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

Exercise No. 8: Toll Road (dfm)

This simplified E/R schema shows a vehicle driving on a toll road.

Each vehicle is of a certain type (e.g. various sizes of trucks, private cars, etc.) and can use different types of roads (interstates, tunnels, bridges, etc.).
The time dimension consists of day, month and year.

Figure D.E.54.1 - toll road

Please identify the fact of interest and build the attribute tree.
Attributes that cannot be used for aggregation in a meaningful way 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.

Please include an additional fact attribute counting the number of vehicles and calculate the fact attribute toll.

Solution

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

Exercises List