本篇内容介绍了“数据库中ORACLE的启动验证分析”的有关知识，在实际案例的操作过程中，不少人都会遇到这样的困境，接下来就让小编带领大家学习一下如何处理这些情况吧！希望大家仔细阅读，能够学有所成！
oradebug dump file_hdrs 3 DATA FILE #5: (name #8) /dev/raw/raw12 creation size=64000 block size=8192 status=0xe head=8 tail=8 dup=1 tablespace 5, index=6 krfil=5 prev_file=0 unrecoverable scn: 0x0000.00000000 01/01/1988 00:00:00 Checkpoint cnt:43 scn: 0x0000.000a5310 09/13/2018 06:18:03 Stop scn: 0x0000.000a5310 09/13/2018 06:18:03 Creation Checkpointed at scn: 0x0000.00002249 08/29/2018 09:27:02 thread:1 rba:(0x1.7a18.10) enabled threads: 01000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 Offline scn: 0x0000.00000000 prev_range: 0 Online Checkpointed at scn: 0x0000.00000000 thread:0 rba:(0x0.0.0) enabled threads: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 Hot Backup end marker scn: 0x0000.00000000 aux_file is NOT DEFINED above information from ctl ------------------------------------------------------------------------------------------ V10 STYLE FILE HEADER: Compatibility Vsn = 169870592=0xa200500 Db ID=880153879=0x34761517, Db Name='NGKF' Activation ID=0=0x0 Control Seq=280=0x118, File size=64000=0xfa00 File Number=5, Blksiz=8192, File Type=3 DATA Tablespace #5 - USERS rel_fn:5 Creation at scn: 0x0000.00002249 08/29/2018 09:27:02 Backup taken at scn: 0x0000.00000000 01/01/1988 00:00:00 thread:0 reset logs count:0x3abc6817 scn: 0x0000.00000001 reset logs terminal rcv data:0x0 scn: 0x0000.00000000 prev reset logs count:0x0 scn: 0x0000.00000000 prev reset logs terminal rcv data:0x0 scn: 0x0000.00000000 recovered at 09/13/2018 06:11:32 status:0x0 root dba:0x00000000 chkpt cnt: 43 ctl cnt:42 begin-hot-backup file size: 0 Checkpointed at scn: 0x0000.000a5310 09/13/2018 06:18:03 thread:1 rba:(0xb.185.10) enabled threads: 01100000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 Backup Checkpointed at scn: 0x0000.00000000 thread:0 rba:(0x0.0.0) enabled threads: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 External cache id: 0x0 0x0 0x0 0x0 Absolute fuzzy scn: 0x0000.00000000 Recovery fuzzy scn: 0x0000.00000000 01/01/1988 00:00:00 Terminal Recovery Stamp 01/01/1988 00:00:00 Platform Information: Creation Platform ID: 13 Current Platform ID: 13 Last Platform ID: 13 DUMP OF TEMP FILES: 1 files in database
当使用 file_hdrs 事件来转储数据文件头信息时，Oracle 会转储两部分信息，一部分来自控制文件，一部分来自数据文件，在数据库启动过程中，这两部分信息要用来进行启动验证。
验证过程：
第一次检查数据文件头中的 Checkpoint cnt 是否与对应控制文件中的 Checkpoint cnt
一致，如果相等,进行第二次检查;
file_hdrs.chkpt.cnt=ctl.chkpt.cnt
第二次检查数据文件头的开始SCN和对应控制文件中的结束SCN是否一致如果结束
SCN 等于开始 SCN,则不需要对那个文件进行恢复。
file_hdrs.start_scn = clt.stop.scn
对每个数据文件都完成检查后,打开数据库.同时将每个数据文件的结束 SCN 设置为无穷
大。
以上面的转储信息为例：
clt中（横线上半部分中）最重要的几个地方
这部分中包含的重要信息有:
检查点计数: Checkpoint cnt:检查点 SCN: scn:
Checkpoint cnt:43 scn: 0x0000.000a5310 09/13/2018 06:18:03
数据文件 Stop SCN
Stop scn: 0x0000.000a5310 09/13/2018 06:18:03
数据文件头的信息（横线上半部分中）最重要的几个地方
u 检查点 SCN: Checkpointed at scn
u 检查点计数: chkpt cnt
Checkpointed at scn: 0x0000.000a5310 09/13/2018 06:18:03
chkpt cnt: 43 ctl cnt:42
这两者都和控制文件中所记录的一致。如果这两者一致，数据库启动时就能通过验证，启动数据库。
如果不一致，启动的时候，会有报错
ERROR at line 1: ORA-01113: file 4 needs media recovery ORA-01110: data file 4: '/opt/oracle/oradata/eygle/eygle01.dbf'
执行恢复
recover datafile 4;
“数据库中ORACLE的启动验证分析”的内容就介绍到这里了，感谢大家的阅读。如果想了解更多行业相关的知识可以关注亿速云网站，小编将为大家输出更多高质量的实用文章！
原创文章，作者：Maggie-Hunter，如若转载，请注明出处：https://blog.ytso.com/tech/database/205262.html