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RBA(Redo Byte Address)

原创 Linux操作系统 作者:caleble 时间:2009-04-17 22:11:24 0 删除 编辑

Redo Byte Address (RBA)

An RBA points to a specific location in a particular redo thread. It 
is ten bytes long and has three components: log sequence number, 
block number within log, and byte number within block.

let me just rephrase.

It is as straight forward as it looks in this case, don't over analyze it.  Pretend the checkpoint 
rba is a "time".  dbwr flushed out blocks to disk older than that time. 
 
RBA 就是重做位地址,也就是用来定位Redo Log中一点的指针,类似于rowid的概念。
它有三个部分,log sequence number,block number within log,byte number within block。
通过log sequence number找到哪一个log,再通过block number找到log 中哪一个数据块,最后通过块中的位定位到最终目的地--回恢复中开始应用redo log的那一点。
 
http://asktom.oracle.com/pls/asktom/f?p=100:11:0::::P11_QUESTION_ID:402216939004

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