Data Vault Anti-pattern: Using Historized Links to store Transactional data that does not change

 

Transactional Data that does not change e.g. sensor data, stock trades, call center call data log, medical test results, event logs etc. should reside in a Non-historized Link (NHL) aka. Transaction Link. There is no point in using a Historized Link to store data that can not change.  All of the attributes of the Transaction can be stored within the NHL. Here is an example:

 

Note that the PATIENT_HK, LOCATION_HK, COVID_TEST_ID, and LOAD_DATE form the Unique Key for the Non-historized Link. The descriptive attributes are stored in the Non-historized Link instead of a SAT hanging from the Link.

"Non-historised links are used when the data in the source should not be modified at any time"