6/2     NetFlix rental queue, is it just pure sql to store it or do they
        use a "priority queue" for each member?
        \_ does this mean anything?
        \_ priority queues do exist already. They're called
        relational databases, so they use pure sql
        \_ they store member info in the database, but when it
        comes time to ship they probably build a "priority queue"
        data structure and figure out what the customer wants
        then update the database. So you need both
        \_ it's all real-time, whenever you update your priority
        on NetFlix's queue, your priorities get renumbered starting
        with 1, 2, .etc. ie: if you put 3, 4, they get reset to 1,2
        there, this indicates some business logic which utilizes
        a priority queue before they write back to the database.
        \_ but if multiple people vy for the same titles, NetFlix will give
           priority to those who rent less frequently.
           \_ just add more business rules, yes