Global dimensions is a feature which makes it possible to link else unrelated hierarchies (Different connection/cube) – provided the hierarchies unique names are identical.
When using a criteria on one of the hierarchies in a Global dimension, the criteria is also applied to the other hierarchies in the Global dimension.
Unique names in Analysis Services are prefixed with [Dimension].[Hierarchy], meaning that a unique name belonging to a dimension with the name ‘Period’ cannot immediately be applied in another cube where the dimension is named ‘Posting period’, but the system is made in such a way that the prefix is exchanged before the query reaches Analysis Services.
At present there is no UI for configuring Global dimensions. It all happens in an XML-file: ProgramData\TARGIT\ANTserver\Settings\GlobalDimensions\GlobalDimensions.xml.
This is an example of the GlobalDimensions.xml file:
<?xml version="1.0" encoding="utf-8"?>
The id attribute is not displayed, but must be unique. The hierarchies to be linked must be written in the same element.
In the example Period->Period from Sales in DemoData is linked to Posting Period->Hierarchy from Clothing in CasualClothing (id=”time_hierarchy”). This also happens with the Month hierarchies (id=”time_month”).