TB1 54 %    90880   41383   49497   46  98304   50 %    ONLINE  PERMANENT

E:ORACLEORADATAxxTB1.DBF    33554416    True    100
F:ORACLEORADATAxxTB1_2.DBF  33554416    True    100
G:ORACLEORADATAxxTB1_3.DBF  25344000    True    100

select segment_name, sum(bytes)/1024/1024 as mb
from dba_segments
where tablespace_name='TB1' and segment_type like 'INDEX%'
group by segment_name
order by mb;

alter index ind_big_stuff rebuild;

exec dbms_space_admin.drop_empty_segments(schema_name=>'HR');