Oracle redo 日志切换时间频率

DB: 11.2.0.3.0

查看Oracle的redo日志切换频率

两条SQL，原理是一样的，第二个用到了统计函数

时间单位：分钟

方法一、 
select * from v$log　a　where a.THREAD# = 1 ;

 

set line 200
select b.SEQUENCE#, b.FIRST_TIME,a.SEQUENCE#,a.FIRST_TIME,round(((a.FIRST_TIME-b.FIRST_TIME)*24)*60,2) from v$log_history a, v$log_history b where a.SEQUENCE#=b.SEQUENCE#+1 and b.THREAD#=1 order by a.SEQUENCE# desc;
   

方法二、

set line 200
select sequence#,first_time,nexttime,round(((first_time-nexttime)*24)*60,2) diff from (select sequence#,first_time,lag(first_time) over(order by sequence#) nexttime from v$log_history where thread#=1) order by sequence# desc;