Re: Fwd: increasing parallel_max_servers.

John,

Thanks for your response

I see that the total number of the parallel slave processes on my DB consistently equal to the current value
of my parallel_max_servers parameter AND I see a number of sessions running in sequential mode while
they could benefit from the parallel execution. I also see that the degree of parallelism on the parallel queries
often times is less than the requested degree of parallelism. All of that tells me that there is a need for more
parallel processes.

I'll take a look at the article you mentioned.

thank you

Gene Gurevich

                                                                           
             "John Kanagaraj"                                              
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Gene,

What makes you think that your current value of parallel_max_servers is not enough or that it is fully utilized so you need more? I ask because long ago, I had to step into a situation where an "expert" recommended setting this value to a large one in a 2 CPU box (albeit on 7.x) to "increase the performance" and that killed the CPUs :) Not sure how many CPUs you have on your system, but these days you rarely see anything more than a 32 CPU box.

You might want to take a look at an excellent article on Tuning Parallel Execution by Doug Burns in the Q3 2005 issue of IOUG's SELECT Journal before you finalize this.

--

John Kanagaraj <><
DB Soft Inc
http://jkanagaraj.wordpress.com (Sorry - not an Oracle blog!) ** The opinions and facts contained in this message are entirely mine and do not reflect those of my employer or customers **

On 8/24/07, genegurevich_at_discover.com <genegurevich_at_discover.com > wrote:

  Hello:

  I am planning to increase the parallel_max_servers from its current value

  (32) to either 64 or 128.
  I am trying to figure out if I need to increase shared_pool or large_pool   to avoid running out of memory.
  Right now my shared_pool is 464M the reserved_shared_pool is 23M,   large_pool is 112M.

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John Kanagaraj <><
DB Soft Inc
http://jkanagaraj.wordpress.com (Sorry - not an Oracle blog!) ** The opinions and facts contained in this message are entirely mine and do not reflect those of my employer or customers **

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http://www.freelists.org/webpage/oracle-l Received on Mon Aug 27 2007 - 07:01:06 CDT