CREATE EXTENSION pg_stat_monitor;
Set pg_stat_monitor.pgsm_track='all';
SELECT pg_stat_monitor_reset();
 pg_stat_monitor_reset 
-----------------------
 
(1 row)

CREATE OR REPLACE FUNCTION add(int, int) RETURNS INTEGER AS
$$
BEGIN
	return (select $1 + $2);
END; $$ language plpgsql;
CREATE OR REPLACE function add2(int, int) RETURNS int as
$$
BEGIN
	return add($1,$2);
END;
$$ language plpgsql;
SELECT add2(1,2);
 add2 
------
    3
(1 row)

SELECT query, top_query FROM pg_stat_monitor ORDER BY query COLLATE "C";
             query              |    top_query     
--------------------------------+------------------
 (select $1 + $2)               | SELECT add2(1,2)
 SELECT add2(1,2)               | 
 SELECT pg_stat_monitor_reset() | 
(3 rows)

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

DROP EXTENSION pg_stat_monitor;