Re: student question: incremental backups (level 0 and level 1)
From: Holger Baer <baer_at_dont_ask.com>
Date: Fri, 27 Jun 2008 17:36:41 +0200
Message-ID: <g431e9$gkh$1@news.belwue.de>
>
> The metalink note: 134214.1 states clearly that if a block *EVER*
> contained data
> (i.e. if an oracle process *EVER* wrote to it), that block will be
> backed up.
> Only empty blocks are skipped in the backup, where empty means the
> block was never written to *ever*.
>
> Anurag
>
Date: Fri, 27 Jun 2008 17:36:41 +0200
Message-ID: <g431e9$gkh$1@news.belwue.de>
Anurag Varma schrieb:
>
> Holger Baer wrote:
> --snip--
>> The documentation is a little bit clearer (http://download.oracle.com/docs/cd/B19306_01/backup.102/b14191/rcmconc1005.htm#sthref241): >> >> <quote> >> Multilevel Incremental Backups >> >> RMAN can create multilevel incremental backups. Each incremental level is denoted by a value of 0 or 1. A level 0 incremental backup, which is the base for >> subsequent incremental backups, copies all blocks containing data. >> The only difference between a level 0 incremental backup and a full backup is that a full backup is never included in an incremental strategy. >> >> </quote> >> >> The important point to note: >> - a level 0 incremental backup copies all blocks containing data >> >> This does not mean all blocks that *ever* contained data, think of truncate table for example. So the OP is right to express his doubts about the wording, >> even if it's not in the sense he originally meant. Another example: drop a table/index/partition and you're likely to to have lots of blocks that once contained >> data but now don't. They shouldn't (and to the best of my knowledge don't) get backed up. >> >> Cheers >> Holger
>
> The metalink note: 134214.1 states clearly that if a block *EVER*
> contained data
> (i.e. if an oracle process *EVER* wrote to it), that block will be
> backed up.
> Only empty blocks are skipped in the backup, where empty means the
> block was never written to *ever*.
>
> Anurag
>
Thanks for the correction
Holger Received on Fri Jun 27 2008 - 10:36:41 CDT