CREATE OR REPLACE FUNCTION "public"."get_doc_parents" (inout node_id integer) RETURNS SETOF integer AS
$body$
DECLARE
  parent_id INTEGER;
BEGIN
  IF node_id IS NOT NULL THEN
    RETURN NEXT;
    WHILE node_id IS NOT NULL LOOP
      SELECT parent_id FROM docs WHERE id = node_id INTO parent_id;
        IF parent_id IS NULL THEN
          RETURN;
        END IF;
        node_id := parent_id;
        RETURN NEXT;
    END LOOP;
  END IF;
  RETURN;
END;
$body$
LANGUAGE 'plpgsql' VOLATILE CALLED ON NULL INPUT SECURITY INVOKER;

SELECT * FROM get_doc_parents( 300 );

CREATE OR REPLACE FUNCTION range10 (out id integer, out name text) RETURNS SETOF record AS
$body$
DECLARE
  rec RECORD;
BEGIN
  FOR rec IN EXECUTE 'SELECT id, name FROM table1' LOOP
    id := rec.id;
    name := rec.name;
    RETURN NEXT;
  END LOOP;
  RETURN;
END;
$body$
LANGUAGE 'plpgsql' VOLATILE CALLED ON NULL INPUT SECURITY INVOKER;

SELECT id, name FROM range10()