Re: Include history in logical model or physical design

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and read it. You'll be glad you did.

"OlegJay" <olegjay_at_yahoo.com> wrote in message news:47d21956.0303070804.baa2a59_at_posting.google.com...
> I need to build a 3rd normal form logical model that has more
nuances
> than I've handled in the past.
>
> In particular, how do I include into my logical model the saving of
> records that are updated in each evening load? Users will want to
know
> what was in the database at any prior time.
>
> Does anyone know of any simple history maintaining logical models
> described on the internet where I can easily get to? Or is history
> records and retrieval purely a physical design consideration?
>
> As a simple example consider the two entity CUSTOMER - ORDER logical
> model where there is one 1 to many relationship and the attributes
may
> be:
>
> CUSTOMER
> cust id
> cust name
>
> ORDER
> order id
> bill amount
> product ordered
> date ordered
>
> What if at a later date some attribute changed and the database is
> supposed to keep both the original and the update; like cust named
> changed or bill amount changed. Should I add a create-modify-date
> field or a sequence-number to each entity in the logical model to
> handle this updateability feature of the entity(s) or should I not
be
> concerned about this capability or history for a deliverable 3rd
> normal form logical model for industry.
>
> I thank you for any help in advance,
>
> Oleg Jay
Received on Sat Mar 08 2003 - 00:35:21 CET