SCD2 stands for “Slowly Changing Dimension Type 2.” It is a widely used technique in data warehousing and data modeling to track and manage changes in dimensional data. “Dimensions” are attributes used to organize data, such as customers, products or locations.
SCD2 handles situations where dimension data changes over time, and it is especially useful for historical analysis and reporting. Here are the main features of SCD2:
-
Historical tracking:
SCD2 tracks how dimension data changes over time by adding new records for each change, rather than overwriting existing records. -
Effective date ranges:
Effective date ranges are recorded for each version of a dimension record, allowing you to see when a specific version of the record was valid. -
Historical Reporting:
SCD2 allows users to create historical reports based on the historical versions of dimension data.
A common SCD2 example is a customer dimension. If a customer’s name changes, for example, with a company name change, SCD2 would create a new line with the updated name and an end date for the old record. This allows users to continue to view customer identity in the past and present.
share post
