[ZODB-Dev] Changing Baseclass

[Christian Robottom Reis]

On Fri, Nov 28, 2003 at 02:15:32PM +0100, Thomas Guettler wrote:
> Now I am rewriting the prototype. This time it was no problem, since
> I could throw away all old objects. But if the application is in production,
> I need to migrate.
> 
> How would you migrate existing objects, if you want to change
> the baseclass?

FWIW if your classes are Persistent from day 0 I don't think you'll have
any problems adding mixins or changing class as you go. I've done this
on occasion (I just added a mixin to a class today) and it worked
without a problem. I do run into trouble if I remove a class before
changing all instances which use it, but that's expected. 

I do think I understand why adding Persistent as a base class to a
pickled instance is bad, but I don't want to risk confusing you without
being sure of it, so I won't <wink>

Take care,
--
Christian Robottom Reis | http://async.com.br/~kiko/ | [+55 16] 261 2331