[Ronald Bourret]
>  Manos Batsis wrote:
>  > > XML is pretty good for tables, but not so good
>  > > for enforcing relational normalization rules.
>  >
>  > Of course. Enforcing relational normalization rules shuts down most good
>  > reasons to use XML in the first place, with the possible exception of
>  > exchanging DB data between servers via http.
> 
>  I don't think this is quite true. One of the questions I wrestled with
>  in trying to understand native XML databases was what "normalization"
>  meant. While there's undoubtedly a lot of room for thought here, I did
>  take a look at the first, second, and third (relational) normal forms
>  and tried to see what they meant in XML terms.
> 
>  ...
>  To explain: Consider our sales order documents. It is unlikely that the
>  data for these documents lives in XML. More likely, the data lives in a
>  relational database. In this case, the sales order document is a
>  historical record of a given transaction, so the fact that the same
>  customer data is used in multiple sales order documents doesn't matter
>  -- nobody is going to try to update it and there is no/low risk of
>  update anomalies.
> 

I think that xml documents like these correspond most to relational views
rather than tables.  Views are not necessarily desired to follow
normalization rules.  Views do not "live" in the database (using Ron's
phrase) in the sense that they are temporarily assembled using data that
does reside in tables.  Good database practice suggests exposing your data
using views rather than direct table access.  These documents could be
considered non-updatable XML views into some (possibly relational) database.

Cheers,

Tom P


-----------------------------------------------------------------
The xml-dev list is sponsored by XML.org <http://www.xml.org> , an
initiative of OASIS <http://www.oasis-open.org> 

The list archives are at http://lists.xml.org/archives/xml-dev/

To subscribe or unsubscribe from this list use the subscription
manager: <http://lists.xml.org/ob/adm.pl>