ORACLE 如何檢查找出損壞索引 ( Corrupt Indexes )
2018-09-19 來源：importnew
在Oracle數(shù)據(jù)庫中如何找出損壞索引呢？ 下面我們?nèi)藶闃?gòu)造一個(gè)案例，將索引塊損壞。如下案例所示：
SQL> create tablespace test_data 2 datafile '/u01/app/oracle/oradata/gsp/test_data_01.dbf' 3 size 200M autoextend off 4 logging 5 segment space management auto 6 extent management local; Tablespace created. SQL> create tablespace test_index 2 datafile '/u01/app/oracle/oradata/gsp/test_idx_01.dbf' 3 size 200M autoextend off 4 logging 5 segment space management auto 6 extent management local; Tablespace created. SQL> create user kerry 2 identified by 123456 3 default tablespace test_data; User created. SQL> grant connect to kerry; SQL> grant resource to kerry;
上述腳本是創(chuàng)建表空間，創(chuàng)建用戶kerry并授權(quán)，然后使用kerry賬號登錄數(shù)據(jù)庫，構(gòu)造測試數(shù)據(jù)，在TEST表上創(chuàng)建索引IX_TEST
SQL> show user;
USER is "KERRY"
SQL>
SQL> CREATE TABLE TEST(ID NUMBER(10), NAME VARCHAR2(64));
Table created.
SQL> DECLARE I NUMBER;
2 BEGIN
3 FOR I IN 1..1000 LOOP
4 INSERT INTO TEST VALUES(I, LPAD('T', 60));
5 END LOOP;
6 COMMIT;
7 END;
8 /
PL/SQL procedure successfully completed.
SQL> CREATE INDEX IX_TEST ON KERRY.TEST(NAME) TABLESPACE TEST_INDEX;
Index created.
然后使用下面腳本找到索引段數(shù)據(jù)庫文件ID，以及索引段的第一個(gè)塊的塊號。
SQL> show user; USER is "SYS" SQL> col segment_name for a32; SQL> col header_file for 9999; SQL> col header_block for 9999; SQL> select segment_name 2 ,header_file 3 ,header_block 4 ,blocks 5 from dba_segments ds 6 where ds.owner='KERRY' and ds.segment_name='IX_TEST'; SEGMENT_NAME HEADER_FILE HEADER_BLOCK BLOCKS -------------------------------- ----------- ------------ ---------- IX_TEST 8 130 16 SQL>
構(gòu)造壞塊的方法有不少（例如BBED等），這里我們使用RMAN下面的命令clear,可以標(biāo)記數(shù)據(jù)塊為corrupt,標(biāo)記數(shù)據(jù)文件8中130號數(shù)據(jù)塊為壞塊。
[oracle@DB-Server ~]$ rman target / Recovery Manager: Release 11.2.0.1.0 - Production on Thu Sep 13 17:41:05 2018 Copyright (c) 1982, 2009, Oracle and/or its affiliates. All rights reserved. connected to target database: GSP (DBID=644393201) RMAN> recover datafile 8 block 130 clear; Starting recover at 13-SEP-18 using target database control file instead of recovery catalog allocated channel: ORA_DISK_1 channel ORA_DISK_1: SID=12 device type=DISK Finished recover at 13-SEP-18 RMAN>
那么我們先來看看使用那些方法驗(yàn)證索引損壞了，測試驗(yàn)證一下看看是否可行。?
1：使用ANALYZE分析驗(yàn)證索引結(jié)構(gòu)
[oracle@DB-Server ~]$ sqlplus / as sysdba SQL*Plus: Release 11.2.0.1.0 Production on Thu Sep 13 17:42:03 2018 Copyright (c) 1982, 2009, Oracle. All rights reserved. Connected to: Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production With the Partitioning, OLAP, Data Mining and Real Application Testing options SQL> analyze index kerry.ix_test validate structure; analyze index kerry.ix_test validate structure * ERROR at line 1: ORA-01578: ORACLE data block corrupted (file # 8, block # 130) ORA-01110: data file 8: '/u01/app/oracle/oradata/gsp/test_idx_01.dbf'
如上截圖所示，如果索引損壞（Corrupt Index），那么使用analyze index validate structure就會(huì)報(bào)錯(cuò)。要檢查整個(gè)數(shù)據(jù)庫所有的損壞索引（Corrupt Indexes）的話，就可以借助下面腳本：?
spool analy_index.sql SET PAGESIZE 50000; SELECT 'ANALYZE INDEX ' || OWNER || '.' || INDEX_NAME|| ' VALIDATE STRUCTURE;' FROM DBA_INDEXES; spool off; @analy_index.sql
2：使用系統(tǒng)視圖v$database_block_corruption查看損壞索引
如下所示，我們使用這個(gè)腳本來查看出現(xiàn)壞塊的索引，發(fā)現(xiàn)這個(gè)腳本無法找出壞塊索引。
set pagesize 50 linesize 170
col segment_name format a30
col partition_name format a30
SELECT DISTINCT file#,
segment_name,
segment_type,
tablespace_name,
partition_name
FROM dba_extents a,
v$database_block_corruption b
WHERE a.file_id = b.file#
AND a.block_id <= b.block#
AND a.block_id + a.blocks >= b.block#;
原因分析如下，視圖v$database_block_corruption中有壞塊記錄，但是我們將索引段的第一個(gè)塊標(biāo)記為壞塊后，在dba_extents中沒有該索引段的記錄了。所以這種情況下的索引損壞，這個(gè)SQL語句根本無法找出壞塊索引。
SQL> SELECT file_id,
2 segment_name,
3 segment_type
4 FROM dba_extents
5 WHERE file_id = 8 ;
no rows selected
SQL> SELECT file_id,
2 segment_name,
3 segment_type
4 FROM dba_extents
5 WHERE owner = 'KERRY';
FILE_ID SEGMENT_NAME SEGMENT_TYPE
---------- -------------------------------- ------------------
7 TEST TABLE
7 TEST TABLE
SQL>
因?yàn)橐粋�(gè)段的第一個(gè)區(qū)的第一個(gè)塊是FIRST LEVEL BITMAP BLOCK，第二個(gè)塊是SECOND LEVEL BITMAP BLOCK，這兩個(gè)塊是用來管理free block的，第三個(gè)塊是PAGETABLE SEGMENT HEADER，這個(gè)塊才是segment里的HEADER_BLOCK，再后面的塊就是用來記錄數(shù)據(jù)的。關(guān)于這些知識，可以參考我博客ORACLE關(guān)于段的HEADER_BLOCK的一點(diǎn)淺析。而我們最上面的例子，是將第一個(gè)塊構(gòu)造為壞塊，所以導(dǎo)致上面SQL無法查出。 我們重新構(gòu)造案例，如我們將索引段的數(shù)據(jù)塊構(gòu)造為壞塊，例如下面，將塊號148人為構(gòu)造壞塊。那么此時(shí)這個(gè)腳本就能找出壞塊索引了。所以綜上述實(shí)驗(yàn)可以看出，這個(gè)腳本查找壞塊索引是有條件的，要看索引段損壞的塊是什么類型
SQL> SELECT FILE_ID,
2 BLOCK_ID,
3 BLOCKS
FROM DBA_EXTENTS
4 5 WHERE OWNER ='&OWNER'
6 AND SEGMENT_NAME = '&TABLE_NAME';
Enter value for owner: KERRY
old 5: WHERE OWNER ='&OWNER'
new 5: WHERE OWNER ='KERRY'
Enter value for table_name: IX_TEST
old 6: AND SEGMENT_NAME = '&TABLE_NAME'
new 6: AND SEGMENT_NAME = 'IX_TEST'
FILE_ID BLOCK_ID BLOCKS
---------- ---------- ----------
8 144 8
8 152 8
SQL> SELECT HEADER_FILE
2 , HEADER_BLOCK
3 , BYTES
4 , BLOCKS
5 , EXTENTS
FROM DBA_SEGMENTS
6 7 WHERE OWNER='&OWNER' AND SEGMENT_NAME='&SEGMENT_NAME';
Enter value for owner: KERRY
Enter value for segment_name: IX_TEST
old 7: WHERE OWNER='&OWNER' AND SEGMENT_NAME='&SEGMENT_NAME'
new 7: WHERE OWNER='KERRY' AND SEGMENT_NAME='IX_TEST'
HEADER_FILE HEADER_BLOCK BYTES BLOCKS EXTENTS
----------- ------------ ---------- ---------- ----------
8 146 131072 16 2
SQL>
RMAN> recover datafile 8 block 148 clear;
標(biāo)簽： 腳本 數(shù)據(jù)庫
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