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

Exercise No. 14: Bus Maintenance (dfm)

This E/R schema is about bus maintenance. A mechanic - who works for a certain garage - maintains a bus which is of a certain type. The driver of the bus is also included in this E/R schema because he/she plays an important role. The time dimension consists of month, quarter and year.

Figure D.E.29.1 - bus maintenance

Please identify the fact of interest and build the attribute tree. 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.

Solution

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

Exercises List