Re: OPTIMIZER_DYNAMIC_SAMPLING Level 11

thank you for the additions. I saw some result cache answers for the DS_SVC queries - but did not expect the mentioned "statistics repository" to be just a cache layer.

Good to hear that you are writing a paper covering the topic: I am sure it will answer lots of questions.

Regards

Martin

Am 12.12.2014 um 09:41 schrieb Christian Antognini:
> Hi Martin
>
>> is there an interface to check the persisted information?
> ADS doesn't store information into the DD. It only caches the result of the DS to save time during the next parses. For that purpose the optimizer uses two caches: 1) the result cache 2) another internal cache that, AFAIK, is not externalized.
>
>> My impression is that the documentation is not very verbose in describing the
>> details - so I hope that you can shed some light on the affair.
> As soon as the paper I'm writing for the next Hotsos Symposium (see http://www.hotsos.com/sym15/sym_speaker_antognini.html for the abstract of the presentation) will be available, I hope that it will answer lot of questions that aren't covered from the official documentation.
>
>
> HTH
> Chris Antognini
>
> Troubleshooting Oracle Performance, Apress 2008/2014
> http://top.antognini.ch
>
>

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