Role Playing Dimension confusion

[MissyEd]

Im currently learning SSAS using the a simplified order schema. The order fact contains multiple dates i.e create_date_key, order_date_key, shipped_date_key each of which is linked back to the calender dimension via a foreign key relationship.

When I process the cube, I end up with a single calendar dimension and multiple dimensions within the cube named after each date_key i.e. CREATE DATE, ORDER DATE, SHIPPED DATE.

Now I thought this was all fine and dandy, then I started reading about role-playing dimensions and did some testing on my cube. It seems OK. The data correlates on a daily basis to what I expected. If I drag in for example both order and invoice date, they seem to group fine.

I'm still concerned I'm missing something with the role playing dimensions. Should I be explicitly creating these? What is the implication if I dont?


"There are only two lasting bequests we can hope to give our children; one of these is roots, the other wings" - Hodding Carter

 

[RiverGuy]

SSAS has basically created role-playing dimensions for you. If you were using another tool, or doing your reports directly off of the relational star schema, then you would want to do something like creating a view for each date over your date dimension table.

 

[MDXer]

A Role Playing Dimension is a single dimension, such as date, that is used multiple times. The cube uses the Same Physical Dimension object but assigns a new name to it in the cube. This prevents you from having to build multiple versions of the same object in order for it to fulfill multiple roles. Date is one of the more common dimensions where you will see it as a role playing dimension. As long as the relationships maintain the same level of granularity there should be no issue.

Paul
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[MissyEd]

Thank you, has put my mind at rest.

"There are only two lasting bequests we can hope to give our children; one of these is roots, the other wings" - Hodding Carter

 

[johnherman]

Company" is another example of a role-playing dimensions, as a "Company" can be both a customer and a vendor/supplier. In a legal scenario, a "Person" might be a plantiff in one lawsuit, a defendant in another, and a witness in another.

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