Note: This was originally posted by an inactive account. Content was preserved by moving under an admin account.
Originally posted by: stonysmithBuild a Static Data node with one record in it, and CAT that to your main stream.
Then in the Agg, you'll get one record out even if there are zero records in the (main) stream.
In the Agg, you'd use some code like this:
c=count()
emit c-1 as Count
where lastInGroup