Re: Impact of auto-adjustment of Dynamic Sampling : Note 1102413.1
Date: Fri, 26 Sep 2014 09:54:35 -0500
Message-ID: <CAEueRAUzdLdrT8uSJkrOZ=q-XKGPq7pDhOnmW_EjAqipmep3Hw_at_mail.gmail.com>
Instead of trying to figure out how to prevent dynamic sampling on your queries, I think it would be more advantageous to you to find out why dynamic sampling is being used at all.
You mentioned that statistics are current on the table but are you sure there are proper histograms in place? Perhaps you could post your findings.
Seth Miller
On Fri, Sep 26, 2014 at 3:44 AM, Chitale, Hemant K <Hemant-K.Chitale_at_sc.com> wrote:
> The auto-adjusted dynamic sampling “explained” in Support Note
> 1102413.1 seems to negatively impacting some of my Parallel DML
> operations. I do have updated statistics on the underlying table and yet
> Oracle is auto-adjusting the dynamic sampling (and reporting the higher
> level). This is happening for SQLs where I do NOT specify a dynamic
> sampling hint or session specification but leave the instance level
> unchanged at 2. Is there a method to disable this ?
>
> Hemant K Chitale
>
>
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-- http://www.freelists.org/webpage/oracle-lReceived on Fri Sep 26 2014 - 16:54:35 CEST