191 )How to add a completely new metric to an existing Fact table

 191 )How  to add a completely new metric to an existing Fact table  

Answer:

• If the business wants a new metric and we never captured
•  the underlying source data in the past, we cannot magically generate historical data.
•  I would explain this limitation clearly to the stakeholder. 
• The correct approach is to update the ETL pipeline and source mapping moving forward so we capture that metric from today onward, and
•  document clearly in the reports that historical data for this specific metric is unavailable prior to the implementation date.