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

CREATE FUNCTION add(int, int) RETURNS int AS
$$
BEGIN
    RETURN (SELECT $1 + $2);
END
$$ LANGUAGE plpgsql;
CREATE 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);
 CREATE FUNCTION add(int, int) RETURNS int AS +| 
 $$                                           +| 
 BEGIN                                        +| 
     RETURN (SELECT $1 + $2);                 +| 
 END                                          +| 
 $$ LANGUAGE plpgsql                           | 
 CREATE FUNCTION add2(int, int) RETURNS int AS+| 
 $$                                           +| 
 BEGIN                                        +| 
     RETURN add($1, $2);                      +| 
 END                                          +| 
 $$ LANGUAGE plpgsql                           | 
 SELECT add2(1, 2)                             | 
 SELECT pg_stat_monitor_reset()                | 
(5 rows)

-- make sure that we handle nested queries correctly
DO $$
DECLARE
    i int;
BEGIN
    -- default stack limit is 2000kB, 50000 is much larger than that
    FOR i IN 1..50000 LOOP
        EXECUTE format('SELECT %s', i);
    END LOOP;
END
$$;
SELECT pg_stat_monitor_reset();
 pg_stat_monitor_reset 
-----------------------
 
(1 row)

DROP EXTENSION pg_stat_monitor;