RE: Query Database while shutdown in progress

On 6/27/07, Andrew Kerber <andrew.kerber_at_gmail.com> wrote:   Sometime shutdown abort is necessary. However, its not recommended. I would rather not risk having to recover a database w/o a good reason. If all that is needed is to monitor a shutdown immediate. there are a lot of ways to handle that. If nothing else, you can tail the alert log, and see the id thats keep the instance form shutting down, then kill that session. That would be much safer than an abnormal termination of the instance.

I agree with Jared, whats up with this? Yes, a shutdown abort assures that you will be doing crash/instance recovery, but so what? If you are truly concerned about that, do a checkpoint before you do the shutdown abort (assuming that does not take forever). In what cases will a shutdown require media recovery? I know of none unless you are planning on rm'ing a bunch of datafiles afterwards.

One of the beauties of Oracle, and a fact that seems little known, is the rule with regards to checkpoints and redo logs. Everyone knows that a redo log can not be reused in ARCHIVELOG mode until the archived redo log is created. What seems less known is the rule that an online redo log can not be reused until all dirty blocks associated with that online redo log have been checkpointed and written to the datafiles. Thus, shutdown abort should NEVER lead to a media recovery.

I will say, as a point of caution, that back in the 7.x days, there was a bug that I discovered that would cause you to have to do media recovery after a shutdown abort. So if you are running 7.x then be careful about a shutdown abort.

RF

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