CREATE TABLE public.parent
(
  recordid integer NOT NULL,
  CONSTRAINT pk_parent_recordid PRIMARY KEY (recordid)
)
WITH (
  OIDS=FALSE
);
ALTER TABLE public.parent
  OWNER TO postgres;

CREATE TABLE public.child1
(
  test1 integer DEFAULT 0,
  CONSTRAINT pk_child1_recordid PRIMARY KEY (recordid)
)
INHERITS (public.parent)
WITH (
  OIDS=FALSE
);
ALTER TABLE public.child1
  OWNER TO postgres;

CREATE TABLE public.child2
(
  test2 integer DEFAULT 0,
  CONSTRAINT pk_child2_recordid PRIMARY KEY (recordid)
)
INHERITS (public.parent)
WITH (
  OIDS=FALSE
);
ALTER TABLE public.child2
  OWNER TO postgres;

insert into public.child1 (recordid, test1) values (1,2);
insert into public.child2 (recordid, test2) values (1,2);
select * from public.parent;

CREATE TABLE doc_id (
  id integer NOT NULL,
  CONSTRAINT doc_id_pk PRIMARY KEY (id)
);

CREATE TABLE doc (
  id integer NOT NULL,
  basicdata text
); -- в doc вставка запрещена триггером, это "виртуальная" таблица

CREATE TABLE doc_specific1
(
-- Inherited from table doc:  id integer NOT NULL,
-- Inherited from table doc:  basicdata text
  specificdata1 text,
  CONSTRAINT doc_specific1_fk_id FOREIGN KEY (id) REFERENCES doc_id (id),
)
INHERITS (doc);

-- Аналогично doc_specific2,3,4,...