[Zope] ZODB Caching and XML Document

[Rahul Dave]

Hi,
I'm implementing a site which as a mix of html and Docbook XML documents.
I looked at the XML Document Product and liked the philosophy. 
The way I understand it, a DOM tree is created at document checkin time and 
stored in the object database. When a request comes in for some method on the
tree, it is retrieved from the database and displayed, etc.

ZODB has a cache. On such a DOM tree request, what exactly is cached. Is
it the entire DOM tree object. If so how can I control the individual caching
of the object(can I do that). Having to pull a large DOM tree out of the ZODB
will hurt in time I would think(any benchmarks?) and having that tree
available in memory would be great.

Also, are results of methods on the DOM tree cached. So If the client requests
to display node6 and all under it, will the results os the method implementing
the request be cached?

In general, can a particulay python data structure be marked with some cache
properties. I would like to use 4DOM/4XSLT later so I can provide PDF hardcopy
for the online documents on a section/by section basis (a "print basket" if
you may)

Thanks,
Rahul