Re: foundations of relational theory? - some references for the truly starving

Bob Badour wrote:
> "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

>>>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

>>> 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

>>>>>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

>>>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).

Patrick, <;=)

P.S. Bob you're an Idiot, and unfortunatately too narrowminded to even realize it. It's the pity. (Big compensatory truck huh?) Received on Tue Nov 04 2003 - 03:29:38 CET