Hi @William Scardua​ Delta table gives you the option where you can match with either source or target table and decide the possible action on your target table.

Please try to use the below approach and let us know it this meets your requirement.

-- Delete all target rows that have no matches in the source table.
> MERGE INTO target USING source
  ON target.key = source.key
  WHEN NOT MATCHED BY SOURCE THEN DELETE
 
-- Multiple NOT MATCHED BY SOURCE clauses conditionally deleting unmatched target rows and updating two columns for all other matched rows.
> MERGE INTO target USING source
  ON target.key = source.key
  WHEN NOT MATCHED BY SOURCE AND target.marked_for_deletion THEN DELETE
  WHEN NOT MATCHED BY SOURCE THEN UPDATE SET target.value = DEACTIVATE

Thanks,

Vignesh