| Oracle FAQ | Your Portal to the Oracle Knowledge Grid | |
Home -> Community -> Usenet -> comp.databases.theory -> Re: foundations of relational theory? - some references for the truly starving
Mr. Badour,
Frankly, you sir (and I use that term loosely), are an ass. I am tired of your uneducated, unprofessional, snide comments that serve no purpose. Get a life!!!
"Bob Badour" <bbadour_at_golden.net> wrote in message
news:CtOdnSqF9973SDuiRVn-gw_at_golden.net...
> "Dave Best" <davebest_at_usa.net> wrote in message
> news:ea757642.0311031305.1beca7a4_at_posting.google.com...
> > "Anthony W. Youngman" <thewolery_at_nospam.demon.co.uk> wrote in message
> news:<fHrE46GYsFo$EwWN_at_thewolery.demon.co.uk>...
> > > In article <CUYmb.86063$Ms2.64480_at_fed1read03>, daveb
> > > <davebest_at_SuPsAaM.net> writes
> > > >"Ross Ferris" <ross_at_stamina.com.au> wrote in message
> > > >news:26f6cd63.0310260541.7a6a9af9_at_posting.google.com...
> > > >> "Bob Badour" <bbadour_at_golden.net> wrote in message
> > > news:<GumdnaAjFvrJmQaiU-KYvg_at_golden.net>...
> > > >> > The values in a foreign key reference are redundant because they
> appear
> > > in
> > > >> > multiple relations. In this case, the redundancy is appropriate
and
> > > >> > necessary to represent the data.
> > > >>
> > > >> Interesting "admission", or at least an observation. Of course this
> > > >> redundancy is ONLY necessary because of the "flat earth" nature of
> SQL
> > > >> implementations.
> > > >>
> > > >> If the data were stored in a multi-valued database, or even an XML
> > > >> data store, then the redundant data could be removed.
> > > >
> > > >No, you have merely encoded the redundancy in the structural
> relationship.
> > > >
> > > Where? There is no key (foreign or otherwise) with which to do the
link,
> > > because there is no need to do a link.
> > >
> > > So yes there is a structural relationship, but there is no redundancy
> > > because no information is stored - it is IMplicit in the data store,
not
> > > EXplicit.
> > >
> > > Cheers,
> > > Wol
> >
> > The foreign key is in the logical model. Any nested relation has a
> > primary key consisting of the primary key columns of the containing
> > relation (and which form a foreign key to it) plus its own primary key
> > columns. In Pick, the primary key of a MV element is the primary key
> > of the record plus its array index.
> >
> > A relational database with relation-value (nested) attributes can
> > choose to physically store them clustered with the containing
> > relation, and so does not have to physically store the redundant
> > columns.
> >
> > The logical model of the data can be thought of as the API which a
> > program uses to access the data. This is distinct from the way it is
> > physically stored on the disk, which can be anything the vendor
> > chooses, including the Pick method of value-encoded variable-length
> > strings (so long as this representation is not exposed by the API).
>
>
>
![]() |
![]() |