Slowly Changing Dimension

Definitions

1. A data warehousing technique for tracking how dimension attributes change over time. Type 1 overwrites the old value, Type 2 adds a new row with version dates (preserving history), and Type 3 adds columns for current and previous values. Essential for accurate historical reporting.

   In plain English: A way to track how reference data (like customer addresses) changes over time in a data warehouse.

   Example: "Use SCD Type 2 for the customer dimension — when someone changes their address, we need both the old and new values for historical orders."

Related Terms

• Webhook vs. Polling
• Event-Driven Architecture
• Circuit Breaker
• Binary
• Event Sourcing
• Star Schema
• Medallion Architecture
• Idempotent Pipeline