什么是塊損壞：
所謂損壞的數據塊，是指塊沒有采用可識別的 Oracle 格式，或者其內容在內部不一致。通常情況下，損壞是由硬件故障或操作系統問題引起的。Oracle 數據庫將損壞的塊標識為“邏輯損壞”或“介質損壞”。如果是邏輯損壞，則是 Oracle 內部錯誤。Oracle 數據庫檢測到不一致之后，就將邏輯損壞的塊標記為損壞。如果是介質損壞，則是塊格式不正確；從磁盤讀取的塊不包含有意義的信息。實驗：某個分區數據塊損壞，不完全恢復此分區表數據。
背景：數據庫沒有有效備份，某個分區中有數據塊損壞。
要求：最大限度恢復此分區數據。
環境：RHEL 6.4 + Oracle 11.2.0.4
下面這篇文章主要給大家介紹了關于Oracle數據塊損壞之10231內部事件的相關內容，分享出來供大家參考學習，下面來看看詳細的介紹：
1. 初始化實驗環境
初始化創建模擬實驗環境用到的表空間、業務用戶、表，并導入測試數據。
本次實驗用到表空間DBS_D_JINGYU, 業務用戶JINGYU, 分區表T_PART(含兩個分區的測試數據)。
-- 數據表空間
create tablespace dbs_d_jingyu datafile '/u02/oradata/jingyu/dbs_d_jingyu01.dbf' size 30M autoextend off;
-- 臨時表空間
create temporary tablespace temp_jingyu tempfile '/u02/oradata/jingyu/temp_jingyu01.tmp' size 30M autoextend off;
-- 索引表空間(可選)
create tablespace dbs_i_jingyu datafile '/u02/oradata/jingyu/dbs_i_jingyu01.dbf' size 30M autoextend off;
-- 假設創建用戶 jingyu 密碼 jingyu，默認臨時表空間 temp_jingyu， 默認數據表空間 dbs_d_jingyu。
CREATE USER jingyu IDENTIFIED BY jingyu
TEMPORARY TABLESPACE temp_jingyu
DEFAULT TABLESPACE dbs_d_jingyu
QUOTA UNLIMITED ON dbs_d_jingyu;
-- 賦予普通業務用戶權限
grant resource, connect to jingyu;
-- 賦予DBA用戶權限
grant dba to jingyu;
-- 業務用戶登錄
conn jingyu/jingyu
-- 1.1 創建分區表
create table t_part(
id number,
name varchar2(20),
start_time date,
content varchar2(200)
)partition by range(start_time)
(
partition P20150101 values less than (TO_DATE(' 2015-01-01 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))
tablespace dbs_d_jingyu,
partition P20150102 values less than (TO_DATE(' 2015-01-02 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))
tablespace dbs_d_jingyu,
partition P20150103 values less than (TO_DATE(' 2015-01-03 00:00:00', 'SYYYY-MM-DD HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN'))
tablespace dbs_d_jingyu
);
-- 1.2 插入測試數據
--分區P20150102插入10000行數據
begin
for i in 1..10000 loop
insert into t_part values (i,'alfred'||i, to_date('2015-01-01','yyyy-mm-dd'), 'AAAAAAAAAA');
end loop;
commit;
end;
/
--分區P20150103插入20000行數據
begin
for i in 10001..30000 loop
insert into t_part values (i,'alfred'||i, to_date('2015-01-02','yyyy-mm-dd'), 'AAAAAAAAAA');
end loop;
commit;
end;
/
-- 1.3查詢表數據量和大小
select count(1) from t_part;
--result: 30000
select count(1) from t_part partition(P20150102);
--result: 10000
select count(1) from t_part partition(P20150103);
--result: 20000
--普通表/分區表的每個分區大約__G大小
set linesize 160
col segment_name for a30
select (t.bytes/1024/1024) "MB", t.owner, t.segment_name, t.partition_name, t.tablespace_name from dba_segments t where segment_name = 'T_PART';
MB OWNER SEGMENT_NAME PARTITION_NAME TABLESPACE_NAME
---------- ------------------------------ ------------------------------ ------------------------------ ------------------------------
8 JINGYU T_PART P20150102 DBS_D_JINGYU
8 JINGYU T_PART P20150103 DBS_D_JINGYU
2. 模擬分區中有數據塊損壞情景
我這里使用BBED制造壞塊，修改t_part分區表的分區P20150103中的某個塊內容，模擬真實環境中有數據塊損壞的情景。
--查詢分區P20150103的HEADER_BLOCK
select header_file,header_block from dba_segments where segment_name='T_PART' and partition_name='P20150103' and owner='JINGYU';
SQL> select header_file,header_block from dba_segments where segment_name='T_PART' and partition_name='P20150103' and owner='JINGYU';
HEADER_FILE HEADER_BLOCK
----------- ------------
5 1169
--查詢某一行記錄所在的塊
select
rowid,
dbms_rowid.rowid_relative_fno(rowid)rel_fno,
dbms_rowid.rowid_block_number(rowid)blockno,
dbms_rowid.rowid_row_number(rowid) rowno
from t_part where id = 20000;
SQL> select
2 rowid,
3 dbms_rowid.rowid_relative_fno(rowid)rel_fno,
4 dbms_rowid.rowid_block_number(rowid)blockno,
5 dbms_rowid.rowid_row_number(rowid) rowno
6 from t_part where id = 20000;
ROWID REL_FNO BLOCKNO ROWNO
------------------ ---------- ---------- ----------
AAAVveAAFAAAATBABX 5 1217 87
使用bbed工具破壞5號文件1217塊內容，
BBED工具：https://www.jb51.net/article/118349.htm
[oracle@JY-DB01 ~]$ bbed parfile=/tmp/bbed.par
Password:
BBED: Release 2.0.0.0.0 - Limited Production on Tue Jan 19 11:37:59 2016
Copyright (c) 1982, 2011, Oracle and/or its affiliates. All rights reserved.
************* !!! For Oracle Internal Use only !!! ***************
BBED> set dba 5,1217
DBA 0x014004c1 (20972737 5,1217)
BBED> map
File: /u02/oradata/jingyu/dbs_d_jingyu01.dbf (5)
Block: 1217 Dba:0x014004c1
------------------------------------------------------------
KTB Data Block (Table/Cluster)
struct kcbh, 20 bytes @0
struct ktbbh, 72 bytes @20
struct kdbh, 14 bytes @100
struct kdbt[1], 4 bytes @114
sb2 kdbr[177] @118
ub1 freespace[815] @472
ub1 rowdata[6901] @1287
ub4 tailchk @8188
BBED> d /v offset 0 count 128
File: /u02/oradata/jingyu/dbs_d_jingyu01.dbf (5)
Block: 1217 Offsets: 0 to 127 Dba:0x014004c1
-------------------------------------------------------
06a20000 c1044001 52733100 00000106 l ......@.Rs1.....
a18b0000 01000c00 de5b0100 4d733100 l .........[..Ms1.
0000e81f 021f3200 81044001 02001b00 l ......2...@.....
5d0b0000 fc0fc000 df030600 b1200000 l ]............ ..
52733100 00000000 00000000 00000000 l Rs1.............
00000000 00000000 00000000 00000000 l ................
00000000 0001b100 ffff7401 a3042f03 l ..........t.../.
2f030000 b100711f 4a1f231f fc1ed51e l /.....q.J.#.....
16 bytes per line>
BBED> modify /x 19901010 offset 0
File: /u02/oradata/jingyu/dbs_d_jingyu01.dbf (5)
Block: 1217 Offsets: 0 to 127 Dba:0x014004c1
------------------------------------------------------------------------
19901010 c1044001 52733100 00000106 a18b0000 01000c00 de5b0100 4d733100
0000e81f 021f3200 81044001 02001b00 5d0b0000 fc0fc000 df030600 b1200000
52733100 00000000 00000000 00000000 00000000 00000000 00000000 00000000
00000000 0001b100 ffff7401 a3042f03 2f030000 b100711f 4a1f231f fc1ed51e
32 bytes per line>
BBED> sum apply
Check value for File 5, Block 1217:
current = 0xa9ae, required = 0xa9ae
BBED>
至此破壞了5號文件，1217塊。
查詢v$database_block_corruption
select * from v$database_block_corruption;
SQL> select * from v$database_block_corruption;
FILE# BLOCK# BLOCKS CORRUPTION_CHANGE# CORRUPTIO
---------- ---------- ---------- ------------------ ---------
5 1217 1 0 CORRUPT
--此時查詢分區表T_PART
alter system flush buffer_cache;
select count(1) from t_part;
--查詢報錯ORA-01578
select count(1) from t_part partition(P20150102);
--查詢正常，即分區P20150102未受影響
select count(1) from t_part partition(P20150103);
--查詢報錯ORA-01578
--嘗試邏輯導出表數據失敗
[oracle@JY-DB01 ~]$ exp jingyu/jingyu tables=t_part file=t_part.dmp log=exp_t_part.log
Export: Release 11.2.0.4.0 - Production on Tue Jan 19 11:52:21 2016
Copyright (c) 1982, 2011, Oracle and/or its affiliates. All rights reserved.
Connected to: Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
With the Partitioning, Automatic Storage Management, OLAP, Data Mining
and Real Application Testing options
Export done in ZHS16GBK character set and AL16UTF16 NCHAR character set
About to export specified tables via Conventional Path ...
. . exporting table T_PART
. . exporting partition P20150101 0 rows exported
. . exporting partition P20150102 10000 rows exported
. . exporting partition P20150103
EXP-00056: ORACLE error 1578 encountered
ORA-01578: ORACLE data block corrupted (file # 5, block # 1217)
ORA-01110: data file 5: '/u02/oradata/jingyu/dbs_d_jingyu01.dbf'
Export terminated successfully with warnings.
[oracle@JY-DB01 ~]$
3. 嘗試使用Oracle內部事件10231進行不完全恢復
使用Oracle 10231內部事件可以跳過壞塊
--啟用10231內部事件
alter system set events='10231 trace name context forever,level 10';
--關閉10231內部事件
alter system set events='10231 trace name context off';
測試設置10231事件后是否可以邏輯導出：
[oracle@JY-DB01 ~]$ sqlplus / as sysdba
SQL*Plus: Release 11.2.0.4.0 Production on Tue Jan 19 14:01:43 2016
Copyright (c) 1982, 2013, Oracle. All rights reserved.
Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
With the Partitioning, Automatic Storage Management, OLAP, Data Mining
and Real Application Testing options
SQL> alter system set events='10231 trace name context forever,level 10';
System altered.
SQL> exit
Disconnected from Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
With the Partitioning, Automatic Storage Management, OLAP, Data Mining
and Real Application Testing options
[oracle@JY-DB01 ~]$ exp jingyu/jingyu tables=t_part file=t_part.dmp log=exp_t_part.log
Export: Release 11.2.0.4.0 - Production on Tue Jan 19 14:01:57 2016
Copyright (c) 1982, 2011, Oracle and/or its affiliates. All rights reserved.
Connected to: Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
With the Partitioning, Automatic Storage Management, OLAP, Data Mining
and Real Application Testing options
Export done in ZHS16GBK character set and AL16UTF16 NCHAR character set
About to export specified tables via Conventional Path ...
. . exporting table T_PART
. . exporting partition P20150101 0 rows exported
. . exporting partition P20150102 10000 rows exported
. . exporting partition P20150103 19823 rows exported
Export terminated successfully without warnings.
--成功導出后記得要關閉10231內部事件
alter system set events='10231 trace name context off';
20000 - 19823 = 177行，也就是說該數據塊損壞直接導致了177行數據丟失。不過還好，保住了大部分數據。
實際上設置10231內部事件后，如果上面邏輯導出沒問題，這種情況自然還可以把數據直接導出到臨時表，更加方便。
SQL> select count(1) from t_part;
select count(1) from t_part
*
ERROR at line 1:
ORA-01578: ORACLE data block corrupted (file # 5, block # 1217)
ORA-01110: data file 5: '/u02/oradata/jingyu/dbs_d_jingyu01.dbf'
SQL> alter system set events='10231 trace name context forever,level 10';
System altered.
SQL> select count(1) from t_part;
COUNT(1)
----------
29823
SQL> create table temp_t_part_20150103 as select * from t_part partition(P20150103);
Table created.
SQL> alter system set events='10231 trace name context off';
System altered.
SQL> select count(1) from t_part partition(P20150103);
select count(1) from t_part partition(P20150103)
*
ERROR at line 1:
ORA-01578: ORACLE data block corrupted (file # 5, block # 1217)
ORA-01110: data file 5: '/u02/oradata/jingyu/dbs_d_jingyu01.dbf'
SQL> select count(1) from temp_t_part_20150103;
COUNT(1)
----------
19823
Reference
•http://blog.csdn.net/tianlesoftware/article/details/5024966
•http://blog.csdn.net/seertan/article/details/8507045
•http://blog.csdn.net/coolyl/article/details/195919
總結
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