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+{{box title="**Contents**"}} |
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+{{toc/}} |
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+{{/box}} |
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+== {{id name="_Toc371021"/}}6.1 Context == |
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+Some statistical systems create views of data based on a “cube” structure. In essence, a cube is an n-dimensional object where the value of each [[dimension>>doc:sdmx:Glossary.Dimension.WebHome]] can be derived from a [[hierarchical code list>>doc:sdmx:Glossary.Hierarchical code list.WebHome]]. The utility of such cube systems is that it is possible to “roll up” or “drill down” each of the [[hierarchy>>doc:sdmx:Glossary.Hierarchy.WebHome]] (% style="color:#e74c3c" %)levels(%%) for each of the [[dimensions>>doc:sdmx:Glossary.Dimension.WebHome]] to specify the (% style="color:#e74c3c" %)level(%%) of granularity required to give a “view” of the data – some [[dimensions>>doc:sdmx:Glossary.Dimension.WebHome]] may be rolled up, others may be drilled down. Such systems give a dynamic view of the data, with aggregated values for rolled up [[dimension>>doc:sdmx:Glossary.Dimension.WebHome]] positions. For example, the individual countries may be rolled up into an economic region such as the EU, or a geographical region such as Europe, whilst another [[dimension>>doc:sdmx:Glossary.Dimension.WebHome]], such as “type of road” may be drilled down to its lower (% style="color:#e74c3c" %)level(%%). The resulting [[measure>>doc:sdmx:Glossary.Measure.WebHome]] (such as “number of accidents”) would then be an aggregation of the value for each individual country for the specific type of road. |
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+Such cube systems rely, not on simple [[code lists>>doc:sdmx:Glossary.Code list.WebHome]], but on [[hierarchical code>>doc:sdmx:Glossary.Hierarchical code.WebHome]] sets (see section 8). |
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+== {{id name="_Toc371022"/}}6.2 Support for the Cube in the Information Model == |
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+Data reported using a [[Data Structure Definition>>doc:sdmx:Glossary.Data structure definition.WebHome]] structure (where each [[dimension>>doc:sdmx:Glossary.Dimension.WebHome]] value, if coded, is taken from a flat [[code list>>doc:sdmx:Glossary.Code list.WebHome]]) can be described by a cube definition and can be processed by cube aware systems. The [[SDMX-IM>>doc:sdmx:Glossary.SDMX Information Model.WebHome]] supports the definition of such cubes in the following way: |
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+* The HierachicalCodelist defines the (often complex) [[hierarchies>>doc:sdmx:Glossary.Hierarchy.WebHome]] of [[codes>>doc:sdmx:Glossary.Code.WebHome]] |
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+* If required, the StructureSet can |
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+** group DataStructureDefinition that describe the cube |
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+** provide a mapping mechanism between the [[codes>>doc:sdmx:Glossary.Code.WebHome]] in the flat [[code lists>>doc:sdmx:Glossary.Code list.WebHome]] used by the DataStructureDefinition and a HierarchicalCodelist where the HierarchicalCodelist uses [[code lists>>doc:sdmx:Glossary.Code list.WebHome]] that are not used in the DataStructureDefinition |
