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RE: DASL solicits your opinions on structured queries (e.g. for Dublin Core)

From: Slein, Judith A <JSlein@crt.xerox.com>
Date: Mon, 12 Oct 1998 17:42:36 -0400
Message-ID: <201BB34B3A73D1118C1F00805F1582E8B76CA6@x-wb-0128-nt8.wrc.xerox.com>
To: "'Jim Davis'" <jdavis@parc.xerox.com>, slein@wrc.xerox.com, "'WebDAV'" <w3c-dist-auth@w3.org>
I assumed based on the DASL charter and the requirements that it would be
possible to query on any property that could be exposed through WebDAV.
That would certainly include structured properties.

Aside from meeting expectations, DASL would be dramatically more useful if
it could accept queries on structured properties.  The arguments already
presented on the DASL mailing list are compelling: There are already
structured properties in the DAV: namespace, and there will certainly be
more when the rest of the WebDAV specifications are in place.  Just finding
out basic information like what resources I have locked would require a
structured query.

Imagine an application that lets users construct queries.  It presents the
user with a list of queryable attributes, and a lot of the properties that
the user knows exist are not on the list.  Why not?  Because they are
structured.  I would find this extremely frustrating.  Why can't I query on
creator?  Because it's a list-valued property.  Why can't I query on
resource type? Because its values are XML elements rather than strings.


Judith A. Slein

> -----Original Message-----
> From: Jim Davis [mailto:jdavis@parc.xerox.com]
> Sent: Thursday, October 08, 1998 2:56 PM
> To: slein@wrc.xerox.com
> Subject: DASL solicits your opinions on structured queries (e.g. for
> Dublin Core)
> If you have an opinion about whether DASL should support queries on
> structured properties (e.g. for Dublin Core) *please* speak 
> up in the DASL
> list. There have been several posts there asking for opinions on this
> point, with little or no response.
> As a result of this silence, the current DASL requirements ID does not
> include a requirement for queries on structured properties.  
> We need to
> hear from you on this.
> The DASL home page is http://www.ics.uci.edu/pub/ietf/dasl/
> (Archived) mail messages of greatest relevance are:
> Structure criteria for DASL queries
> http://lists.w3.org/Archives/Public/www-webdav-dasl/1998JulSep
> /0087.html
> (tries to  "make (or reopen) the case for defining a 
> structure criteria
> (also called "structured query") in DASL.")
> Should DASL have structure queries?
> http://lists.w3.org/Archives/Public/www-webdav-dasl/1998JulSep
> /0113.html
> (Attempt to provoke discussion on the need for structured queries)
> If you want to contribute to the design of DASL structured 
> criteria, there
> are two proposals on the table right now, or you can add your own.
> Please see
> initial proposal for structure criteria
> http://lists.w3.org/Archives/Public/www-webdav-dasl/1998JulSep
(Davis's proposal for syntax for structured criteria)

Querying WebDAV Hierarchical Properties -- The Proposal
(Babich's proposal for structured query.)

Some background on the above

what kinds of structure criteria are needed?
(lists the structural features that must be testable)

Querying WebDAV Hierarchical Properties -- Motivation
(Design rationale for the Babich proposal)
Received on Monday, 12 October 1998 17:42:24 UTC

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