实例恢复的深入解析(三)
er database open
Beginning crash recovery of 1 threads
Started redo scan
Completed redo scan
read 81 KB redo, 55 data blocks need recovery
Started redo application at
Thread 1: logseq 19, block 3 --实例恢复开始的重做日志：19号日志第3个块
Recovery of Online Redo Log: Thread 1 Group 1 Seq 19 Reading mem 0
Mem# 0: /oradata/bxocp/redo01.log
Completed redo application of 0.06MB
Completed crash recovery at
Thread 1: logseq 19, block 166, scn 1475516 --实例恢复结束点的重做日志：19号日志第166个块
55 data blocks read, 55 data blocks written, 81 redo k-bytes read
Tue Dec 11 23:46:42 2012
Thread 1 advanced to log sequence 20 (thread open)
Thread 1 opened at log sequence 20
Current log# 2 seq# 20 mem# 0: /oradata/bxocp/redo02.log
Successful open of redo thread 1
MTTR advisory is disabled because FAST_START_MTTR_TARGET is not set
[12867] Successfully onlined Undo Tablespace 2.
Undo initialization finished serial:0 start:20725234 end:20725294 diff:60 (0 seconds)
Verifying file header compatibility for 11g tablespace encryption..
Verifying 11g file header compatibility for tablespace encryption completed
Tue Dec 11 23:46:42 2012
SMON: enabling cache recovery
SMON: enabling tx recovery
Database Characterset is ZHS16GBK
No Resource Manager plan active
replication_dependency_tracking turned off (no async multimaster replication found)
Starting background process QMNC
Tue Dec 11 23:46:43 2012
QMNC started with pid=21, OS id=13839
Completed: alter database open
Tue Dec 11 23:46:44 2012
Starting background process CJQ0
Tue Dec 11 23:46:44 2012
CJQ0 started with pid=22, OS id=13851
Setting Resource Manager plan SCHEDULER[0x318A]:DEFAULT_MAINTENANCE_PLAN via scheduler window
Setting Resource Manager plan DEFAULT_MAINTENANCE_PLAN via parameter
Tue Dec 11 23:46:47 2012
Starting background process VKRM
Tue Dec 11 23:46:47 2012
VKRM started with pid=23, OS id=13857
9、可以看出，实例恢复的起始的重做日志是以控制文件中的low cache rba:(0x13.3.0)：19号日志，第3个块，第0个字节开始恢复，而不是从文件头的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
10、最后总结一下实例恢复
(1)数据文件、在线日志文件、控制文件不得有损坏
(2)数据库自动恢复，无需DBA干涉
(3)恢复只需在线日志文件，无需归档日志
(4)数据库在open的时候开始实例恢复
实际上我做的这个实例恢实验的还没有写完整， 还有最后一步回滚！这个就留给你们思考！
实例恢复三步：前滚--->打开库---->后滚(也叫回滚)
其实:On Disk RBA不是Instance Recovery的终点！！！