RE: [regrep-query] XQuery, XPath and Content Based Query

[Matthew MacKenzie <matt@xmlglobal.com>]

Team,

With a classification-based query model being the basis of CBQ, I don't
think that we are even likely to use all of the features of Xpath, let
alone Xquery.  If you think about it, what is needed is a syntax for
defining an index and a syntax for querying against that index.  Let's
take for example indexing an XML document, or automatically classifying
it - I don't know how the group wants to refer to this.

Here is an instance:

<?type DOCUMENT?>
<Document>
	<Author rating="100">Dan Chang</Author>
	<Title>Regrep Query Requirements</Title>
	<Version>0.1</Version>
	<Abstract>This is Blah Blah Blah</Abstract>
	<Content><![CDATA[...]]></Content>
</Document>


We've decided that we only want to index author, author rating and
title, so:

Indexes:
--------
/Document/Author/text() -> Author
/Document/Author/@rating/text() -> Rating of author
/Document/Title/text() -> Title

So now, whenever the registry sees a document of type text/xml and a PI
type of DOCUMENT, we index it
As shown above.

Now...the content model of the index is Xpath compliant, and really very
simplistic.  We are indexing simple data, so realistically Xpath for
query is likely sufficient as long as we can do Xpath AND|NOT|OR Xpath.
If we want to use Xquery, we really should attempt to define a virtual
document object model for classifications, so that the Xqueries are made
against the classification's actual structure rather than the structure
of the structure holding the classifications.

Any of this make sense?

-Matt



-----Original Message-----
From: Dan Chang [mailto:dtchang@us.ibm.com] 
Sent: October 24, 2001 9:56 AM
To: regrep-query@lists.oasis-open.org
Subject: [regrep-query] XQuery, XPath and Content Based Query


Team,

I would like to propose that we start thinking about and working on the
subject items for V3. As you know, Content Based Query has been an
action item for us and is supposed to use XPath for indexing.
Independently, XPath has been proposed for representing Classification
based query, which remains as an open item. Then on the Query proposal,
a vote was cast against it because it was felt that XQuery would be a
better approach. I believe we should work on all these together since
they are closely related and they must be done in a consistent manner.

If you would like to discuss this in a telecon, please let me know. We
can do it on Friday morning. If you have suggestions on how to approach
this, please let the team know.

Regards,  Dan

Metadata Management Technology and Standard
IBM DBTI for e-Business
Notes:     Dan Chang/Santa Teresa/IBM@IBMUS
Internet:  dtchang@us.ibm.com
VM:          IBMUSM50(DTCHANG)
Phone:    (408)-463-2319


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