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Hot Backups, Redo, and Fractured Blocks

All posts relating to Oracle database administration.

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shrinika
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Hot Backups, Redo, and Fractured Blocks

Postby shrinika » Wed Jan 02, 2013 3:38 am

Tim, I read the below link and have question.

Code: Select all

http://www.oraclealchemist.com/oracle/hot-backups-redo-and-fractured-blocks/


When the tablespace is begin backup mode, oracle does not update the scn on data file header. Instead, it update the SCN
on the redo block. However, it continue writing in the data file. but the data file header is frozen. When we bring the data file
to end backup mode, it will repair the data file and reconcile the data file with redo block.

My question is, when log switch happens, the redo log file will be archived to archived redo logs. when we bring the data file
to end backup mode, the info in redo log file will be disappeared and how does oracle reconcile the block when info is lost in
redo log file?

Please help me to understand.

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Re: Hot Backups, Redo, and Fractured Blocks

Postby Tim... » Wed Jan 02, 2013 8:47 am

Hi.

It only needs to know the latest SCN, so that will always be in an online redo log.

Cheers

Tim...
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shrinika
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Posts: 260
Joined: Fri Jun 13, 2008 3:18 pm

Re: Hot Backups, Redo, and Fractured Blocks

Postby shrinika » Thu Jan 03, 2013 3:51 am

Thanks Tim!

Tim...
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Posts: 18437
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Re: Hot Backups, Redo, and Fractured Blocks

Postby Tim... » Thu Jan 03, 2013 8:22 am

:)
Tim...
Oracle ACE Director
Oracle ACE of the Year 2006 - Oracle Magazine Editors Choice Awards
OakTable Member
OCP DBA 7.3, 8, 8i, 9i, 10g, 11g
OCP Advanced PL/SQL Developer
Oracle Database: SQL Certified Expert
My website: http://www.oracle-base.com
My blog: http://www.oracle-base.com/blog


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