Revoking RESOURCE/DBA role removes UNLIMITED TABLESPACE (Grant)

if you grant a user RESOURCE or DBA role, the user then also has the UNLIMITED TABLESPACE privilege.  OK, that's fine.  However, if you revoke either RESOURCE or DBA, the UNLIMITED TABLESPACE priv is also revoked, even if it was given indepently in a grant statement.

SQL> ALTER USER JAY QUOTA UNLIMITED ON JAY_INDEX;

User altered.

SQL> select tablespace_name from dba_ts_quotas where username='JAY';

TABLESPACE_NAME
------------------------------
JAY_INDEX

SQL> grant dba to JAY;  

Grant succeeded.

SQL> revoke dba from JAY;

Revoke succeeded.

SQL> select tablespace_name from dba_ts_quotas where username='JAY';

no rows selected