oracle 数据文件删除根据进程恢复

场景描述：在数据库尚在运行的情况下，数据文件被误删除，此时根据数据库正在运行的进程进行恢复，因为在数据库还在运行当中执行rm删除数据文件，并不是真正的删除。
注意：数据文件删除后不要关闭数据库。

恢复演示
1.删除数据文件

rm -rf /opt/oracle/oradata/ORCLCDB/users01.dbf

2.查看数据库dbw进程pid

[oracle@instance-ej1hspdt ~]$ ps -ef | grep dbw                                                                                  
oracle   13859 13538  0 02:51 pts/0    00:00:00 grep --color=auto dbw                                                            
oracle   22831     1  0 Sep05 ?        00:01:48 ora_dbw0_ORCLCDB

3.根据进程pid在/proc/pid/fd目录找寻删除的数据文件
1.注意系统屏幕显示红色并且后面标注(deleted)字样的为删除的文件

[oracle@instance-ej1hspdt ~]$ cd /proc/22831/fd/  
[oracle@instance-ej1hspdt fd]$ ls -ltr                                                                                           
total 0                                                                                                                          
lr-x------ 1 oracle oinstall 64 Sep 11 02:52 8 -> /opt/oracle/product/18c/dbhome_1/rdbms/mesg/oraus.msb                          
lrwx------ 1 oracle oinstall 64 Sep 11 02:52 7 -> /opt/oracle/product/18c/dbhome_1/dbs/lkORCLCDB                                 
lrwx------ 1 oracle oinstall 64 Sep 11 02:52 6 -> /opt/oracle/product/18c/dbhome_1/dbs/hc_ORCLCDB.dat                            
lr-x------ 1 oracle oinstall 64 Sep 11 02:52 5 -> /proc/22831/fd                                                                 
lr-x------ 1 oracle oinstall 64 Sep 11 02:52 4 -> /opt/oracle/product/18c/dbhome_1/rdbms/mesg/oraus.msb                          
lr-x------ 1 oracle oinstall 64 Sep 11 02:52 3 -> /dev/null                                                                      
lrwx------ 1 oracle oinstall 64 Sep 11 02:52 274 -> /opt/oracle/oradata/ORCLCDB/pdbseed/temp012019-08-09_11-51-17-153-AM.dbf     
lrwx------ 1 oracle oinstall 64 Sep 11 02:52 273 -> /opt/oracle/oradata/ORCLCDB/pdbseed/system01.dbf                             
lrwx------ 1 oracle oinstall 64 Sep 11 02:52 272 -> /opt/oracle/oradata/ORCLCDB/pdbseed/sysaux01.dbf                             
lrwx------ 1 oracle oinstall 64 Sep 11 02:52 271 -> /opt/oracle/oradata/ORCLCDB/pdbseed/undotbs01.dbf                            
lrwx------ 1 oracle oinstall 64 Sep 11 02:52 270 -> /opt/oracle/oradata/ORCLCDB/ORCLCDB/datafile/o1_mf_temp3_goyqsl8r_.tmp       
lrwx------ 1 oracle oinstall 64 Sep 11 02:52 269 -> /opt/oracle/oradata/ORCLCDB/ORCLCDB/datafile/o1_mf_temp2_goyqsl41_.tmp       
lrwx------ 1 oracle oinstall 64 Sep 11 02:52 268 -> /opt/oracle/oradata/ORCLCDB/ORCLCDB/datafile/o1_mf_temp1_goyo6hlk_.tmp       
lrwx------ 1 oracle oinstall 64 Sep 11 02:52 267 -> /opt/oracle/oradata/ORCLCDB/temp01.dbf                                       
lrwx------ 1 oracle oinstall 64 Sep 11 02:52 266 -> /opt/oracle/oradata/ORCLCDB/ORCLCDB/datafile/o1_mf_fixf_gphjvk84_.dbf        
lrwx------ 1 oracle oinstall 64 Sep 11 02:52 265 -> /opt/oracle/oradata/ORCLCDB/ORCLCDB/datafile/o1_mf_shadow_gpcsfzpt_.dbf      
lrwx------ 1 oracle oinstall 64 Sep 11 02:52 264 -> /opt/oracle/oradata/ORCLCDB/ORCLCDB/datafile/o1_mf_undotbs0_gp1qljq8_.dbf    
lrwx------ 1 oracle oinstall 64 Sep 11 02:52 263 -> /opt/oracle/oradata/ORCLCDB/ORCLCDB/datafile/o1_mf_undotbs0_gp1qjjvg_.dbf    
lrwx------ 1 oracle oinstall 64 Sep 11 02:52 262 -> /opt/oracle/oradata/ORCLCDB/ORCLCDB/datafile/o1_mf_undotbs0_gp1m3g1f_.dbf    
lrwx------ 1 oracle oinstall 64 Sep 11 02:52 261 -> /opt/oracle/oradata/ORCLCDB/ORCLCDB/datafile/o1_mf_whs01_gopv7wd5_.dbf       
lrwx------ 1 oracle oinstall 64 Sep 11 02:52 260 -> /opt/oracle/oradata/ORCLCDB/users01.dbf (deleted)                            
lrwx------ 1 oracle oinstall 64 Sep 11 02:52 259 -> /opt/oracle/oradata/ORCLCDB/sysaux01.dbf                                     
lrwx------ 1 oracle oinstall 64 Sep 11 02:52 258 -> /opt/oracle/oradata/ORCLCDB/system01.dbf                                     
lrwx------ 1 oracle oinstall 64 Sep 11 02:52 257 -> /opt/oracle/oradata/ORCLCDB/control02.ctl                                    
lrwx------ 1 oracle oinstall 64 Sep 11 02:52 256 -> /opt/oracle/oradata/ORCLCDB/control01.ctl                                    
l-wx------ 1 oracle oinstall 64 Sep 11 02:52 2 -> /dev/null                                                                      
l-wx------ 1 oracle oinstall 64 Sep 11 02:52 1 -> /dev/null                                                                      
lr-x------ 1 oracle oinstall 64 Sep 11 02:52 0 -> /dev/null

4.进行cp 恢复，之后最好进行一致性关闭shudown immediate;

[oracle@instance-ej1hspdt fd]$ cp 260 /opt/oracle/oradata/ORCLCDB/users01.dbf