[TriZPUG] Off topic - social networking site experience

[Tom Bryan]

OK, a lot off topic, but I know that we have a lot of web developers here.  I 
was wondering whether anyone had worked on any social networking software.  
Things like facebook, twitter, etc.  

Specifically, I'm interested in their schema design.  For one of my projects, I 
may need to take a large network of inter-related objects (stored in a DB) and 
answer questions about them.  I care less about "how many friends does X 
have?" and more about questions like "show the top 10 hits for users sorted by 
the number of their friends who are also software engineers."  

I may be able to get away with just supporting reports on data that's a day 
old, so I'm looking at data marts and star schemas and such.  I was just 
thinking that some social networking sites may have to solve this type of 
problem without the time lag of a nightly ETL process.  

I've done some searching, but I'm not finding much.  Perhaps I'm looking in the 
wrong places.  I come up with a lot of information about social networking 
sites but very little about their design.  Is anyone talking about this stuff?  
Is it all hush hush?  Or is it all technically straightforward once you have 
the "big idea" to create a site based around the members and their 
interactions?  

Thanks,
---Tom