1.查询数据库状态，MOUNTED
SYS@ bys001>select status,startup_time from v$instance;
STATUS STARTUP_TIME
------------ -------------------
MOUNTED 2013/07/16 16:54:36
2.重命令一个数据文件，模拟文件丢失。
SYS@ bys001>host
[oracle@oel-01 oradata]$ cd bys001/
[oracle@oel-01 bys001]$ ls
bys_flashback.dbf redo01.log test1.dbf
catalog1.dbf redo02.log test1_undo.dbf
control01.ctl redo03.log undotbs01.dbf
example01.dbf sysaux01.dbf users01.dbf
redo01a.log system01.dbf users01.dbf2
redo01a.logbak temp01.dbf
[oracle@oel-01 bys001]$
mv users01.dbf users01.dbf.bak
[oracle@oel-01 bys001]$ ls
bys_flashback.dbf redo01.log temp01.dbf
catalog1.dbf redo02.log test1.dbf
control01.ctl redo03.log test1_undo.dbf
example01.dbf sysaux01.dbf undotbs01.dbf
redo01a.log system01.dbf
users01.dbf.bak
查看日志：
[oracle@oel-01 ~]$ cat alert_bys001.log
alter database mount
Tue Jul 16 21:58:24 2013
Successful mount of redo thread 1, with mount id 2045113404
Allocated 3981204 bytes in shared pool for flashback generation buffer
Starting background process RVWR
Tue Jul 16 21:58:24 2013
RVWR started with pid=20, OS id=4553
Database mounted in Exclusive Mode
Lost write protection disabled
Completed: alter database mount
Tue Jul 16 22:08:53 2013
Checker run found 1 new persistent data failures ---系统发现了，
运行检查发现1个新的持久性数据失败
with mount id 2045113404 mount id 在正常MOUNT数据库过程中，数据库计算MOUNT ID并记录在
控制文件中，然后开始启动心跳heartbeat，每3秒更新一次控制文件。
heartbeat表示实例已经被特定例程MOUNT，此属性主要用于RAC环境。在单实例环境中同样存在。
使用ASM时，还会增加一个ASM实例的心跳事件。
SYS@ bys001>select event#,name from v$event_name where name like '%heart%';
EVENT# NAME
---------- ----------------------------------------
75 heartbeat monitor sleep
380 ASM mount : wait for heartbeat
563 control file heartbeat
SYS@ bys001>select name from v$datafile;
NAME
----------------------------------------
/u01/app/oracle/oradata/bys001/system01.dbf
/u01/app/oracle/oradata/bys001/sysaux01.dbf
/u01/app/oracle/oradata/bys001/undotbs01.dbf
/u01/app/oracle/oradata/bys001/users01.dbf
/u01/app/oracle/oradata/bys001/example01.dbf
/u01/app/oracle/oradata/bys001/catalog1.dbf
/u01/app/oracle/oradata/bys001/test1.dbf
/u01/app/oracle/oradata/bys001/bys_flashback.dbf
8 rows selected.
3.打开数据库，提示找不到数据文件。
SYS@ bys001>alter database open;
alter database open
*
ERROR at line 1:
ORA-01157: cannot identify/lock data file 4 - see DBWR trace file
ORA-01110: data file 4: '/u01/app/oracle/oradata/bys001/users01.dbf'
日志中的信息：
Tue Jul 16 22:11:18 2013
alter database open
Tue Jul 16 22:11:18 2013
Errors in file /u01/app/oracle/diag/rdbms/bys001/bys001/trace/bys001_dbw0_3837.trc:
ORA-01157: cannot identify/lock data file 4 - see DBWR trace file
ORA-01110: data file 4: '/u01/app/oracle/oradata/bys001/users01.dbf'
ORA-27037: unable to obtain file status
Linux Error: 2: No such file or directory
Additional information: 3
Errors in file /u01/app/oracle/diag/rdbms/bys001/bys001/trace/bys001_ora_4540.trc:
ORA-01157: cannot identify/lock data file 4 - see DBWR trace file
ORA-01110: data file 4: '/u01/app/oracle/oradata/bys001/users01.dbf'
ORA-1157 signalled during: alter database open...
[oracle@oel-01 ~]$
SYS@ bys001>select status from v$instance;
STATUS
------------
MOUNTED
SYS@ bys001>col error for a20
SYS@ bys001>select * from v$recover_file;
FILE# ONLINE ONLINE_ ERROR CHANGE# TIME
---------- ------- ------- -------------------- ---------- -------------------
1 ONLINE ONLINE FILE NOT FOUND 0
4.重新移回原文件，数据库可以正常打开
[oracle@oel-01 bys001]$ pwd
/u01/app/oracle/oradata/bys001
[oracle@oel-01 bys001]$ ls
bys_flashback.dbf control01.ctl redo01a.log redo02.log sysaux01.dbf temp01.dbf test1_undo.dbf users01.dbf.bak
catalog1.dbf example01.dbf redo01.log redo03.log system01.dbf test1.dbf undotbs01.dbf
[oracle@oel-01 bys001]$ mv users01.dbf.bak users01.dbf
SYS@ bys001>alter database open;
Database altered.
SYS@ bys001>select status from v$instance;
STATUS
------------
OPEN
SYS@ bys001>select * from v$recover_file;
no rows selected
[oracle@oel-01 ~]$ tail -n 100 alert_bys001.log
Tue Jul 16 22:19:30 2013
alter database open
Beginning crash recovery of 1 threads
Started redo scan
Completed redo scan
read 0 KB redo, 0 data blocks need recovery
Started redo application at
Thread 1: logseq 49, block 25811, scn 2241514
Recovery of Online Redo Log: Thread 1 Group 1 Seq 49 Reading mem 0
Mem# 0: /u01/app/oracle/oradata/bys001/redo01.log
Mem# 1: /u01/app/oracle/oradata/bys001/redo01a.log
Completed redo application of 0.00MB
Completed crash recovery at
Thread 1: logseq 49, block 25811, scn 2261515
0 data blocks read, 0 data blocks written, 0 redo k-bytes read
Tue Jul 16 22:19:31 2013
LGWR: STARTING ARCH PROCESSES
Tue Jul 16 22:19:32 2013
ARC0 started with pid=21, OS id=4743
ARC0: Archival started
LGWR: STARTING ARCH PROCESSES COMPLETE
ARC0: STARTING ARCH PROCESSES
Tue Jul 16 22:19:33 2013
ARC1 started with pid=22, OS id=4746
Thread 1 advanced to log sequence 50 (thread open)
Tue Jul 16 22:19:33 2013
ARC2 started with pid=23, OS id=4748
ARC1: Archival started
ARC2: Archival started
Tue Jul 16 22:19:33 2013
ARC3 started with pid=24, OS id=4750
ARC1: Becoming the 'no FAL' ARCH
ARC1: Becoming the 'no SRL' ARCH
ARC2: Becoming the heartbeat ARCH
Thread 1 opened at log sequence 50
Current log# 2 seq# 50 mem# 0: /u01/app/oracle/oradata/bys001/redo02.log
Successful open of redo thread 1
MTTR advisory is disabled because FAST_START_MTTR_TARGET is not set
Tue Jul 16 22:19:33 2013
SMON: enabling cache recovery
ARC3: Archival started
ARC0: STARTING ARCH PROCESSES COMPLETE
Successfully onlined Undo Tablespace 2.
Verifying file header compatibility for 11g tablespace encryption..
Verifying 11g file header compatibility for tablespace encryption completed
SMON: enabling tx recovery
Database Characterset is AL32UTF8
No Resource Manager plan active
Starting background process FBDA
Tue Jul 16 22:19:40 2013
FBDA started with pid=25, OS id=4752
Tue Jul 16 22:19:40 2013
replication_dependency_tracking turned off (no async multimaster replication found)
Archived Log entry 141 added for thread 1 sequence 49 ID 0x79c75bdb dest 1:
Starting background process QMNC
Tue Jul 16 22:19:44 2013
QMNC started with pid=26, OS id=4754
Completed: alter database open