实例恢复的深入解析(二)
16
Prior resetlogs scn: 0x0000.00000001 Prior resetlogs Timestamp 09/17/2011 09:46:04
Redo Version: compatible=0xb200000
#Data files = 6, #Online files = 6
Database checkpoint: Thread=1 scn: 0x0000.0016344c --数据库检查点SCN＝16344c转成10进制为1455180
Threads: #Enabled=1, #Open=1, Head=1, Tail=1
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CHECKPOINT PROGRESS RECORDS
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(size = 8180, compat size = 8180, section max = 11, section in-use = 0,
last-recid= 0, old-recno = 0, last-recno = 0)
(extent = 1, blkno = 2, numrecs = 11)
THREAD #1 - status:0x2 flags:0x0 dirty:55
low cache rba:(0x13.3.0) on disk rba:(0x13.a6.0)
-- low cache rba:(0x13.3.0)实例恢复的起点：19号日志，第3个块，第0个字节
--on disk rba:(0x13.a6.0)：实例恢复的终点：19号日志，第166个块，第0个字节
on disk scn: 0x0000.0016359c 12/11/2012 22:57:42
resetlogs scn: 0x0000.000f30dc 12/07/2012 10:36:16
heartbeat: 801789080 mount id: 848836772
THREAD #2 - status:0x0 flags:0x0 dirty:0
low cache rba:(0x0.0.0) on disk rba:(0x0.0.0)
on disk scn: 0x0000.00000000 01/01/1988 00:00:00
resetlogs scn: 0x0000.00000000 01/01/1988 00:00:00
heartbeat: 0 mount id: 0
***************************************************************************
DATA FILE RECORDS
***************************************************************************
(size = 520, compat size = 520, section max = 100, section in-use = 6,
last-recid= 43, old-recno = 0, last-recno = 0)
(extent = 1, blkno = 11, numrecs = 100)
DATA FILE #1:
name #7: /oradata/bxocp/system01.dbf
creation size=0 block size=8192 status=0xe head=7 tail=7 dup=1
tablespace 0, index=1 krfil=1 prev_file=0
Checkpoint cnt:121 scn: 0x0000.0016344c 12/11/2012 22:54:36
--控制文件中保存的数据文件检查点SCN＝16344c转成10进制为1455180
Stop scn: 0xffff.ffffffff 12/11/2012 22:53:05
--结束的SCN填无穷大，说明是异常关机的，重启数据库必须做实例恢复
Creation Checkpointed at scn: 0x0000.00000007 09/17/2011 09:46:08
thread:0 rba:(0x0.0.0)
7、dump数据文件头
alter session set events 'immediate trace name file_hdrs level 10';
显示数据文件头的部分内容：
V10 STYLE FILE HEADER:
Compatibility Vsn = 186646528=0xb200000
Db ID=848459038=0x3292751e, Db Name='BXOCP'
Activation ID=0=0x0
Control Seq=2099=0x833, File size=79360=0x13600
File Number=2, Blksiz=8192, File Type=3 DATA
Tablespace #1 - SYSAUX rel_fn:2
Creation at scn: 0x0000.0000088c 09/17/2011 09:46:16
Backup taken at scn: 0x0000.00000000 01/01/1988 00:00:00 thread:0
reset logs count:0x2fc45da0 scn: 0x0000.000f30dc
prev reset logs count:0x2d6c775c scn: 0x0000.00000001
recovered at 12/11/2012 22:54:36
status:0x4 root dba:0x00000000 chkpt cnt: 121 ctl cnt:120
begin-hot-backup file size: 0
Checkpointed at scn: 0x0000.0016344c 12/11/2012 22:54:36
--数据文件的文件头中的检查点SCN＝16344c转成10进制为1455180
thread:1 rba:(0x13.2.10)
--重做日志的地址0x13.2.10－> 19号日志，第2号块，第16个字节开始恢复
注意：
从控制文件中得到重做日志恢复起始地址：
low cache rba:(0x13.3.0)：19号日志，第3个块，第0个字节开始恢复
从数据文件头部得到重做日志恢复起始地址：
thread:1 rba:(0x13.2.10) ：9号日志，第2号块，第16个字节开始恢复
8、最后我们打开数据库，然后监控告警日志alert_bxocp.log日志，看是怎么恢复的
[oracle@guoyj trace]$ tail -f alert_bxocp.log
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