Dear Knimers,
I thought it would be nice for the Missing Value node to have the option to assign empty Sets/Lists for missing values in a Set/List column.
Currently the only options Knime offers for columns of this type are [Next Value | Previous Value | Remove Row].
Best
Aswin
We have a pair of nodes internally at the moment at @Vernalis which will convert missingcells in collection columns to empty collections, and empty collections to missing cells. Tbh, I thought we had released them to the community already, but it looks like we haven’t. Let me know if you would like me to get them on our release list!
Steve
I’ve requested permission this morning - I dont anticipate a problem… more in due course!
Steve
Hi there @Aswin,
if I got you right then this is already possible using GroupBy node. Use Append elements method on your collection column. Of course make sure you do not group anything 
It is not intuitive but can work until Steve does his job 
Br,
Ivan
Ah @ipazin , that’s a good idea… And it turns out the Column Aggregator also works, which may be more convenient when there are others columns and one does not want to ruin the rowIDs.
They are on our trunk (nightly) build now, under Community Nodes -> Vernalis -> Collections, along with a 3rd new node, ‘Collection Size’:
One slight caveat is that I have a problem uploading test cases to the build server this evening, so the new nodes are technically untested - I will put an announcement out on the Vernalis forum page when that is resolved, but they should work OK! (I just installed them on my PC at home and they work fine)
Steve
This is now live with test cases. See
for details.
Steve
Also the “Collection Size” node is very useful! 
yes it is easy to make a Java snippet that does the same thing, but using a dedicated node is much more elegant…
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= yes please put them on your release list 