Title: Re: [xml-dev] Better design: "flatter is better" or "nesting is better" ?



Remember that XML Schema is an XML document based on another XML document 
(the schema for schemas), and sort of rooted in a DTD.  Sometimes and 

XML 
document is not a storage medium or 'bits on the wire'.  It is an 
application language.
 
len

  -----Original Message-----
From: Costello, Roger L. 
  [mailto:costello@m...]
Sent: Monday, October 03, 2005 4:12 
  PM
To: xml-dev@l...
Subject: RE: [xml-dev] Better 
  design: "flatter is better" or "nesting is better" ?


  
  
  Hi Folks,
   
  Excellent discussion!
   
  A lot of important issues have been raised.  
  I would like to focus on one issue, and then come back to the other 
  issues.
   
  The issue is this: what are the roles of an XML 
  document?
   
  As I have been doing with my previous 
  messages, I will make a hypothesis and then invite your critique.
  Hypothesis: The Role of an XML Document is either as a Storage Medium 
  or as a Transport Format
  An XML document may take one of these 
  roles:
   
  (1) The XML document is a storage 
  medium.  Applications operate directly on the XML document.
   
  (2) The XML document is a (transient) transport 
  format.  Upon arrival at its destination the data is moved into a storage 
  medium (such as a relational database).  Applications do not operate on 
  the XML document.  Applications operate on the data in the storage 
  medium.
   
  Questions:
   
  1. I believe that these two roles represent 
  the two ends of the spectrum for all possible uses of XML.  (Of course, 
  mixed forms are possible)  Is there another role that is not 
  captured?  (i.e., a third dimension?)
   
  2. Peter: I think that XML documents containing presentation-specific 
  data falls under the first category (XML as a storage medium).  Do you 
  agree?
   
  3. Doug: you make an interesting point about not knowing who will be the 
  consumer of an XML document.  I suppose in those cases the XML designer 
  simply makes a best-guess on the role of the XML document.  What do you 
  think?
   
  4. Joe: you make an interesting point about XML documents that are 
  transformed into another XML vocabulary.  Would such documents fall under 
  the second category (XML as a transport format)?
   
  5. Ken: you mentioned the case of XML being stuffed into a relational 
  database as a whole document (i.e., not shredded into tables), and 
  applications operating directly on the XML documents in the database.  
  How does this fit into the above categories, or does it?
   
  Comments?  
/Roger