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

From: Jan Hidders <>
Date: 13 Feb 2003 17:39:07 +0100
Message-ID: <>

Lauri Pietarinen wrote:
>>The book is agnostic on this issue. It's starting point is that you want to
>>build an SQL database (and so there are duplicates in your results) and then
>>explains how you should do that.
>OK, thanks.
>So the answer to my question is
>"they have taken SQL as a basis _in_this_book_


>but probably agree otherwise that duplicates should be avoided


>and better optimisations would be obtained without duplicates"

No. In fact, in theory, all optimizations that can be done in a set-based algebra can also be done in a bag-based algebra but not the other way around.

  • Jan Hidders
Received on Thu Feb 13 2003 - 17:39:07 CET

Original text of this message