When at the data warehouse, drawing up the summary data from the detailed data, it is summary level.

For example, whenever the sale data it totals the detailed data which is voucher level, as type classified by week, classified by month or commodity said small classification, dividing into two equal parts and large classification from classified by day, it keeps enlarging the totaling unit, level of summary keeps becoming rough.

At the data warehouse, adjusting to the needs of the data application person, you prepare the summary data of various