重做日誌文件實驗

@@@if you want to do this lab the logfile group member must have more than one member


conn / as sysdba
SQL> alter database add logfile member '/u01/app/oracle/oradata/orcl/redo05.log' to group 1;@@@the redo05.log is added to current loggroup because group 1 have only one member redo01.log before adding

SQL>conn hr/hr

SQL> update employees set salary=24002 where employee_id=100;

1 row updated.

SQL> commit;

Commit complete.

SQL> conn / as sysdba
Connected.

SQL> alter system switch logfile;

SQL> alter database drop logfile member '/u01/app/oracle/oradata/orcl/redo05.log' ;

Database altered.

SQL> alter database add logfile member '/u01/app/oracle/oradata/orcl/redo05a.log' to group 1;

Database altered.

SQL> select * from v$logfile;

    GROUP# STATUS  TYPE    MEMBER                                                  IS_
---------- ------- ------- -------------------------------------------------------------------------------- ---
         3         ONLINE  /u01/app/oracle/oradata/orcl/redo03.log                 NO
         2         ONLINE  /u01/app/oracle/oradata/orcl/redo02.log                 NO
         1         ONLINE  /u01/app/oracle/oradata/orcl/redo01.log                 NO
         1 INVALID(新增的日誌組成員狀態) ONLINE  /u01/app/oracle/oradata/orcl/redo05.log                 NO


@@@@alert log information

Sat Mar  9 15:35:53 2013
Thread 1 cannot allocate new log, sequence 59
Checkpoint not complete
  Current log# 1 seq# 58 mem# 0: /u01/app/oracle/oradata/orcl/redo01.log
  Current log# 1 seq# 58 mem# 1: /u01/app/oracle/oradata/orcl/redo05.log
Sat Mar  9 15:35:56 2013
Completed checkpoint up to RBA [0x39.2.10], SCN: 2044130
Sat Mar  9 15:35:57 2013
Beginning log switch checkpoint up to RBA [0x3b.2.10], SCN: 2044309
Thread 1 advanced to log sequence 59
  Current log# 2 seq# 59 mem# 0: /u01/app/oracle/oradata/orcl/redo02.log
Sat Mar  9 15:35:57 2013
Errors in file /u01/app/oracle/admin/orcl/bdump/orcl_arc1_18718.trc:
ORA-00313: open failed for members of log group 1 of thread 1
ORA-00312: online log 1 thread 1: '/u01/app/oracle/oradata/orcl/redo05.log'
ORA-27037: unable to obtain file status
Linux Error: 2: No such file or directory
Additional information: 3
Sat Mar  9 15:35:57 2013
Errors in file /u01/app/oracle/admin/orcl/bdump/orcl_arc1_18718.trc:
ORA-00313: open failed for members of log group 1 of thread 1
ORA-00312: online log 1 thread 1: '/u01/app/oracle/oradata/orcl/redo05.log'
ORA-27037: unable to obtain file status
Linux Error: 2: No such file or directory
Additional information: 3


Sat Mar  9 15:36:54 2013
alter database drop logfile member '/u01/app/oracle/oradata/orcl/redo05.log'
Sat Mar  9 15:36:54 2013
Completed: alter database drop logfile member '/u01/app/oracle/oradata/orcl/redo05.log'