目的：添加多路复用在线日志组
1.添加成员至4号在线日志组
alter database add logfile member '/arp/oraarp/oradata/arpdb/redo041.log' to group 4;
2.查看在线日志组日志位置
column MEMBER format a20;
set linesize 200;
SQL> select group#,MEMBER,TYPE,STATUS from v$logfile;
GROUP# MEMBER TYPE STATUS
---------- -------------------- -------------- --------------
4 /arp/oraarp/oradata/ ONLINE
arpdb/redo041.log
4 /arp/oraarp/oradata/ ONLINE
arpdb/redo04.log
5 /arp/oraarp/oradata/ ONLINE
arpdb/redo05.log
6 /arp/oraarp/oradata/ ONLINE
arpdb/redo06.log
3.查看当前日志组的状态
SQL> select group#,members,bytes/1024/1024,status from v$log;
GROUP# MEMBERS BYTES/1024/1024 STATUS
---------- ---------- --------------- --------------------------------
4 2 512 INACTIVE
5 1 512 CURRENT
6 1 512 INACTIVE
4.删除一个非活动的重做日志组的成员
SQL> alter database drop logfile member '/arp/oraarp/oradata/arpdb/redo041.log';
