CREATE OR REPLACE FUNCTION insert_event(... куча параметров...)
  RETURNS bigint AS
$BODY$
declare
 ...
begin
...
execute check_event_part(..);
insert into event (...) values(...);
...
end;

CREATE OR REPLACE FUNCTION check_event_part(...)
  RETURNS void AS
$BODY$
declare 
..
BEGIN
...
	execute create_event_part(...);
...
END;

CREATE OR REPLACE FUNCTION create_event_part(...)
  RETURNS void AS
$BODY$
declare 
..
BEGIN
...
	execute 'create table '||p_part_name|| 
	'( CONSTRAINT '||p_part_name||'_check CHECK (event_date >= DATE '''||p_date||
	''' and event_date<DATE '''||p_next_date||'''))'||
	' INHERITS (event)';
	execute 'CREATE INDEX '||p_part_name||'_eventdate ON '||p_part_name||' (event_date)';
	execute 'CREATE OR REPLACE RULE '||p_part_name||'insert AS ON INSERT TO event '||
	'WHERE new.event_date >= DATE '''||p_date||''' and new.event_date<DATE '''||p_next_date||
	''' DO INSTEAD  INSERT INTO '||p_part_name||' VALUES (new.*)';
	execute 'CREATE TRIGGER tr_event_new AFTER INSERT ON '||p_part_name||
	' FOR EACH ROW EXECUTE PROCEDURE tr_event_new()';
END;