The Data Vault Handbook - Concepts and Applications

main immutable. This is where Non-Historized Links (also known as Trans- actional Links) prove themselves useful. Unlike standard Links, which store distinct relationships and omit duplicate relationships, Non-Historized links capture every transaction or event at its original granularity. This means each transaction, regardless of whether the relationship already exists in the system, is preserved without modification or omission. The goal of Non-Historized Links is to ensure high performance both during data loading and querying. By retaining the original granularity of trans- actions from the source systems, the need for costly grain shifts—common with standard Links—is eliminated. These grain shifts, often involving

GROUP BY operations or complex joins, add unnecessary complexity and perfor- mance overhead when trying to restore the original transaction-level granularity for reporting purposes. Non-Historized Links resolve this issue by directly cap- turing each transaction as it occurs, with- out altering the data’s granularity. In terms of structure, Non-Historized Links follow the same logic as regular Links but include additional descriptive attributes as payload, allowing them to store transactional or event-specific de- tails. These attributes can be stored di- rectly within the Link itself, as there’s no need for a separate Satellite to track historical changes—since the data is im- mutable.

“ The goal of Non- Historized Links is to ensure high performance both during data loading and querying, additionally providing a good foundation for building fact tables.”