# Re: Extending my question. Was: The relational model and relational algebra - why did SQL become the industry standard?

Date: 18 Feb 2003 14:08:48 -0800

Message-ID: <e4330f45.0302181408.121a939f_at_posting.google.com>

"Mikito Harakiri" <mikharakiri_at_ywho.com> wrote in message news:<8BT2a.11$O%2.25_at_news.oracle.com>...

> "Alfredo Novoa" <alfredo_at_ncs.es> wrote in message

*> news:e4330f45.0302130552.5f51736a_at_posting.google.com...
**> > I only want to add that duplicates also ruin updateable views.
**> >
**> > http://www.pgro.uk7.net/views3_0110.htm
**>
**> Why? View updates is about ability to solve equations with relational
**> operators. While one can certainly claim that Set Algebra is superior to
**> Bag Algebra, you have to demonstrate what exact technical difficulties are
**> solving equations in the Bag Algebra.
*

The systematic approaches to the view update problem based on predicate logic does not work with bags.

Alfredo Received on Tue Feb 18 2003 - 23:08:48 CET