Re: Len Silverston's Universal Data Models sanity

On Wed, 05 May 2004 14:17:08 -0300,
=?iso-8859-1?q?Leandro_Guimar=E3es_Faria_Corsetti_Dutra?= <leandro_at_dutra.fastmail.fm> wrote:

>Em Wed, 05 May 2004 14:31:30 +0000, Alfredo Novoa escreveu:
>
>> Physical data independence is for that. The DBMS must ensure that the sum
>> of the movements matches with the stocks. If not, you would have
>> uncontrolled redundancy. To control this redundancy has the same
>> performance cost as to not have logical redundancy at all.
>
> Agreed, but with SQL physical data independence simply ain't
>here.

This is what the Transrelational Model offers, and why it is a so important advance.

> At least I have never seen a way of doing that decently in,
>say, ANSI SQL or Oracle SQL.
>
> I hope our next system will be done in a RDBMS. But my
>current ones are stuck in Oracle SQL.

Oracle has something called "materialized views" intented to do that.

>> BTW What do you think about to use Tutorial D or D4 instead of XML for
>> data exchange?
>
> The obvious thing.

Although ASCII text is never very efficient.

Regards
  Alfredo Received on Thu May 06 2004 - 14:01:37 CEST