[mcdonc]

It's best to keep object records small when using ZODB. This does mean you need to do some planning about object structure. Objects that inherit from "persistent.Persistent" are kept as separate records in ZODB, so you can break up a large object into several smaller ones by attaching persistent attributes to another object. If you just make a big structure out of nonpersistent objects, ZODB will have all the downsides of plain old pickle (like slow loading time for large objects) indeed, but its entire purpose is to allow you to not do this.