由于服务器突然掉电，重启机器后发现数据库无法启动。
数据库版本 Oracle11g R2，OS RedHat 5.7
数据库无归档，无备份
[oracle@localhost ~]$ sqlplus /nolog

SQL*Plus: Release 11.2.0.1.0 Production on Sun Jan 15 09:21:53 2012

Copyright (c) 1982, 2009, Oracle.  All rights reserved.
SQL> conn /as sysdba
Connected to an idle instance.
尝试打开数据库
SQL> startup;
ORACLE instance started.

Total System Global Area  238530560 bytes
Fixed Size                  1335724 bytes
Variable Size             155192916 bytes
Database Buffers           79691776 bytes
Redo Buffers                2310144 bytes
Database mounted.
ORA-01172: recovery of thread 1 stuck at block 272 of file 3
ORA-01151: use media recovery to recover block, restore backup if needed
 

SQL> recover datafile 3;    // 恢复成功
Media recovery complete.
SQL> startup;
ORACLE instance started.

Total System Global Area  238530560 bytes
Fixed Size                  1335724 bytes
Variable Size             155192916 bytes
Database Buffers           79691776 bytes
Redo Buffers                2310144 bytes
Database mounted.
Database opened.
SQL> conn /as sysdba

Connected.
SQL> conn system
Enter password:
Connected.