Understanding Slowly Changing Dimensions (SCDs) in Data Warehousing

Introduction to Slowly Changing Dimensions Slowly Changing Dimensions (SCDs) are a crucial concept in data warehousing, helping to track and preserve historical changes in dimension data. Since the core objective of a data warehouse is to enable historical analysis, it’s important to store the different states of data over time. In data warehouses, we work with fact tables to record transactions and dimension tables to describe those facts. Data originates from operational databases and is transferred to the warehouse using Extract-Transform-Load (ETL) processes. For instance, customer or product data are examples of dimensions. These attributes can evolve over time, and unlike operational systems, where changes overwrite existing data, in data warehousing, we must maintain the historical record for analytical purposes. SCDs allow us to manage such changes effectively. What are Slowly Changing Dimensions? There are several types of SCDs, each designed to handle changes in dimension dat...