title: In MongoDb, when only updating 2 fields of a document, is it faster to do a regular update or an atomic update?
body: <p>In MongoDb, if I only need to update 2 fields of a document that has 10-20 columns, is it more performant to do regular update of the whole document or an atomic update($set) of the two fields?</p>
  
  <p>If only updating a few fields, should I always prefer doing atomic updates?</p>