SYS@RACDB1 rac1>select group#,member,status from v$logfile order by 2;
GROUP# MEMBER STATUS
---------- --------------------------------------------------------------------------- -----------
1 +DATA/racdb/onlinelog/group_1.261.942339581
1 +DATA/racdb/onlinelog/group_1.272.942466389 INVALID
2 +DATA/racdb/onlinelog/group_2.262.942339581
2 +DATA/racdb/onlinelog/group_2.271.942466411
3 +DATA/racdb/onlinelog/group_3.266.942339807
3 +DATA/racdb/onlinelog/group_3.273.942466441
4 +DATA/racdb/onlinelog/group_4.267.942339809
4 +DATA/racdb/onlinelog/group_4.274.942466783
8 rows selected.
SYS@RACDB1 rac1>select group#,thread#,members,status,bytes/1024/1024 as size_m from v$log;
GROUP# THREAD# MEMBERS STATUS SIZE_M
---------- ------------ ------------ ------------------ ----------
1 1 2 INACTIVE 50
2 1 2 CUR 50
3 2 2 INACTIVE 50
4 2 2 CUR 50
SYS@RACDB1 rac1>alter database drop logfile member ‘+DATA/racdb/onlinelog/group_1.272.942466389‘;
Database altered.
SYS@RACDB1 rac1>select group#,thread#,members,status,bytes/1024/1024 as size_m from v$log;
GROUP# THREAD# MEMBERS STATUS SIZE_M
---------- ------------- ----------- ------------------ ----------
1 1 1 INACTIVE 50
2 1 2 CURRRENT 50
3 2 1 INACTIVE 50
4 2 2 CURRRENT 50
SYS@RACDB1 rac1>select group#,member,status from v$logfile order by 2;
GROUP# MEMBER STATUS
---------- --------------------------------------------------------------------------- -----------
1 +DATA/racdb/onlinelog/group_1.261.942339581
2 +DATA/racdb/onlinelog/group_2.262.942339581
2 +DATA/racdb/onlinelog/group_2.271.942466411
3 +DATA/racdb/onlinelog/group_3.266.942339807
4 +DATA/racdb/onlinelog/group_4.267.942339809
4 +DATA/racdb/onlinelog/group_4.274.942466783
6 rows selected.
SYS@RACDB1 rac1>alter system switch logfile;
GROUP# THREAD# MEMBERS STATUS SIZE_M
---------- ------------- ----------- ------------------ ----------
1 1 1 CURRRENT 50
2 1 2 INACTIVE 50
3 2 1 CURRRENT 50
4 2 2 INACTIVE 50
SYS@RACDB1 rac1>alter database drop logfile member ‘+DATA/racdb/onlinelog/group_2.271.942466411‘;
Database altered.
SYS@RACDB1 rac1>alter database drop logfile member ‘+DATA/racdb/onlinelog/group_4.274.942466783‘;
Database altered.
SYS@RACDB1 rac1>alter system switch logfile;
GROUP# THREAD# MEMBERS STATUS SIZE_M
---------- ------------- ----------- ------------------ ----------
1 1 1 CURRRENT 50
2 1 1 INACTIVE 50
3 2 1 CURRRENT 50
4 2 1 INACTIVE 50
原文：http://www.cnblogs.com/KT-melvin/p/6785274.html