Sessions, transactions and rollback segments query

select  sess.sid, c.segment_name, b.used_ublk, b.log_io, b.phy_io,
            case when bitand(b.flag,power(2,7)) > 0 then 'RB in Progress'
            else 'Not Rolling Back'
            end as "F Status",
        to_date(start_time,'mm/dd/yy hh24:mi:ss') start_time
from v$session sess,
        v$transaction b,
        dba_rollback_segs c,
        v$process e
where b.ses_addr=sess.saddr
        and b.xidusn=c.segment_id
        and e.ADDR=sess.PADDR
        --and sid=9999;




select  sess.sid, c.segment_name, b.used_ublk, b.log_io, b.phy_io,
            case when bitand(b.flag,power(2,7)) > 0 then 'RB in Progress'
            else 'Not Rolling Back'
            end as "F Status",
        r.rssize, r.gets, r.writes, r.waits, round(r.hwmsize/1024/1024) as "HWM size Mb",
r.SHRINKS, r.WRAPS,
        to_date(start_time,'mm/dd/yy hh24:mi:ss') start_time
from v$session sess,
        v$transaction b,
        dba_rollback_segs c,
        v$process e,
        v$rollstat r
where b.ses_addr=sess.saddr
        and b.xidusn=c.segment_id
        and e.ADDR=sess.PADDR
        and c.SEGMENT_ID = r.USN
        and sid in (1286, 227, 790);