检测ORACLE数据块损坏的方法汇总
1：使用初始化参数
使用初始化参数db_block_checksum\db_block_checking可以设置数据库对块的物理一致性和逻辑一致性检查。
Db_block_checksum:物理一致性检查，默认开启。始终对system表空间数据进行检查，如果开启还会对日志进行检查，开启后会有1～2%的性能影响，建议开启。
Db_block_checking：逻辑一致性检查，默认未开启。始终对system表空间进行检查，如果开启会有1～10%的性能影响。DML越频繁，性能影响越大。不建议开启。
有关该参数的详细内容可以参考：
http://blog.csdn.net/yidian815/article/details/39932903
2：使用dbv工具
使用dbv可以进行物理和逻辑一致性检查，但是不会检测表数据和索引数据的匹配关系。使用该工具有以下特点：
只读方式打开数据文件
可以在线检查数据文件，数据库无需关闭
不可以检测控制文件和日志文件
可以检测asm文件
有时文件名称需要有后缀名，并且有时不可以检测超过2G大小的文件
3：使用analyze命令
语法格式：analyze table validate structure cascade online (offline).
该命令会同时进行物理和逻辑检查，同时还可以进行表数据和索引数据的匹配性检查，检查分区表的记录是否在正确的分区中，检测结果会存储在trace文件中。
如果没有使用cascade关键字，则只会进行表数据的检测，使用cascade后会进行表数据和索引数据的检测。
如果使用了online关键字，则可以对表数据进行在线检查，此时不会对表添加锁，DML语句可以继续进行，如果使用了offline关键字，则会对表加锁，此时用户不能对该表进行修改操作。
如果需要检测分区表记录是否在正确的分区内，可以使用如下语句：
Anlyze table table_name validte structure into invalid_rows.
使用该命令前，请使用utlvalid.sql 脚本创建相应的invalid_rows表。
4：使用rman工具
使用rman备份工具时，oracle会将数据先读入读缓冲区，然后将数据写入写缓冲区，最后写入磁盘，在从读缓冲区转移到写缓冲区时，rman工具会进行数据一致性检测。
语法格式：backup validate database.
使用backup validate 命令会对数据文件进行物理一致性检测（前提是db_block_checksum启用), 此时并不会生成备份文件。如：
RMAN> backup validate database; Starting backup at 2014-11-05 15:44:21 using channel ORA_DISK_1 channel ORA_DISK_1: starting full datafile backupset channel ORA_DISK_1: specifying datafile(s) in backupset input datafile fno=00001 name=/home/app/oraten/oradata/oraten/system01.dbf input datafile fno=00003 name=/home/app/oraten/oradata/oraten/sysaux01.dbf input datafile fno=00002 name=/home/app/oraten/oradata/oraten/undotbs01.dbf input datafile fno=00005 name=/home/app/oraten/oradata/oraten/test01.dbf input datafile fno=00004 name=/home/app/oraten/oradata/oraten/users01.dbf channel ORA_DISK_1: backup set complete, elapsed time: 00:00:01 channel ORA_DISK_1: starting full datafile backupset channel ORA_DISK_1: specifying datafile(s) in backupset including current control file in backupset including current SPFILE in backupset channel ORA_DISK_1: backup set complete, elapsed time: 00:00:01 Finished backup at 2014-11-05 15:44:23 RMAN> list backup; RMAN>
我们也可以添加check logical选项，以便rman进行逻辑一致性检测。注意：check logical是命令选项，如果单独使用check logical会生成备份:
RMAN> backup check logical validate database;
Starting backup at 2014-11-05 15:45:59
using channel ORA_DISK_1
channel ORA_DISK_1: starting full datafile backupset
channel ORA_DISK_1: specifying datafile(s) in backupset
input datafile fno=00001 name=/home/app/oraten/oradata/oraten/system01.dbf
input datafile fno=00003 name=/home/app/oraten/oradata/oraten/sysaux01.dbf
input datafile fno=00002 name=/home/app/oraten/oradata/oraten/undotbs01.dbf
input datafile fno=00005 name=/home/app/oraten/oradata/oraten/test01.dbf
input datafile fno=00004 name=/home/app/oraten/oradata/oraten/users01.dbf
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:03
channel ORA_DISK_1: starting full datafile backupset
channel ORA_DISK_1: specifying datafile(s) in backupset
including current control file in backupset
including current SPFILE in backupset
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:01
Finished backup at 2014-11-05 15:46:04
RMAN> list backup;
RMAN> backup check logical database;
Starting backup at 2014-11-05 15:46:14
using channel ORA_DISK_1
channel ORA_DISK_1: starting full datafile backupset
channel ORA_DISK_1: specifying datafile(s) in backupset
input datafile fno=00001 name=/home/app/oraten/oradata/oraten/system01.dbf
input datafile fno=00003 name=/home/app/oraten/oradata/oraten/sysaux01.dbf
input datafile fno=00002 name=/home/app/oraten/oradata/oraten/undotbs01.dbf
input datafile fno=00005 name=/home/app/oraten/oradata/oraten/test01.dbf
input datafile fno=00004 name=/home/app/oraten/oradata/oraten/users01.dbf
channel ORA_DISK_1: starting piece 1 at 2014-11-05 15:46:14
channel ORA_DISK_1: finished piece 1 at 2014-11-05 15:46:39
piece handle=/home/app/oraten/flash_recovery_area/ORATEN/backupset/2014_11_05/o1_mf_nnndf_TAG20141105T154614_b5mog6kr_.bkp tag=TAG20141105T154614 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:25
channel ORA_DISK_1: starting full datafile backupset
channel ORA_DISK_1: specifying datafile(s) in backupset
including current control file in backupset
including current SPFILE in backupset
channel ORA_DISK_1: starting piece 1 at 2014-11-05 15:46:40
channel ORA_DISK_1: finished piece 1 at 2014-11-05 15:46:41
piece handle=/home/app/oraten/flash_recovery_area/ORATEN/backupset/2014_11_05/o1_mf_ncsnf_TAG20141105T154614_b5moh030_.bkp tag=TAG20141105T154614 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:02
Finished backup at 2014-11-05 15:46:41
List of Backup Sets
===================
BS Key Type LV Size Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ -------------------
59 Full 545.84M DISK 00:00:17 2014-11-05 15:46:31
BP Key: 41 Status: AVAILABLE Compressed: NO Tag: TAG20141105T154614
Piece Name: /home/app/oraten/flash_recovery_area/ORATEN/backupset/2014_11_05/o1_mf_nnndf_TAG20141105T154614_b5mog6kr_.bkp
List of Datafiles in backup set 59
File LV Type Ckp SCN Ckp Time Name
---- -- ---- ---------- ------------------- ----
1 Full 870906 2014-11-05 15:46:14 /home/app/oraten/oradata/oraten/system01.dbf
2 Full 870906 2014-11-05 15:46:14 /home/app/oraten/oradata/oraten/undotbs01.dbf
3 Full 870906 2014-11-05 15:46:14 /home/app/oraten/oradata/oraten/sysaux01.dbf
4 Full 870906 2014-11-05 15:46:14 /home/app/oraten/oradata/oraten/users01.dbf
5 Full 870906 2014-11-05 15:46:14 /home/app/oraten/oradata/oraten/test01.dbf
BS Key Type LV Size Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ -------------------
60 Full 6.80M DISK 00:00:01 2014-11-05 15:46:40
BP Key: 42 Status: AVAILABLE Compressed: NO Tag: TAG20141105T154614
Piece Name: /home/app/oraten/flash_recovery_area/ORATEN/backupset/2014_11_05/o1_mf_ncsnf_TAG20141105T154614_b5moh030_.bkp
Control File Included: Ckp SCN: 870915 Ckp time: 2014-11-05 15:46:39
SPFILE Included: Modification time: 2014-11-05 15:16:33<span style="font-size: 12px; font-family: Arial, Helvetica, sans-serif; background-color: rgb(255, 255, 255);"> </span>
关于rman备份与恢复的验证，可以参照：
http://blog.csdn.net/yidian815/article/details/40824689
5：使用dbms_repair包
关于dbms_repaire包的使用，请参见：
http://blog.csdn.net/yidian815/article/details/40825511