XML Schema response to XML Query Requirements

Paul Cotton, DB2 Language Architecture & Standards
IBM Canada Ltd, 17 Eleanor Drive, Nepean, Ontario K2E 6A3
Phone: (613) 225-5445   Fax:  (613) 226-6913
email: cotton@ca.ibm.com


---------------------- Forwarded by Paul Cotton/Toronto/IBM on 03/24/2000
02:29 PM ---------------------------

David Beech <dbeech@us.oracle.com> on 03/24/2000 12:49:57 PM

Please respond to David Beech <dbeech@us.oracle.com>

To:   w3c-xml-query-wg@w3.org
cc:   w3c-xml-schema-wg@w3.org
Subject:  XML Schema response to XML Query Requirements




On behalf of the chairs of the XML Schema WG, I am pleased to
forward our response to the XML Query Requirements WD, as
agreed by the Schema WG today.

Respectfully submitted,

  David Beech


XML Schema WG response to XML Query Requirements WD [1]
-------------------------------------------------------

XML Schema WG thanks XML Query WG for the opportunity to review
this requirements document.  We apologize for some delay in our
response due to our preoccupation with completing our own
Last Call document prior to seeking to go to CR.

We approve of the general scope of the requirements, and the
reliance on information provided by XML Schema processing
where available.

We have the following comments and questions.


1. Usage scenarios (2.7)
------------------------

Could some more explicit mention be made of querying XML Schemas
in usage scenarios such as 2.7?


2. Reliance on XML Information Set (3.3.1)
------------------------------------------

We would welcome early coordination to ensure that the
PostSchemaValidation-Infoset provides the desired information
for the Query Data Model.


3. Collections (3.3.3)
----------------------

How do you intend to handle "collections of ... [instances of]
simple and complex types" in the Query Data Model?
Is the limited treatment in the current PSV-Infoset
(whitespace-separated lists in text-based simple types,
and maxOccurs for elements) a satisfactory base on which to build?



4. Schema Availability (3.3.5)
------------------------------

We suggest an additional requirement, that it should be possible
in an XML query to specify the schema(s) to be applied to the
input Infoset, either
(a) to add PSV information if it does not have any, or
(b) to override the PSV information from a previous validation.


5. Operations on Schemas (3.4.15)
---------------------------------

Please clarify the nature of access required to "the XML schema
or DTD for a document, if there is one."  We are in process
of determining whether the PSV-infoset for an instance
document should contain an item referring to its schema,
and, if so, what form this should take.


6. References (non-normative)
-----------------------------

XML Schema might usefully be added as a non-normative reference
in any revision of the Query Requirements WD.


================================================================


[1]  XML Query Requirements WD  31 Jan 2000
http://www.w3.org/TR/2000/WD-xmlquery-req-20000131

================================================================

Received on Friday, 24 March 2000 19:30:59 UTC