Hello,

I'm currently developing an application to allow students to manage their courses, and I don't really know how to design the database for a specific feature. The client wants, a lot like Facebook, that when a student displays the list of people currently in a specific course, the people with the most mutual courses are displayed first.

As an additional feature, I would like to add a search feature to allow students to search for another one, and displaying first in the search results the people with most mutual courses.

I currently use MySQL, I plan to use Cassandra for some other features, and I also use Memcached for result caching.

Thanks.