UNLISTEN — stop listening for a notification
UNLISTEN { channel | * }   UNLISTEN is used to remove an existing
   registration for NOTIFY events.
   UNLISTEN cancels any existing registration of
   the current PostgreSQL session as a
   listener on the notification channel named channel.  The special wildcard
   * cancels all listener registrations for the
   current session.
  
   NOTIFY
   contains a more extensive
   discussion of the use of LISTEN and
   NOTIFY.
  
channelName of a notification channel (any identifier).
*All current listen registrations for this session are cleared.
You can unlisten something you were not listening for; no warning or error will appear.
   At the end of each session, UNLISTEN * is
   automatically executed.
  
   A transaction that has executed UNLISTEN cannot be
   prepared for two-phase commit.
  
To make a registration:
LISTEN virtual; NOTIFY virtual; Asynchronous notification "virtual" received from server process with PID 8448.
   Once UNLISTEN has been executed, further NOTIFY
   messages will be ignored:
UNLISTEN virtual; NOTIFY virtual; -- no NOTIFY event is received
   There is no UNLISTEN command in the SQL standard.