? ? GROUP#? ? THREAD# STATUS
---------- ---------- ----------
? ? ? ? 4? ? ? ? ? 1 UNASSIGNED
? ? ? ? 5? ? ? ? ? 1 UNASSIGNED
? ? ? ? 6? ? ? ? ? 1 UNASSIGNED
? ? ? ? 7? ? ? ? ? 1 UNASSIGNED
SQL> select member from v$logfile;
MEMBER
--------------------------------------------------------------------------------
/oradata/orcl/REDO03.LOG
/oradata/orcl/REDO02.LOG
/oradata/orcl/REDO01.LOG
/u01/app/oracle/oradata/orcl/sredo01.log
/oradata/orcl/sredo02.log
/oradata/orcl/sredo03.log
/oradata/orcl/sredo04.log
7 rows selected.
SQL> alter database drop logfile group 4;
Database altered.
成功DROP该日志组。
SQL> select member from v$logfile;
MEMBER
--------------------------------------------------------------------------------
/oradata/orcl/REDO03.LOG
/oradata/orcl/REDO02.LOG
/oradata/orcl/REDO01.LOG
/oradata/orcl/sredo02.log
/oradata/orcl/sredo03.log
/oradata/orcl/sredo04.log
6 rows selected.
? ? ? ?
SQL> select group#,thread#,bytes/1024/1024 mb from v$standby_log;
? ? GROUP#? ? THREAD#? ? ? ? MB
---------- ---------- ----------
? ? ? ? 5? ? ? ? ? 1? ? ? ? 50
? ? ? ? 6? ? ? ? ? 1? ? ? ? 50
? ? ? ? 7? ? ? ? ? 1? ? ? ? 50
SQL> ALTER DATABASE ADD STANDBY LOGFILE? group 4 ('/oradata/orcl/sredo01.log') SIZE 50M;
Database altered.
添加GROUP 4新的位置。
SQL> select member from v$logfile;
MEMBER
--------------------------------------------------------------------------------
/oradata/orcl/REDO03.LOG
/oradata/orcl/REDO02.LOG
/oradata/orcl/REDO01.LOG
/oradata/orcl/sredo01.log
/oradata/orcl/sredo02.log
/oradata/orcl/sredo03.log
/oradata/orcl/sredo04.log
7 rows selected.
完成Standby Logfile的迁移。
Data Guard备库一定要是一致的状态才能open read only打开，否者执行alter database recover managed standby database应用日志，恢复到一致性的状态，再open read only。