Re: Shutdown problem

Following this thread, many people seem to complain of "hanging" when using shutdown immediate. What you must all realize is with a shutdown immediate, any transaction currently active in the database will be terminated and its work will be ROLLED BACK. This means if a transaction has been updating constantly for 30 minutes without performing a commit, it is going to take approximately 30 minutes to rollback the changes. If a shutdown abort is done, the database comes down immediately (to the delight of many a dba), but the difference is the rollback is deferred until the next startup.

Pre-7.3, that meant the startup could take about 30 minutes in the above mentioned scenario. With 7.3 and beyond, there is a feature enabled by default called deferred transaction rollback, where either the first transaction to touch a block after startup (or smon when it is posted) will rollback any non-active uncommited transactions left in the transaction list in the block. This may slow down some transactions after startup. To see if this is happening, select status from dba_rollback_segs, any status of "PARTIAL ONLINE" (I think, I know PARTIAL is part of it), tells you some cleanup is going on. SMON will not clean all of the blocks up at once, it will do a predetermined amount (20-50), finish those, and then do another set the next time it posts.

HTH, Frank

On Tue, 23 Jun 1998 05:26:36 GMT, shreterh_at_my-dejanews.com wrote:

>Confession: I'm doing the same thing as the original author (shutdown abort /
>startup / shutdown). I changed it one day to "immediate" and was immediately
>rewarded with a hung backup and angry sys admin/helpline.
>
>Is there an alternative? Look for running processes against Oracle
>(LOCAL=NO; LOCAL=YES) and kill them, letting Oracle groom itself afterward?
>What can we do between ABORT and IMMEDIATE that gets the job done?
>
>Appreciate in advance any suggestions. - Hilary Shreter.
>
>In article <6mlq97$h93$1_at_hdxf08.telecom.ptt.nl>,
> Alfons Riesebeek <A.Riesebeek_at_wxs.nl> wrote:
>>
>> You should do a shutdown immediate. In this way Oracle rolls back
>> actions of processes with are still running before killing them.
>>
>> In most cases this works fine. Never do a shutdown abort !!
>>
>> Regards,
>> Alfons Riesebeek
>>
>> Gilberto Casiraghi <edipi_at_candy.it> schrijfbewerkingen: > Hello all !
>...
>> > shutdown hanging (it seems incredible but it's true).
>> > To avoid this situation I change the shutdown script in this way:
>> > alter system checkpoint
>> > shutdown abort
>> > startup
>> > shutdown
>> > So the db will be ALWAYS closed and with the checkpoint I don't
>> > lose any data (I hope!).
>> > What do you think about it ? Is there a better way ? (I want to be SURE
>> > the shutdown CLOSE the db, so the backup procedure can end rightly).
>> > Any suggestion it will be appreciated.
>> >
>> > Thanks in advanced.
>> > Gilberto Casiraghi.
>> >
>>
>>
>
>
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Received on Tue Jun 23 1998 - 07:01:54 CDT