title: Database level lock on mongodb?
body: <p>I must be wrong about this. I'm considering using mongodb in my project, but I read this:</p>
  
  <p><a href="http://docs.mongodb.org/manual/faq/concurrency/#what-type-of-locking-does-mongodb-use">http://docs.mongodb.org/manual/faq/concurrency/#what-type-of-locking-does-mongodb-use</a></p>
  
  <p>It says that mongodb uses a database level reader-writer lock.</p>
  
  <p>MySQL InnoDB uses row-level locking. Well, doesn't it means, theoretically, mongodb is 2 levels slower than MySQL for concurrent access?</p>