Re: Cold Backups in NOMOUNT Stage

From: <frank.van.bortel_at_gmail.com>
Date: 17 Aug 2006 07:46:43 -0700
Message-ID: <1155826003.113027.176870@b28g2000cwb.googlegroups.com>

Raaj schreef:

> Friends,
> I am fresher in Oracle DBA. I have some few doubts. Pls
> clarify me.
>
> 1) Can we take cold backup in NOMOUNT Stage.
> At nomount stage only pfile is read and SGA is allocated and
> background process are started. So to my knowledge, i think we can take
> backups. Please correct me if i am wrong.
>

Not with RMAN:
RMAN> startup nomount

Oracle instance started

Total System Global Area 139534344 bytes

Fixed Size                      454664 bytes
Variable Size                113246208 bytes
Database Buffers              25165824 bytes
Redo Buffers                    667648 bytes

RMAN> backup database;

Starting backup at 17-AUG-06
using target database controlfile instead of recovery catalog allocated channel: ORA_DISK_1

channel ORA_DISK_1: sid=9 devtype=DISK
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================

RMAN-03002: failure of backup command at 08/17/2006 16:43:13 ORA-01507: database not mounted

RMAN>
> 2) How to monitor LOG SWITCH.
> Is it by monitoring ALERT LOG and by querying V$LOG and
> V$LOGFILE.
What did you try? What exactly are you trying to do? You can even alter the system to see switches in the alert log file.

>
> 3) If one of my online redolog is corrupted in which it contains more
> than half of REDO entries, how can i recover. Is it a nice thing to
> drop the online log which has more than half of redo entries. How to
> recover the data ie redo entries in redolog in that case.
>

Don't quite understand the more than half bit. AFAIK, you cannot recover
REDO entries in a dropped log file, unless that file is archived. The online file is in use, so not yet archived. Received on Thu Aug 17 2006 - 09:46:43 CDT