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Representing Repeating Groups within A Dimension

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Representing Repeating Groups within A Dimension Empty Representing Repeating Groups within A Dimension

Post  4l4nrbl4ck Fri May 18, 2012 5:24 am

Hi,

What is the best way to represent repeating groups within a Dimension.

I have, for example, a simple start schema that has DIM_CUSTOMER and FACT_SALES.

For my customer, I want to record their nationality; however, for some customers, they may have multiple nationalities. How is this best represented?

There could be other data items that could have 1-n occurrences.

If it was a time related attribute, for example, Occupation, then I could have a slowly changing dimension, although some people have multiple concurrently running occupations that we may want to record.

Thanks,
Al.

4l4nrbl4ck

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Post  ngalemmo Fri May 18, 2012 12:38 pm

If you are in retail, good luck. It's hard enough to get a name let alone a nationality. It would seem to me that trying to collect more than one is a bit overkill. But, if you must, include a second or third column.
ngalemmo
ngalemmo

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Post  4l4nrbl4ck Sun May 20, 2012 4:05 am

Thanks for the reply.

It's actually a system for Criminal Justice. I was picking a common example, when using Sales.

Maybe this problem is not as common as I thought it may be. For some attributes, adding column1...column2 will certainly work. For some, not so easy when there are an unknown number of members in the group.

Let's say I was writing the Facebook 'advertising' Data Warehouse. I have DIM_MEMBERS, DIM_DISPLAYS_ADS and FACT_CLICKS_ON_DISPLAY_ADS.

Facebook allows its Members to record their Interests (to allow for targeted advertising), so I could also have DIM_INTERESTS.

A Member has many concurrent interests.

I wonder how the relationship between a Member, their Interests and the Facts would be represented?

I may want to run a report that shows the number of Ads clicked on my people under 21 and who are interested in Football and Rugby.

Al.

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