title: How to recover a dropped MongoDB database?
body: <p>If somebody accidentally dropped a MongoDB database but executing db.dropDatabase(), how can he recover the database?</p>
  
  <p>Dropping a database in MongoDB is simple, and the command db.dropDatabase() won't erase all the data on it but marks it as to be deleted, so the size of the database would not change after using the drop command, which I think there should be some way to remove the to-be-deleted marker. Can some one point me how?</p>