Re: SuperUser check in pg_stat_statements

You can create a Security Definer Funtion which can then be executed by
then non-superuser monitoring role:

(Assuming you have a role monitoring and pg_stat_statements is installed in
schema public)

-- connected as a superuser
CREATE FUNCTION pg_stat_statements()
RETURNS SETOF pg_stat_statements
LANGUAGE SQL
SET search_path='public'
SECURITY DEFINER
AS
$BODY$
SELECT *
FROM pg_stat_statements;
$BODY$;

REVOKE ALL ON FUNCTION pg_stat_statements() FROM public;
GRANT EXECUTE ON FUNCTION pg_stat_statements() TO monitoring;

-- connected as monitoring
SELECT * FROM pg_stat_statements();