RE: Recovery scenario

From: Jeremiah Wilton <jeremiah_at_ora-600.net>
Date: Wed, 30 Jan 2008 21:33:01 -0800
Message-ID: <00bf01c863ca$bf3f27f0$3dbd77d0$@net>


Pedro Espinoza wrote:
> Ram Raman wrote:

>> Why would oracle ask for a file that is from 5am when the backup finished at

>> 1 30am. Is it the "UNTIL CANCEL" that made the difference?

>
> Because system01.dbf required redo to bring in consistent with all
> other datafiles. One way to avoid this is: switch logfiles immediately
> after backuping up datafiles, and then backup those archived redo.

I am pretty sure that both assertions above are not right. Ram had the right idea. When you add the UNTIL... clause, the recovery session is an incomplete, or point-in-time recovery, and you can open it at any SCN after the last datafile finished backup (or backup mode ended if not using RMAN). Without the UNTIL clause, it is a complete, or continuous recovery, which will ask for logs forever.

Switching logs (or more properly, archiving the current log - '...archive log current') upon completion of a backup would not do anything to change the behavior that Ram observed. Further, failing to archive the current log would not cause a recovery to demand additional logs beyond the log in which the last tablespace came out of backup mode or last datafile finished backup (if RMAN).

Regards,

Jeremiah Wilton
ORA-600 Consulting
http://www.ora-600.net

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Received on Wed Jan 30 2008 - 23:33:01 CST

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