rman 恢复数据报ORA-19573: cannot obtain exclusive enqueue for ...

报错现象：
RMAN> run {
2> restore database;
3> recover database;
4> }
Starting restore at 12-AUG-22
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=96 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 00001 to
/u01/app/oracle/oradata/orcl/system01.dbf
channel ORA_DISK_1: restoring datafile 00002 to
/u01/app/oracle/oradata/orcl/sysaux01.dbf
channel ORA_DISK_1: restoring datafile 00003 to
/u01/app/oracle/oradata/orcl/undotbs01.dbf
channel ORA_DISK_1: restoring datafile 00004 to
/u01/app/oracle/oradata/orcl/users01.dbf
channel ORA_DISK_1: restoring datafile 00005 to
/u01/app/oracle/oradata/orcl/example01.dbf
channel ORA_DISK_1: restoring datafile 00006 to
/u01/app/oracle/oradata/orcl/test1.dbf
channel ORA_DISK_1: reading from backup piece
/home/oracle/rmanback/incremental_ORCL_1575005578_22_1_20220812.bak
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of restore command at 08/12/2022 14:24:53
ORA-19870: error while restoring backup piece
/home/oracle/rmanback/incremental_ORCL_1575005578_22_1_20220812.bak
ORA-19573: cannot obtain exclusive enqueue for datafile 1
ORA-19890: data file already in use
ORA-45909: restore, recover or block media recovery may be in progress
原来是database 在open下，忘了将datafile offline，造成此低级错误；将数据文件offline 后，重启数据库到mount下，在执行恢复，问题解决！