Greetings. I'm developing a Zope (2.7) product, and I've got a particular persistent object that's going to be a real bottleneck, in that there will be many threads trying to change the state of the object more or less simultaneously. I'd like to "spread out" the problem by taking member fields of the object (lists, dictionaries, etc.) and making them persistent sub-objects in their own right. That way, changes made to one of them can be saved to the ZODB without causing thread conflicts with changes being made to others, removing at least some of the thred conflicts. However, I don't know how to do this. Is it as simple as using a PersistentMapping where I'd normally use a standard Python dictionary? Or shall I wrap each one in a custom class that subclasses Persistent? Does my parent object have to handle these in any special way so that the ZODB knows to give them their own DB records? I've tried looking at how ObjectManager does things, and found it less than enlightening. Thanks, ..Ian Beatty University of Massachusetts Amherst