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

[Jim Fulton]

Jim Fulton wrote:
> 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 support doesn't necessarily cause out of date database records to be 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?

I got no response, so I assume that we are free to rip out the
current backward-compatability code.  I'll plan to do that on Thursday.

On Wednesday, I'll tag the CVS head to capture the state of the system just prior
to conversion of the CVS head to subversion.

Jim

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