CREATE EXTENSION pg_stat_monitor;
SELECT pg_stat_monitor_reset();
 pg_stat_monitor_reset 
-----------------------
 
(1 row)

SELECT 1 AS num;
 num 
-----
   1
(1 row)

SET application_name = '';
SELECT 1 AS num;
 num 
-----
   1
(1 row)

SELECT query, application_name, application_name IS NULL AS isnull FROM pg_stat_monitor ORDER BY query, application_name COLLATE "C";
             query              |      application_name       | isnull 
--------------------------------+-----------------------------+--------
 SELECT 1 AS num                | pg_regress/application_name | f
 SELECT 1 AS num                |                             | t
 SELECT pg_stat_monitor_reset() | pg_regress/application_name | f
 SET application_name = ''      | pg_regress/application_name | f
(4 rows)

SELECT pg_stat_monitor_reset();
 pg_stat_monitor_reset 
-----------------------
 
(1 row)

-- The parameter is deprecated and has no effect, but setting it must still
-- emit a deprecation warning.
SET pg_stat_monitor.pgsm_track_application_names = off;
WARNING:  pg_stat_monitor.pgsm_track_application_names is deprecated and has no effect
DETAIL:  Application names are always tracked.
DROP EXTENSION pg_stat_monitor;