Processing Past Data

If your data warehouse is processing files from other systems, and one day you didn't get a file from a source system, what would you do? Of course you will still run the data warehouse ETL, to process the available data files. The data warehouse ETL (or "the daily batch") must run every day, so that the business gets the latest data.

How, here's the question, if that 1 missing file was produced the next day, what would you do with it? Can you process it into your data warehouse?