[Zope-dev] ZODB: interface for walking object graph?

Toby Dickenson tdickenson@geminidataloggers.com
Fri, 24 Mar 2000 09:25:32 +0000


On Thu, 23 Mar 2000 16:07:17 -0500 (EST), "Andrew M. Kuchling"
<akuchlin@mems-exchange.org> wrote:

>I'd like a way to find all instances of a given class in a ZODB.  (In
>ODBMS jargon, this feature seems to be called "class extents".)  The
>purpose is to handle changes to a class that require rearranging; you
>can do it lazily in a __setstate__ method, but after you've had 10
>changes, that __setstate__ will be really complicated.

This is an effect that concerned me when I first looked at ZODB, but I
was pleasantly suprised at the lack of complicated __setstate__
methods in the Zope source.

So far my products are free of this effect too.

Andrew, are your experiences different?


Toby Dickenson
tdickenson@geminidataloggers.com