In Section 3.3, we used BW's default simple one-to-one mappings for characteristic data. In this section, we will write a transfer rule in the ABAP language.
Table 1.4 lists the material per unit sales price and quantity sold. It does not provide any sales revenue data, however. To improve future query performance, it is recommended that we calculate the sales revenue and save this result in the fact table, rather than calculate the sales revenue during a query run. The database design in Figure 1.1 reflects this idea, and the following procedure shows how to implement it.
