In the RDB's I have seen, each field (column in a table) often (typically?)
represents one relation on the type represented by the table, so the number
of columns does not have any relation to the arity of the relations used.
Two or more columns can be used together to represent higher-arity
relations, but they may be quite independent. (01)
Pat (02)
Patrick Cassidy
MICRA, Inc.
908-561-3416
cell: 908-565-4053
cassidy@xxxxxxxxx (03)
> -----Original Message-----
> From: ontolog-forum-bounces@xxxxxxxxxxxxxxxx [mailto:ontolog-forum-
> bounces@xxxxxxxxxxxxxxxx] On Behalf Of Mitch Harris
> Sent: Friday, January 30, 2009 2:05 PM
> To: [ontolog-forum]
> Subject: Re: [ontolog-forum] Is there something I missed?
>
> On Fri, Jan 30, 2009 at 1:41 PM, Matthew West
> <dr.matthew.west@xxxxxxxxx> wrote:
> > Dear Mitch
> >
> >> - Any (relational) database schema describes a set of relations/an
> >> ontology and most are extremely multi-ary.
> >
> > [MW] Yes but these are mostly denormalisations to overcome the costs
> of
> > table joins.
>
> Are you saying that most of the table schemas you see in rdb's have
> large numbers of fields because they were purposefully re-enginneered
> that way (from collections of binary relations) in order to make
> access (and joins) more efficient?
>
> --
> Mitch Harris
>
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