Re: Deterioration in performance when query executed in multi threads

От: ktm@rice.edu
Тема: Re: Deterioration in performance when query executed in multi threads
Дата: ,
Msg-id: 20130501141236.GG27807@aart.rice.edu
(см: обсуждение, исходный текст)
Ответ на: Deterioration in performance when query executed in multi threads  (Anne Rosset)
Ответы: Re: Deterioration in performance when query executed in multi threads  (Anne Rosset)
Список: pgsql-performance

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Deterioration in performance when query executed in multi threads  (Anne Rosset, )
 Re: Deterioration in performance when query executed in multi threads  ("", )
  Re: Deterioration in performance when query executed in multi threads  (Anne Rosset, )
   Re: Deterioration in performance when query executed in multi threads  ("", )
    Re: Deterioration in performance when query executed in multi threads  (Scott Marlowe, )
    Re: Deterioration in performance when query executed in multi threads  (Anne Rosset, )
     Re: Deterioration in performance when query executed in multi threads  (Igor Neyman, )
      Re: Deterioration in performance when query executed in multi threads  (Anne Rosset, )
       Re: Deterioration in performance when query executed in multi threads  (Igor Neyman, )
        Re: Deterioration in performance when query executed in multi threads  (Anne Rosset, )
         Re: Deterioration in performance when query executed in multi threads  (Thomas Kellerer, )
          Re: Deterioration in performance when query executed in multi threads  (Igor Neyman, )
          Re: Deterioration in performance when query executed in multi threads  (Anne Rosset, )
           Re: Deterioration in performance when query executed in multi threads  (Gavin Flower, )
         Re: Deterioration in performance when query executed in multi threads  (Igor Neyman, )
          Re: Deterioration in performance when query executed in multi threads  (Anne Rosset, )
           Re: Deterioration in performance when query executed in multi threads  (Igor Neyman, )
            Re: Deterioration in performance when query executed in multi threads  (Anne Rosset, )
       Re: Deterioration in performance when query executed in multi threads  (Merlin Moncure, )

On Wed, May 01, 2013 at 02:05:06PM +0000, Anne Rosset wrote:
> Hi all,
> We are running a stress test that executes one select query with multiple threads.
> The query executes very fast (10ms). It returns 100 rows.  I see deterioration in the performance when we have
multiplethreads executing the query. With 100 threads, the query takes between 3s and 8s. 
>
> I suppose there is a way to tune our database. What are the parameters I should look into? (shared_buffer?,
wal_buffer?)
>
> Thanks for your help,
> Anne

Try a connection pooler like pgbouncer to keep the number of simultaneous queries
bounded to a reasonable number. You will actually get better performance.

Regards,
Ken



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