Table A.E.55.1 - workout

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

1) "a monthly report for the exercises a certain athlete has done"

2) "all athletes who are assissted by a certain personal coach"

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

Figure A.E.55.1 - The resulting APA with the redundancy free-set highlighted

Size of the redundancy-free set (including the base cube): 72

Required cubes, the materialization decision and derivatives

The blue area represents the end-user requirement 1 ("a monthly report for the exercises a certain athlete has done") and the end-user requirement 2 ("all athletes who are assissted by a certain personal coach").

Materializing cube v = (P_*, A_at, E_ex, T_m) (dark blue cell "T_m", representing end-user requirement 1) and cube w = (P_pc, A_at, E_*, T_*) (dark green cell "P_gr", representing end-user requirement 2) offer us the following sets of derivatives.

Figure A.E.55.2 - Derivatives of cube v = (P_*, A_at, E_ex, T_m)

Figure A.E.55.3 - Derivatives of cube w = (P_pc, A_at, E_*, T_*)

Figures A.E.55.2 and A.E.55.3 show that end-user requirement 2 is not covered by the derivatives of v. To meet all end-user requirements we will have to materialize both cubes, v and w.