RE: Comments on 06 spec

>    Scenario A:	Jane directs that the page P and all subordinate
objects be
>deleted from the web W.
>		Joe directs his web browser to retrieve page P from the
web W.
>
>		Issue here is: If deletion of page P and associated
subordinate objects
>from the Web W
>		takes sometime to process, then Joe requests this page
and by that time
>some references
>		to that page might have deleted already and hence joe
sees broken links on
>page P. This throws an
>		integrity issue.  Or in other case, assume joe had
already started editing
>this page P. Jane deleted
>		this and when joe gets into publishing stage there is no
matching
>properties associated with the same
>		document. 

Maybe I am assuming too much, but if I was a user of a commercial-grade
WebDAV system, I would just assume that appropriate locks were taken out
automatically on the subordinate objects, so that Joe could not access P
or its subordinate objects once Jane had set the deletion in motion.  I
would assume this without it being in the spec, as this has been
standard practice in the relational DB world for a number of years, and
this problem is nearly (maybe exactly) isomorphic to the "SQL DELETE on
related tables" problem.  (For a non-DBA, it seems like I've spent a lot
of time on DB-related issues...)  However, other users might make a
different assumption.

(For a freeware WebDAV system, it might be acceptable to let Joe look at
a page with broken links while a deletion was in progress.  One of the
major strengths of Tim BL's approach to hypertext was breaking out of
the Dexter hypertext model, where every link was guaranteed to work --
Dexter-based hypertext would never have worked over the Internet, which
is never all working at the same time.)
==========================================================
Mark Leighton Fisher          Thomson Consumer Electronics
fisherm@indy.tce.com          Indianapolis, IN
"Browser Torture Specialist, First Class"

Received on Monday, 26 January 1998 12:43:55 UTC