RE: Differential incremental backups

From: <>
Date: Thu, 18 Mar 2010 13:03:57 -0400
Message-ID: <>

I read him as asking something nobody is picking up on. As I read his concern it says regardless of type of backup, if the level 0, or whatever base is taken on Sunday, March 14th, and he has archives for the entire month of march, can he recover to Friday March 12th. For the sake of the example he does not have another base backup supporting Friday, March 12th.    

Orlando can confirm if this isn't the actual question. Of course as with all backup scenarios, as Jared pointed out, one should test it regardless of whether you believe you have the answers or not.  

Joel Patterson
Database Administrator
904 727-2546

[] On Behalf Of Orlando L Sent: Thursday, March 18, 2010 11:21 AM
To: Guillermo Alan Bort
Subject: Re: Differential incremental backups    

Thanks. I wonder how it can restore to previous Friday if a base backup gets taken Sunday night. I thought it would restore base backup first and then apply incremental on the top of that base backup. I thought the backups taken before base backup were useless and cannot be used to restore to a point in time in last week, even if recovery window of 7 days is specified. ie, in this example, wanting to go back to last Friday on a given Monday, with a base backup on Sunday.  

On Thu, Mar 18, 2010 at 8:55 AM, Guillermo Alan Bort
<> wrote:


  Also keep in mind that RMAN automatically manages retentions for you, so if you tell it that you need to have a retention policy of 'RECOVERY WINDOW 7 DAYS', it will automatically keep all the backup files required to guarantee that policy. You will also have to use RMAN commands to ensure backup consistency when deleteing files (namely: delete obsolete).

Also, read the RMAN documentation, there are a lot of answers there: w.htm Alan.-

On Thu, Mar 18, 2010 at 10:43 AM, andrey khudyakov
<> wrote:

William, you are mistaken.

differential and comulative are exclusive to each other, but each of them is incremental backup.  

Orlando, if you want recover your database till some <recover_point>, you should have available all incremental backups until recover_point and all archived logs between start_time of last incremental backup and recover_point  

2010/3/18 William Muriithi <>          

        First, you said differential incremental backup. I believe differential and incremental are exclusive to each other if I am not wrong.         

        Now assuming incremental, you use the monday full backup and all incrementals up to Thursday.         

        If its differential, you use the full backup and the last differential backup, which is Thursday                   

Received on Thu Mar 18 2010 - 12:03:57 CDT

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