SQL & PL/SQL :: Display Temporary Column Of Two Users

I have created a query that display the difference in the tables and column of two users. Some of the column in the new user have been added new which were not there in the old user and some columns from the old user still exits but their data_type is changed.

Now I want to select one more column in the select statement specifying whether the column is modified or has been added.

SELECT TABLE_NAME,COLUMN_NAME,DATA_TYPE,DATA_LENGTH
FROM DBA_TAB_COLUMNS
WHERE OWNER = 'ABC' AND
TABLE_NAME NOT IN (SELECT table_name FROM all_tables where owner = 'ABC'
MINUS
SELECT table_name FROM all_tables where owner = 'XYZ' )
MINUS
SELECT TABLE_NAME,COLUMN_NAME,DATA_TYPE,DATA_LENGTH
FROM DBA_TAB_COLUMNS
WHERE OWNER = 'XYZ'
[code]....