Description
UNLISTEN
is used to remove an existing NOTIFY registration.
UNLISTEN cancels any existing registration of the current
PostgreSQL session as a listener on the notify
condition notifyname.
The special condition wildcard * cancels all listener registrations
for the current session.
NOTIFY
contains a more extensive
discussion of the use of LISTEN and
NOTIFY.
Notes
notifyname
need not be a valid class name but can be any string valid
as a name up to 64 characters long.
The backend does not complain if you unlisten something you were not
listening for.
Each backend will automatically execute UNLISTEN * when
exiting.
Usage
To subscribe to an existing registration:
LISTEN virtual;
LISTEN
NOTIFY virtual;
NOTIFY
Asynchronous NOTIFY 'virtual' from backend with pid '8448' received
Once UNLISTEN has been executed, further NOTIFY commands will be
ignored:
UNLISTEN virtual;
UNLISTEN
NOTIFY virtual;
NOTIFY
-- notice no NOTIFY event is received
