id |tab | idfkp
-------------
1|'sh0.tab0'|
2|'sh0.tab0'|
3|'sh0.tab0'|2
54|'sh1.tab1'|

CREATE TRIGGER tab0_adr9
    AFTER DELETE ON tab0
    FOR EACH ROW
    EXECUTE PROCEDURE tab0_adr9('sh0.tab0');
	
CREATE TRIGGER tab1_adr9
    AFTER DELETE ON tab1
    FOR EACH ROW
    EXECUTE PROCEDURE sh0.tab0_adr9('sh1.tab1');
		
CREATE TRIGGER tab2_adr9
    AFTER DELETE ON tab2
    FOR EACH ROW
    EXECUTE PROCEDURE sh0.tab0_adr9('sh2.tab2');
	
---
CREATE TRIGGER tab3_adr9
    AFTER DELETE ON tab3
    FOR EACH ROW
    EXECUTE PROCEDURE tab3_adr9();

----
--sh0.tab0_adr9('sh2.tab2') -- функция только для проставления флага, если удаляемый объект последний в цепочке был
----------
CREATE FUNCTION tab0_adr9() RETURNS "trigger"
    AS '
DECLARE
 cmnd text;
BEGIN
-- comment
 IF TG_NARGS=0 OR TG_ARGV[0]=''sh0.tab0'' THEN -- if table-parents
  UPDATE sh0.tab0 SET fl=true WHERE id=OLD.idfkp AND NOT EXISTS
    (SELECT * FROM sh0.tab0 WHERE idfkp=OLD.idfkp); -- set "fl" where somewhere
 ELSE
  cmnd := ''UPDATE '' || TG_ARGV[0] || '' SET fl=true WHERE id='' || trim(OLD.idfkp::text)
       || '' AND NOT EXISTS(SELECT * FROM '' || TG_ARGV[0] || '' WHERE idfkp='' || trim(OLD.idfkp::text) || '')'';
  EXECUTE cmnd;
 END IF;
 RETURN NEW;
END;
'
    LANGUAGE plpgsql;
---
--sh3.tab3_adr9() -- собственно, функция из-за которой удаление записи сворачивается
---------------
CREATE FUNCTION tab3_adr9() RETURNS "trigger"
    AS '
DECLARE
 cmnd        text;
 rec         RECORD;
 rstxt       text;
BEGIN
 cmnd := ''SELECT id FROM ONLY '' || OLD.tab || '' WHERE id='' || trim(OLD.id::text); -- в поле tab хранится название таблицы, из которой удаляем, в данном случае 'sh0.tab0' 
 FOR rec IN EXECUTE cmnd
 LOOP
  rstxt := rec.id;
  IF rec.id = OLD.id THEN -- Если запись существует
   rstxt := rstxt || '' in ''  || OLD.tab;
  RAISE EXCEPTION ''EXIST rec.id = OLD.id = %'',rstxt; -- То выдаем сообщение об ошибке, например, EXIST rec.id = OLD.id = 1
  END IF;
  EXIT;
 END LOOP;
 RETURN OLD;
END;
'
    LANGUAGE plpgsql;

 DELETE FROM sh0.tab0 WHERE id = 1

CREATE RULE name AS ON DELETE
    TO sh0.tab0 
    DO DELETE FROM sh3.tab3 WHERE id = old.id