Re: logical differing from physical

From: Jared Still <jkstill_at_bcbso.com>
Date: Wed, 23 Aug 2000 08:44:51 -0700 (PDT)
Message-Id: <10598.115390@fatcity.com>

The DA may have generated the logical model, but the DBA may not agree with it for many reasons.

1. Supertypes and Subtypes. There are no corresponding=20 phyical objects, and the DBA may wish to implement them differently than shown on the logical model.
2. Partitions. No need for these to be on a logical model.
3. Arcs. More than one way to implement them.
4. Many to Many relationships. This only requires 2 tables to model, but at least 3 to implement. ( properly )

Many more I'm sure, but this illustrates the point.

Jared

On Tue, 22 Aug 2000, james ellis wrote:

> Does anyone have any good reasons why a database's
> logical model would differ from the physical model?=20
> Haven't run across any good business reasons why this
> should/would happen.

>=20

> james

>=20


> __________________________________________________

> Do You Yahoo!?
> Yahoo! Mail =96 Free email you can access from anywhere!
> http://mail.yahoo.com/
> --=20
> Author: james ellis
> INET: jellis24_gso_at_yahoo.com

>=20


> Fat City Network Services    -- (858) 538-5051  FAX: (858) 538-5051

> San Diego, California        -- Public Internet access / Mailing Lists

> --------------------------------------------------------------------

> To REMOVE yourself from this mailing list, send an E-Mail message
> to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in
> the message BODY, include a line containing: UNSUB ORACLE-L
> (or the name of mailing list you want to be removed from). You may
> also send the HELP command for other information (like subscribing).
>=20

Jared Still
Certified Oracle DBA and Part Time Perl Evangelist ;-) Regence BlueCross BlueShield of Oregon
jkstill_at_bcbso.com - Work - preferred address Received on Wed Aug 23 2000 - 10:44:51 CDT