>> If that's the case, then I'm sceptical about
>> whether this information belongs in the XML.
> Why are you sceptical?
>
Remember third normal form?
My postcode is RG4 7BS. That's a relationship, between me and where I
live. If I want to record my postcode in an XML data file, that is the
way I should record it. If someone wants to use that fact to get
information about that postcode from a web service provide by the UK
Post Office, or the Ordnance Survey, or Google, that's a matter for the
user of the data and/or the application. The address of the web service
and the domain name of its provider doesn't need to be stored
redundantly with every postcode. To do so is simply bad normalization;
and it violates the objectives of normalization, which is to maximize
potential for change. If the application decides to get its information
about postcodes from Google rather than from the PostOffice, why should
that mean changing the address data for every customer?
Michael Kay
Saxonica
