Thursday, February 10, 2011

Junk Dimensions?!

Quite often SSAS/DWH designers face with the situation with several if not dozens of small what could be called small dimensions, e.g. Yes/No flags, status etc. To make each of them a separate dimension (say 20 different Yes/No flags dimensions) would simply clutter the data mart and eventually the SSAS cube. The convenient way in my opinion is to rather combine all of them in one dimension with all possible combinations (Cartesian product) from of them from Fact table in the combined dimensions.

So it could look like this:  

DimFlags(FlagID,Status1Flag, Status2Flag, Status3Flag, … etc)

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