Re: Parallel Select query performance and shared buffers - Mailing list pgsql-hackers

From Amit Kapila
Subject Re: Parallel Select query performance and shared buffers
Date
Msg-id CAA4eK1+QTp3rcB_Mq7aWQ2wfBHstSRiUnK0Ouu6MbSX9W5OASA@mail.gmail.com
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In response to Re: Parallel Select query performance and shared buffers  (Metin Doslu <metin@citusdata.com>)
List pgsql-hackers
On Wed, Dec 4, 2013 at 11:49 PM, Metin Doslu <metin@citusdata.com> wrote:
> Here are some extra information:
>
> - When we increased NUM_BUFFER_PARTITIONS to 1024, this problem is
> disappeared for 8 core machines and come back with 16 core machines on
> Amazon EC2. Would it be related with PostgreSQL locking mechanism?

  I think here there is a good chance of improvement with the patch
suggested by Andres in this thread, but
  still i think it might not completely resolve the current problem as
there will be overhead of associating data
  with shared buffers.

  Currently NUM_BUFFER_PARTITIONS is fixed, so may be auto tuning it
based on some parameter's can
  help such situations.

With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com


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