The Data Vault Handbook - Concepts and Applications

A Transient Staging Area is designed to hold data temporarily. Once the data has been processed and moved to subsequent layers, it might be discard- ed from the Staging Area. The main advantage of this approach is that it reduces storage requirements, as data is not retained long-term. This can be particularly beneficial in environments with limited storage capacity or where data sources are extremely large. Additionally, a Transient Staging Area simplifies the management and maintenance of the staging layer, as outdated data is automatically purged. However, the downside of a Transient Staging Area is that if an error occurs or data needs to be reprocessed in our Enterprise Data Warehouse, it cannot be retrieved from the Staging Area and must be re-extracted from the origi- nal source systems. This might not be always possible, posing a risk of losing historical data. In contrast, a Persistent Staging Area can store the full history of data sources. This approach offers signif- icant benefits, particularly in terms of data recovery and reprocessing. If errors are detected or data needs to be reloaded, the Persistent Staging Area allows for easy retrieval of pre- vious data loads without requiring a fresh extraction from the source sys- tems. However, the trade-off is that it requires more storage space and can lead to increased management com- plexity. The Persistent Staging Area also demands robust governance to ensure data integrity over time. “ [A Persistent Staging Area] offers significant benefits, particularly in terms of data recovery and reprocessing.”