闪回恢复数据库故障？

oushitianxia915

通过闪回还原点对数据库恢复

SQL> flashback database to restore point liulong;
flashback database to restore point liulong
*
ERROR at line 1:
ORA-38795: warning: FLASHBACK succeeded but OPEN RESETLOGS would get error
below
ORA-01245: offline file 8 will be lost if RESETLOGS is done
ORA-01110: data file 8: '/home/ora10g/product/oradata/orcl/liulong.dbf'

之后数据库就打不开了
SQL> startup
ORACLE instance started.

Total System Global Area  285212672 bytes
Fixed Size                  2020224 bytes
Variable Size              92277888 bytes
Database Buffers          188743680 bytes
Redo Buffers                2170880 bytes
Database mounted.
ORA-01589: must use RESETLOGS or NORESETLOGS option for database open


SQL> alter database open resetlogs;
alter database open resetlogs
*
ERROR at line 1:
ORA-01245: offline file 8 will be lost if RESETLOGS is done
ORA-01110: data file 8: '/home/ora10g/product/oradata/orcl/liulong.dbf'


SQL>


请看看这是什么原因啊，怎么解决？