While I am often amazed at what can be done in Qlik scripting language, often solutions seem to me to be "tricky", not elegant or well-related to the abstract problem. Thus, I would much prefer dealing directly with set language. The following solution to me seems to approach that ideal. I have used two tables as source for the date. Ideally, I would give the dates different names according to their respective table (e.g., "Date1" and "Date2"), but in the interest of generalizing the solution, I have kept the same name for each.
First I get the intersection of the source tables into "Intersection", and then I reload the source tables into "Complement" if its respective date not already exist in "Intersection".
This is my first foray into this, perhaps someone else may propose something even better.
