POOP / Python (Object Oriented Persistence) ?

[Dirk-Ulrich Heise]

Sounds nice. But imagine this problem:
You write an app for a customer, say, a
paint program that lets the user compose
a picture of elements like boxes, circles etc.
Saving is done by storing the state of the
objects using ZODB.

Later, you want to give the customer a new
version of the program. The object structure
will have changed. Especially, some already
existing classes might have more attributes
now.

Isn't this a very real problem? I mean, i could
get around it using some export/import feature
that saves to a certain file format i define.
So i'd be writing save/load stuff myself again.
So what do i gain using ZODB or pickle or whatever?

That's my principal problem with all this
persistency stuff - interoperability between
versions of a program. Or is ZODB the first
thing to overcome this, and i missed
something?

--
Dipl.Inform. Dirk-Ulrich Heise
hei at adtranzsig.de
dheise at debitel.net


"Tony J Ibbs (Tibs)" <tony at lsl.co.uk> schrieb im Newsbeitrag
news:002e01bfeb19$619a11a0$f0c809c0 at lslp7o.lsl.co.uk...
> OK - I spent some of my "spare" time last night reading
>
> http://starship.python.net/crew/amk/python/writing/zodb-zeo.html
>
...