Re: XQuery, UPDATES and XML repositories

At 02:30 PM 12/27/2001 -0800, Dare Obasanjo wrote:
>In certain discussions on the xml-dev mailing list it came to my attention
>that the W3C is considering letting XQuery go to recommendation status without
>UPDATE or DELETE semantics being a part of the recommendation. Below are
>various comments I've made regarding the lack of a data manipulation language
>for XML  and how it adversely affects XMl repositories like native XML
>databases and XML-enabled databases.
>
>1.)  What has struck me particularly as being unfortunate is that I've yet to
>see an XML data
>manipulation language with the simple SELECT-UPDATE-DELETE semantics that
>users of relational databases (i.e SQL users) and hierarchical databases (i.e.
>DL/I users) have had for years and have come to take for granted.

Hi Dare,

You are probably aware that both Software AG and Microsoft have implemented 
updates as an extension to XQuery. The following thesis describes the 
Software AG implementation of updates:

http://www.lehti.de/beruf/diplomarbeit.pdf

You can download Software AG's implementation here:

http://www.softwareag.com/developer/quip/default.htm

I am not aware whether there is documentation for the Microsoft 
implementation (perhaps Michael Rys can say?), but there is a grammar and 
some running examples, which you can find here:

http://xmlqueryservices.com/

Both the Microsoft and Software AG implementations go back to an earlier 
proposal created jointly with IBM and CrossGain. The companies who worked 
on this proposal, and those that have implemented updates, obviously agree 
with you that updates are important. However, it is vital that updates be 
based on a well-defined language, and getting the current set of operators 
in XQuery to be completely defined is clearly the first step.

I think you will continue to see pressure on the XML Query WG to do 
updates. If you had to choose between an XQuery spec without updates, and 
one with updates perhaps 6 months later, which would you prefer? What if 
the update proposal were a separate proposal that came out 6 later, would 
that be acceptable to you?

Jonathan

Received on Friday, 11 January 2002 15:54:54 UTC