Re: Automatic startup of pluggable databases - why not the default?

From: Andrew Kerber <andrew.kerber_at_gmail.com>
Date: Fri, 28 Aug 2015 07:25:04 -0500
Message-Id: <A237F65B-AE74-486E-B9B5-5EAF66AAE178_at_gmail.com>



See section 1.18.
http://docs.oracle.com/database/121/NEWFT/chapter12102.htm#NEWFT514 Sent from my iPad
> On Aug 27, 2015, at 10:42 PM, Ethan Post <post.ethan_at_gmail.com> wrote:
> 
> Why wouldn't it simply restart anything that was running prior to crash or shutdown and leave anything that was not running alone?
> 

>> On Mon, Jul 27, 2015 at 5:41 AM, Mark W. Farnham <mwf_at_rsiz.com> wrote:
>> +42 to Jared’s notion that there should be a proper startup control mechanism with fine grained control.
>>
>>
>>
>> Further notions (risking the creation of a design by committee camel when we’re looking for a horse):
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>>
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>> 1) A full table describing things like workshift definitions. (Hey, the container got restarted, what is supposed to be open NOW.)
>>
>> 2) Order of start
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>> 3) Alert instruction mechanism if unable to start, possibly unable to start within delta time
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>> 4) IF it requires recovery beyond instance recovery from the online redo, do you want to proceed automatically?
>>
>> 5) …
>>
>>
>>
>> Probably want to make it easy to instantiate and edit and external table version of the control table, which, in addition to Jared’s suggestion of a command option to start nothing, could be used to observe and alter the start based on an external table instead of the routine one. (I think of this as analogous to pfile versus system parameters). After all, it would be when you’re having trouble or wanting to start up selectively that this would be most in need, so you’d want to be able to toggle things without first doing a startup, right?
>>
>>
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>> Probably there is a child table with services per database and workshifts, order of start, and alerting rules as well.
>>
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>> I’m uncertain how this should dovetail with the Pete Sharman’s product. Clearly it needs to work for an individual container as well as being referenced in a natural way from EM.
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>>
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>> Figuring out the best balance between having all the useful features and having this be simple, like a NEST thermostat, will be the tricky part.
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>>
>> mwf
>>
>>
>>
>> From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Jared Still
>> Sent: Friday, July 24, 2015 12:24 PM
>> To: John Hallas
>> Cc: Brent Day; oracle-l_at_freelists.org
>> Subject: Re: Automatic startup of pluggable databases - why not the default?
>>
>>
>>
>>
>>
>> On Fri, Jul 24, 2015 at 7:17 AM, John Hallas <John.Hallas_at_morrisonsplc.co.uk> wrote:
>>
>> Yes I agree Brent that is the workaround that the changes in 12.1.0.2 were meant to address. I am interested in understanding why it was not seen as reasonable to start the pdb databases up after a container restart
>>
>>
>> I can see why it would not be reasonable to start all PDB's at startup.
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>>
>>
>> - there may be hundreds of them; you don't want to start these all at once.
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>> - of those hundreds, possibly a fraction of them are used regularly and should be started.
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>>
>>
>> What I don't understand is the lack of a proper method for dealing this this.
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>>
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>> Neither the trigger nor the save state seem good options to me.
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>> Why not a pdb control table with a START_MODE column?
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>>
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>> Possible values
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>> - NEVER: Never open the pdb at startup
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>> - ALWAYS: Always start this pdb.
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>> - ON_DEMAND: Start this pdb when someone tries to connect to it.
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>>
>>
>> And then some mechanism to override this.
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>>
>>
>> 'startup open cdb nomount nopdb' for instance.
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>>
>>
>>
>>
>> Jared Still
>> Certifiable Oracle DBA and Part Time Perl Evangelist
>>
>> Principal Consultant at Pythian
>>
>> Pythian Blog http://www.pythian.com/blog/author/still/
>> Oracle Blog: http://jkstill.blogspot.com
>> Home Page: http://jaredstill.com
>>

>
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Received on Fri Aug 28 2015 - 14:25:04 CEST

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