>From: pgsql-general-owner@xxxxxxxxxxxxxx [mailto:pgsql-general-owner@xxxxxxxxxxxxxx] On Behalf Of Klaus P. >Sent: Mittwoch, 4. Mai 2016 10:28 >To: pgsql-general@xxxxxxxxxxxxxx >Subject: Do parallel queries work with only dblink not with fdw? > >In order to improve cpu and disk utilization, I am testing parallel queries. > >The approach with dblink_send_query() and dblink_get_result() works in my proof-of-concept. Runtime of my reference query was reduced from 55 seconds to ~20seconds using 4 parallel connections. Not what I had hoped but certainly a significant improvement. >My approach is fairly easy: >db_link_send_query('conn1', 'statement based on partitioning field'); >db_link_send_query('conn2', 'statement based on partitioning field'); > >... >SELECT >dblink_get_result('conn1') >UNION ALL >dblink_get_result('conn2') > >... Hello, I'm using the db_link approach too, but rather than using dblink_get_result, I store the result in an additional table. This was faster, at least for my use case and at the time when I implemented that solution... something like db_link_send_query('conn0', 'CREATE UNLOGGED TABLE my_result... db_link_send_query('conn1', 'INSERT INTO my_result statement based on partitioning field'); db_link_send_query('conn2', 'INSERT INTO my_result statement based on partitioning field'); ... select * from my_result regards, Marc Mamin -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
