create table main (
  main_id   int8 not null,
  main_part timestamp,
  primary key (main_id));

create table main_shadow (
  main_id bigserial not null,
  primary key (main_id));

create table sub_one (
  main_id            int8 not null,
  sub_one_data_field text);

alter table main add constraint test_cnstrnt_main_main_shadow_main_id foreign key (main_id) references main_shadow (main_id) on update Cascade on delete Cascade;

alter table sub_one add constraint test_cnstrnt_sub_one_main_shadow_main_id foreign key (main_id) references main_shadow (main_id) on update Cascade on delete Cascade;

create or replace function test_tfnc_main_delete()
    returns trigger as
$body$
begin
    --'on delete cascade' takes care of the related rows
    delete from main_shadow where main_id = old.main_id;
    return old;
end;
$body$
    language plpgsql volatile;

create trigger test_tg_ad_main_delete
    after delete
    on main
    for each row
    execute procedure test_tfnc_main_delete();

create trigger test_tg_ad_main_p1_delete
    after delete
    on main_p1
    for each row
    execute procedure test_tfnc_main_delete();

create trigger test_tg_ad_main_p2_delete
    after delete
    on main_p2
    for each row
    execute procedure test_tfnc_main_delete();

-- and so on for each partition