Some join keys unmatched

Some key values on one side of a Join node have no match on the other side. An inner join leaves those rows out of its result; this is reported as information, because it is often the filter you meant. A join that keeps unmatched rows keeps them with empty values for the other side's columns; this is reported as a warning.

What to do

If the other table covers only some keys on purpose, nothing needs to change. Otherwise check the listed values against the other table for typos, case or spacing, and correct them in the source data. If the rows belong in the result, use a left join instead of an inner join; if the empty values cause problems later, add the missing rows to the other table.

Where it comes from

Shown by Join. It is one of the messages about a node.