Re: database could not be started

"Anton Buijs" <remove_aammbuijs_at_xs4all.nl> wrote in message news:3f3510b5$0$49108$e4fe514c_at_news.xs4all.nl...
>
> quarkman <quarkman_at_myrealbox.com> schreef in berichtnieuws
> oprtm7jmjizkogxn_at_haydn...
> | On Sat, 9 Aug 2003 16:48:34 +0200, Anton Buijs
> <remove_aammbuijs_at_xs4all.nl>
> | wrote:
>
> | >
> | > | Note: Make sure you are backing up ALL files , especially the REDO
> logs
> | > for
> | > | an offline/cold backup - and especially if a shutdown abort is ever
> | > issued.
> |
> |
> | Agree with everything else you said. But this comment from earlier is
gob-
> | smackingly bad advice.
> |
> | Never, ever, ever back up the online redo logs. Ever.
> |
> | It is marginally less bad to do so in noarchivelog mode than archivelog,
> | but only marginally. And it is *always* redundant to do so, never mind
> | dangerous.
> |
> | Did I say "never ever"?
> |
> | Good.
> |
> | ~QM
>
> It's Burton's remark to backup the redo files and I did not react on it
> because frankly I am in favor to backup the online redos when:
> a. the database runs in noarchivelogmode
> b. and you don't use rman to make backups (rman never backup redos anyway)
> For 2 reasons:
> a. if you did a shutdown abort you need them to recover the database

This is the main reason where you would need the REDO logs. I thought that was what I said? After re-reading my post, it IS what I said.

Just to be clear... I did not mean to imply and I know you do NOT recover REDO logs when recovering from a hot backup. The entire context of the OP was a problem with a cold backup. All of the comments in my post were about cold backups ONLY.

Hot backups are different, of course.

Anyway, it sounded like a real possibility (needing the REDO logs or having to do a reset logs) for this person who is doing a cold/offline backup and does a shutdown abort every now and then because the immediate isn't coming back soon enough.

I would add for the OP... if this is occuring often, I would look into what is running at the time you are attempting a cold backup. Someone probably has a job that is kicking off at the same time or right before and you could get them to change the start time.

Note: I have had problems before trying to get a "clean shutdown" such as:

(1) Some job or snapshot would kick off in the middle of my "clean startup/shutdown" even with the listener shutdown. So, then I would need a second init.ora with jobs = 0 and have to do the "clean startup/shutdown" using a different init.ora .

(2) The "crash recovery" step would take a lot longer than you would like when doing the "clean startup/shutdown".

So, can someone/quarkman? please explain to me what is the problem / disadvantage of recovering the REDO logs, IF recovering from COLD backup (even if a shutdown abort was not issued).

Seems cleaner to me to recover the cold backup with REDO logs than to do a reset logs command or having a potential problem getting a "clean shutdown".

> b. when you have them you can normally open the database and you have a
real
> complete set; without the redologs you must do an open resetlogs.
> Your reaction will probably be: "make sure you do a clean shutdown" and
> "what the heck, open resetlogs isn't so bad" but my reaction would be: not
a
> problem to backup the redo's too and I am protected against these 2
possible
> mistakes.
>
> For a database in archivelogmode I agree: never backup the redologs
because
> you probably do a roll forward and have the archives available for that
> purpose. And you can't be tempted to restore them, loosing the real ones
and
> therefore loosing transactions.
>
> Altough a "best practice" would be to always make a savety copy of a
control
> file and redolog files and if possible the entire database or involved
files
> before beginning a restore/recovery.
>
>
Received on Sat Aug 09 2003 - 12:39:31 CDT