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Exercise No. 22: Travel Booking (apa)

As the result of DFM Case "travel booking" this cube stores data about travel booking.

We have four dimensions with the following hierarchical structure:

Table A.E.46.1 - travel booking

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

1) "an annual report on the tour operator level independent of all other dimensions"

2) "a roll up by the time dimension starting at quarters for each combination of customer type and country, independent 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.46.1 - The resulting APA with the redundancy free-set highlighted

Size of the redundancy-free set (including the base cube): 144

Required cubes, the materialization decision and derivatives

The blue area represents the end-user requirement 1 ("an annual report on the tour operator level independent of all other dimensions") and requirement 2 ("a roll up by the time dimension starting at quarters for each combination of customer type and country, independent of all other dimensions").

Materializing cube v = (C_*,TA_to,TR_*,T_y) (dark blue cell "T_y", representing end-user requirement 1) and cube w = (C_ty,TA_*,TR_co,T_q) (dark green cell "T_q", representing end-user requirement 2) offer us the following sets of derivatives.

Figure A.E.46.2 - Derivatives of cube v = (C_*,TA_to,TR_*,T_y)

Figure A.E.46.3 - Derivatives of cube w = (C_ty,TA_*,TR_co,T_q)

Figures A.E.46.2 and A.E.46.3 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 cube v and w.

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