Message-ID: <3f24365a-c440-47de-88cf-7ee7cd02c7dd@postgrespro.ru>
Date: Wed, 24 Jun 2026 10:26:14 +0700
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Subject: Re: Pgbench: remove synchronous prepare
To: Robert Haas <robertmhaas@gmail.com>
Cc: pgsql-hackers@lists.postgresql.org
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From: Dmitrii Bondar <d.bondar@postgrespro.ru>
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On 5/27/26 7:39 PM, Robert Haas wrote:
> On Tue, May 5, 2026 at 3:48 AM Dmitrii Bondar <d.bondar@postgrespro.ru> wrote:
> [ Catching up after pgconf.dev ]
>
> ... there should be a solution possible by
> using the non-blocking variant of the same function (which in this
> case is PQsendPrepare). If using that causes pgbench to die with some
> weird error, that seems like a sign that other parts of pgbench also
> need a bit of adjustment, rather than a sign that we need a new libpq
> entrypoint.
>
You are right that there is another solution, but it requires changes in other parts of pgbench. As I mentioned in my previous message, using PQsendPrepare is absolutely possible, but it would require changes to the pgbench state machine. In particular, a new state would be needed to wait asynchronously for the response to a Prepare message. The only reason I have not done that is that it would require rewriting code in several places, whereas adding a new libpq entry would mostly extend the code rather than modify the existing logic.