Run following query as sysdba.
alter session set nls_date_format=’DD-MON-RRRR:HH24:MI:SS’;
alter session set nls_date_format='DD-MON-RRRR:HH24:MI:SS';
select username, created, account_status /* Users who granted role with DML privs */
from dba_users
where oracle_maintained = 'N'
and username in
(select grantee from dba_role_privs
where granted_role in
(select role
from dba_roles
where role in (select GRANTEE from dba_tab_privs where privilege in ('INSERT','UPDATE', 'DELETE') ) ) )
Union
select username, created, account_status /* Users who granted direct DML privs */
from dba_users
where oracle_maintained = 'N'
and username in (select GRANTEE from dba_tab_privs where privilege in ('INSERT','UPDATE', 'DELETE') );
