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Re: Recovery Question

From: Richard Foote <richard.foote_at_bigpond.com>
Date: Mon, 15 Jul 2002 18:18:42 +1000
Message-ID: <QsvY8.35329$Hj3.105980@newsfeeds.bigpond.com>


Hi Brian,

Imagine being a passenger on a Qantas 747 flight from Sydney to LA. Approaching LA airport, the pilot discovers that the undercarriage won't come down and he has to attempt an emergency landing. You would be S**T scared right ?

Imagine if the pilot said he was a little bit confused about whether or not to ditch the fuel first. Or was always wondering what that red flashing button up there was for and whether it's relevant to the current situation. Imagine if he told the passengers that everything should be OK once he finds the right page in the flying manual. You would be more than S**T scared, you'll be dead.

Well if you were the DBA of any organisation that valued their data, they'll be S**T scared right now !! Now I suspect your not and Qantas pilots are highly trained so of course the above scenario is all make believe. However the point I want to make is that probably of all the tasks and responsibilities of a DBA, the ability or otherwise to protect and successfully recover your database is what makes you a hero or a zero.

Pilots are highly trained to be able to handle emergency procedures. Emergencies don't happen very often but when they do a good pilot *instinctively* knows what to do and how to recover the aircraft with (hopefully) no loss of passengers. In an emergency situation, a good DBA *instinctively* knows how to recover a database with (hopefully) no loss of data. The same thing.

Read as much doco as you can (Backup and Recovery Concepts would be a good start), attend the excellent Oracle Backup and Recovery course, practice at work (or at home) all the various recovery scenarios until they become second nature and my friend a DBA hero you might one day become.

Good Luck

Richard

"Brian Li" <brian_li_at_newyorklife.com.hk> wrote in message news:3df45b1d.0207142006.799e8276_at_posting.google.com...
> I'm a newbie using Oracle 9i.
> I have some questions in the followings, please kindly answer the
question.
>
> Question 1
> If I lost a control file (no backup),
> how can I startup a database?
> how can I recover a control file?
>
> Question 2
> If I lost all archive log,
> how can I recover the database?
>
> Question 3
> If I lost all redo log,
> how can I recover the database?
>
> Question 4
> If I lost all control file, redo log and archive log,
> how can I recover the database?
>
> Question 5
> About Offline Backup Procedure,
> shutdown normal;
> copy all datafile to backup folder
> copy all control file to backup folder
> copy all redo logs to backup folder
> copy all archive logs to backup folder
>
> Is it a correct procedure?
> Why I have to need to backup redo log only?
> Why NOT I have to need to backup archive log?
>
> Question 6
> Why NOT I have to backup init.ora?
> How can I recover init.ora if I lost it?
>
> Question 7
> What is the their difference?
> ALTER DATABASE OPEN;
> ALTER DATABASE OPEN RESETLOGS;
> ALTER DATABASE OPEN NORESETLOGS;
> When use them?
> How sometimes I call ALTER DATABASE OPEN RESETLOGS;
> sometimes call ALTER DATABASE OPEN;?
>
> Question 8
> What is the their difference?
> recover database;
> recover database until cancel;
> recover database using backup controlfile;
> recover database until cancel using backup controlfile;
> recover database using backup controlfile until cancel;
> What is using backup controlfile? where/what backup controlfile it is
using?
> what until cancel means?
> Please tell me more details.
>
> The above question make me confusing during recovery the database.
>
> Thanks a lot! ^^
>
> Brian
Received on Mon Jul 15 2002 - 03:18:42 CDT

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