Thomas B. Passin writes:

But it will be in your book, right? Currently, I do not expect it.

The book should come with complete examples, ready to be examined and run. Incorporating an external database seems to be too demanding. Gadfly, on the other hand, seems to be not thread safe. Thus, I should probably not use this, either. This probably means, I will skip relational database integration (which is covered in the Zope book). Dieter