This is a technical question aimed at the Stack Exchange developers
I'm wondering about the database storage of each Stack Exchange site. Is each site stored in it's own database?
Mainly however, how do the multiple Stack Exchange websites link a users profile together?
It seems like each Stack Exchange website is a separate database, that then has a master database which records a list of all the sites a users profile is active on. This would seem to allow for a user to easily sign up to one site, with the Stack Exchange network knowing which other sites a user is signed up on.