Cube - Measures and MeasureGroup

In cases where you need a better overview of all measures, want to provide additional context for a Measure, or need to organize a list of measures, you can use a MeasureGroup.

Database Schema

The cube defined in this example is based on a single table that stores all the data. The table, named Fact, contains two columns: KEY and VALUE. The KEY column acts as a discriminator, while the VALUE column holds the measurements to be aggregated.

<roma:DatabaseSchema   id="databaseSchema">
  <tables xsi:type="roma:PhysicalTable" id="_tab" name="Fact">
    <columns xsi:type="roma:PhysicalColumn" id="_col_key" name="KEY"/>
    <columns xsi:type="roma:PhysicalColumn" id="_col" name="VALUE" type="Integer"/>
  </tables>
</roma:DatabaseSchema>

Note: This is only a symbolic example. For the exact definition, see the Definition section.

Query

This example uses a TableQuery, as it directly references the physical table Fact.

<roma:TableQuery  id="_query" table="_tab"/>

Note: This is only a symbolic example. For the exact definition, see the Definition section.

Grouping Measures

A MeasureGroup is a logical container designed to group related measures. Each MeasureGroup can have a name. Names must be unique within the Cube. Measure only can be in Cubes if they are contained in MeasureGroups. In this example we group all alphabetic measures in one group and all other measures in another group.

<roma:PhysicalCube   id="_cube" name="MeasureGroupCube" query="_query">
  <measureGroups name="Group Alphabetic">
    <measures xsi:type="roma:SumMeasure" id="_measure1" name="Measure A" column="_col"/>
    <measures xsi:type="roma:SumMeasure" id="_measure2" name="Measure B" column="_col"/>
  </measureGroups>
  <measureGroups name="Group Other">
    <measures xsi:type="roma:SumMeasure" id="_measure3" name="Measure 1" column="_col"/>
  </measureGroups>
</roma:PhysicalCube>

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 name="Measure - MeasureGroups" cubes="_cube" dbschemas="databaseSchema"/>
  <roma:DatabaseSchema id="databaseSchema">
    <tables xsi:type="roma:PhysicalTable" id="_tab" name="Fact">
      <columns xsi:type="roma:PhysicalColumn" id="_col_key" name="KEY"/>
      <columns xsi:type="roma:PhysicalColumn" id="_col" name="VALUE" type="Integer"/>
    </tables>
  </roma:DatabaseSchema>
  <roma:TableQuery id="_query" table="_tab"/>
  <roma:PhysicalCube id="_cube" name="MeasureGroupCube" query="_query">
    <measureGroups name="Group Alphabetic">
      <measures xsi:type="roma:SumMeasure" id="_measure1" name="Measure A" column="_col"/>
      <measures xsi:type="roma:SumMeasure" id="_measure2" name="Measure B" column="_col"/>
    </measureGroups>
    <measureGroups name="Group Other">
      <measures xsi:type="roma:SumMeasure" id="_measure3" name="Measure 1" column="_col"/>
    </measureGroups>
  </roma:PhysicalCube>
</xmi:XMI>

Turorial Zip

This files contaisn the data-tables as csv and the mapping as xmi file.

Download Zip File