Daanse Tutorial - Virtual Cube Dimensions
Cube with virtual cube with dimension references from other cubes A virtual cube that combines measures and dimensions from multiple physical cubes into a unified analytical view. Virtual cubes enable cross-cube analysis by creating a logical integration layer over existing physical cubes, allowing users to analyze related metrics from different business processes in a single query Catalog have two physical cubes Cube1 and Cube2 and virtual cube Cube1Cube2.
Database Schema
The cube defined in this example is based on a table that stores all the data. The table is named Fact uses for Cube1 and contains two columns: KEY and VALUE. The KEY column serves as a discriminator, while the VALUE column contains the measurements to be aggregated.
<roma:DatabaseSchema id="_databaseSchema_dimensions">
<tables xsi:type="roma:PhysicalTable" id="_table_fact" name="Fact">
<columns xsi:type="roma:PhysicalColumn" id="_column_fact_key" name="KEY"/>
<columns xsi:type="roma:PhysicalColumn" id="_column_fact_value" name="VALUE" type="Integer"/>
</tables>
</roma:DatabaseSchema>Note: This is only a symbolic example. For the exact definition, see the Definition section.
Query
The bridge between the cube and the database is the query element. In this case, it is a TableQuery, as it directly references the physical table Fact.
<roma:TableQuery id="_table_factQuery" table="_table_fact"/>Note: This is only a symbolic example. For the exact definition, see the Definition section.
MeasureCube1
Measure use `C1_Fact` table `VALUE` column with sum aggregation in Cube1.
<roma:SumMeasure id="_measurecube1" name="MeasureCube1" column="_column_fact_value"/>Note: This is only a symbolic example. For the exact definition, see the Definition section.
MeasureCube2
Measure use `Fact` table `VALUE` column with sum aggregation in Cube2.
<roma:SumMeasure id="_measurecube2" name="MeasureCube2" column="_column_fact_value"/>Note: This is only a symbolic example. For the exact definition, see the Definition section.
Cube1
In this example uses cube with fact table Fact as data.
<roma:PhysicalCube id="_cube1" name="Cube1" query="_table_factQuery">
<dimensionConnectors foreignKey="roma:PhysicalColumn _column_fact_key" dimension="roma:StandardDimension _dimension1" overrideDimensionName="Cube1Dimension1" id="_dc_cube1Dimension1"/>
<measureGroups>
<measures xsi:type="roma:SumMeasure" id="_measurecube1" name="MeasureCube1" column="_column_fact_value"/>
</measureGroups>
</roma:PhysicalCube>Note: This is only a symbolic example. For the exact definition, see the Definition section.
Cube1
In this example uses cube with fact table Fact as data.
<roma:PhysicalCube id="_cube1" name="Cube1" query="_table_factQuery">
<dimensionConnectors foreignKey="roma:PhysicalColumn _column_fact_key" dimension="roma:StandardDimension _dimension1" overrideDimensionName="Cube1Dimension1" id="_dc_cube1Dimension1"/>
<measureGroups>
<measures xsi:type="roma:SumMeasure" id="_measurecube1" name="MeasureCube1" column="_column_fact_value"/>
</measureGroups>
</roma:PhysicalCube>Note: This is only a symbolic example. For the exact definition, see the Definition section.
VirtualCubeMeasureOnly
Virtual cube uses mesures from Cube1 and Cube2. Virtual cube has references for them. Also virtual cube has references to dimensions from Cube1 and Cube2
<roma:VirtualCube id="_cube1cube2" name="Cube1Cube2" defaultMeasure="roma:SumMeasure _measurecube1" dimensionConnectors="_dc_cube1Dimension1 _dc_cube2Dimension1" referencedMeasures="roma:SumMeasure _measurecube1 roma:SumMeasure _measurecube2"/>Note: This is only a symbolic example. For the exact definition, see the Definition section.
Definition
This files represent the complete definition of the catalog.
<?xml version="1.0" encoding="UTF-8"?>
<xmi:XMI xmi:version="2.0" xmlns:xmi="http://www.omg.org/XMI" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:roma="https://www.daanse.org/spec/org.eclipse.daanse.rolap.mapping">
<roma:Catalog description="Dimension configuration in virtual cubes" name="Daanse Tutorial - Virtual Cube Dimensions" cubes="_cube1 _cube2 _cube1cube2" dbschemas="_databaseSchema_dimensions"/>
<roma:DatabaseSchema id="_databaseSchema_dimensions">
<tables xsi:type="roma:PhysicalTable" id="_table_fact" name="Fact">
<columns xsi:type="roma:PhysicalColumn" id="_column_fact_key" name="KEY"/>
<columns xsi:type="roma:PhysicalColumn" id="_column_fact_value" name="VALUE" type="Integer"/>
</tables>
</roma:DatabaseSchema>
<roma:TableQuery id="_table_factQuery" table="_table_fact"/>
<roma:Level id="_level" name="Level" column="_column_fact_key"/>
<roma:ExplicitHierarchy id="_hierarchywithouthasall" name="HierarchyWithoutHasAll" hasAll="false" primaryKey="_column_fact_key" query="_table_factQuery" levels="_level"/>
<roma:StandardDimension id="_dimension1" name="Dimension1" hierarchies="_hierarchywithouthasall"/>
<roma:PhysicalCube id="_cube1" name="Cube1" query="_table_factQuery">
<dimensionConnectors foreignKey="_column_fact_key" dimension="_dimension1" overrideDimensionName="Cube1Dimension1" id="_dc_cube1Dimension1"/>
<measureGroups>
<measures xsi:type="roma:SumMeasure" id="_measurecube1" name="MeasureCube1" column="_column_fact_value"/>
</measureGroups>
</roma:PhysicalCube>
<roma:PhysicalCube id="_cube2" name="Cube2" query="_table_factQuery">
<dimensionConnectors foreignKey="_column_fact_key" dimension="_dimension1" overrideDimensionName="Cube2Dimension1" id="_dc_cube2Dimension1"/>
<measureGroups>
<measures xsi:type="roma:SumMeasure" id="_measurecube2" name="MeasureCube2" column="_column_fact_value"/>
</measureGroups>
</roma:PhysicalCube>
<roma:VirtualCube id="_cube1cube2" name="Cube1Cube2" defaultMeasure="_measurecube1" dimensionConnectors="_dc_cube1Dimension1 _dc_cube2Dimension1" referencedMeasures="_measurecube1 _measurecube2"/>
</xmi:XMI>Tutorial Zip
This files contaisn the data-tables as csv and the mapping as xmi file.