Re: Interoperability between Mutable and Immutable Versioning

Chris Kaler (ckaler@microsoft.com)
Thu, 21 Jan 1999 09:30:47 -0800


Message-ID: <4FD6422BE942D111908D00805F3158DF0A757BD3@RED-MSG-52>
From: Chris Kaler <ckaler@microsoft.com>
To: "'Geoffrey M. Clemm'" <gclemm@tantalum.atria.com>,
Date: Thu, 21 Jan 1999 09:30:47 -0800
Subject: RE: Interoperability between Mutable and Immutable Versioning


Personally, I like the THAW/FREEZE idea we discussed because it requires an
overt action to replace an older revision.  I guess I don't really get what
it means to "checkout" an old revision that will be replaced on checkin and
not branched.  To mean they seem like dissimilar things that need to
interoperate.  Doing a THAW, GET, PUT, FREEZE seems a viable approach for
DMS systems that need to do this.  I still think the mainline case is that
you checkout/in and create immutable revisions.  The THAW/FREEZE is just a
way to support DMS scenarios within the versioning model.

Chris

-----Original Message-----
From: Geoffrey M. Clemm [mailto:gclemm@tantalum.atria.com]
Sent: Thursday, January 21, 1999 8:42 AM
To: ietf-dav-versioning@w3.org
Subject: Interoperability between Mutable and Immutable Versioning



To clarify my position on this topic, it is my belief that the protocol
could be designed in a way to make mutable and immutable versioning
incompatible (i.e. by providing a THAW and FREEZE operations that
would fail on versioned resources that supported immutable revisions),
or could be written in a way to make them compatible (i.e. by providing
a consistent interpretation of CHECKOUT/CHECKIN for both.

The CHECKOUT/CHECKIN model I posted in my earlier message is the
latter (i.e. interoperable) protocol.  In this form, I not only
believe that mutable versioning is acceptable, but I advocate it as an
interoperable simplification of the more powerful but more complex
configuration management protocol.

Cheers,
Geoff