关于控制文件与数据文件头信息的说明(二)

文章作者 100test 发表时间 2007:03:14 13:44:02
来源 100Test.Com百考试题网

我们看看恢复完成之后，控制文件和数据文件的变化.
首先看控制文件的变化:

DATA FILE #4:
(name #4) /opt/oracle/oradata/eygle/eygle01.dbf
creation size=0 block size=8192 status=0xe head=4 tail=4 dup=1
tablespace 4, index=4 krfil=4 prev_file=0
unrecoverable scn: 0x0000.00000000 01/01/1988 00:00:00
Checkpoint cnt:59 scn: 0x0000.002ac8ee 08/11/2006 09:48:29
Stop scn: 0x0000.002ac8ed 08/11/2006 09:48:29
Creation Checkpointed at scn: 0x0000.0015078d 06/06/2006 09:41:54
......................

检查点计数: Checkpoint cnt:59
执行了恢复之后，检查点计数较前增加了1

检查点SCN: scn: 0x0000.002ac8ee 08/11/2006 09:48:29
数据文件Stop scn: 0x0000.002ac8ed 08/11/2006 09:48:29
数据文件Stop scn和数据文件进行了同步。

数据文件头信息:

FILE HEADER:
Software vsn=153092096=0x9200000, Compatibility Vsn=134217728=0x8000000
Db ID=1407686520=0x53e79778, Db Name=EYGLE
Activation ID=0=0x0
Control Seq=983=0x3d7, File size=1280=0x500
File Number=4, Blksiz=8192, File Type=3 DATA
Tablespace #4 - EYGLE rel_fn:4
Creation at scn: 0x0000.0015078d 06/06/2006 09:41:54
Backup taken at scn: 0x0000.00000000 01/01/1988 00:00:00 thread:0
reset logs count:0x232bee1f scn: 0x0000.0007c781 recovered at 08/11/2006 10:11:26
status:0x0 root dba:0x00000000 chkpt cnt: 59 ctl cnt:58
begin-hot-backup file size: 0
Checkpointed at scn: 0x0000.002ac8ed 08/11/2006 09:48:29
..........................

我们看到此时数据文件的信息：
检查点是：Checkpointed at scn: 0x0000.002ac8ed 08/11/2006 09:48:29
这个检查点和控制文件中记录的stop scn一致，数据库启动可以顺利进行。

检查点计数为:chkpt cnt: 59 ctl cnt:58

我们打开数据库:

SQL> alter database open.
Database altered.
SQL> alter session set events immediate trace name file_hdrs level 10.
Session altered.

此时数据库恢复正常运行。
控制文件信息如下：

DATA FILE #4:
(name #4) /opt/oracle/oradata/eygle/eygle01.dbf
creation size=0 block size=8192 status=0xe head=4 tail=4 dup=1
tablespace 4, index=4 krfil=4 prev_file=0
unrecoverable scn: 0x0000.00000000 01/01/1988 00:00:00
Checkpoint cnt:60 scn: 0x0000.002ac8ef 08/11/2006 10:19:30
Stop scn: 0xffff.ffffffff 08/11/2006 09:48:29
Creation Checkpointed at scn: 0x0000.0015078d 06/06/2006 09:41:54

此时stop scn被置为无穷大。
数据文件头信息如下:

FILE HEADER:
Software vsn=153092096=0x9200000, Compatibility Vsn=134217728=0x8000000
Db ID=1407686520=0x53e79778, Db Name=EYGLE
Activation ID=0=0x0
Control Seq=984=0x3d8, File size=1280=0x500
File Number=4, Blksiz=8192, File Type=3 DATA
Tablespace #4 - EYGLE rel_fn:4
Creation at scn: 0x0000.0015078d 06/06/2006 09:41:54
Backup taken at scn: 0x0000.00000000 01/01/1988 00:00:00 thread:0
reset logs count:0x232bee1f scn: 0x0000.0007c781 recovered at 08/11/2006 10:11:26
status:0x4 root dba:0x00000000 chkpt cnt: 60 ctl cnt:59
begin-hot-backup file size: 0
Checkpointed at scn: 0x0000.002ac8ef 08/11/2006 10:19:30