I am new to Datawarehouses.
I have a pre existing dimension table that I have to link to to get the Surrogate Key. My problem is that the table contains 70 rows, I only need 4 of them. I do not have an existing business Key to join to the Dim table so I need to join on a varchar column halfway across the dimension table. For info - If I did a distinct on the column I need to join to it would return 6 values (4 I need and 2 I don't).
I can do the join but I am concerned on what surrogate keys will be returned. I only want 1 surrogate for each of the 4 codes but there are multiple surrogate for the same code that I pass in. What should I do?