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

Exercise No. 8: Toll Road (apa)

This cube stores data about vehicles driving on a toll road.

We have three dimensions with the following hierarchical structure:

Table A.E.54.1 - toll road

Please build the Aggregation Path Array and assume the following end-user requirement:

"a monthly report for the types of vehicles on each road"

Select the corresponding cells in the APA and choose a cube to materialize, then highlight the derivatives of this cube.

Solution

Figure A.E.54.1 - The resulting APA with the redundancy free-set highlighted

Size of the redundancy-free set (including the base cube): 36

Required cubes, the materialization decision and derivatives

The blue area represents the end-user requirements ("a monthly report for the types of vehicles on each road"), they are met by materializing cube v = (V_ty, R_ro, T_m) (dark blue cell "T_m"). The area to the right of the black line includes all derivatives of v.

Figure A.E.54.2 - Derivatives of cube v = (V_ty, R_ro, T_m)

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

Exercises List