Oracle: To get frequency of REDO log switches

 select

   b.recid,

   to_char(b.first_time,'dd-mon-yy hh24:mi:ss') start_time,

   a.recid,

   to_char(a.first_time,'dd-mon-yy hh24:mi:ss') end_time,

   round(((a.first_time-b.first_time)*25)*60,2) minutes

from

   v$log_history a,

   v$log_history b

where

   a.recid = b.recid+1

and

   a.first_time between to_date('2023-01-30:21:45:00','yyyy-mm-dd:hh24:mi:ss')

and

   to_date('2023-01-30:22:15:00','yyyy-mm-dd:hh24:mi:ss')

order by

   a.first_time desc;