From: Michael Paquier <michael@paquier.xyz>
To: pgsql-committers@lists.postgresql.org
Subject: pgsql: Fix relcache reference leak when decoding TRUNCATE
Date: Wed, 19 Aug 2026 02:33:22 +0000
Message-ID: <E1wwW7F-0000000191b-2oyW@gemulon.postgresql.org> (raw)
Fix relcache reference leak when decoding TRUNCATE
ReorderBufferProcessTXN() opens every relation referenced by a
TRUNCATE change. When RelationIsLogicallyLogged() returns false,
it skips the relation without releasing the reference acquired
by RelationIdGetRelation().
Looking at the in-core code paths building XLOG_HEAP_TRUNCATE records,
no relation OIDs would be included if they do not satisfy
RelationIsLogicallyLogged(). One pattern that could go through is if a
table is switched to SET UNLOGGED, but that would not be reachable in
practice as the decoding happens after a historical snapshot is taken,
so the relation should still be valid.
This is a defense-in-depth measure in practice, and we tend to be
careful about how Relations are handled when sending changes to output
plugins, so backpatch all the way down.
Author: Chao Li <li.evan.chao@gmail.com>
Reviewed-by: Xuneng Zhou <xunengzhou@gmail.com>
Discussion: https://postgr.es/m/7DD65D03-3B5A-43B2-99AD-8E6AF5372BAB@gmail.com
Backpatch-through: 14
Branch
------
REL_18_STABLE
Details
-------
https://git.postgresql.org/pg/commitdiff/ecf2492b44545dd2cf0bf6411bf3bdbb6a5b5f22
Modified Files
--------------
src/backend/replication/logical/reorderbuffer.c | 3 +++
1 file changed, 3 insertions(+)
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To: pgsql-committers@postgresql.org
Cc: michael@paquier.xyz, pgsql-committers@lists.postgresql.org
Subject: Re: pgsql: Fix relcache reference leak when decoding TRUNCATE
In-Reply-To: <E1wwW7F-0000000191b-2oyW@gemulon.postgresql.org>
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