[askdba] Re: Question in HOT BACKUP

  • From: "Irfan Khan" <irfan.khan@xxxxxxxxxxxx>
  • To: <askdba@xxxxxxxxxxxxx>, <oracle-l@xxxxxxxxxxxxx>
  • Date: Sun, 3 Oct 2004 11:25:56 -0400

Hi Chirag

U dont need to copy Online Redo log files when u are doing hot backup

many reasons not to do that since :-

1)      In case of recovery u need current online redo log at a point in time =
and not redo logs of past.=20
2)      If u backup online redo log, chances are very high that u will over =
write the current redo logs and this making complete recovery =
impossible.
3)      Also ur online redo logs will be archived anyways and it can be used =
to roll things forward.

Now u tell me, if u backup online redo logs and use the same in recovery =
scenario. How is it going to be complete recovery till current point in =
time?

Let me know if it is still not clear to u.

Regards
Irfan Khan

-----Original Message-----
From: Chirag DBA [mailto:ChiragDBA@xxxxxxxxx]
Sent: Saturday, October 02, 2004 4:40 PM
To: oracle-l@xxxxxxxxxxxxx; askdba@xxxxxxxxxxxxx
Subject: [askdba] Question in HOT BACKUP


Hi,

I just appeared in an interview.=20

When I was asked which filese I will copy for hot backup, I said redo =
too.

Cause I think they can help us always to recover database upto point of =
time.

I was pulled a lot, but my only question that if not redo then how
will you recover yr DB upto point of failure, stopped the arguements.

M I true in this case? I have done expoerts in hot backups in
production database.

Can anyone clear my doubts? If u copy couple datafiles in hotback with
begin backup, n yr DB crashes... what will happen? Assume that an
archive log file is generated every 30 minutes and my DB crashed after
15 minutes of Last Archive file generated.

Can I go without REDO Log File ???

 - Chirag


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