48.8. Synchronous Replication Support for Logical Decoding
  Logical decoding can be used to build
  
   synchronous
    replication
  
  solutions with the same user interface as synchronous
    replication for
  
   streaming
    replication
  
  .  To do this, the streaming replication interface
    (see
  
   Section 48.3
  
  ) must be used to stream out
    data. Clients have to send
  
   Standby status update (F)
  
  (see
  
   Section 52.4
  
  ) messages, just like streaming
    replication clients do.
 
Note
   A synchronous replica receiving changes via logical decoding will work in
     the scope of a single database. Since, in contrast to
     that,
   
    
     synchronous_standby_names
    
   
   currently is
     server wide, this means this technique will not work properly if more
     than one database is actively used.