On Wed, Dec 4, 2013 at 11:49 PM, Metin Doslu <metin@xxxxxxxxxxxxx> 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 -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance