Re: [xml-dev] XML spec and XSD

[Jim Melton <jim.melton@acm.org>]

I'm one of those people who don't fall in love with technologies for 
their own sake, regardless of how beautiful and/or useful they might 
be.  I do have a fondness for elegance, as well as for practicality, 
but I believe that technology provides tools and nothing more.  XSD 
is one such tool, DTD is another.  Each has its uses, and I use them both.

As Simon has pointed out, DTDs do a great job for document-centric 
applications where there is little that needs to be known about the 
semantics of atomic data types.  I use DTDs for my editing work on 
the SQL standard and on W3C documents, as well as for a host of other 
documents I do in other aspects of my day job and my life.

Schemas are often very clumsy for validating "ustructured" textual 
documents, such as fiction books, biographies, and the like.  But 
schemas (XSD being the W3C-defined instance of this technology) are 
very useful when dealing with structured documents, especially those 
that contain lots of traditional data and/or those that are generated 
specifically from data (not to mention those that *are* data 
expressed in an XML tree).

I get very, very frustrated when I'm trying to drive a nail into 
their wall using a screwdriver, as well as when I'm trying to get a 
screw out of the wall using a hammer.  That doesn't make me hate the 
screwdriver or the hammer -- nor, for that matter, to love either one 
when I figure out that I got it backwards and start using the proper 
tool for each job.  They're just tools.  Pick the right one for your job.

If your management is forcing you to use XSD for unstructured 
document validation (or DTDs for highly structured data validation), 
don't hate XSD (or DTD)...hate the bureaucracy that limits your choice of tool!

Hope this helps,
    Jim

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Jim Melton --- Editor of ISO/IEC 9075-* (SQL)     Phone: +1.801.942.0144
   Chair, W3C XML Query WG; XQX (etc.) editor       Fax : +1.801.942.3345
Oracle Corporation        Oracle Email: jim dot melton at oracle dot com
1930 Viscounti Drive      Standards email: jim dot melton at acm dot org
Sandy, UT 84093-1063 USA          Personal email: jim at melton dot name
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=  Facts are facts.   But any opinions expressed are the opinions      =
=  only of myself and may or may not reflect the opinions of anybody   =
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