Subject: Re: Defer selection of asynchronous subplans until the executor
 initialization stage
To: Etsuro Fujita <etsuro.fujita@gmail.com>
Cc: Zhihong Yu <zyu@yugabyte.com>, Kyotaro Horiguchi
 <horikyota.ntt@gmail.com>, Justin Pryzby <pryzby@telsasoft.com>,
 PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
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From: "Andrey V. Lepikhov" <a.lepikhov@postgrespro.ru>
Organization: Postgres Professional
Message-ID: <8891e9b4-040f-6d71-fa63-3069046dfb3d@postgrespro.ru>
Date: Mon, 30 Aug 2021 13:36:38 +0500
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On 8/23/21 2:18 PM, Etsuro Fujita wrote:
> To just execute what was planned at execution time, I think we should
> return to the patch in [1].  The patch was created for Horiguchi-san’s
> async-execution patch, so I modified it to work with HEAD, and added a
> simplified version of your test cases.  Please find attached a patch.
> [1] https://www.postgresql.org/message-id/7fe10f95-ac6c-c81d-a9d3-227493eb9055@postgrespro.ru
I agree, this way is more safe. I tried to search for another approach, 
because here isn't general solution: for each plan node we should 
implement support of asynchronous behaviour.
But for practical use, for small set of nodes, it will work good. I 
haven't any objections for this patch.

-- 
regards,
Andrey Lepikhov
Postgres Professional