BEGIN DECLARE v_enabled ENUM('YES', 'NO', 'UNKNOWN');  IF (in_connection_id IS NULL) THEN RETURN NULL; END IF;  SELECT INSTRUMENTED INTO v_enabled FROM performance_schema.threads  WHERE PROCESSLIST_ID = in_connection_id;  IF (v_enabled IS NULL) THEN RETURN 'UNKNOWN'; ELSE RETURN v_enabled; END IF; END