Update boucle toutes les 10000

declare i number := 0;
begin
  for r in (select id from dps_user)
  loop
    update dps_user
       set password = lower(password)
     where id = r.id;
  i := i+1;
if mod(i, 10000) = 0 THEN    -- Commit every 10000 records
      COMMIT;
end if;
  end loop;
commit;
end;