Update Method option on dataflow
So I was editing a redshift dataflow this morning and I noticed a new option on the output dataset named Update Method. It has a replace and an append option. I am not sure when this became available or how it should be implemented. I understand that all current datasets replace themselves and normally to append you need to create a recursive dataflow feeding the base data back into itself. Could someone give me an example of a use case for the append option?