Oracle重做日志文件组-新增、删除

查看日志文件组信息

SQL> select *  from v$log;

    GROUP#    THREAD#  SEQUENCE#      BYTES  BLOCKSIZE    MEMBERS ARCHIVED STATUS           FIRST_CHANGE# FIRST_TIME  NEXT_CHANGE# NEXT_TIME

---------- ---------- ---------- ---------- ---------- ---------- -------- ---------------- ------------- ----------- ------------ -----------

         1          1         13   52428800        512          1 NO       INACTIVE           21995736819 2017-9-21 9  21995740613 2017-9-21 1

         2          1         14   52428800        512          1 NO       CURRENT            21995740613 2017-9-21 1 281474976710

         3          1         12   52428800        512          1 NO       INACTIVE           21995708930 2017-9-21 7  21995736819 2017-9-21 9

SQL> select *  from v$logfile;

    GROUP# STATUS  TYPE    MEMBER                                                                           IS_RECOVERY_DEST_FILE

---------- ------- ------- -------------------------------------------------------------------------------- ---------------------

         3         ONLINE  C:\ORACEL\BASE\ORADATA\ORCL\REDO03.LOG                                           NO

         2         ONLINE  C:\ORACEL\BASE\ORADATA\ORCL\REDO02.LOG                                           NO

         1         ONLINE  C:\ORACEL\BASE\ORADATA\ORCL\REDO01.LOG                                           NO

新增日志组：

SQL> alter database add logfile

  2  ('C:\orcl1122\disk1\REDO04.LOG','C:\orcl1122\disk1\REDO05.LOG') size 50M;

Database altered

SQL>  select *  from v$log

  2  ;

    GROUP#    THREAD#  SEQUENCE#      BYTES  BLOCKSIZE    MEMBERS ARCHIVED STATUS           FIRST_CHANGE# FIRST_TIME  NEXT_CHANGE# NEXT_TIME

---------- ---------- ---------- ---------- ---------- ---------- -------- ---------------- ------------- ----------- ------------ -----------

         1          1         13   52428800        512          1 NO       INACTIVE           21995736819 2017-9-21 9  21995740613 2017-9-21 1

         2          1         14   52428800        512          1 NO       CURRENT            21995740613 2017-9-21 1 281474976710

         3          1         12   52428800        512          1 NO       INACTIVE           21995708930 2017-9-21 7  21995736819 2017-9-21 9

         4          1          0   52428800        512          2 YES      UNUSED                       0                        0

SQL> select *  from v$logfile;

    GROUP# STATUS  TYPE    MEMBER                                                                           IS_RECOVERY_DEST_FILE

---------- ------- ------- -------------------------------------------------------------------------------- ---------------------

         3         ONLINE  C:\ORACEL\BASE\ORADATA\ORCL\REDO03.LOG                                           NO

         2         ONLINE  C:\ORACEL\BASE\ORADATA\ORCL\REDO02.LOG                                           NO

         1         ONLINE  C:\ORACEL\BASE\ORADATA\ORCL\REDO01.LOG                                           NO

         4         ONLINE  C:\ORCL1122\DISK1\REDO04.LOG                                                     NO

         4         ONLINE  C:\ORCL1122\DISK1\REDO05.LOG                                                     NO

删除日志组：

SQL> alter database drop logfile group 4;