做系统管理的都是这样，难免会误删文件，某天要是把某个Oracle数据文件删除，那该如何恢复呢？(这里数据库是OPEN的，并且未关闭)
建立测试表空间
创建测试用户
插入测试数据
删除数据文件
恢复数据库文件
建立测试表空间
SQL> select name from v$datafile;NAME--------------------------------------------------------------------------------/opt/oracle/oradata/member/system01.dbf/opt/oracle/oradata/member/sysaux01.dbf/opt/oracle/oradata/member/undotbs01.dbf/opt/oracle/oradata/member/users01.dbfSQL> create tablespace test datafile '/opt/oracle/oradata/member/test01.dbf' size 10m;Tablespace created.SQL> select name from v$datafile;NAME--------------------------------------------------------------------------------/opt/oracle/oradata/member/system01.dbf/opt/oracle/oradata/member/sysaux01.dbf/opt/oracle/oradata/member/undotbs01.dbf/opt/oracle/oradata/member/users01.dbf/opt/oracle/oradata/member/test01.dbf
2.创建测试账户
SQL> create user test identified by test default tablespace test;SQL> grant connect,resource to test;
3.插入测试数据
SQL> conn test/testSQL> create table t1(id int);SQL> insert into t1 values(1);SQL> select * from t1; ID---------- 1
4.删除数据文件
[oracle@db2 ~]$ rm -f /opt/oracle/oradata/member/test01.dbf[oracle@db2 ~]$ sqlplus test/testSQL> create table t2 as select * from t1;create table t2 as select * from t1 *ERROR at line 1:ORA-01116: error in opening database file 5ORA-01110: data file 5: '/opt/oracle/oradata/member/test01.dbf'ORA-27041: unable to open fileLinux-x86_64 Error: 2: No such file or directoryAdditional information: 3SQL> select table_name,tablespace_name from user_tables;TABLE_NAME TABLESPACE_NAME------------------------------ ------------------------------T1 TEST
数据文件被删除了，这怎么办呢？这个时候千万别重启数据库，否则数据就丢失了
5.数据文件恢复
[oracle@db2 ~]$ ps -ef |grep dbw0oracle 3309 1 0 12:07 ? 00:00:00 ora_dbw0_memberoracle 6217 5105 0 15:29 pts/0 00:00:00 grep dbw0#找到ora_dbw0_SID的进程号3309[oracle@db2 ~]$ cd /proc/3309/fd#以上3309就是进程号，然后执行ls -al查看文件的链接
可以看到文件27就是被删除的文件
[oracle@db2 fd]$ cp 27 /opt/oracle/oradata/member/test01.dbf
查看test表空间状态
SQL> select name,status from v$datafile;NAME STATUS---------------------------------------- -------/opt/oracle/oradata/member/system01.dbf SYSTEM/opt/oracle/oradata/member/sysaux01.dbf ONLINE/opt/oracle/oradata/member/undotbs01.dbf ONLINE/opt/oracle/oradata/member/users01.dbf ONLINE/opt/oracle/oradata/member/test01.dbf ONLINE
下线test01表文件
SQL> alter database datafile '/opt/oracle/oradata/member/test01.dbf' offline;SQL> recover datafile '/opt/oracle/oradata/member/test01.dbf';Media recovery complete.SQL> alter database datafile '/opt/oracle/oradata/member/test01.dbf' online;Database altered.
#以上就成功恢复了，若是出现
SQL> recover datafile '/opt/oracle/oradata/member/test01.dbf';ORA-00283: recovery session canceled due to errorsORA-01110: data file 5: '/opt/oracle/oradata/member/test01.dbf'ORA-01157: cannot identify/lock data file 5 - see DBWR trace fileORA-01110: data file 5: '/opt/oracle/oradata/member/test01.dbf'
则有可能是/opt/oracle/oradata/member/test01.dbf文件的权限问题引起，在root用户下
[root@db2 ~]# chown -R oracle.oinstall /opt/oracle/oradata/member/test01.dbf 再recover datafile '/opt/oracle/oradata/member/test01.dbf'
实验完成后，删除测试用户及测试表空间
SQL> drop user test cascade;SQL> drop tablespace test INCLUDING CONTENTS AND DATAFILES;