Table A.E.26.1 - pizza service

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

1) "a daily report for each combination of cook and employee independent of all other dimensions"

2) "a weekly report on customer groups and the branch of pizza service independent of all other dimensions"

3) "a weekly report for each combination of customer group and city district, irrespective of the other dimensions"

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

Figure A.E.26.1 - The resulting APA with the redundancy free-set highlighted

Size of the redundancy-free set (including the base cube): 216

Required cubes, the materialization decision and derivatives

The blue area represents the end-user requirement 1 ("a daily report for each combination of cook and employee independent of all other dimensions"), requirement 2 ("a weekly report on customer groups and the branch of pizza service independent of all other dimensions") and requirement 3 ("a weekly report for each combination of customer group and city district, irrespective of the other dimensions").

Materializing cube v = (CO_co,B_*,C_*,T_d,E_em) (dark blue cell "C_*", representing end-user requirement 1), cube w = (CO_*,B_bp,C_gr,T_w,E_*) (dark green cell "T_w", representing end-user requirement 2) and cube x = (CO_*,B_*, C_gr,T_w,E_cd) (red cell "E_cd", representing end-user requirement 3) offer us the following sets of derivatives.

Figure A.E.26.2 - Derivatives of cube v = (CO_co,B_*,C_*,T_d,E_em)

Figure A.E.26.3 - Derivatives of cube w = (CO_*,B_bp,C_gr,T_w,E_*)

Figure A.E.26.4 - Derivatives of cube x = (CO_*,B_*, C_gr,T_w,E_cd)

Figures A.E.26.2, A.E.26.3 and A.E.26.4 show that no end-user requirement is covered by the derivatives of another. To meet all end-user requirements we will have to materialize all three cubes, v, w and x.