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ssasaggregationolapcube

How to add aggregation tables in an SASS cube?


In a transition from Mondrian OLAP server to Microsoft's SSAS OLAP server, I'm trying to find out where the aggregation tables fit in. The database have various fact tables, each with accompanying aggregation tables for year, month and day.

How can one design such a structure in Visual Studio? The current project is "Multidimensional and Data Mining". In cube designer, cube structure only handles measures and dimensions. Aggregations seem to not take any additional tables as parameters. I've found no help online for this issue either, most of the information is about aggregation design. The design is already in place, but how to connect it to the cube?

In Pentaho Mondrian, this was simply done in the schema xml adding aggregation tables inside cube section.

Can anyone share some thoughts on this topic?


Solution

  • In an SSAS Multidimensional model there's no such thing as an aggregation table (unlike in Tabular, which I believe does support them).

    In SSAS MD the only storage structure is the cube. The equivalent of aggregation tables is aggregation designs, which store pre-aggregated values, as part of the cube, but not in a way that is visible and separate, as an aggregation table is.

    Since your legacy system does use aggregation tables, maybe the migration would be easier if it went to MS SSAS Tabular rather than SSAS Multidimensional?