arc_hour

col HOUR for a20
select TO_CHAR(TRUNC(completion_time,'HH24'), 'YYYY-MM-DD HH24:MI') Hour,thread# , round(sum(BLOCKS*BLOCK_SIZE)/1024/1024/1024) GB, count(*) Archives
from v$archived_log
WHERE completion_time >= SYSDATE - (&num_hours/24)
group by trunc(COMPLETION_TIME,'HH24'),thread# order by 1;