Re: parallel-processing multiple similar query tasks - any example? - Mailing list pgsql-general

From Shaozhong SHI
Subject Re: parallel-processing multiple similar query tasks - any example?
Date
Msg-id CA+i5JwamNV4Wi0yOBpSTFW+X3KEt9LdC+qusu6brVoQUG7B0Xg@mail.gmail.com
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In response to Re: parallel-processing multiple similar query tasks - any example?  (Alvaro Herrera <alvherre@alvh.no-ip.org>)
Responses Re: parallel-processing multiple similar query tasks - any example?  (Alvaro Herrera <alvherre@alvh.no-ip.org>)
List pgsql-general
No, No.

Why sleep(1)?

It should be all active - doing work concurrently.

Regards,

David

On Thu, 28 Apr 2022 at 16:17, Alvaro Herrera <alvherre@alvh.no-ip.org> wrote:
On 2022-Apr-28, Shaozhong SHI wrote:

> multiple similar query tasks are as follows:
>
> select * from a_table where country ='UK'
> select * from a_table where country='France'
> and so on
>
> How best to parallel-processing such types of multiple similar query tasks?
>
> Any example available?

for country in UK France Germany Ireland; do
  echo "select pg_sleep(1); select * from a_table where country = '${country//\'/''/}'"
done | \
  xargs -d"\n" -P10 -n1 psql -X -c

Note the ${country/} stuff is a bash-ism.

--
Álvaro Herrera

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