Oracle：热备时，突然断电情况处理

    我们在热备时，如果此时突然停电，再次启动时会发生什么情况呢？

SQL> alter tablespace users begin backup;

Tablespace altered.


SQL> desc v$backup
 Name                       Null?    Type
 ----------------------------------------- -------- ----------------------------
 FILE#                            NUMBER
 STATUS                         VARCHAR2(18)
 CHANGE#                        NUMBER
 TIME                            DATE

SQL> select * from v$backup;

     FILE# STATUS         CHANGE# TIME
---------- ------------------ ---------- ---------
     1 NOT ACTIVE               0
     2 NOT ACTIVE               0
     3 NOT ACTIVE               0
     4 ACTIVE         1376996 21-NOV-13
     6 NOT ACTIVE               0

SQL> 

SQL> shutdown abort
ORACLE instance shut down.
SQL> startup
ORACLE instance started.

Total System Global Area  599785472 bytes
Fixed Size            2022632 bytes
Variable Size          218104600 bytes
Database Buffers      377487360 bytes
Redo Buffers            2170880 bytes
Database mounted.
ORA-01113: file 4 needs media recovery
ORA-01110: data file 4:
'/u01/app/oracle/product/10.2.0/db_2/oradata/orcl/users01.dbf'


SQL> select * from v$backup;

     FILE# STATUS         CHANGE# TIME
---------- ------------------ ---------- ---------
     1 NOT ACTIVE               0
     2 NOT ACTIVE               0
     3 NOT ACTIVE               0
     4 ACTIVE         1376996 21-NOV-13
     6 NOT ACTIVE               0


SQL> alter tablespace users end backup;

Tablespace altered.

SQL> alter database open;

Database altered.

SQL>