Flashback

ALTER TABLE matthiash ENABLE ROW MOVEMENT;

FLASHBACK TABLE matthiash TO TIMESTAMP TO_TIMESTAMP('2013-05-03 13:00:00', 'YYYY-MM-DD HH24:MI:SS');


select * from v$tablespace where FLASHBACK_ON='YES';

*******************************************************

also try this 

select count(*) from SIEBEL.S_CS_QUEST as of timestamp to_timestamp('30-MAY-2022 18:00:00', 'DD-MON-YYYY HH24:MI:SS');