Slowly Changing Dimension in Data Warehousing | 1Keydata
Describes the issue of slowly changing dimension in data warehousing and several methods to handle this.
Common ways to handle this include the following:
Type 0: Only keep the original value. Do not track any changes.
Type 1: Always keep the current data. Do not keep any historical value.
Type 2: Add a new record to the dimension table when there is a change.
Type 3: Add additional columns in the dimension table to preserve history.
Type 4: Use a history table to track historical changes.