Date: Fri, 3 Dec 1999 12:13:42 -0500 Message-Id: <9912031713.AA11923@tantalum> From: "Geoffrey M. Clemm" <geoffrey.clemm@rational.com> To: ietf-dav-versioning@w3.org In-Reply-To: <"i41fs1.ira.834:03.12.99.13.50.10"@ira.uka.de> (jjh@ira.uka.de) Subject: Re: immutable DAV:merge-predecessors <gmc/> I have come to believe that the cost to a server implementation resulting from requiring the mutablity of DAV:merge-predecessors outweighs the benefit that results, so I'd like to propose that we follow Jim's suggestion and make DAV:merge-predecessors be an immutable property. <jjh/> Is there a concept of set once properties, i.e. properties that need not be set a revision creation time but once set they are no longer changeable? <gmc/> No, we currently have no such notion. <jjh/> How strictly is immutable defined in terms of check-in time. <gmc/> Very strictly. The idea is that you check something in to make it immutable (and the server implementation can then take advantage of that immutability to make workspace caching efficient). <jjh/> Do all immutable revision properties need to specified with the corresponding check-in request? <gmc/> Yes, in the sense that the current values of those properties of a working resource become immutable when the working resource is checked in to create a revision. <jjh/> I would agree that one should not change DAV:merge-predecessors once it is set, but it may be convenient to set it later. <gmc/> Why would you set it later? Since the body of the revision cannot be changed after check-in, there could be no new contributors (i.e. predecessors) after the check-in. <jjh/> Though I do not see a big difference for merging either way. If merging is done on the server, then this is probably a none issue. <gmc/> So just to make sure, I read this as agreement to make DAV:merge-predecessors immutable? Cheers, Geoff