Re: Why does a hard parse access data in the table in the query?

Hello Norman,
any chance that PX is involved or at least costed?

I am talking about behavior described in MOS ID #1102413.1

Best Regards
Stefan Koehler

Independent Oracle performance consultant and researcher Website: http://www.soocs.de
Twitter: _at_OracleSK

> Norman Dunbar <oracle_at_dunbar-it.co.uk> hat am 7. Februar 2019 um 15:06 geschrieben:
>
>
> On 07/02/2019 10:19, Norman Dunbar wrote:
> > I get the feeling I should know this, but it seems to have aged out of
> > the cache!
>
> Thanks to everyone who said "dynamic sampling" because that's what it
> appears to be. I haven't traced it yet, but:
>
> * It was a hard parse;
> * Optimizer_dynamic_Sampling = 2 (the default)
>
> Unfortunately, the stats on this database are gathered very frequently.
> So the default says to "gather dynamically when one or more of the
> tables has no stats" means that I shouldn't be seeing dynamic sampling.
>
> Maybe, because stats go stale pretty quickly on some tables, it's taking
> "stale" to mean "none"? I wonder.
>
> Anyway, thanks again, you have been most helpful and hopefully, this
> won't age out of cache too soon! :o)
>
> Cheers,
> Norm.

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