问题描述：备库恢复数据文件报错ORA-19573、ORA-19870，如下所示：
数据库：oracle 11.2.0.4
主机名：主库leo-oel150 备库 leo-oel151
1、问题重现
--备库检查users表空间，发现存在坏块.
RMAN> backup validate check logical tablespace users;

Starting backup at 02-FEB-23
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=13 device type=DISK
channel ORA_DISK_1: starting full datafile backup set
channel ORA_DISK_1: specifying datafile(s) in backup set
input datafile file number=00004 name=/u01/app/oracle/oradata/orcl151/users01.dbf
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:01
List of Datafiles
=================
File Status Marked Corrupt Empty Blocks Blocks Examined High SCN
---- ------ -------------- ------------ --------------- ----------
4    FAILED 0              20           666             1090741   
  File Name: /u01/app/oracle/oradata/orcl151/users01.dbf
  Block Type Blocks Failing Blocks Processed
  ---------- -------------- ----------------
  Data       0              26              
  Index      0              21              
  Other      237            573             

validate found one or more corrupt blocks
See trace file /u01/app/oracle/diag/rdbms/orcl151/orcl151/trace/orcl151_ora_22289.trc for details
Finished backup at 02-FEB-23
--尝试恢复数据文件4，报错ORA-19573、ORA-19870
[oracle@leo-oel151 ~]$ rman target /

Recovery Manager: Release 11.2.0.4.0 - Production on Thu Feb 2 14:35:43 2023

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

connected to target database: ORCL150 (DBID=4073973096)

RMAN> restore datafile 4;

Starting restore at 02-FEB-23
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=134 device type=DISK

channel ORA_DISK_1: starting datafile backup set restore
channel ORA_DISK_1: specifying datafile(s) to restore from backup set
channel ORA_DISK_1: restoring datafile 00004 to /u01/app/oracle/oradata/orcl151/users01.dbf
channel ORA_DISK_1: reading from backup piece /home/oracle/rmanbak/data_full_20230201_8_1
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of restore command at 02/02/2023 14:36:00
ORA-19870: error while restoring backup piece /home/oracle/rmanbak/data_full_20230201_8_1
ORA-19573: cannot obtain exclusive enqueue for datafile 4
2、异常处理
2.1、解决过程
--查数据文件的备份情况.
RMAN> list backup of datafile 4;


List of Backup Sets
===================


BS Key  Type LV Size       Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ ---------------
6       Full    268.27M    DISK        00:00:28     01-FEB-23      
        BP Key: 6   Status: AVAILABLE  Compressed: YES  Tag: TAG20230201T213409
        Piece Name: /home/oracle/rmanbak/data_full_20230201_8_1
  List of Datafiles in backup set 6
  File LV Type Ckp SCN    Ckp Time  Name
  ---- -- ---- ---------- --------- ----
  4       Full 1070504    01-FEB-23 /u01/app/oracle/oradata/orcl151/users01.dbf

说明：可以看到备库存在数据文件4的备份.
--将备库启动到mount状态
SYS@orcl151> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
SYS@orcl151> startup mount
ORACLE instance started.

Total System Global Area 1586708480 bytes
Fixed Size                  2253624 bytes
Variable Size             989859016 bytes
Database Buffers          587202560 bytes
Redo Buffers                7393280 bytes
Database mounted.
--再次进行restore恢复.
[oracle@leo-oel151 ~]$ rman target /

Recovery Manager: Release 11.2.0.4.0 - Production on Thu Feb 2 17:08:18 2023

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

connected to target database: ORCL150 (DBID=4073973096, not open)

RMAN> restore datafile 4;

Starting restore at 02-FEB-23
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=192 device type=DISK

channel ORA_DISK_1: starting datafile backup set restore
channel ORA_DISK_1: specifying datafile(s) to restore from backup set
channel ORA_DISK_1: restoring datafile 00004 to /u01/app/oracle/oradata/orcl151/users01.dbf
channel ORA_DISK_1: reading from backup piece /home/oracle/rmanbak/data_full_20230201_8_1
channel ORA_DISK_1: piece handle=/home/oracle/rmanbak/data_full_20230201_8_1 tag=TAG20230201T213409
channel ORA_DISK_1: restored backup piece 1
channel ORA_DISK_1: restore complete, elapsed time: 00:00:01
Finished restore at 02-FEB-23

说明：数据文件4成功恢复.
2.2、数据验证
[oracle@leo-oel151 admin]$ sqlplus sys/oracle_4U@orcl151 as sysdba

SQL*Plus: Release 11.2.0.4.0 Production on Thu Feb 2 17:18:46 2023

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, OLAP, Data Mining and Real Application Testing options

SYS@orcl151> select * from v$database_block_corruption;

no rows selected

[oracle@leo-oel151 ~]$ rman target /

Recovery Manager: Release 11.2.0.4.0 - Production on Fri Feb 3 14:41:50 2023

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

connected to target database: ORCL150 (DBID=4073973096)

RMAN> backup validate check logical tablespace users;

Starting backup at 03-FEB-23
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=13 device type=DISK
channel ORA_DISK_1: starting full datafile backup set
channel ORA_DISK_1: specifying datafile(s) in backup set
input datafile file number=00004 name=/u01/app/oracle/oradata/orcl151/users01.dbf
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:01
List of Datafiles
=================
File Status Marked Corrupt Empty Blocks Blocks Examined High SCN
---- ------ -------------- ------------ --------------- ----------
4    OK     0              21           668             1090741   
  File Name: /u01/app/oracle/oradata/orcl151/users01.dbf
  Block Type Blocks Failing Blocks Processed
  ---------- -------------- ----------------
  Data       0              30              
  Index      0              21              
  Other      0              568             

Finished backup at 03-FEB-23

说明：可以看到数据文件恢复正常.