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

Exercise No. 43: Flyer (apa)

As the result of DFM Case "flyer" this cube stores data about the "process" of offering flyers.

We have five dimensions with the following hierarchical structure:

Table A.E.19.1 - the "process" of offering flyers

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

1) "a roll up by the time dimension starting at months for each designer independent of the student, the company, the employee and the person taking a flyer "

2) "a daily report of the student independent of the designer, the company, the employee and the person taking a flyer"

3) "a complete drill-down by the time dimension down to week for each employee, irrespective of all other dimensions"

Select the corresponding cells in the APA and choose the cubes to materialize, then highlight the derivatives of those cubes.

Solution

Figure A.E.19.1 - The resulting APA with the redundancy free-set highlighted

Size of the redundancy-free set (including the base cube): 192

Required cubes, the materialization decision and derivatives

The blue area represents the end-user requirement 1 ("a roll up by the time dimension starting at months for each designer independent of the student, the company, the employee and the person taking a flyer "), requirement 2 ("a daily report of the student independent of the designer, the company, the employee and the person taking a flyer") and requirement 3 ("a complete drill-down by the time dimension down to week for each employee, irrespective of all other dimensions").

Materializing cube v = (S_*,D_de,P_*,C_*,E_*,T_m) (dark blue cell "T_m", representing end-user requirement 1), cube w = (S_st,D_*,P_*,C_*,E_*,T_d) (dark green cell "E_*", representing end-user requirement 2) and cube x = (S_*,D_*,P_*,C_*,E_em,T_m) (red cell "T_m", representing end-user requirement 3) offer us the following sets of derivatives.

Figure A.E.19.2 - Derivatives of cube v = (S_*,D_de,P_*,C_*,E_*,T_m)

Figure A.E.19.3 - Derivatives of cube w = (S_st,D_*,P_*,C_*,E_*,T_d)

Figure A.E.19.4 - Derivatives of cube x = (S_*,D_*,P_*,C_*,E_em,T_m)

Figures A.E.19.2 to A.E.19.4 show that no end-user requirement is covered by the derivatives of another vector. To meet all end-user requirements we will have to materialize all three cubes, v, x and w.

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

Exercises List