Re: [xml-dev] The limitations of XPath and navigation- A XPath/XQuery

[John Snelson <john.snelson@oracle.com>]

mike@adatinc.com wrote:
> The above description of LCA processing applies for standard 
> hierarchical processing required for database data use. Duplicate 
> database data types in the document should not be allowed. They should 
> be renamed or always fully qualified. They can cause variable LCAs and 
> database data should not allow this. This is OK for markup data, not 
> database data. Just imagine performing an aggregation for record sales 
> on “SALES” and a missing record data causes “SALES” of book sales to be 
> added in. This is what you would want for markup use, but not database 
> data use.

I find some of your ideas quite interesting, but I still haven't seen 
the market demand them yet.

I think the biggest problem with what you're saying is contained in the 
paragraph above - XML users don't want to be constrained to not have 
duplicate "database data types" as you call them, and they frequently 
have element and attribute names that are the same but mean different 
things in different documents and different parts of the same document.

John

-- 
John Snelson, Oracle Corporation            http://snelson.org.uk/john
Berkeley DB XML:        http://www.oracle.com/database/berkeley-db/xml
XQilla:                                  http://xqilla.sourceforge.net