AFAIK, ETL integrates data from a fixed number of sources/tables. Is it possible that ETL can integrate data from an unknown number of tables which might be added in the future, given that these tables might be of different types (customer, shipping, employee, accounting etc.) ?
EDIT -
Let A,B,C be tables. We can have the following ETL scenarios - A + B + C = 1 row or A + B + C = 3 rows
I have the first one. Later, we can add tables D,E,F,G...etc all of which might be different from each other in terms of the data they contain.