[Zope-dev] any limits on object number?

We are builiding a large portal using Zope. We need to create a large number of objects. The data component of the objects is small, but each object carries lots of metadata. My question is: Is there any limit on the number of objects in a given folder? I am not planning to use any external RDBMS. Are there any known performace isssues when the numbeer of objects increase, particularly when we store them in the same folder? thanks in advance. Nagarjuna