oracle 操作实例(一)----redolog 损坏恢复

一,实验前的准备

　　　数据库全备保证自己没成功还能补救一下

vim full.sh
export ORACLE_BASE=/u01/app/oracle
export ORACLE_HOME=$ORACLE_BASE/product/11.2/db_1
export ORACLE_SID=proc
export NLS_LANG=AMERICAN_AMERICA.ZHS16GBK
export PATH=$ORACLE_HOME/bin:$PATH
rman target / log /u01/backup/rman_full.log append<<EOF
run
{allocate channel c1 type disk;
allocate channel c2 type disk;
backup database filesperset 4 format '/u01/backup/full_%d_%T_%s_%p';
sql 'alter system archive log current';
sql 'alter system archive log current';
sql 'alter system archive log current';
backup archivelog all format '/u01/backup/arch_%d_%T_%s_%p' delete input;
backup current controlfile format '/u01/backup/ctl_%d_%T_%s_%p';
crosscheck backup;
crosscheck archivelog all;
delete noprompt obsolete;
delete noprompt  expired backup;
delete noprompt  expired archivelog all;
}
EOF

　　　　查看日志组的状态

size_MB,members,archived,status,first_change#,to_char(FIRST_TIME,'yyyy-mm-dd hh24:mi:ss') first_time from v$log;

　　　　日志文件位置

SELECT group#,member FROM v$logfile;

　　　　记录下来: 开始破坏

　　　　第一步,关闭数据库

　　　　第二步,删除或者移动一个rodo日志.

二,恢复

　　启动数据库报错

　　发现启动到mount状态后开始报错了

　　报错说的还不怎么详细.我们深入看一下

show parameter background_dump

进入报错日志里面查看--报错日志为第一个log文件...

查看最近的报错信息

可以看见日志文件redo3找不到了

　　查看日志状态:

　　　　哇,不行.

　　　　现在关闭数据库

　　　　也报错了

　　　　强制关闭

　　　　shutdown abort

启动数据库到mount状态　　

　　　　 查看日志状态:

　　　　　　有一个日志文件报错了

 select a.group#,a.thread#,b.member,a.bytes/1024/1024
 size_MB,a.members,a.archived,a.status from v$log a,v$logfile b where a.group#=b.group#;

　　处理文件:

　　alter database clear logfile group 3;

　　开启数据库:

　　 没有报错了

假如日志成员全部删除了也是这样恢复的

　　　 全部删除了,

　　启动报错　

　　按照上文恢复

　　好像并不能关闭了----

 SQL> startup mount
 ORACLE instance started.
 
 Total System Global Area 1803841536 bytes
 Fixed Size            2254144 bytes
 Variable Size         1577061056 bytes
 Database Buffers      218103808 bytes
 Redo Buffers            6422528 bytes
 Database mounted.
 SQL>  select group#,thread#,sequence#,bytes/1024/1024
  size_MB,members,archived,status,first_change#,to_char(FIRST_TIME,'yyyy-mm-dd hh24:mi:ss') first_time from v$log;
   2
     GROUP#    THREAD#  SEQUENCE#    SIZE_MB    MEMBERS ARC STATUS
 ---------- ---------- ---------- ---------- ---------- --- ----------------
 FIRST_CHANGE# FIRST_TIME
 ------------- -------------------
      1        1       10749    512         1 NO  CURRENT
      39958366 2019-02-27 17:17:59
 
      3        1           0    512         1 YES UNUSED
      39938038 2019-02-27 16:47:59
 
      2        1       10747    512         1 YES INACTIVE
      39938029 2019-02-27 16:47:59
 
 SQL> alter database clear logfile group 3;^H^H^H^H^H^H
   2
 SQL> s^H^H
 SP2-0042: unknown command " - rest of line ignored.
 SQL>
 SQL>
 SQL>
 SQL> alter database open;
 alter database open
 *
 ERROR at line 1:
 ORA-03113: end-of-file on communication channel
 Process ID: 3292
 Session ID: 1705 Serial number: 5
 
 SQL> alter database clear logfile group 3;
 ERROR:
 ORA-03114: not connected to ORACLE
 
 SQL> exit
 Disconnected from Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
 With the Partitioning, OLAP, Data Mining and Real Application Testing options
 [oracle@dataknown prod]$ sqlplus / as sysdba
 
 SQL*Plus: Release 11.2.0.4.0 Production on Wed Feb 27 17:51:40 2019
 
 Copyright (c) 1982, 2013, Oracle.  All rights reserved.
 
 Connected to an idle instance.
 
 SQL> startup mount
 ORACLE instance started.
 
 Total System Global Area 1803841536 bytes
 Fixed Size            2254144 bytes
 Variable Size         1577061056 bytes
 Database Buffers      218103808 bytes
 Redo Buffers            6422528 bytes
 Database mounted.
 SQL> alter database clear logfile group 3;
 
 Database altered.
 
 SQL> alter database open;
 
 Database altered.
 
 SQL>

插入发现以下报错的可以参考参考

 SQL> alter database clear logfile group 3;
 alter database clear logfile group 3
 *
 ERROR at line 1:
 ORA-00350: log 3 of instance prod (thread 1) needs to be archived
 ORA-00312: online log 3 thread 1: '/data/oradata/prod/redo03.log'

执行以下命令:

alter database clear unarchived logfile group 3;

然后在打开数据库