create or replace function creatData2() returns 
boolean AS
$BODY$
declare ii integer;
 begin
 II:=1;
 FOR ii IN 1..10000000 LOOP
 INSERT INTO ipm_model_history_data (res_model, res_id) VALUES (116, ii);
 end loop;
 return true;
 end;
$BODY$
LANGUAGE plpgsql;
select * from creatData2() as tab;

Postgresql V8.3
CREATE OR REPLACE FUNCTION insert_host_status(_log_date timestamp without time zone, _host inet, _cpu integer, _mem integer, _disk integer)
 RETURNS void AS
$BODY$
DECLARE
  new_start timestamp without time zone;
  current_start timestamp without time zone;
  c_id integer;
  c_log_date timestamp without time zone;
  c_cpu integer;
  c_mem integer;
  c_disk integer;
  c_count integer;
  date_span interval;
BEGIN
  -- insert or update
  SELECT id, log_date, cpu, mem, disk, count INTO c_id, c_log_date, c_cpu, c_mem, c_disk, c_count FROM host_status_byminute WHERE host=_host ORDER BY id DESC limit 1;
  SELECT timestamp_mi(_log_date, c_log_date) INTO date_span;
  IF date_span >= '00:00:60' OR c_id IS NULL THEN
    INSERT INTO host_status_byminute (log_date, host, cpu, mem, disk, count) values (_log_date, _host, _cpu, _mem, _disk, 1);
  ELSIF date_span >= '-00:00:60' THEN
    c_mem := ((c_mem * c_count) + _mem)/(c_count + 1);
    c_cpu := ((c_cpu * c_count) + _cpu)/(c_count + 1);
    c_disk := ((c_disk * c_count) + _disk)/(c_count + 1);
    c_count := c_count + 1;
    UPDATE host_status_byminute SET mem=c_mem, cpu=c_cpu, disk=c_disk, count=c_count WHERE id=c_id;
  END IF;
  -- delete old data
  SELECT date_mii(date(now()), 6) INTO new_start;
  SELECT date(log_date) from host_status_byminute limit 1 INTO current_start; -- omit a bug happened when date is disordered.
  IF new_start > current_start THEN
    DELETE FROM host_status_byminute where log_date < new_start;
  END IF;
END;
$BODY$
 LANGUAGE 'plpgsql' VOLATILE
 COST 100;
ALTER FUNCTION insert_host_status(timestamp without time zone, inet, integer, integer, integer) OWNER TO dbuser_test;