RE: Primary and Foreign Keys

["Bullard, Claude L (Len)" <clbullar@ingr.com>]

Ah, but if the first requirement is to work 
in the context of XML Schema, how will RDF 
fit with this for the key relationships?

Consider a design in which the schema represents 
the data-centric approach and should be 
agnostic about what database implementation 
is used.  In other words, it starts out life 
as a relational database (really a hybrid 
because of the GUI layer with business logic, 
so a mid 90s design), then one wants to make 
the data available to different systems at 
different scales (big agencies, little agencies, 
tweeny agencies, sometimes using desktop 
interfaces, sometime handhelds).   That is 
where many of us are today.  We need to 
open our dbs up to different services and 
migrate the push models of delivery to 
pull models in the sense that most large 
reporting systems collate and send their 
data up to collection agencies that then 
regularize them and send them on to a central 
collection agency, like mountain, to stream 
to river to ocean with a data-centric schema 
as the cohesive force.


Len 
http://www.mp3.com/LenBullard

Ekam sat.h, Vipraah bahudhaa vadanti.
Daamyata. Datta. Dayadhvam.h


-----Original Message-----
From: Uche Ogbuji [mailto:uogbuji@fourthought.com]
Sent: Saturday, July 21, 2001 2:18 PM
To: xml-dev
Cc: Bullard, Claude L (Len)
Subject: Re: Primary and Foreign Keys


> A more fun question:
>
> Given a relational database for which one creates a
> parallel XML schema, how do others think key relationships
> should be described:
>
> 1.  Simple types with the insurance that corresponding
> values exist in both tables (doesn't seem very strong to me).
>
> 2.  Key/keyrefs
>
> 3.  ID/IDREFs (probably a non-starter given the caveat)
>
> 4.  XLinks

5.  RDF

Now, you knew I hadn't got *that* far away, didn't you?

Seriously, one would have to know much more about the RDBMS schemata in
question to make an informed choice.  Your caveat merely gives a cryptic
hint.


-- 
Uche Ogbuji                               Principal Consultant
uche.ogbuji@fourthought.com               +1 303 583 9900 x 101
Fourthought, Inc.                         http://Fourthought.com
4735 East Walnut St, Boulder, CO 80301-2537, USA
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