Re: Database-valued attributes?
From: Jonathan Leffler <jleffler_at_earthlink.net>
Date: Wed, 12 Nov 2003 05:11:36 GMT
Message-ID: <cijsb.8002$nz.6409_at_newsread2.news.pas.earthlink.net>
Date: Wed, 12 Nov 2003 05:11:36 GMT
Message-ID: <cijsb.8002$nz.6409_at_newsread2.news.pas.earthlink.net>
Paul Vernon wrote:
> Q. Do D&D explicitly define what a possiable representaion is. I.e. is a
> poss rep with more than 1 component a tuple of those components, or a list,
> a set, an array or just 'a thing with components'?
>
> E.g. would
>
> POSSREP XY_POINT { X NUMERIC, Y NUMERIC }
>
> be the same poss rep as
>
> POSSREP XY_POINT { Y NUMERIC, X NUMERIC }
>
> in thier book?
Those would be the same, I'm sure. The attributes are identified by name, not position. See the Database Foundation Papers #3, IIRC, at dbdebunk.com.
-- Jonathan Leffler #include <disclaimer.h> Email: jleffler_at_earthlink.net, jleffler_at_us.ibm.com Guardian of DBD::Informix v2003.04 -- http://dbi.perl.org/Received on Wed Nov 12 2003 - 06:11:36 CET