The Data Vault Handbook - Concepts and Applications

BRIDGE TABLE STRUCTURE

— Hub 1 Hash Key: Foreign Key referencing the hash key of the first Hub involved in the Bridge

— Link Hash Key: Foreign Key referencing the hash key of the Link entity. This field may be optional, depending on whether a calculated field is needed and the type of aggregation required — Hub 2 Hash Key: Foreign Key referencing the hash key of the second Hub involved in the bridge. This field may be optional, depending on whether a calculated field is needed and the type of aggregation required

— Snapshot Date: Timestamp defined by the business requirements, which establishes the target granularity for the data

— Calculated Field or Business Key: Optional field that can include computed values or business keys. It provides additional context or aggregation information that can be useful for reporting and analysis

BRIDGE TABLE EXAMPLE

In a hospital data platform, you might want to analyze the relationship be- tween the patients and the departments they visited. These two Hubs are con- nected by a Non-Historized Link that represents the check-ins (Section 3.2.1).