How should business rules be implemented in ETL?

Question

I work on an product that imports data from a mainframe using SSIS via flat file. The SSIS packages use a stage database to transform flat file data and then call stored procedures in the ODS to load the transformed data. There is a potential plan to route all ETL data through a .NET service layer (instead of directly to the ODS via stored procedures) to centralize business rules/activity, etc. I'm looking for input on this approach and dissenting opinions.

Answer 1

Sounds fine; you're turning basic ETL into ETVL, adding a "validate" step. Normally this is considered part of the "transform" stage, but I prefer to keep that stage purer when I conceptualize an architecture like this; transform is turning the raw fields which were pulled out and chopped up in the extract stage into objects of my domain model. Verifying that those objects are in a valid state for the system is validation.