Number of DML Operations on a database

DML operation on database:

set lines 160;

set pages 999;

select *

from (SELECT

to_char(first_time,'YYYY-MON-DD') day,

to_char(sum(decode(to_char(first_time,'HH24'),'00',1,0)),'999') "00",

to_char(sum(decode(to_char(first_time,'HH24'),'01',1,0)),'999') "01",

to_char(sum(decode(to_char(first_time,'HH24'),'02',1,0)),'999') "02",

to_char(sum(decode(to_char(first_time,'HH24'),'03',1,0)),'999') "03",

to_char(sum(decode(to_char(first_time,'HH24'),'04',1,0)),'999') "04",

to_char(sum(decode(to_char(first_time,'HH24'),'05',1,0)),'999') "05",

to_char(sum(decode(to_char(first_time,'HH24'),'06',1,0)),'999') "06",

to_char(sum(decode(to_char(first_time,'HH24'),'07',1,0)),'999') "07",

to_char(sum(decode(to_char(first_time,'HH24'),'08',1,0)),'999') "08",

to_char(sum(decode(to_char(first_time,'HH24'),'09',1,0)),'999') "09",

to_char(sum(decode(to_char(first_time,'HH24'),'10',1,0)),'999') "10",

to_char(sum(decode(to_char(first_time,'HH24'),'11',1,0)),'999') "11",

to_char(sum(decode(to_char(first_time,'HH24'),'12',1,0)),'999') "12",

to_char(sum(decode(to_char(first_time,'HH24'),'13',1,0)),'999') "13",

to_char(sum(decode(to_char(first_time,'HH24'),'14',1,0)),'999') "14",

to_char(sum(decode(to_char(first_time,'HH24'),'15',1,0)),'999') "15",

to_char(sum(decode(to_char(first_time,'HH24'),'16',1,0)),'999') "16",

to_char(sum(decode(to_char(first_time,'HH24'),'17',1,0)),'999') "17",

to_char(sum(decode(to_char(first_time,'HH24'),'18',1,0)),'999') "18",

to_char(sum(decode(to_char(first_time,'HH24'),'19',1,0)),'999') "19",

to_char(sum(decode(to_char(first_time,'HH24'),'20',1,0)),'999') "20",

to_char(sum(decode(to_char(first_time,'HH24'),'21',1,0)),'999') "21",

to_char(sum(decode(to_char(first_time,'HH24'),'22',1,0)),'999') "22",

to_char(sum(decode(to_char(first_time,'HH24'),'23',1,0)),'999') "23"

from

v$log_history

GROUP by

to_char(first_time,'YYYY-MON-DD'))

order by to_date(day,'YYYY-MON-DD');