An example of the event data is depicted in FIG. 2B. In the example of FIG. 2B, records respectively including the event name, the time (the time stamp which is the occurrence time of the event), the event ID (here, ID1) and other values and records respectively including the event name, the time (the time stamp), ID1, ID2 and the like are extracted from plural table (e.g. databases), and when one