Re: The Practical Benefits of the Relational Model

From: Peter Koch Larsen <pkl_at_mailme.dk>
Date: 17 Sep 2002 01:14:31 -0700
Message-ID: <61c84197.0209170014.5f609493_at_posting.google.com>


hidders_at_hcoss.uia.ac.be (Jan.Hidders) wrote in message news:<3d73c210$1_at_news.uia.ac.be>...
> In article <akvgqp$2mks$1_at_sp15at20.hursley.ibm.com>,
> Paul Vernon <paul.vernon_at_ukk.ibmm.comm> wrote:
> >> Sure, try saying "there are no cycles in this binary relation" in one SQL
> >> statement.
> >
> >I guess this is cheating as I don't believe recursive SQL is part of the
> >SQL standard, but in DB2 SQL:
>
> Yes, that is cheating. :-) I never knew that DB2 could do that. Impressive.
> Thanks for showing it.
>
> Made me wonder for a moment if such a recursive SQL would be computationally
> complete, but since you stay within PSPACE it is of course not.
>
> -- Jan Hidders

Actually, recursion is part of the SQL:1999 standard. Correct me if I am wrong.

Kind regards
Peter Koch Larsen Received on Tue Sep 17 2002 - 10:14:31 CEST

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