Horton

RE: Re-read subscription state after lock in AlterSubscription

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

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From: "Hayato Kuroda (Fujitsu)" <kuroda.hayato@fujitsu.com>
To: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Cc: "pgsql-hackers@lists.postgresql.org" <pgsql-hackers@lists.postgresql.org>, 'Dilip Kumar' <dilipbalaut@gmail.com>
Date: 2026-07-02T12:48:53Z
Lists: pgsql-hackers 
Dear Bertrand,

Good catch. Current code allows that old `sub` value is retained, so it sounds
reasonable fix even for me.

BTW, the issue that GetSubscription() is called before the LockSharedObject() looks
the existing issues even on REL_13_STABLE. So does it mean that there were no
cases that concurrent altering can be the unexpected state? At least,
"retain_dead_tuples" can avoid the issue because the launcher manages the
conflict slot.

Best regards,
Hayato Kuroda
FUJITSU LIMITED