Avoid super; speeds up Model.new by about 12%

activerecord/lib/active_record/locking/optimistic.rb

@@ -65,7 +65,7 @@ def increment_lock
         end
 
         def attributes_from_column_definition
-          result = super
+          result = self.class.column_defaults.dup
 
           # If the locking column has no default value set,
           # start the lock version at zero. Note we can't use