From: | Haribabu Kommi <kommi(dot)haribabu(at)gmail(dot)com> |
---|---|
To: | "Madusudanan(dot)B(dot)N" <b(dot)n(dot)madusudanan(at)gmail(dot)com> |
Cc: | "pgsql-hackers(at)postgresql(dot)org" <pgsql-hackers(at)postgresql(dot)org> |
Subject: | Re: Unable to test parallel aggregate/joins in Postgres beta 2 |
Date: | 2016-07-14 13:39:51 |
Message-ID: | CAJrrPGdF7+_jOf5nHRABh754p4TakdWEXbcygN3yx3qY2xGxtw@mail.gmail.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
On Thu, Jul 14, 2016 at 11:16 PM, Madusudanan.B.N
<b(dot)n(dot)madusudanan(at)gmail(dot)com> wrote:
>
> 3) Is there any kind of toggle to enable parallel aggregate/join feature ?
>
I am able to generate parallel plan, The parallel plan may be costly
in your query compared
to other scans, because of which it is not selecting the parallel plan.
It is possible that if the table size is very small or you are
selecting all records of the table
and etc.
postgres=# insert into test values(generate_series(1,1000000), 'Test');
INSERT 0 1000000
postgres=# explain select * from test where f1 < 9900;
QUERY PLAN
-----------------------------------------------------------------------------
Gather (cost=1000.00..23719.93 rows=188964 width=105)
Workers Planned: 2
-> Parallel Seq Scan on test (cost=0.00..22719.93 rows=78735 width=105)
Filter: (f1 < 9900)
(4 rows)
Regards,
Hari Babu
Fujitsu Australia
From | Date | Subject | |
---|---|---|---|
Next Message | Madusudanan.B.N | 2016-07-14 13:49:41 | Re: Unable to test parallel aggregate/joins in Postgres beta 2 |
Previous Message | Magnus Hagander | 2016-07-14 13:39:38 | Re: pg_xlogdump bad error msg? |