Mladen,

I apologize - I didn't want to imply that you were not aware of the way RMAN
works. However, I am not sure I got my point across on the Hot backup issue,
so here goes... 

You should not take a backup of a BCV mirror _without_ putting the whole
database in Hot backup, even if you suspend all I/O using SUSPEND. AFAIK,
the SUSPEND command was provided to enable an 'instance recoverable'
database copy and NOT a day-to-day backup copy. In other words, a copy taken
after a successful SUSPEND can be restored and started up, in which case an
_instance_ recovery is done. The issue is that you cannot perform _media_
recovery to this copy to bring it up a particular point in time, which is
the whole point of a backup... 

The way I see it, a DBA can use the SUSPEND command to backup a
Development/Test database, which would not demand a point-in-time recovery
requirement but require a end-of-day backup without having to shut it down.
The other use of couse is to reduce or even eliminate IO activity to the BCV
while the split occcurs. The split can take quite a while to complete if a
session performs heavy writing - a Hash join writing to TEMP can very
quickly overwhelme the Write cache of a SAN and delay the split.

I found ML Note:91059.1 useful in understanding the SUSPEND command...

John Kanagaraj
DB Soft Inc
Phone: 408-970-7002 (W)

Grace - Getting something we do NOT deserve
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** The opinions and facts contained in this message are entirely mine and do
not reflect those of my employer or customers **

>-----Original Message-----
>From: Mladen Gogala [mailto:[EMAIL PROTECTED] 
>Sent: Monday, January 12, 2004 11:34 AM
>To: Multiple recipients of list ORACLE-L
>Subject: Re: re BCV / SnapShot / SnapClone and the ALTER SYSTEM
>
>
>John, I know that fro RMAN tablespaces need not be in hot backup
>mode. The trick with susspend is quick & dirty way of achieving
>the same effect as with the cold backup, without bringing the
>database down. No RMAN involved. 
>
-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.net
-- 
Author: John Kanagaraj
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