Have you tried:CREATE TABLE blah AS SELECT ... ?
Sent via the Samsung Galaxy S® 6, an AT&T 4G LTE smartphone -------- Original message --------From: James Sewell <james.sew...@jirotech.com> Date: 11/13/16 18:04 (GMT-05:00) To: pgsql-general <pgsql-general@postgresql.org> Subject: [GENERAL] Sequential parallel scan / agg Hi all, I have a customer who is making use of the new parallel features on a 64 core box - this is working really well for them. However one issue (which I've since realised I've never seen an example of) is getting the data from these queries into a table. I can't seem to create a plan which does this and still uses multiple workers, probably best to just show by example. Below you can see:INSERT ... SELECT doesn't workWITH a AS (SELECT ...) INSERT FROM a doesn't workSELECT .. INTO doesn't workSELECT with no insert does work as expected test=# explaininsert into jirotech.test(select count(*) FROM meter_read mr where TIMESTAMP_ROUNDED >= (timestamp'2016-03-30 00:00:00' - interval '2' day) and TIMESTAMP_ROUNDED < timestamp'2016-03-30 00:00:00' ); QUERY PLAN -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Insert on test (cost=13336866.41..13336866.44 rows=1 width=438) -> Subquery Scan on "*SELECT*" (cost=13336866.41..13336866.44 rows=1 width=438) -> Aggregate (cost=13336866.41..13336866.42 rows=1 width=8) -> Append (cost=0.00..12405302.12 rows=372625715 width=0) -> Seq Scan on meter_read mr (cost=0.00..0.00 rows=1 width=0) Filter: ((timestamp_rounded >= '2016-03-28 00:00:00'::timestamp without time zone) AND (timestamp_rounded < '2016-03-30 00:00:00'::timestamp without time zone)) -> Seq Scan on meter_read_2016_03_29 mr_1 (cost=0.00..6201295.24 rows=186240748 width=0) Filter: ((timestamp_rounded >= '2016-03-28 00:00:00'::timestamp without time zone) AND (timestamp_rounded < '2016-03-30 00:00:00'::timestamp without time zone)) -> Seq Scan on meter_read_2016_03_28 mr_2 (cost=0.00..6204006.88 rows=186384966 width=0) Filter: ((timestamp_rounded >= '2016-03-28 00:00:00'::timestamp without time zone) AND (timestamp_rounded < '2016-03-30 00:00:00'::timestamp without time zone))(10 rows) test=# explainwith a as(select count(*) FROM meter_read mr where TIMESTAMP_ROUNDED >= (timestamp'2016-03-30 00:00:00' - interval '2' day) and TIMESTAMP_ROUNDED < timestamp'2016-03-30 00:00:00' )INSERT INTO jirotech.test SELECT * FROM A; QUERY PLAN ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Insert on test (cost=13336866.42..13336866.45 rows=1 width=438) CTE a -> Aggregate (cost=13336866.41..13336866.42 rows=1 width=8) -> Append (cost=0.00..12405302.12 rows=372625715 width=0) -> Seq Scan on meter_read mr (cost=0.00..0.00 rows=1 width=0) Filter: ((timestamp_rounded >= '2016-03-28 00:00:00'::timestamp without time zone) AND (timestamp_rounded < '2016-03-30 00:00:00'::timestamp without time zone)) -> Seq Scan on meter_read_2016_03_29 mr_1 (cost=0.00..6201295.24 rows=186240748 width=0) Filter: ((timestamp_rounded >= '2016-03-28 00:00:00'::timestamp without time zone) AND (timestamp_rounded < '2016-03-30 00:00:00'::timestamp without time zone)) -> Seq Scan on meter_read_2016_03_28 mr_2 (cost=0.00..6204006.88 rows=186384966 width=0) Filter: ((timestamp_rounded >= '2016-03-28 00:00:00'::timestamp without time zone) AND (timestamp_rounded < '2016-03-30 00:00:00'::timestamp without time zone)) -> CTE Scan on a (cost=0.00..0.03 rows=1 width=438)(11 rows) test=# explainselect count(*) into jirotech.jamestest FROM meter_read mr where TIMESTAMP_ROUNDED >= (timestamp'2016-03-30 00:00:00' - interval '2' day) and TIMESTAMP_ROUNDED < timestamp'2016-03-30 00:00:00'; QUERY PLAN -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Aggregate (cost=13336866.41..13336866.42 rows=1 width=8) -> Append (cost=0.00..12405302.12 rows=372625715 width=0) -> Seq Scan on meter_read mr (cost=0.00..0.00 rows=1 width=0) Filter: ((timestamp_rounded >= '2016-03-28 00:00:00'::timestamp without time zone) AND (timestamp_rounded < '2016-03-30 00:00:00'::timestamp without time zone)) -> Seq Scan on meter_read_2016_03_29 mr_1 (cost=0.00..6201295.24 rows=186240748 width=0) Filter: ((timestamp_rounded >= '2016-03-28 00:00:00'::timestamp without time zone) AND (timestamp_rounded < '2016-03-30 00:00:00'::timestamp without time zone)) -> Seq Scan on meter_read_2016_03_28 mr_2 (cost=0.00..6204006.88 rows=186384966 width=0) Filter: ((timestamp_rounded >= '2016-03-28 00:00:00'::timestamp without time zone) AND (timestamp_rounded < '2016-03-30 00:00:00'::timestamp without time zone))(8 rows) Time: 29.229 ms test=# explain select count(*) FROM meter_read mr where TIMESTAMP_ROUNDED >= (timestamp'2016-03-30 00:00:00' - interval '2' day) and TIMESTAMP_ROUNDED < timestamp'2016-03-30 00:00:00'; QUERY PLAN -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Finalize Aggregate (cost=7631566.71..7631566.72 rows=1 width=8) -> Gather (cost=7631566.68..7631566.69 rows=8 width=8) Workers Planned: 8 -> Partial Aggregate (cost=7630566.68..7630566.69 rows=1 width=8) -> Append (cost=0.00..7514121.14 rows=46578216 width=0) -> Parallel Seq Scan on meter_read mr (cost=0.00..0.00 rows=1 width=0) Filter: ((timestamp_rounded >= '2016-03-28 00:00:00'::timestamp without time zone) AND (timestamp_rounded < '2016-03-30 00:00:00'::timestamp without time zone)) -> Parallel Seq Scan on meter_read_2016_03_29 mr_1 (cost=0.00..3756417.28 rows=23280094 width=0) Filter: ((timestamp_rounded >= '2016-03-28 00:00:00'::timestamp without time zone) AND (timestamp_rounded < '2016-03-30 00:00:00'::timestamp without time zone)) -> Parallel Seq Scan on meter_read_2016_03_28 mr_2 (cost=0.00..3757703.86 rows=23298121 width=0) Filter: ((timestamp_rounded >= '2016-03-28 00:00:00'::timestamp without time zone) AND (timestamp_rounded < '2016-03-30 00:00:00'::timestamp without time zone))(11 rows) Time: 29.819 ms Cheers, James Sewell, PostgreSQL Team Lead / Solutions Architect Suite 112, Jones Bay Wharf, 26-32 Pirrama Road, Pyrmont NSW 2009 P (+61) 2 8099 9000 W www.jirotech.com F (+61) 2 8099 9099 The contents of this email are confidential and may be subject to legal or professional privilege and copyright. 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