Re: Help with hot backups

From: Howard J. Rogers <hjr_at_dizwell.com>
Date: Wed, 19 May 2004 06:12:43 +1000
Message-ID: <40aa6e2c$0$3033$afc38c87@news.optusnet.com.au>

Paul Drake wrote:

> "Chuck Lucas" <chuck.lucas_at_mspbNOSPAM.gov> wrote in message news:<c8ato3$p6p$1_at_ngspool-d02.news.aol.com>...
> 

>>I've been charged with taking hot backups of our database. It's Oracle
>>8.1.7 on Solaris 8 (sparc).
>>
>>I've come up with a RMAN script, but I'm not sure where to tell Oracle to
>>"archive log current". Below is the current script.
>>
>>run {
>> allocate channel tape1 type 'sbt_tape';
>> backup
>> format '%d_%u_%s_%p_%t'
>> (database);
>> sql 'alter system archive log current';
>> backup
>> format '%d_%u_%s_%p_%t'
>> (archivelog all delete input);
>> release channel tape1;
>> }
>>
>>After reading the documentation, it stated placing the "archive log current"
>>after the database backup, to ensure the "backup information" is included in
>>the redo (archive) logs. But, I'm thinking placing it there, won't give
>>enough time for the archive process to archive the log before RMAN actually
>>starts working on the archive logs. I thought about moving the "archive log
>>current" statement to BEFORE the database backup (which should give it
>>enough time to archive), but then I'm afraid I won't get everything in the
>>current redo log. Or maybe I should put the statement in BOTH places, to
>>make sure I get everything?
>>
>>Really appreciate any assistance anyone could offer on this.
>>
>>Much thanx,
>>Chuck

> 
> 
> Chuck,
> 
> might you consider having rman include the archived redo logs in at
> least 2 backup sets prior to deleting them?
> 
> I have not worked with RMAN in 8.1.7, only in 9.2.
> 
> In 9.2, one can configure a static setting such that each archivelog
> would have to have been backed up at least twice prior to deleting the
> source archived redo log. I don't know how you would accomplish that
> in 8.1.7.
> 
> "archivelog all delete input"  still scares me with only one backup
> set between you and loss of data.
> 
> hth.
> 
> Paul

Oracle thought of that for you in 8i, Paul. Cunningly, you arrange to archive to two destinations, and RMAN is never aware of the second, leaving it totally untouched.

This was considered by some to be, er, something of an "oversight", and got fixed in 9i.

But for the nervous and paranoid, it was actually not a bad thing!

Regards
HJR Received on Tue May 18 2004 - 15:12:43 CDT