Re: Recovery Catalog vs Control File

On Sat, 30 Aug 2008 13:59:34 -0700 (PDT), hpuxrac <johnbhurley_at_sbcglobal.net> wrote:

>On Aug 29, 5:30 pm, sybra..._at_hccnet.nl wrote:
>
>snip
>
>> The controlfile autobackup is stored in a file including the dbid of
>> the database, the date in the format yyyymmdd and a piece number.
>> It can be restored seperately and it pretty much replaces the ...
>> recovery catalog.
>>
>> If you know the dbid and controlfile autobackup is on, you can always
>> restore the database.
>
>Probably trying to say you should always record or have available your
>database id. With that knowledge and being able to identify the tape/
>media ( perhaps from logs from your tape/media backup system or from
>rman output ) that a controlfile backup is stored on ... you can
>restore the database.
>
>You might have to restore the control file first (not usually ) then
>do the database restore.
>
>

Not quite.
If you don't have a recovery catalog and you don't have autobackup controlfile on, and you lost all your controlfiles, how does RMAN know which controlfile to restore?
Apart from that: is this the controlfile containing the correct backup info?

So controlfile autobackup comes in.
It has a fixed filename format (the %F modifier is mandatory) and using
set dbid .....
and
restore controlfile from autobackup
using several other parameters it will go back until it finds a viable backup. So this doesn't need to be the most recent.

This is why I consider the controlfile autobackup to function as a replacement for the recovery catalog.

-- 
Sybrand Bakker
Senior Oracle DBA