还原Oracle数据库时出现ORA-19870和ORA-19573错误，如：
RMAN> restore database;
Starting restore at 11-DEC-12
using channel ORA_DISK_1
channel ORA_DISK_1: starting datafile backupset restore
channel ORA_DISK_1: specifying datafile(s) to restore from backup set
restoring datafile 00001 to /u02/oradata/orcl/system01.dbf
restoring datafile 00002 to /u02/oradata/orcl/undotbs01.dbf
restoring datafile 00003 to /u02/oradata/orcl/sysaux01.dbf
restoring datafile 00004 to /u02/oradata/orcl/users01.dbf
restoring datafile 00005 to /u02/oradata/orcl/dolphin01.dbf
channel ORA_DISK_1: reading from backup piece /home/oracle/backup/dbf_07nsjs47_1_1.bak
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of restore command at 12/11/2012 16:07:19
ORA-19870: error reading backup piece /home/oracle/backup/dbf_07nsjs47_1_1.bak
ORA-19573: cannot obtain exclusive enqueue for datafile 1
该问题的原因是由于数据库处于open状态导致的，将数据库置于mount状态该问题即可解决。