[Zope3-dev] Does anyone have databases they need to save? (was Re: Database reset)

[Jim Fulton]

Jim Fulton wrote:
> 
> We now have a process for database schema migration:
> 
>   http://dev.zope.org/Zope3/DatabaseGenerations
> 
> We can't use it however, until we get Zope to a baseline,
> generation 0. Once this happens, we can remove all of the existing
> database-backward-compatibility code and use the generation mechanism
> going forward.  I'd like to set a time, sometime in the next week or three,
> to remove the existing backward compatibility code. After we do this,
> the Zope 3 head will no longer be usable for people with databases that
> haven't kept up with the various changes over the last few months.
 >
> How about a week from Today?  How about this Monday? :)
> 
> Does anyone actually care? :)

Well, I forgot something important. The existing backward-compatability
support doesn't necessarily cause out of date database records to be rewritten,
For example, module aliases just make old records usable.  To actually
update the database, we'll need  code that causes objects
to be rewritten to the database.  For staaarters, we'll need to
provide a ZODB database-iteration api.  We plan to do this, but
have haven't done it and we hadn't planned to do it soon.

If no one has data they need to keep, then I'll go ahead and rip out
the existing backward-compatability code on Monday. If anyone does have data
they *need* to keep, then we'll write the necessary iteration code next week
and provide a conversion script.  We could still "logically" do the reset,
assuming that everyone was at generation 0, which would requite the
backward compatability code. Then we'd define a generation 1 that didn't need the
backward-compatability code and an evolver from generation 0 to generation 1.
We still wouldn't be able to rip out all of the backward-compatability code
until later.

So, does anyone actually have data they need to keep?

Jim


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