Re: Searching MOS Note on dynamic sampling

From: Mladen Gogala <gogala.mladen_at_gmail.com>
Date: Tue, 3 Mar 2020 08:53:29 -0500
Message-ID: <f7752dcc-28ec-00fb-2082-a7c9c563ed21_at_gmail.com>



Hi Lothar!

That is one of my pet peeves with Oracle Support: they have stopped publishing technical details long time ago. Allegedly, you can get those if you decide to become a certifiable Oracle master, which I do not want to do.

Regards

On 3/3/20 8:20 AM, l.flatz_at_bluewin.ch wrote:
> Hi Mladen,
>
> thanks, I know what dynamic sampling is.
> I had deep level questions on how it works internally.
> You will find the questions below.
>
> Thanks and Reagrds
>
> Lothar
>
> ----Urspr├╝ngliche Nachricht----
> Von : gogala.mladen_at_gmail.com
> Datum : 01/03/2020 - 02:12 (MN)
> An : oracle-l_at_freelists.org
> Betreff : Re: Searching MOS Note on dynamic sampling
>
> Hi Lothar!
>
> This is not a MOS note but Nigel Baylis's blog:
>
> https://blogs.oracle.com/optimizer/dynamic-sampling-and-its-impact-on-the-optimizer
>
> There is also an old Oracle Magazine Article by The Oracle Master
> (Tom for short) Kyte:
>
> https://blogs.oracle.com/oraclemagazine/on-dynamic-sampling
>
> This is one of the very few articles by Tom Kyte that have
> survived his retirement.
>
> Regards
>
>
>
>
> On 2/28/20 3:22 AM, Lothar Flatz wrote:
>> Hi Guys,
>>
>> I colleague of mine told me that he read a MOS Note that was
>> describing the details of the way dynamic sampling is done.
>> The note was mentioning that only bitmap blocks  are sampled and
>> blocks less than 25% full are considered empty.
>> In that same note also deferred segment creation is mentioned.
>> As my colleague is very experienced I believe is memory is correct.
>> However, we cannot find that note any more.
>>
>>
>> Can somebody point us to the doc?
>>
>> Regards and thank
>>
>> Lothar
>>
>>
>> --
>>
>>
>>
>>
> --
> Mladen Gogala
> Database Consultant
> Tel: (347) 321-1217
>
>
>

-- 
Mladen Gogala
Database Consultant
Tel: (347) 321-1217


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Received on Tue Mar 03 2020 - 14:53:29 CET

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