Interview Question #4: Slowly Changing Dimensions

Question

Which type of Slowly Changing Dimension (SCD) would you use if your data was time dependent and you do not require historical comparisons?

A.  Like vs. Like

B.  As Is vs. As Was (Type II)

C.  As Is vs. As Is (Type I)

D.  As Is vs. As Was

Answer

C.   As Is vs. As Is (Type I) involves analyzing all data in accordance with the attribute relationships as they currently exist.

Regardless of how relationships change over time, you aggregate and qualify all data (current and historical) based on the current values in the lookup and relationship tables. If aggregate tables exist, you either have to modify how the values roll up to reflect the current attribute relationships, or you have to ignore the tables when you perform this type of analysis.

MicroStrategy Course Where You Will Learn About This Topic

MicroStrategy Advanced Data Warehousing Course

 

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