I have seen it implemented in one of the financial services companies. Both data warehouse and and data lake type databases lived on MS SQL servers (with the us

I have seen it implemented in one of the financial services companies. Both data warehouse and and data lake type databases lived on MS SQL servers (with the usual production/testing division), and nightly batch processes performed clean up from data lake to data warehouse. It kind of worked. The usual problems with these are: (1) getting hold of external clean up functionality. Sometimes it was stored with the database itself as stored procedures, but sometimes it was not. Remedy: make sure clean up functionality is readily available. (2) dealing with new kinds of "dirt" (i.e. problematic data in the data lake). Remedy: this is unavoidable. The best you can do is to insert lots and lots safety checks and diagnostics into your clean up programs