So in Kimball modeling there were some assumptions made in1996 that just aren’t true in 2019:
- Databases are slow and expensive
- SQL language is limited
- You can never join fact tables because of one to many or many to one joins
- Businesses are slow to change
A lot has happened:
- databases are now fast and cheap
- SQL has evolved to include many more date functions and window functions that cut down on ETL work required
- Looker solved this with Symmetric Aggregates
- Business doesn’t wait for you to finish your perfect DWH
So I respect the work of Kimball and there are some great tips and techniques in the DWH Toolkit that I use everyday. But I see too many “over engineered” data warehouses that don’t need to be that complex and don’t encompass new things happening in the business.