Purpose of ‘Previous Surrogate key’

When Configuring dimension role in dimension properties, I came across ‘Previous Surrogate key’ role in Astera DW Builder. I don’t understand its purpose or how it’s used.

The purpose of ‘Previous Surrogate Key’ is that it stores the surrogate key of the previous version of the record. You can add a new field in your dimension and assign it the ‘Previous surrogate key’ role.


As you can see from the above table, the ‘PreviousSurrogateKey’ field stores the surrogate key of the previous version of the record. Here ‘CitiesKey’ is your surrogate key and ‘CityID’ your Business Key.