Here is my notes #8 about more keys in a star schema.

In the previous notes, MS BI Workshop #7 – What are all those keys in a star schema?, I showed two typical keys you are seeing in a dimensional table, a surrogate key and an alternate key.

In this notes, I will show two types of foreign keys you will sometimes see in a dimensional table.

This Organization view in DSV in BIDS is showing two FKs, ParentOrganizationKey, which references the DimOrganization table itself, and CurrencyKey, which references the DimCurrency dimension table.

Here is the creation script of dimension table DimOrganization. The first FK on column CurrencyKey references the DimCurrency dimension table. The second FK on column ParentOrganizationKey references the DimOrganization table itself.

1. By referencing the table itself, we know that this table has a recursive relationship, and a parent-child hierarchies among its rows.
2. By referencing another dimension table DimCurrency, we know that this table is somehow normalized.
3. But in the DSV Organization view, we see that an attribute (column) Currency Code is added. By doing this, the data is denormalized in DSV.