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Use cases for Star Joins in Calc Views

Apr 15, 2017 at 09:04 AM

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Former Member

Hi All,

A calculation view can be used in Star join mode as well. But why should I use it over a regular calc view? I never found a satisfactory answer.

Can someone outline a scenario where a star join would offer better performance or any type of gain over a regular calc view?

Just want the use case for this checkbox.

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Former Member Apr 15, 2017 at 05:08 PM
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Lets say you have a 1 Fact:n DIM model. A Sales table(Fact) connected to Customer(DIM1) and Product(DIM2), not considering data quality.

In a Star join I can connect the Fact.CustNo > Dim1.CustNo and Fact.Product > Dim2.Product. A user who wants to aggregate sales by product can write a ad-hoc query without having to consider the Customer join and vice versa.

If I have to model this is a regular Calc. view. I would have to do either Fact.CustNo > Dim1.CustNo(Node1) and Node1.Product > DIM2.Product OR Fact.CustNo > Dim2.Product(Node1) and Node1.CustNo > Dim1.CustNo. Which will not give me the same results if I do not have the right customer/product info in my first join.

This is not a perfect example but nevertheless it should help clarify your question :)

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