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

From: Bob Badour <>
Date: Sun, 16 Feb 2003 13:46:24 -0500
Message-ID: <AmR3a.85$>

"Lauri Pietarinen" <> wrote in message
> 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;

I have to say I like this better than SQL, and I think it obviates the distinctions leading to Paul's comments. In Dataphor, the unadorned relation express is always a relation, and the operation to convert the data to an external physical representation requires an explicit SELECT keyword. It's clearer when different things look different.

> 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.

I think this is much clearer and easier to use than some of the quota query specifications I have seen. (I guess TOP...ORDER BY is a proprietary SqlServer extension?)

It's very clear that one can output the results in a different order:

SELECT emp OVER {salary} WHERE deptno = 1 RETURN 10 BY {salary desc} ORDER BY surname; Received on Sun Feb 16 2003 - 19:46:24 CET

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