Dealing with SCDs
The term slowly changing dimensions, or in short, SCD, is a data warehousing concept introduced by the amazing Ralph Kimball. You can learn more about Ralph Kimball here: https://www.kimballgroup.com/about-kimball-group/.
The SCD concept deals with moving a specific dataset from one state to another. Let us look at SCD in more detail with a scenario.
The Adventure Works organization has a human resources (HR) system in which its data is captured in the organization’s data warehouse. Stephen Jiang is a Sales Manager with 10 sales representatives on his team. The source for this scenario is the AdventureWorksDW2019 database, which you can download from here: https://learn.microsoft.com/en-us/sql/samples/adventureworks-install-configure?view=sql-server-ver16&WT.mc_id=DP-MVP-5003466.
The following image shows the sample data for our scenario:
Figure 12.1: Stephen Jiang is the sales manager of a team of 10 sales representatives
Brian...
