"Howard J. Rogers" <hjr_at_dizwell.com> wrote in message news:<419d0a11$0$27449$afc38c87_at_news.optusnet.com.au>...
> Pete's wrote:
> > oracle_man_at_yahoo.com (rich) wrote in message news:<56f4f26c.0411171456.2bf2a10f_at_posting.google.com>...
> >
> >>According to most docs: RMAN incremental backups only backup the data
> >>blocks that have changed since the last incremental.
> >>
> >>I don't believe it. I do believe it probably backs up the data files
> >>that have changed since the last incremental,but NOT block changes.
> >>
> >>Anyone want to challenge this?
> >>
> >>Please send email to rheadrick_at_monster(REMOVE_ME).com
> >
> >
> >
> > It does. However if you read a little closer, it's only the changed
> > blocks from the last full backup, i.e. 'incremental level 0'.
>
>
> Please. Can we get a little precision and accuracy in this discussion?
>
> First, a level 0 backup and a full backup are two different things as
> far as RMAN is concerned. Both happen to include all blocks (except
> never-used ones), and therefore both would be identical in size and
> content. But a level 0 backup can be part of an incremental strategy,
> and a full backup cannot. That is, a level 1, 2, 3 or 4 incremental
> backup cannot use the full backup as the baseline from which to assess
> what has changed and therefore what needs backing up.
>
> Secondly, a level 1 incremental can use a level 0 incremental as it's
> baseline. True enough. But it can also 'compare notes' with another
> level 1. And a level 2 can compare notes with a level 2 or a level 1 as
> well as a level 0.
>
> So: your statement that "it's only the changed blocks from the last full
> backup" is totally incorrect.
>
> Also, you haven't mentioned incremental cumulative backups. A level 3
> cumulative can compare notes with a level 2, a level 1 or a level 0, but
> not another level 3. You go on to mention it, sure enough. But the
> description you give is vague, and you are still confusing level 0 and
> full backups.
>
> HJR
Yes your right Howard regarding the levels of incrementals. After I
pressed the 'Go' button on the reply, I realized I failed to mentioned
them. I should have re-replied back to it, but even so, I thought
should have given the OP enough information to go back and re-test or
re-read the Recovery Guide.
Pete's
Received on Fri Nov 19 2004 - 08:22:50 CST
