ORACLE 如何檢查找出損壞索引
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來源:瀟湘隱者 ,
www.cnblogs.com/kerrycode/p/9645605.html
在Oracle資料庫中如何找出損壞索引呢? 下面我們人為構造一個案例,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;
上述腳本是創建表空間,創建用戶kerry並授權,然後使用kerry賬號登錄資料庫,構造測試數據,在TEST表上創建索引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.
然後使用下面腳本找到索引段資料庫文件ID,以及索引段的第一個塊的塊號。
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>
構造壞塊的方法有不少(例如BBED等),這裡我們使用RMAN下面的命令clear,可以標記數據塊為corrupt,標記數據文件8中130號數據塊為壞塊。
[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>
那麼我們先來看看使用那些方法驗證索引損壞了,測試驗證一下看看是否可行。
1:使用ANALYZE分析驗證索引結構
[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),那麼使用analyze index validate structure就會報錯。要檢查整個資料庫所有的損壞索引(Corrupt Indexes)的話,就可以藉助下面腳本:
spool analy_index.sql
SET PAGESIZE 50000;
SELECT
"ANALYZE INDEX " || OWNER || "." || INDEX_NAME|| " VALIDATE STRUCTURE;" FROM DBA_INDEXES;
spool off;
@analy_index.sql
2:使用系統視圖v$database_block_corruption查看損壞索引
如下所示,我們使用這個腳本來查看出現壞塊的索引,發現這個腳本無法找出壞塊索引。
set pagesize 50 linesize 170
col segment_name format a30
col partition_name format a30
SELECT DISTINCT file#,
segment_name,
segment_type,
tablespace_name,
partition_name
FROM dba_extents a,
v$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塊標記為壞塊後,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>
因為一個段的第一個區的第一個塊是FIRST LEVEL BITMAP BLOCK,第二個塊是SECOND LEVEL BITMAP BLOCK,這兩個塊是用來管理free block的,第三個塊是PAGETABLE SEGMENT HEADER,這個塊才是segment里的HEADER_BLOCK,再後面的塊就是用來記錄數據的。關於這些知識,可以參考我博客ORACLE關於段的HEADER_BLOCK的一點淺析。而我們最上面的例子,是將第一個塊構造為壞塊,所以導致上面SQL無法查出。 我們重新構造案例,如我們將索引段的數據塊構造為壞塊,例如下面,將塊號148人為構造壞塊。那麼此時這個腳本就能找出壞塊索引了。所以綜上述實驗可以看出,這個腳本查找壞塊索引是有條件的,要看索引段損壞的塊是什麼類型
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;
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