Re: startup and shutdown.....

From: Jurij Modic <jurij.modic_at_mf.sigov.mail.si>
Date: 1997/07/10
Message-ID: <33c51dc0.1214640@www.sigov.si>#1/1

On 8 Jul 1997 16:49:27 -0400, jtesta_at_freenet.columbus.oh.us (Joseph Testa) wrote:

>Jurij Modic (jurij.modic_at_mf.sigov.mail.si) wrote:
>: On Tue, 01 Jul 1997 11:09:47 -0700, "V.K. Sundaresan"
>: <sundarvk_at_ntserver1.photodisc.com> wrote:
>: >...[SNIP]....
>:
>: You don't need STARTUP -> SHUTDOWN NORMAL after you shut down the DB
>: in IMMEDIATE mode because Oracle won't perform any instance recovery
><snip>
>
>I beg to differ back in version 7.2, it was stated by oracle that the best
>way to do get the database shutdown was to do a shutdown immediate
>followed by a startup and a shutdown normal. It then leaves the database
>in a clean state for off-line backups. That is the best policy.

I don't doubt that you've heard or read this from some Oracle manuals or other sources, but I just can't see any reason for this sequence of shutdown_immediate-startup-shutdown_normal juggling. Furthermore, here is a quote from "Oracle7 Sever Administrator's Guide, ver. 7.2", Chapter 16: Backing Up a Database:

[***begin quote ***]
Preparing to Take a Full Backup

To guarantee that a database's datafiles are consistent, always shut down the database with normal or immediate priority before making a full database backup.
[*** end quote ***]

Ater you shutdown your database IMMEDIATE it is in perfectly consistent state, in fact it is in exactly the same state as when you do SHUTDOWN NORMAL. The only difference between the two methods is that SHUTDOWN immediate does not wait untill all users exit, it rather disconnects them itself and rollbacks all uncommited transactions. All other steps during shutdown process are exactly the same.

However, it is not so rare among DBAs to do SHUTDOWN IMMEDIATE -> STARTUP RESTRICT -> SHUTDOWN NORMAL befor making cold backup, but the rational reasons are not in "database consistency". The true reasons are, that you don't want any other users to be connected when you perform some ususal pre-backup steps (list of all db files and log files, backing control file to trace, ...), so that you can be sure no one is doing any changes in database layout. That is why STARTUP RESTRICT -> SHUTDOWN NORMAL are often perform after DB is shutted down IMMEDIATEly.

>
>Joe
>--
>BDJoseph S. Testa, Database Administrator, Ohio EPA
> IRCop on Atlantis.sorcery.net, If your gonna IRC anywhere make it
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Regards,

---

Jurij Modic                             Republic of Slovenia
jurij.modic_at_mf.sigov.mail.si		Ministry of Finance
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The above opinions are mine and do not represent any official standpoints of my employer Received on Thu Jul 10 1997 - 00:00:00 CDT