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Re: Oracle Parallel Query

From: Jonathan Lewis <jonathan_at_jlcomp.demon.co.uk>
Date: Fri, 29 Dec 2006 16:03:03 -0000
Message-ID: <ifqdnTLZnbaEoQjYRVnyswA@bt.com>


"Oradba Linux" <oradba_linux_at_verizon.net> wrote in message news:K1alh.11$SQ1.5_at_trnddc03...
> Is there a way to determine how oracle splits the Query? I have looked at
> v$pq_tqstat after executing the query. It shows me information on
> consumers,producers and how many each consumers processed. The question
> that i have is, i have a function as a column in the select list and want
> to know if the filter is happening for every row using the PQ slaves. I
> want to make sure if this is happening because of performance.
> I dont want all rows returned to QC and filter happens there which means
> the QC executes the function for all the rows.
>
> 9206
> 4 node RAC
> RHLinux 2.4.21
>
>
>
>

9.2.0.6

explain plan for ...

select * from table(dbms_xplan.display)

Check the "predicates" section of the report to see what filters are happening where.

However if you have a function-call in the select list then that's not a filter. In 9.2.0.6 the SQL being executed by the slaves is available in the 'other' column of the plan_table, which you can see through:

select * from table(dbms_xplan.display(null,null,'ALL'));

-- 
Regards

Jonathan Lewis
http://jonathanlewis.wordpress.com

Author: Cost Based Oracle: Fundamentals
http://www.jlcomp.demon.co.uk/cbo_book/ind_book.html

The Co-operative Oracle Users' FAQ
http://www.jlcomp.demon.co.uk/faq/ind_faq.html
Received on Fri Dec 29 2006 - 10:03:03 CST

Original text of this message

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