SQL脚本:监控当前重做日志文件使用情况

这个脚本可以用来分析当前重做日志文件(redo logfile)已被用到了什么位置(position)、还剩余多少空间和已使用的百分比:

set linesize 200 pagesize 1400;
select le.leseq "Current log sequence No",100 * cp.cpodr_bno / le.lesiz "Percent Full",(cpodr_bno - 1) * 512  "bytes used exclude header",le.lesiz * 512 - cpodr_bno * 512 "Left space",le.lesiz  *512       "logfile size"from x$kcccp cp, x$kccle lewhere LE.leseq = CP.cpodr_seqand bitand(le.leflg, 24) = 8;

Sample:

SQL> set linesize 200 pagesize 1400;
SQL> select le.leseq "Current log sequence No",2         100 * cp.cpodr_bno / le.lesiz "Percent Full",3         (cpodr_bno - 1) * 512  "bytes used exclude header",4         le.lesiz * 512 - cpodr_bno * 512 "Left space",5         le.lesiz  *512       "logfile size"6    from x$kcccp cp, x$kccle le7   where LE.leseq = CP.cpodr_seq8     and bitand(le.leflg, 24) = 8;Current log sequence No Percent Full bytes used exclude header Left space logfile size
----------------------- ------------ ------------------------- ---------- ------------189   90.7612305                  95169536    9687552    104857600/*  如上结果显示当前重做日志号为189，使用量百分比是90.7%当前日志被使用到了95169536+512 bytes(重做日志文件头)的位置，还剩余9687552 bytes的空间，该重做日志的总大小为104857600=100MB
*/