compare3

SELECT 'ONLY_IN_US_1' AS location, t1.table_name
FROM dba_tables t1
LEFT JOIN dba_tables t2
       ON t1.table_name = t2.table_name
      AND t2.owner = 'GLOBAL_COMET_US_2'
WHERE t1.owner = 'GLOBAL_COMET_US_1'
  AND t2.table_name IS NULL

UNION ALL

SELECT 'ONLY_IN_US_2' AS location, t2.table_name
FROM dba_tables t2
LEFT JOIN dba_tables t1
       ON t2.table_name = t1.table_name
      AND t1.owner = 'GLOBAL_COMET_US_1'
WHERE t2.owner = 'GLOBAL_COMET_US_2'
  AND t1.table_name IS NULL

ORDER BY location, table_name;