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

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

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

SELECT query,application_name FROM pg_stat_monitor ORDER BY query, application_name COLLATE "C";
                                              query                                              |          application_name          
-------------------------------------------------------------------------------------------------+------------------------------------
 SELECT $1 AS num                                                                                | naeem
 SELECT $1 AS num                                                                                | psql
 SELECT pg_stat_monitor_reset()                                                                  | pg_regress/application_name_unique
 SELECT query,application_name FROM pg_stat_monitor ORDER BY query, application_name COLLATE "C" | psql
 Set application_name = 'naeem'                                                                  | naeem
 Set application_name = 'psql'                                                                   | psql
(6 rows)

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

DROP EXTENSION pg_stat_monitor;