[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message] RE: XPath 1.5? (was RE: typing and markup)
> -----Original Message----- > From: Jonathan Robie > [mailto:jonathan.robie@d...] > Sent: Tuesday, May 07, 2002 12:52 PM > To: Elliotte Rusty Harold; xml-dev@l... > Subject: RE: XPath 1.5? (was RE: typing > and markup) > > >Here's just one: > > > > avg( input()//person/name ) > > > >You say you want this to fail. I say I want it to return NaN > if any of > >the > >identified name elements contains a non-number and the > actual average if > >they all do contain strings that can be parsed as numbers. > Neither of us > >is right. Neither is wrong. We simply have different needs > in our local > >environments. Tomorrow I may move to a different local > environment with > >different needs. > > If error handling is different in each environment, then real > interoperability is very hard to achieve. > I'll let you in one an Open Secret, Jonathan; XQuery is not going to be interoperable. The XQuery WG set out to create the SQL of the XML world and they have succeeded. Interoperability between RDBMSs breaks down beyond the simple cases with proprietary extensions holding sway while lip service is paid to standards. No one fully implements SQL92, SQL99 may as well be a myth for all RDBMS vendors care about. From conversations with XQuery implementers both within and outside MS, I am confident that this situation is about to be replicated with XQuery especially since a number of its requirements simply cannot be efficiently implemented over certain data repositories. Throw in the fact that everyone will probably have their own homebrew update syntax, I can't imagine why anyone would expect interoperability between XQuery implementations. Then again, it's not like XQueries are data like XML documents or XML schemas so interoperability is probably shouldn't be a goal in any case. PS: If the XQuery WG is judicious in how they treat conformance levels, XQuery may yet avoid becoming the SQL of the XML world. DISCLAIMER: This is my personal opinion and does not reflect the intentions, opinions, strategies or plans of my employer. -- PITHY WORDS OF WISDOM Never put off until tomorrow what you can put off all together. This posting is provided "AS IS" with no warranties, and confers no rights. You assume all risk for your use. © 2002 Microsoft Corporation. All rights reserved. __________________________________________________ Do You Yahoo!? Yahoo! Health - your guide to health and wellness http://health.yahoo.com
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