The default RRA stores primary data points for a week. More RRA can be added for a month, a quarter and a year. The created RRD is for an acquisition period much less than a week, typically about some hours.

This constructor neads an argument named step which is the period of acquisition. The natural step unit is the hour(h), although second(s), minute(mn) and day(d) are allowed.

    $creator = RRDTool::Creator::WeekPDP(-step => "4h") ;
    $creator->add_RRA(-duration => "month") ;
    $creator->add_RRA(-duration => "quarter") ;
    $creator->add_RRA(-duration => "year") ;