Redo log switch count per day

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

sum(decode(to_char(first_time,'hh24'),'00',1,0)) "00",   

sum(decode(to_char(first_time,'hh24'),'01',1,0)) "01",   

sum(decode(to_char(first_time,'hh24'),'02',1,0)) "02",   

sum(decode(to_char(first_time,'hh24'),'03',1,0)) "03",   

sum(decode(to_char(first_time,'hh24'),'04',1,0)) "04",   

sum(decode(to_char(first_time,'hh24'),'05',1,0)) "05",   

sum(decode(to_char(first_time,'hh24'),'06',1,0)) "06",   

sum(decode(to_char(first_time,'hh24'),'07',1,0)) "07",   

sum(decode(to_char(first_time,'hh24'),'08',1,0)) "08",   

sum(decode(to_char(first_time,'hh24'),'09',1,0)) "09",   

sum(decode(to_char(first_time,'hh24'),'10',1,0)) "10",   

sum(decode(to_char(first_time,'hh24'),'11',1,0)) "11",   

sum(decode(to_char(first_time,'hh24'),'12',1,0)) "12",   

sum(decode(to_char(first_time,'hh24'),'13',1,0)) "13",   

sum(decode(to_char(first_time,'hh24'),'14',1,0)) "14",   

sum(decode(to_char(first_time,'hh24'),'15',1,0)) "15",   

sum(decode(to_char(first_time,'hh24'),'16',1,0)) "16",   

sum(decode(to_char(first_time,'hh24'),'17',1,0)) "17",   

sum(decode(to_char(first_time,'hh24'),'18',1,0)) "18",   

sum(decode(to_char(first_time,'hh24'),'19',1,0)) "19",   

sum(decode(to_char(first_time,'hh24'),'20',1,0)) "20",   

sum(decode(to_char(first_time,'hh24'),'21',1,0)) "21",   

sum(decode(to_char(first_time,'hh24'),'22',1,0)) "22",   

sum(decode(to_char(first_time,'hh24'),'23',1,0)) "23",   

count(to_char(first_time,'MM-DD')) Switches_per_day   

from v$log_history   

where trunc(first_time) between trunc(sysdate) - 16 and trunc(sysdate)   

group by to_char(first_time,'DD-MON')    

order by to_char(first_time,'DD-MON') ;