create trigger ms_mv_showtime_ut after update on movie_showtimes
  for each row execute procedure ms_mv_showtime_ut();

create trigger ms_mv_showtime_dt after delete on movie_showtimes
  for each row execute procedure ms_mv_showtime_dt();

create trigger ms_mv_showtime_it after insert on movie_showtimes
  for each row execute procedure ms_mv_showtime_it();

