GeoBI Architecture Based on Free Software: Experience and Review - Geographical Information Systems: Trends and Technologies - page 260

assigned, e.g., the HealthDivision hierarchy. The hierarchy name is built
from dimension and hierarchy names, separated by dot, e.g., CRDivision.
HealthDivision . The additional attributes of a level can be included as a level
property indicating its name, the corresponding attribute name in the SDW
table, and its type. Using GeoMondrian, the type of attributes is extended
by geometry as can be seen in Fig. 7 for defi ning spatial levels for provinces,
counties, and districts. This property can be displayed in a cube browser as
shown in Fig. 8 for a part of geometry of the San José province.
Furthermore, two additional measures (i.e., Births and Deaths ) with
the sum aggregate operator are defi ned in Fig. 7; the third measure called
Population is semi-additive, i.e., it cannot be summed in the hierarchies of
the Time dimension. In our example, this dimension does not include the
hierarchy since the data is collected on an annual basis. According to user
requirements, if the Population for all periods is required, the avg function
could be applied as specifi ed in Fig. 7. Notice also that, in our example, in
order to aggregate the Time dimension members according to all periods, in
the defi nition of the hierarchy for the Time dimension the value true for the
has All parameter must be established. The additional measure with label
CalculatedMember will be explained in the next sub-section.
To simplify the defi nition, Fig. 7 considers denormalized hierarchies of
the CRDivision , i.e., having all attributes in one table. If several tables are
used representing a snowfl ake schema, e.g., District , County , and Province
tables, before defi ning levels the corresponding join operations must be
specifi ed for each hierarchy as can be seen in Fig. 9 for the administrative
division.
Fig. 8. A part of geometry for defi ning a San José province in Costa Rica (GeoMondrian).