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Home -> Community -> Mailing Lists -> Oracle-L -> Re: How to make query avoid using histograms
we found that this query takes slightly different execution paths based no
input parameters (most number), turning off bind variable peeking and
changing cs=exact didn't help. That's why I wanted to find out what would
happen, if somehow I could turn off usage of histograms for this query.
Christian, RULE hint didn't help either.
Raj
On 4/27/05, Niall Litchfield <niall.litchfield_at_gmail.com> wrote:
>
> On 4/26/05, Lex de Haan <lex.de.haan_at_naturaljoin.nl> wrote:
> > you can't -- if histograms are available, they will be used.
> > of course, you can use various hints and/or session settings
> > to influence the optimizer.
> > just out of curiosity: why would you, in the presence of histograms,
> > ever want to tell the optimizer *not* to use them?
>
> Because you issue a report with bind variables that for 99% of its
> executions *should* use histograms, but for 1% of them - the report to
> the board say, shouldn't use the execution path generated with
> histograms, and bind variable peeking isn't in operation. I don't
> think this applies to 9204 though.
>
> --
> Niall Litchfield
> Oracle DBA
> http://www.niall.litchfield.dial.pipex.com
>
-- ------------------------------ select standard_disclaimer from company_requirements where category = 'MANDATORY'; -- http://www.freelists.org/webpage/oracle-lReceived on Wed Apr 27 2005 - 07:31:45 CDT
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