>From: pgsql-general-ow...@postgresql.org 
>[mailto:pgsql-general-ow...@postgresql.org] On Behalf Of Klaus P.
>Sent: Mittwoch, 4. Mai 2016 10:28
>To: pgsql-general@postgresql.org
>Subject: [GENERAL] 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

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