please explain read path when key not in database

[Igor]

Hello!

Explain please, how this work when I request for key which is not in 
database

 * The closest node (as determined by proximity sorting as described
   above) will be sent a command to perform an actual data read (i.e.,
   return data to the co-ordinating node).
 * As required by consistency level, additional nodes may be sent
   digest commands, asking them to perform the read locally but send
   back the digest only.
     o

       For example, at replication factor 3 a read at consistency level
       QUORUM would require one digest read in additional to the data
       read sent to the closest node. (SeeReadCallback
       <http://wiki.apache.org/cassandra/ReadCallback>, instantiated
       byStorageProxy <http://wiki.apache.org/cassandra/StorageProxy>)


I have multi-DC with NetworkTopologyStrategy and RF:1 per datacenter, 
and reads are at consitency level ONE. If local node responsible for key 
replied that it have no data for this key - will coordinator send digest 
commands?

Thanks!