- From: Jim Whitehead <ejw@cse.ucsc.edu>
- Date: Mon, 6 Oct 2003 12:42:43 -0700
- To: "Dan Connolly" <connolly@w3.org>
- Cc: "Massimo Marchiori" <massimo@w3.org>, "Ralph R. Swick" <swick@w3.org>, <www-archive@w3.org>, "Liam Quin" <liam@w3.org>, "C. M. Sperberg-McQueen" <cmsmcq@acm.org>, "Lisa Dusseault" <lisa@xythos.com>
Hi Dan, Thanks for the update! Note that I'm cc'ing Lisa Dusseault, Co-Chair of the WebDAV WG (and, incidentally, author of a book on WebDAV soon to be published by Prentice-Hall). In the WebDAV community, we've recently started a discussion on what the future of DASL should be. There seems to be some consensus around shipping the current specification more or less as-is, since it's quite useful for searching unstructured DAV properties (that is, it provides a good way to perform SQL-like queries on properties that map well to single relational DB cells). While this isn't as general a protocol as I might like, in practice it's pretty useful. There are multiple interoperabile implementations of DASL currently in existence, so we'll likely go to Proposed with the current specification, though there is some discussion of going to Experimental. Follow-on efforts for this protocol are likely to go in the direction of adding data typing to DAV properties to permit better handling of user-defined ("dead") properties (i.e., properties where the underlying relational database doesn't know how to assign a RDBMS type). This will improve handling of conditionals, sort ordering, etc. More discussion on typing of DAV properties can be found in a recent paper of mine, "The WebDAV Property Design": http://www.soe.ucsc.edu/~ejw/papers/spe-whitehead.pdf One question we're not likely to address in the WebDAV WG is how to remotely perform XML and RDF queries. The DASL architecture is quite open -- a request is a SEARCH verb, followed by a query specification in the request body. This request body, if formulated correctly, could probably be used with either SOAP marshalling or the SEARCH verb. So, the open question is how to marshall XML and RDF queries that are executed over a network, either in the presence of resources that have DAV properties, or not (ideally the protocol should handle both cases). IMO, this question has greater relevance to the W3C community than the DAV community, and I'd be interested in moving consideration of this issue to an appropriate W3C venue, of course subject to the typical concerns of whether it's an appropriate W3C activity, if the W3C members are interested, etc. - Jim
Received on Monday, 6 October 2003 15:44:26 UTC