From: Tomas Vondra <tomas@vondra.me>
To: Tom Lane <tgl@sss.pgh.pa.us>
To: nageshdbaa@gmail.com
Cc: pgsql-bugs@lists.postgresql.org
Subject: Re: BUG #19105: Parallel Hash Join crash when work_mem is small
Date: Sun, 9 Nov 2025 18:49:13 +0100
Message-ID: <2bf93857-aedb-4968-aacc-2add30bea365@vondra.me> (raw)
In-Reply-To: <1649717.1762703245@sss.pgh.pa.us>
References: <19105-7516b55f7ed3a241@postgresql.org>
<1649717.1762703245@sss.pgh.pa.us>
On 11/9/25 16:47, Tom Lane wrote:
> PG Bug reporting form <noreply@postgresql.org> writes:
>> PostgreSQL version: 16.2
>
>> Server terminates with:
>
>> ERROR: could not attach to dynamic shared area
>> DETAIL: invalid dsa_handle
>
> I could not reproduce this problem with current sources
> (either master or v16 branch tip). 16.2 is pretty old,
> so maybe an update will fix it for you.
>
FWIW I couldn't reproduce it on 16.2 either, even after forcing it to
actually do parallel hash join (the posted instructions were not enough
to make that happen on my system).
Presumably there's some additional detail making it fail, but there are
too many options to guess. Maybe it's some kernel limit, something in
ubuntu 22.04, or something else.
It's interesting the report claims this happens only "when work_mem is
small". I wonder if that happens simply because the plan changes.
regards
--
Tomas Vondra
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-bugs@postgresql.org
Cc: tomas@vondra.me, tgl@sss.pgh.pa.us, nageshdbaa@gmail.com, pgsql-bugs@lists.postgresql.org
Subject: Re: BUG #19105: Parallel Hash Join crash when work_mem is small
In-Reply-To: <2bf93857-aedb-4968-aacc-2add30bea365@vondra.me>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox