remove duplicate record from sql

select

    T.operator_id,

    T.platform_serial,

    pvs.time_stamp

from (

                select

                    vc.hardware_id,

                    MAX(decode(vc.data_key, 'operator-id', vc.data_value)) operator_id,

                    MAX(decode(vc.data_key, 'Platform Serial', vc.data_value)) platform_serial

                from

                    verifier_capability vc

                group by

                    vc.hardware_id

) T,

physical_verifier pv,

physical_verifier_status pvs

where

    pvs.physical_id = pv.physical_id

and pv.hardware_id  = T.hardware_id

and T.platform_serial is not null

and T.operator_id is not null

order by pvs.time_stamp desc;

current result:

operator_id, platform_serial, timestamp

3725 569488 1355989538000000000

3725 573592 1354193106000000000

3227 557317 1353561342000000000

3325 000448347 1353490966000000000

3227 555777 1352367525000000000

3511 573595 1350376799000000000

requirement

want to display single operator_id with max timestemp, need to remove minimum timestamp value from duplicate operator_id