Spatial Data Warehouses - Data Warehouse Systems: Design and Implementation - page 445

11.5 GeoMondrian
GeoMondrian 1 is a spatial OLAP (SOLAP) server. It is a spatially extended
version of Pentaho Analysis Services, also known as Mondrian, which we
have discussed in Sect. 5.10 . The open-source version of GeoMondrian only
supports PostGIS-based data warehouses, while the commercial version adds
support for Oracle, SQL Server, and MySQL.
GeoMondrian integrates spatial objects into the OLAP data cube struc-
ture. It implements a native geometry data type and provides spatial
extensions to the MDX query language, thus enabling spatial analysis
capabilities into analytical queries. The geospatial extensions to the MDX
query language include inline geometry constructors, filtering of members
based on topological predicates, spatial calculated members and measures,
and calculations based on scalar attributes derived from spatial features.
As it is the case in Mondrian, a cube schema is defined in GeoMondrian
using an XML syntax. 2 GeoMondrian adds the Geometry data type for
member properties. For example, the spatial hierarchy of the Customer
dimension in the GeoNorthwind cube (Fig. 11.4 )isdefinedasfollows:
< Hierarchy primaryKey= '' CustomerKey '' primaryKeyTable= '' Customer '' >
...
< Level name= '' Continent '' table= '' Continent '' column= '' ContinentName '' / >
< Level name= '' Country '' table= '' Country '' column= '' CountryName '' >
...
< Property name= '' CountryGeo '' column= '' CountryGeo type= '' Geometry '' / >
< /Level >
< Level name= '' Region '' table= '' State '' column= '' RegionName '' >
...
< /Level >
< Level name= '' State '' table= '' State '' column= '' StateName '' >
...
< Property name= '' CapitalGeo '' column= '' CapitalGeo '' type= '' Geometry '' / >
< Property name= '' StateGeo '' column= '' StateGeo '' type= '' Geometry '' / >
< /Level >
< Level name= '' City '' table= '' City '' column= '' CityName '' >
...
< Property name= '' CityGeo '' column= '' CityGeo '' type= '' Geometry '' / >
< /Level >
< Level name= '' Customer '' table= '' Customer '' column= '' CompanyName '' >
...
< Property name= '' CustomerGeo '' column= '' CustomerGeo ''
type= '' Geometry '' / >
< /Level >
< /Hierarchy >
1 http://www.spatialytics.org/projects/geomondrian/
2 Note that in Sect. 5.10 we described Mondrian version 4.0. The current version of
GeoMondrian uses version 3.0 of the Mondrian metamodel.