>Edward also made it clear to me that I am didn't describe that aspect clear enough. Rreading my text, I understand that.
>
>The resulting table should be a concatenation of the 4 tables, with all duplicates removed, but that should happen in an evenly distributed way, like the numerical examples displayed.
Where I am confused about is that if these duplicate records are in fact duplicates how does the final table have any idea where the unique records came from? IOW, why not just do a union of the four tables that is distinct?