Thanks for the confirmation. Not sure I see everything as your text gets truncated, but it basically confirms that it should work.

Anyway: It looks like the incremental load is working. The problem here is, that we receive late arriving facts that touch all previous months. So the merge statement reads in all existing parquet files and with that, rewrites almost all of them. 

We need to see if we can limit the input data to a few months. Don't see any other solution in this case.