>Yes. The relational model is a logical model that is orthogonal to
>"performance" in the abstract. But if you are going to compare it to a
>hierarchical or network model and criticise those models for being
>constrained and hindered because of the use and dependence on pointers,
>which are physical

No, not all pointers are physical. A logical network model uses logical pointers.

>, then their is no reason not to recognize their strengths
>in terms of their physical manifestion as well.

The physical manifestation may be very different to the logical design in both cases.

Regards Received on Fri Nov 12 2004 - 17:44:50 CET