How to find out if it is possible to do a left- or right join in MapInfo Professional

Product Feature: Queries and Selections
Unfortunately a left- or right join is not possible in MapInfo Pro. But there is a workaround which might help to visualize matching features:
  1. Add a column to the geometry table (all data sets).
  2. Join the tables (Natural join).
  3. Now use this query to update the new column (just matching features will get updated).
  4. Use the new column for a thematic map visualizing empty columns.  
UPDATED:  September 7, 2017