Studierende stehen vor dem LC und blicken lächelnd einer Kollegin mit einer Mappe in der Hand nach.

Exercise No. 20: Freight Bookings (dfm)

In this E/R schema a customer - who belongs to a certain customer group (private, business, etc.) - orders a freight booking. It consists of certain freight which belongs to a certain type of freight. The freight booking is carried out by an employee who works for a branch of a forwarding agent. This branch belongs to a certain forwarding agent. Shipping documents which include the date and the costs of the freight booking are attached. The time dimension consists of week, month and quarter.

Figure D.E.28.1 - freight bookings

Please identify the fact of interest and build the attribute tree. Let us assume that shipping documents shall not be part of the date warehouse. Its attributes date and costs are of interest and shall be included! Some attributes cannot be used for aggregation in a meaningful way. Those should be tagged as non-dimension attributes in the fact schema.

Then derive the fact schema from the tree by defining dimensions, fact attributes and hierarchies and build a glossary for the fact attributes if there are any.

This exercise is part of a case study: dfm - apa - log