查看Oracle的redo日志切换频率

转载自：http://blog.itpub.net/12457158/viewspace-721676/

查看Oracle的redo日志切换频率

两个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;