Oracle数据块损坏的恢复实例

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测试环境：11.2.0.4

• 1. 构建数据块损坏的测试环境
• 2. 有备份：常规恢复坏块
• 3. 无备份：跳过坏块

1. 构建数据块损坏的测试环境

1.1 创建测试表

--Create Table t_test
conn jingyu/jingyu
drop table t_test purge;
create table t_test (id number, name char(2000));

--Insert data
insert into t_test values(1, 'alfred 1');
insert into t_test values(2, 'alfred 2');
insert into t_test values(3, 'alfred 3');
insert into t_test values(4, 'alfred 4');
insert into t_test values(5, 'alfred 5');
insert into t_test values(6, 'alfred 6');
insert into t_test values(7, 'alfred 7');
insert into t_test values(8, 'alfred 8');
insert into t_test values(9, 'alfred 9');
insert into t_test values(10, 'alfred 10');
commit;

--Create Index
create index idx_t_test_1 on t_test(id);

--Statistics
--analyze table t_test compute statistics;
EXEC DBMS_STATS.gather_table_stats('JINGYU', 'T_TEST', cascade => TRUE);

1.2 查询表中每一行对应的文件号和块号

-- 查询 t_test 表中每一行对应的文件和块号
select blocks from user_tables where table_name = 'T_TEST';

select dbms_rowid.rowid_relative_fno(rowid) R_FNO,
dbms_rowid.rowid_block_number(rowid) b_no, id
from t_test
order by 1,2;

-- 这里对象占用块数的查询前后不匹配, 与书中不符, 但不影响实验, 结果如下: 
SQL> select blocks from user_tables where table_name = 'T_TEST';

    BLOCKS
----------
         5

SQL> select dbms_rowid.rowid_relative_fno(rowid) R_FNO,
  2  dbms_rowid.rowid_block_number(rowid) b_no, id
  3  from t_test
  4  order by 1,2;

     R_FNO       B_NO         ID
---------- ---------- ----------
         6       3892          1
         6       3892          2
         6       3892          3
         6       3893          4
         6       3893          5
         6       3893          6
         6       3894          7
         6       3894          8
         6       3894          9
         6       3895         10

10 rows selected.

1.3 使用 bbed 工具模拟破坏 6 号数据文件的 3893 数据块

关于 bbed 的编译和使用可参考

• 《Oracle 11g 编译使用 BBED》

1.3.1 准备 bbed 配置文件：
编辑 /tmp/bbed.par 参数配置文件

-- 编辑 /tmp/bbed.par 参数配置文件
blocksize=8192
listfile=/tmp/listfile.txt
mode=edit

-- 编辑 /tmp/listfile.txt 文件 
SQL> select file#||''||name||' '||bytes from v$datafile ;

FILE#||''||NAME||''||BYTES
--------------------------------------------------------------------------------
1 +DATA1/jyzhao/datafile/system.256.919998779 786432000
2 +DATA1/jyzhao/datafile/sysaux.257.919998781 891289600
3 +DATA1/jyzhao/datafile/undotbs1.258.919998783 125829120
4 +DATA1/jyzhao/datafile/users.259.919998789 13107200
5 +DATA1/jyzhao/datafile/undotbs2.264.919999419 78643200
6 +DATA1/jyzhao/datafile/dbs_d_jingyu.268.927427887 104857600
7 +DATA1/jyzhao/datafile/dbs_i_jingyu.270.927427891 31457280
8 +DATA1/jyzhao/datafile/soe.278.939295201 104857600
9 +DATA1/jyzhao/datafile/dbs_d_jingyu.277.939295229 104857600

由于 bbed 不能直接操作 ASM 里面的数据文件，所以需把对应的数据文件转储出来：

RMAN> backup as copy datafile 6 format '/opt/app/Oracle/datafile/dbs_d_jingyu01.dbf';
--mount 
RMAN> switch datafile 6 to copy;
RMAN> recover datafile 6;
RMAN> alter database open;

-- 编辑 /tmp/listfile.txt, 添加6 号文件信息
vi /tmp/listfile.txt
6 /opt/app/oracle/datafile/dbs_d_jingyu01.dbf 104857600

SQL> alter system checkpoint;

测试调用 bbed 正常：

-- 调用 bbed
cd /tmp
bbed parfile=bbed.par

1.3.2 破坏数据文件 6 的 3893 数据块

[oracle@jyrac1 tmp]$ bbed parfile=bbed.par
Password: 

BBED: Release 2.0.0.0.0 - Limited Production on Wed Mar 22 15:28:00 2017

Copyright (c) 1982, 2011, Oracle and/or its affiliates.  All rights reserved.

************* !!! For Oracle Internal Use only !!! ***************

BBED> set dba 6,3893 
        DBA             0x01800f35 (25169717 6,3893)

BBED> find /c alfred
 File: /opt/app/oracle/datafile/dbs_d_jingyu01.dbf (6)
 Block: 3893             Offsets: 2170 to 2681           Dba:0x01800f35
------------------------------------------------------------------------
 616c6672 65642036 20202020 20202020 20202020 20202020 20202020 20202020 
 20202020 20202020 20202020 20202020 20202020 20202020 20202020 20202020 
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 20202020 20202020 20202020 20202020 20202020 20202020 20202020 20202020 

 <32 bytes per line>

BBED> f
 File: /opt/app/oracle/datafile/dbs_d_jingyu01.dbf (6)
 Block: 3893             Offsets: 4179 to 4690           Dba:0x01800f35
------------------------------------------------------------------------
 616c6672 65642035 20202020 20202020 20202020 20202020 20202020 20202020 
 20202020 20202020 20202020 20202020 20202020 20202020 20202020 20202020 
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 <32 bytes per line>

BBED> f
 File: /opt/app/oracle/datafile/dbs_d_jingyu01.dbf (6)
 Block: 3893             Offsets: 6188 to 6699           Dba:0x01800f35
------------------------------------------------------------------------
 616c6672 65642034 20202020 20202020 20202020 20202020 20202020 20202020 
 20202020 20202020 20202020 20202020 20202020 20202020 20202020 20202020 
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 <32 bytes per line>

BBED> f
BBED-00212: search string not found


BBED> dump /v dba 6,3893 offset 2170 count 64
 File: /opt/app/oracle/datafile/dbs_d_jingyu01.dbf (6)
 Block: 3893    Offsets: 2170 to 2233  Dba:0x01800f35
-------------------------------------------------------
 616c6672 65642036 20202020 20202020 l alfred 6        
 20202020 20202020 20202020 20202020 l                 
 20202020 20202020 20202020 20202020 l                 
 20202020 20202020 20202020 20202020 l                 

 <16 bytes per line>

BBED> dump /v dba 6,3893 offset 4179 count 64
 File: /opt/app/oracle/datafile/dbs_d_jingyu01.dbf (6)
 Block: 3893    Offsets: 4179 to 4242  Dba:0x01800f35
-------------------------------------------------------
 616c6672 65642035 20202020 20202020 l alfred 5        
 20202020 20202020 20202020 20202020 l                 
 20202020 20202020 20202020 20202020 l                 
 20202020 20202020 20202020 20202020 l                 

 <16 bytes per line>

BBED> dump /v dba 6,3893 offset 6188 count 64
 File: /opt/app/oracle/datafile/dbs_d_jingyu01.dbf (6)
 Block: 3893    Offsets: 6188 to 6251  Dba:0x01800f35
-------------------------------------------------------
 616c6672 65642034 20202020 20202020 l alfred 4        
 20202020 20202020 20202020 20202020 l                 
 20202020 20202020 20202020 20202020 l                 
 20202020 20202020 20202020 20202020 l                 

 <16 bytes per line>

BBED> modify 901010 dba 6,3893
Warning: contents of previous BIFILE will be lost. Proceed? (Y/N) y
 File: /opt/app/oracle/datafile/dbs_d_jingyu01.dbf (6)
 Block: 3893             Offsets: 6188 to 6251           Dba:0x01800f35
------------------------------------------------------------------------
 0dbf9272 65642034 20202020 20202020 20202020 20202020 20202020 20202020 
 20202020 20202020 20202020 20202020 20202020 20202020 20202020 20202020 

 <32 bytes per line>

BBED> exit

1.3.3 使用 dbv 检查文件

[oracle@jyrac1 tmp]$ dbv file=/opt/app/oracle/datafile/dbs_d_jingyu01.dbf

DBVERIFY: Release 11.2.0.4.0 - Production on Wed Mar 22 15:31:50 2017

Copyright (c) 1982, 2011, Oracle and/or its affiliates.  All rights reserved.

DBVERIFY - Verification starting : FILE = /opt/app/oracle/datafile/dbs_d_jingyu01.dbf
Page 3893 is marked corrupt
Corrupt block relative dba: 0x01800f35 (file 6, block 3893)
Bad check value found during dbv: 
Data in bad block:
 type: 6 format: 2 rdba: 0x01800f35
 last change scn: 0x0000.003b68be seq: 0x1 flg: 0x06
 spare1: 0x0 spare2: 0x0 spare3: 0x0
 consistency value in tail: 0x68be0601
 check value in block header: 0x6485
 computed block checksum: 0xd398



DBVERIFY - Verification complete

Total Pages Examined         : 12800
Total Pages Processed (Data) : 2512
Total Pages Failing   (Data) : 0
Total Pages Processed (Index): 989
Total Pages Failing   (Index): 0
Total Pages Processed (Other): 9025
Total Pages Processed (Seg)  : 0
Total Pages Failing   (Seg)  : 0
Total Pages Empty            : 273
Total Pages Marked Corrupt   : 1
Total Pages Influx           : 0
Total Pages Encrypted        : 0
Highest block SCN            : 3893454 (0.3893454)
[oracle@jyrac1 tmp]$ 

2. 有备份：常规恢复

数据库有有效的 RMAN 备份，那么很简单，直接恢复损害数据块即可。
RMAN> blockrecover datafile 6 block 3893;

常规恢复输出类似下面这样：

RMAN> blockrecover datafile 6 block 3893;

Starting recover at 22-MAR-17
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=148 instance=jyzhao1 device type=DISK

channel ORA_DISK_1: restoring block(s)
channel ORA_DISK_1: specifying block(s) to restore from backup set
restoring blocks of datafile 00006
channel ORA_DISK_1: reading from backup piece +FRA1/jyzhao/backupset/2017_03_22/nnndf0_tag20170322t123922_0.463.939299963
channel ORA_DISK_1: piece handle=+FRA1/jyzhao/backupset/2017_03_22/nnndf0_tag20170322t123922_0.463.939299963 tag=TAG20170322T123922
channel ORA_DISK_1: restored block(s) from backup piece 1
channel ORA_DISK_1: block restore complete, elapsed time: 00:00:01

starting media recovery
media recovery complete, elapsed time: 00:00:04

Finished recover at 22-MAR-17

恢复完成后可以正常访问。

3. 无备份：跳过坏块

3.1 查看 AFN 和 RFN

绝对数据文件号：AFN 是数据文件在整个系统范围内的编号。
相对数据文件号：RFN 是数据文件在表空间范围内的编号。
两个文件可能有相同的 RFN，但是不会有相同的 AFN。

获取普通文件的 AFN 和 RFN:
select tablespace_name, file_id “AFN”, relative_fno “RFN” from dba_data_files;

SQL> select tablespace_name, file_id "AFN", relative_fno "RFN" from dba_data_files;

TABLESPACE_NAME                       AFN        RFN
------------------------------ ---------- ----------
USERS                                   4          4
UNDOTBS1                                3          3
SYSAUX                                  2          2
SYSTEM                                  1          1
UNDOTBS2                                5          5
DBS_D_JINGYU                            6          6
DBS_I_JINGYU                            7          7
SOE                                     8       1024
DBS_D_JINGYU                            9          9

9 rows selected.

注意：实验发现，大文件表空间的 RFN 固定为 1024。

获取临时文件的 AFN 和 RFN：
select tablespace_name, file_id + value “AFN”, relative_fno “RFN” from dba_temp_files, v$parameter where name = ‘db_files’;

SQL> select tablespace_name, file_id + value "AFN", relative_fno "RFN" from dba_temp_files, v$parameter where name = 'db_files';

TABLESPACE_NAME                       AFN        RFN
------------------------------ ---------- ----------
TEMP_JINGYU                           202          1
TEMP                                  201          1

3.2 创建 REPAIR_TABLE 和 ORPHAN_KEY_TABLE
REPAIR_TABLE 用来记录错误检查结果，ORPHAN_KEY_TABLE 用来记录表坏块中记录在索引中对应键值。

-- 通过如下存储过程创建 REPAIR_TABLE 和 ORPHAN_KEY_TABLE
--Repair Table
declare
begin
    dbms_repair.admin_tables(table_name => 'REPAIR_TABLE',
        table_type => dbms_repair.repair_table,
        action => dbms_repair.create_action,
        tablespace => 'USERS'
    );
end;
/

select owner, object_name, object_type from dba_objects where object_name like '%REPAIR_TABLE';

--Orphan Key Table
declare
begin
    dbms_repair.admin_tables(table_name => 'ORPHAN_KEY_TABLE',
        table_type => dbms_repair.orphan_table,
        action => dbms_repair.create_action,
        tablespace => 'USERS'
    );
end;
/

select owner, object_name, object_type from dba_objects where object_name like '%ORPHAN_KEY_TABLE';

-- 不再需要时，可以通过下面的存储过程删除 REPAIR_TABLE 和 ORPHAN_KEY_TABLE 这两个表：
--DROP REPAIR_TABLE
BEGIN
    DBMS_REPAIR.ADMIN_TABLES (TABLE_NAME => 'REPAIR_TABLE',
        TABLE_TYPE => dbms_repair.repair_table,
        ACTION => dbms_repair.drop_action);
END;
/

--DROP ORPHAN_KEY_TABLE
BEGIN
    DBMS_REPAIR.ADMIN_TABLES (TABLE_NAME => 'ORPHAN_KEY_TABLE',
        TABLE_TYPE => dbms_repair.orphan_table,
        ACTION => dbms_repair.drop_action);
END;
/

3.3 使用 CHECK_OBJECT 过程检测坏块

set serveroutput on
declare
    rpr_count int;
begin
    rpr_count := 0;
    dbms_repair.check_object(schema_name => 'JINGYU',
        object_name => 'T_TEST',
        repair_table_name => 'REPAIR_TABLE',
        corrupt_count => rpr_count
    );
    dbms_output.put_line('repair count:' || to_char(rpr_count));
end;
/

select object_name, block_id, corrupt_type, marked_corrupt, corrupt_description, repair_description from repair_table;

执行结果：

SQL> set serveroutput on
SQL> declare
  2     rpr_count int;
  3  begin
  4     rpr_count := 0;
  5     dbms_repair.check_object(6             schema_name => 'JINGYU',
  7             object_name => 'T_TEST',
  8             repair_table_name => 'REPAIR_TABLE',
  9             corrupt_count => rpr_count
 10     );
 11     dbms_output.put_line('repair count:' || to_char(rpr_count));
 12  end;
 13  /
repair count: 1

PL/SQL procedure successfully completed.

SQL> select object_name, block_id, corrupt_type, marked_corrupt, corrupt_description, repair_description from repair_table;

OBJECT_NAME                      BLOCK_ID CORRUPT_TYPE MARKED_COR
------------------------------ ---------- ------------ ----------
CORRUPT_DESCRIPTION
--------------------------------------------------------------------------------
REPAIR_DESCRIPTION
--------------------------------------------------------------------------------
T_TEST                               3893         6148 TRUE

mark block software corrupt

如果 marked_corrupt 不是 true，则需要使用 fix_corrupt_blocks 过程修复：

declare
    fix_count int;
begin
    fix_count := 0;
    dbms_repair.fix_corrupt_blocks(schema_name => 'JINGYU',
        object_name => 'T_TEST',
        object_type => dbms_repair.table_object,
        repair_table_name => 'REPAIR_TABLE',
        fix_count => fix_count
    );
    dbms_output.put_line('fix count:' || to_char(fix_count));
end;
/

这里实验此步骤执行不执行都可以。

3.4 使用 DUMP_ORPHAN_KEYS 过程来保存坏块中的索引键值

select object_name, block_id, marked_corrupt from repair_table;

select index_name from dba_indexes where table_name in (select distinct object_name from repair_table);

SQL> select object_name, block_id, marked_corrupt from repair_table;

OBJECT_NAME                      BLOCK_ID MARKED_COR
------------------------------ ---------- ----------
T_TEST                               3893 TRUE

SQL> select index_name from dba_indexes where table_name in (select distinct object_name from repair_table);

INDEX_NAME
------------------------------
IDX_T_TEST_1

这时还存在着一个潜在的问题。
就是表有坏块，但索引没有损坏，通过表扫描会出现错误，但是通过索引扫描仍然可以返回结果，这会造成数据的不一致性。
比如，这里我知道 id = 4 的记录：

SQL> select * from jingyu.t_test where id = 4;
select * from jingyu.t_test where id = 4
                     *
ERROR at line 1:
ORA-01578: ORACLE data block corrupted (file # 6, block # 3893)
ORA-01110: data file 6: '/opt/app/oracle/datafile/dbs_d_jingyu01.dbf'


SQL> select id from jingyu.t_test where id = 4;

        ID
----------
         4

使用 DUMP_ORPHAN_KEYS 过程来保存坏块中的索引键值：

set serveroutput on
declare
    key_count int;
begin
    key_count := 0;
    dbms_repair.dump_orphan_keys(schema_name => 'JINGYU',
        object_name => 'IDX_T_TEST_1',
        object_type => dbms_repair.index_object,
        repair_table_name => 'REPAIR_TABLE',
        orphan_table_name => 'ORPHAN_KEY_TABLE',
        key_count => key_count
    );
    dbms_output.put_line('orphan key count:' || to_char(key_count));
end;
/

执行结果如下：

SQL> set serveroutput on
SQL> declare
  2     key_count int;
  3  begin
  4     key_count := 0;
  5     dbms_repair.dump_orphan_keys(6             schema_name => 'JINGYU',
  7             object_name => 'IDX_T_TEST_1',
  8             object_type => dbms_repair.index_object,
  9             repair_table_name => 'REPAIR_TABLE',
 10             orphan_table_name => 'ORPHAN_KEY_TABLE',
 11             key_count => key_count
 12     );
 13     dbms_output.put_line('orphan key count:' || to_char(key_count));
 14  end;
 15  /
orphan key count: 3

PL/SQL procedure successfully completed.

这样当之后执行完 SKIP_CORRUPT_BLOCKS 操作后，就可以重新建立索引了（对每个索引都要执行 DUMP_ORPHAN_KEYS 过程）。

3.5 使用 skip_corrupt_blocks 过程来跳过坏块
执行 skip_corrupt_blocks 过程，使后续 DML 操作跳过坏块：

begin
    dbms_repair.skip_corrupt_blocks (schema_name => 'JINGYU',
        object_name => 'T_TEST',
        object_type => dbms_repair.table_object,
        flags => dbms_repair.skip_flag
    );
end;
/

执行结果：

SQL> select count(1) from jingyu.t_test;
select count(1) from jingyu.t_test
                            *
ERROR at line 1:
ORA-01578: ORACLE data block corrupted (file # 6, block # 3893)
ORA-01110: data file 6: '/opt/app/oracle/datafile/dbs_d_Jingyu01.dbf'


SQL> begin
  2     dbms_repair.skip_corrupt_blocks (3             schema_name => 'JINGYU',
  4             object_name => 'T_TEST',
  5             object_type => dbms_repair.table_object,
  6             flags => dbms_repair.skip_flag
  7     );
  8  end;
  9  /

PL/SQL procedure successfully completed.

SQL>  select count(1) from jingyu.t_test;

  COUNT(1)
----------
         7

3.6 重建 freelist
如果不想使用 CTAS 方式重建表而仍是在原表上修复，则需要重建对象的 Freelist，防止这个数据块以后被加到 freelist 中。使用下面的方法：

declare
begin
    dbms_repair.rebuild_freelists (schema_name => 'JINGYU',
        object_name => 'T_TEST',
        object_type => dbms_repair.table_object
    );
end;
/

这里实际已知坏块不在 freelist 中，所以不需要执行，执行会报错如下错误：

SQL> declare
  2  begin
  3     dbms_repair.rebuild_freelists (4             schema_name => 'JINGYU',
  5             object_name => 'T_TEST',
  6             object_type => dbms_repair.table_object
  7     );
  8  end;
  9  /
declare
*
ERROR at line 1:
ORA-10614: Operation not allowed on this segment
ORA-06512: at "SYS.DBMS_REPAIR", line 401
ORA-06512: at line 3

3.7 重建索引
目前索引和数据块仍然存在不一致，必须要重建索引：

-- 以 id=4为例，索引和数据块依然存在不一致：SQL> select * from jingyu.t_test where id = 4;

no rows selected

SQL> select id from jingyu.t_test where id = 4;

        ID
----------
         4

-- 重建索引，不能采用 rebuild，只能 drop 后再 create。因为 rebuild 数据源来自索引：-- 测试 rebuild 发现的确还存在不一致：SQL> alter index jingyu.idx_t_test_1 rebuild;

Index altered.

SQL> select id from jingyu.t_test where id = 4;

        ID
----------
         4

-- 先 drop 再 create index，确认一致：SQL> drop index jingyu.idx_t_test_1;

Index dropped.

SQL> create index jingyu.idx_t_test_1 on jingyu.t_test(id);

Index created.

SQL> select id from jingyu.t_test where id = 4;

no rows selected

当然，如果此时使用 dbv 检查数据文件，依然是有坏块的，上面所有操作只是跳过坏块，并没有解决。

[oracle@jyrac1 ~]$ dbv file=/opt/app/oracle/datafile/dbs_d_jingyu01.dbf

DBVERIFY: Release 11.2.0.4.0 - Production on Wed Mar 22 17:29:42 2017

Copyright (c) 1982, 2011, Oracle and/or its affiliates.  All rights reserved.

DBVERIFY - Verification starting : FILE = /opt/app/oracle/datafile/dbs_d_jingyu01.dbf
Page 3893 is marked corrupt
Corrupt block relative dba: 0x01800f35 (file 6, block 3893)
Bad check value found during dbv: 
Data in bad block:
 type: 6 format: 2 rdba: 0x01800f35
 last change scn: 0x0000.003b68be seq: 0x1 flg: 0x06
 spare1: 0x0 spare2: 0x0 spare3: 0x0
 consistency value in tail: 0x68be0601
 check value in block header: 0x6485
 computed block checksum: 0xd398



DBVERIFY - Verification complete

Total Pages Examined         : 12800
Total Pages Processed (Data) : 2512
Total Pages Failing   (Data) : 0
Total Pages Processed (Index): 989
Total Pages Failing   (Index): 0
Total Pages Processed (Other): 9025
Total Pages Processed (Seg)  : 0
Total Pages Failing   (Seg)  : 0
Total Pages Empty            : 273
Total Pages Marked Corrupt   : 1
Total Pages Influx           : 0
Total Pages Encrypted        : 0
Highest block SCN            : 3907507 (0.3907507)

善后工作（与数据块恢复无关）：
养成一个习惯，做任何实验，如果对实验环境改动较大，建议实验完毕后，尽量恢复到正常状态，避免今后测试其他案例时现修复环境。
我这里就是把实验环境恢复(6 号文件恢复为原来的 ASM 存储上):

RMAN> list copy  of datafile 6;

using target database control file instead of recovery catalog
List of Datafile Copies
=======================

Key     File S Completion Time Ckp SCN    Ckp Time       
------- ---- - --------------- ---------- ---------------
18      6    A 22-MAR-17       3895505    22-MAR-17      
        Name: +DATA1/jyzhao/datafile/dbs_d_jingyu.268.939306177
        Tag: TAG20170322T142256

16      6    A 22-MAR-17       3817798    22-MAR-17      
        Name: /opt/app/oracle/datafile/dbs_d_Jingyu01.dbf

14      6    A 22-MAR-17       3817798    22-MAR-17      
        Name: +FRA1/jyzhao/datafile/dbs_d_jingyu.368.939306031
        Tag: TAG20170322T142027


RMAN> switch datafile 6 to copy;

datafile 6 switched to datafile copy "+DATA1/jyzhao/datafile/dbs_d_jingyu.268.939306177"

RMAN> recover datafile 6;

Starting recover at 22-MAR-17
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=143 instance=jyzhao1 device type=DISK

starting media recovery
media recovery complete, elapsed time: 00:00:01

Finished recover at 22-MAR-17

RMAN> alter database open;

database opened

至此，已完成数据块恢复实例的整个实验。

此外，针对坏块问题，还有一种方式是设置 10231 event，具体可参考：

• 《Oracle 数据块损坏篇之 10231 内部事件》

更多 Oracle 相关信息见Oracle 专题页面 http://www.linuxidc.com/topicnews.aspx?tid=12

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