A data warehouse really should be completely orthogonal to any architecture choices. Good data warehouses are fed by data engineering pipelines that don’t care

A data warehouse really should be completely orthogonal to any architecture choices. Good data warehouses are fed by data engineering pipelines that don’t care if you have a single rdbms or multiple document stores or people dropping CSVs in an FTP directory. I hate to burst your bubble, but you shouldn’t and can’t have truth working along side systems that access it. Data is messy and tends toward dishonesty. The only way to get clean truth for your organization is by thoughtfully applying rules, cleaning and filtering as you go. The more micro your architecture is, the more this is true. Because there is no way 20different teams are all going to have the same understanding of the business rules around what constitutes good, clean input data. Even if your company is very clear and well-documented about business and data rules, if you hand the same spec sheet to 20 different teams, you are going to get 20 variations on that spec. The only way to get usable data that can be agreed upon by an entire company (or even business unit) is by separating your truth from your transactional data. That’s kind of the definitional of a data warehouse. If you let your transactional systems access and update data directly in your warehouse, you are in for a universe of pain.