tags

What are key columns for linked data?

Have you noticed key columns for linked data in Data Table Properties and just want to know more?
Have you tried to use replace value transformations but found options grayed out (screenshot above)?
Have you ever lost the marked data behind tags when opening or closing a file?
Would you like to be able to edit values in a data table?

If any of these apply, read on to find how what key columns are and how to use them.