Re: Bind Variable - Query slow

Hi Greg
Oracle's behaviour seems a bit strange. Contrary to metalink entry
method_opt 254 buckets does get decent response though not the best.
We have more issues to iron out. But at least we seem to have hold of
one issue :-(

On Fri, Mar 23, 2012 at 9:33 AM, Greg Rahn <greg@xxxxxxxxxxxxxxxxxx> wrote:

> Does the column referenced by the bind variable have a histogram on it?
>  If so, is the value a popular one or not? Have you experimented w/o a
> histogram?
>
> I would troubleshoot the root cause, but one option is to use a SQL plan
> baseline to give the plan from the literal version to the bind version.
>
> https://blogs.oracle.com/optimizer/entry/how_do_i_deal_with_a_third_party_application_that_has_embedded_hints_that_result_in_a_sub-optimal_ex
>
>
> On Thu, Mar 22, 2012 at 10:53 PM, GovindanK <gkatteri@xxxxxxxxx> wrote:
>
>> Linux RAC ,11.1.0.7
>> Query runs fast with hard coding / SQL*Plus '&' ; But when run through the
>> application using bind variables , the plan is different and it goes for
>> MERGE CARTESIAN JOIN. Metalink , google , underscore parameters are not of
>> much help. Tried different bucket sizes with statistics ; Tried rewriting
>> the query; Marginal improvement ; If you hard code or with SQL*Plus '&'
>> the
>> query runs in 1 second .. but with bind variable it takes anywhere from 3
>> to 10 minutes depending on the input values.
>> With hard code , it does not do MCJ but plan is different for few tables.
>>  I don't say the query is written the best way.
>>
>>
> --
> Regards,
> Greg Rahn  |  blog <http://bit.ly/u9N0i8>  |  twitter<http://bit.ly/v733dJ>  |
>  linkedin <http://linkd.in/gregrahn>
>


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