From: Laurenz Albe <laurenz.albe@cybertec.at>
To: evgeny.v.smirnov@gmail.com
To: pgsql-docs@lists.postgresql.org
Subject: Re: It would be nice to clarify is there any point in select queries pipelining
Date: Thu, 25 Jan 2024 15:45:13 +0100
Message-ID: <9cc1005603f3d4fc8d676de77d05f1993af05848.camel@cybertec.at> (raw)
In-Reply-To: <170615801656.662.17755050278063339844@wrigleys.postgresql.org>
References: <170615801656.662.17755050278063339844@wrigleys.postgresql.org>
On Thu, 2024-01-25 at 04:46 +0000, PG Doc comments form wrote:
> The following documentation comment has been logged on the website:
>
> Page: https://www.postgresql.org/docs/16/protocol-flow.html
>
> Please consider the following exchange with a PG database (Kotlin + Reactor+
> r2dbc-postgresql):
>
> [trace of a pipelined message flow]
>
> The application code is the following (for the sake of clarity):
>
> [some Java code]
>
> I’m aware that Postgres doesn’t support cursor(portal) multiplexing so its
> impossible to fetch data for two selects simultaneously but should I make
> use of selects pipelining when I want to make the most of the DB? I mean to
> say does a single Postgres backend employs concurrent processing and its
> possible for a DB to transmit results for a query #2 (see the traffic) and
> concurrently parse/rewrite/plan/optimize the subsequent (pipelined) queries
> (issued from the same transaction). Neither chapter 55 nor 52 expand on it
> (or it’s hard to spot at least).
No, PostgreSQL is single-threaded (with the exception of parallel query execution).
Yours,
Laurenz Albe
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To: pgsql-docs@postgresql.org
Cc: laurenz.albe@cybertec.at, evgeny.v.smirnov@gmail.com, pgsql-docs@lists.postgresql.org
Subject: Re: It would be nice to clarify is there any point in select queries pipelining
In-Reply-To: <9cc1005603f3d4fc8d676de77d05f1993af05848.camel@cybertec.at>
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