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

From: Lauri Pietarinen <lauri.pietarinen_at_atbusiness.com>
Date: Sat, 15 Feb 2003 19:43:17 +0200
Message-ID: <3E4E7C35.9010800@atbusiness.com>


It might be interesting to note that Dataphor makes a clear distiction between relations and result sets that are returned to the user (or program etc...):

We would have the relational expression

  emp OVER {salary} WHERE deptno = 1;

and then when it is returned we have  

   SELECT emp OVER {salary} WHERE deptno = 1 ORDER BY salary;

Quota queries look like this:

 emp OVER {salary}

    WHERE deptno = 1
     RETURN 10 BY {salary desc}

so also making a distinction between ordering and quota queries.

regards,
Lauri Pietarinen Received on Sat Feb 15 2003 - 11:43:17 CST

Original text of this message

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