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  • 15. Re: Why oracle instance cannot perform following
    jgarry Guru
    Currently Being Moderated
    971957 wrote:
    Why oracle instance cannot perform following :

    1. Go to mount mode after open;
    "alter database mount" when db is in open mode
    Why would you want to do this? The difference between nomount and mount is just whether the controlfile is open. The difference between mount and open is all the datafiles are checked and opened. Recovery? Well, what about flashback? Look at all the options you have to account for:

    On some versions/platforms, Oracle has been a bit odd about actually closing files when you expect it to. More generally, only redo is really flushed for certain and controls recovery, any other file may be corrupted for all sorts of reasons beyond its control, including asynchronous writes never actually completed. So Oracle really wants to be certain it is starting from a known point. If your redo stream is corrupted, you can't recover beyond that.

    If you want restricted mode, you can enable it with an alter db command. But that doesn't remove existing sessions, if you want to do that you need to kick them all off one way or another.
    2. Why Oracle doesn't have restart command in database
    "alter database restart"
    when it can perform these operation behind very easily
    Well, what makes you think the "operation behind" is easy? There are many things that can keep a clean shutdown from happening, that's why there are a number of shutdown options - do you want to mess up all transactions? If you really don't care, that is what startup force does.
    3. Why sql prompt cannot repeat its command as terminal of linux can do
    Why not oracle
    It has been able to edit the command line for decades. The exact method is OS dependent.

    reply are welcome also at
  • 16. Re: Why oracle instance cannot perform following
    Jonathan Lewis Oracle ACE Director
    Currently Being Moderated
    971957 wrote:
    alter database restart to mount,nomount,open;
    Technically you have
    alter database close;
    alter database dismount;
    However, (a) this leaves the executables still running and (b) you cannot mount the database after dismounting it, and you cannot open the database after closing it.

    It iis possible that Oracle doesn't allow re-opening and re-mounting in case of some unexpected side effects relating to recovery - there's a LOT of historical code around the startup and recover area, so perhaps there's a very good reason why Oracle thinks it dangerous to do this.

    You've been given the "restart" command twice - it's "startup force". A reason why there is no 'alter database restart' is that you can't issue the alter command until the executable are running, and the only good reason for restarting the database is if the executables have become "unstable" in some way and need to be stopped. So an "alter database restart" command would have to fail in mid-run because it would have to stop the executables that allow it to run.

    Jonathan Lewiis
  • 17. Re: Why oracle instance cannot perform following
    Aman.... Oracle ACE
    Currently Being Moderated
    R Monga wrote:
    Gentlemen u r not getting me what i want to say
    after opening database is there any option to go to **mount state** without shutting down database
    then giving command alter database mount, if not why ? oracle was not able to give this command

    there is no logic of OS or Database command .everything is possible in oracle & by oracle
    why oracle was not able to get this feature?,there must by logic in that

    also is there any command of database restart
    shut abort will not restart database we have to restart manually from nomount, mount, open state all three state
    why oracle has not given three statement
    alter database restart to mount,nomount,open;
    Unfortunately, its you who is not trying to follow what we are trying to say. You have been give the command alter database close which is very close to what you are asking. Did you read about it? For your restart issue, we told you startup force . Why did you think in the first place that shut abort would restart the database when the command is clearly for shutting down the db? Did you happen to read about it? And for all these requests , if you have access to Oracle Support, you can raise a request to them and also submit an enhancement request in the product.


    PS: Also read Joanthan's reply given in the last. It should be sufficient to explain that why many of the things that you are asking are not there .
  • 18. Re: Why oracle instance cannot perform following
    Aman.... Oracle ACE
    Currently Being Moderated
    R Monga wrote:
    dnot u think oracle is not used not only in Production environment
    it is also used in Coaching & teaching & standalone ,home envrment where
    Creation of DB & working logically is not important in that
    there matters commands
    Huh? Oracle is , in the first place, a production environment software. For home, training/coaching, its just the advantage that you get from Oracle Corp that they let you use the same software which runs on multi-billion dollars h/w of production on laptop as well. And even then, it shouldn't matter where you use it, its not an open-source project and you must accept what Oracle does and doesn't .

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