[Zope-dev] Versions: should they die?

[Lennart Regebro]

Brad Clements wrote:
> Sorry if is OT.
> 
> I'd like ZODB and Zope to support Revisions. That is, historical copies that do not get 
> removed when ZODB is packed.
> 
> Does the Version mechanism contribute to this kind of functionality?

No, not really. Maybe it can be coached into doing it, but not without 
much ado.

> Maybe this is kind of the reverse way of doing what versions are for. We have used 
> versions a little to work on a "live site". 

That seems to be the only use for it, being able to make several updates 
on a site without the updates being seen. It's not a bad feature, but 
it's too limited for much of the use, where you instead want revisions 
of objects and workflows where you can stage the piublishing of 
different revisions. And for doing that you have no use of the ZODB 
versions at all, as they are done today. You are better off using 
multiple instances of the objects, one for each revision, and then 
creating a staging workflow with DCWorkflow.

> So, I could continue to use ZMI as normal, but run "another zserver" on a different 
> port (the one that feeds the world) with a particular revision. Or I could do this with 
> ZEO.
> 
> Probably there's too much overhead in this idea. 

Well, it's too much overhead in doing it with ZODB, yes.