情況1：  丟失後庫關閉過（且有RMAN備份的情況）


檢視丟失檔案ID
set linesize 120
set pagesize 0
col name format a70
select ts#,file#,name from V$datafile;




select t.file#, t.name, s.name from v$datafile t,v$tablespace s where t.ts#=s.ts#;




set line 135
select log_mode from v$database;
col DBID for 9999999999
col name for a8
col force_logging for a30
set head on
select dbid,name,force_logging from v$database;






RMAN> run{
sql 'alter database datafile 5 offline';
restore datafile 5;
recover datafile 5;
sql 'alter database datafile 5 online';
alter database open;
}




sqlplus / as sysdba
alter database datafile 5 online;


col name for a40
select name,status from v$datafile;




情況2 丟失後未關庫，可以直接用rman 恢復


RMAN> run{
sql 'alter database datafile 5 offline';
restore datafile 5;
recover datafile 5;
sql 'alter database datafile 5 online';

}

情況3 若無RMAN備份，則只能刪除該表空間

aler database datafile 5 offline;

alter databse open;

drop tablespace aaa including contents and datafiles;