[ZODB-Dev] ZODB3 3.3 alpha 1 released

[Jeremy Hylton]

On Thu, 17 Jul 2003 21:48:07 -0400
 "Tim Peters" <tim at zope.com> wrote:
> [Neil Schemenauer]
> > Yay new-style classes, boo to ExtensionClass (although
> you served us
> > well).  Is the on disk DB format the same between 3.2
> and 3.3?  If
> > not, is there some tool that converts a DB that uses
> 3.2
> > ExtensionClass persistent objects to the 3.3 format?
> 
> Hey, we're still trying to figure out how to get 3.3a1
> not to segfault under
> Python 2.2.3 <wink>.  Since we intend that 3.3 eventually
> get used with (the
> then-current) Zope2 too, there will have to be a painless
> way to use a
> database created under 3.2.  I know I haven't done any
> work in that
> direction yet, and I don't think Jeremy has yet either.
>  There was no
> intentional change from the ZODB 3.2 DB format, but how a
> pickle of an
> instance of an ExtensionClass type will get read up when
> ExtensionClass no
> longer exists is something we haven't investigated.  It's
> possible we'll
> have to reimplement ExtensionClass as just another flavor
> of new-style
> class.

We should be in pretty good shape, because Persistent
objects aren't pickled directly.  Instead they're pickled
in two parts -- the class metadata and the instance state.
 I don't think either of those should depend on
ExtensionClass.  I expect an existing database would work
correctly with 3.3a1.

Jeremy