Re: Revision identifier and revisions label namespaces

ÿ (infonuovo@email.com)
Tue, 5 Oct 1999 23:21:46 -0700 

From: <infonuovo@email.com>
To: "'Geoffrey M. Clemm'" <gclemm@tantalum.atria.com>,
Date: Tue, 5 Oct 1999 23:21:46 -0700
Message-ID: <002d01bf0fc3$2975f960$0100007f@conclave>
In-Reply-To: <9910060535.AA14515@tantalum>
Subject: RE: Revision identifier and revisions label namespaces

Yes, I agree with the revision identifiers being in separate namespaces.

Thanks for requesting clarification - I replied to the wrong message!  To be
specific, it is my view that:

1. A system-defined (i.e., server imposed) revision-id is a valuable
mechanisms for insuring invariants of the versioning model regardless of
what is done with properties and whatnot employed for application-specific
purposes.

2. A user-meaningful revision-label is valuable for carrying
application-relevant, human-useful labels that fit someone's notion of
revision identification.

It is useful to provide for both, and they could both occur for a single
revision.  In this case, it does not make much sense for the revision-id and
revision-label to share a namespace.

With regard to interoperability, (1) has no problems, since the server has
complete say in the matter; (2) requires additional agreement if a
revision-creating client is to honor the scheme expected by other users of
the server.  Rather than leave the revision-label underspecified, it might
be prudent not to specify it, so there is no presumption of interoperability
or a priori agreement when there is none.

[I may be using a different sense of interoperability than <gmc>.  I haven't
considered products being from the same vendor as providing any assurance of
interoperability in live application settings.  I'm willing to look for a
better term for what I have in mind, namely multiple parties being able to
achieve a valid cooperative result without being in communication.]

-- Dennis

-----Original Message-----
From: ietf-dav-versioning-request@w3.org
[mailto:ietf-dav-versioning-request@w3.org]On Behalf Of Geoffrey M.
Clemm
Sent: Tuesday, 5 October 1999 22:36
To: ietf-dav-versioning@w3.org
Subject: Re: Revision identifier and revisions label namespaces



   From: <infonuovo@email.com>

   <deh>
   I agree with this.
   It makes no sense to have an user-meaningful label and a system-assigned
   unique identifier have anything to do with each other.  One is for the
   internal integrity of the implementation and preservation of the model.
The
   other is for what people or clients agree to use.

<gmc/> Just to confirm, the position you agree with is that they should
be in separate namespaces?

   It is also valuable to have both notions, though I don't know how you
   propose to have interoperability of the user-meaningful one.
   </deh>

<gmc/> Interoperability between an arbitrary client and an arbitrary
server is probably straightforward (you define the legal set of
strings that can be used as "labels", and define ways to set and
retrieve them).  Making sure that one client creates labels in a way
that is usable by a different client is a separate issue, but not
really one of interoperability, since this issue arises even when you
only use the client and server of a single manufacturer.  Or did you
have some other interoperability issue in mind here?

Cheers,
Geoff