[bdbxml] Space Time Complexity - Performance issues

Hi all
I wanted to know what is the space time complexity (or performance limits) 
for 
1. Querying across a container with n documents (Indexed)
2. Querying across a container with n documents (non-Indexed)
3. Cross-querying across 2 containers having m and n documents (Indexed)

I want to know the theoretical limits of these queries. Also, it wd be great 
if you can fwd me some experimentation values etc. or any other documents 
which provide info abt the theoretical limits of querying, indexing, and 
population. 

Thanks
Regards
Manish