Horton

RE: ReplicationSlotRelease() crashes when the instance is in the single user mode

Hayato Kuroda (Fujitsu) <kuroda.hayato@fujitsu.com>

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From: "Hayato Kuroda (Fujitsu)" <kuroda.hayato@fujitsu.com>
To: 'Robert Haas' <robertmhaas@gmail.com>
Cc: Paul A Jungwirth <pj@illuminatedcomputing.com>, Mutaamba Maasha <maasha@gmail.com>, Amit Kapila <amit.kapila16@gmail.com>, Michael Paquier <michael@paquier.xyz>, "David G. Johnston" <david.g.johnston@gmail.com>, "Zhijie Hou (Fujitsu)" <houzj.fnst@fujitsu.com>, Tom Lane <tgl@sss.pgh.pa.us>, Bertrand Drouvot <bertranddrouvot.pg@gmail.com>, "pgsql-hackers@lists.postgresql.org" <pgsql-hackers@lists.postgresql.org>
Date: 2025-08-18T08:53:05Z
Lists: pgsql-hackers 
Dear Robert,

> The use case for single-user mode is quite limited in general, but
> most things work in single-user mode unless they are something that
> intrinsically can't. For example, parallel query cannot be used in
> single-user mode, because there is only one process. Replication
> cannot work, for the same reason. But manual slot operations can work,
> so I do not think it is good to arbitrarily prohibit them. We do not
> need a reason to specifically allow them; it is enough that there is
> no good reason for them to be blocked.

Thanks for the confirmation. Till now, it is mostly fifty-fifty in the community
whether we should allow the manipulation in the single-user mode.

I did split a patch to fix the initial issue [1]. Let's focus on the 0001 patch
firstly.

[1]: https://www.postgresql.org/message-id/OSCPR01MB14966B39B3ED21229EAEFA10FF531A%40OSCPR01MB14966.jpnprd01.prod.outlook.com

Best regards,
Hayato Kuroda
FUJITSU LIMITED

Commits

  1. Fix assertion failure with replication slot release in single-user mode