inheritance.sql

create table t_order(id int, created_on timestamptz, value int, check (false) no inherit);

create index ON t_order(created_on);

create index ON t_order(id);

create table t_order_201701 (LIKE t_order INCLUDING indexes) INHERITS (t_order);

create table t_order_201612 (LIKE t_order INCLUDING indexes) INHERITS (t_order);

alter table t_order_201612 add constraint part check (created_on >= '2016-12-01' and created_on < '2017-01-01');

CREATE OR REPLACE FUNCTION public.ins_route()
 RETURNS trigger
 LANGUAGE plpgsql
AS $function$
begin
  if NEW.created_on >= '2016-12-01' and NEW.created_on < '2017-01-01' then
   insert into t_order_201612 values(NEW.*);
  end if;
  if NEW.created_on >= '2017-01-01' and NEW.created_on < '2017-02-01' then
   insert into t_order_201701 values(NEW.*);
  end if;
  return null;
end;
$function$;

create trigger trg_rerout before insert on t_order for each row execute procedure ins_route();