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commit    26a9d8ea643520856ca558b926970e70fcbbf6dc
Author:   Michael Paquier <michael@paquier.xyz>
Date:     Wed Aug 19 02:32:52 2026 +0000
First released in: 14.25, 15.20, 16.16, 17.12, 18.7

    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


 src/backend/replication/logical/reorderbuffer.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/backend/replication/logical/reorderbuffer.c b/src/backend/replication/logical/reorderbuffer.c
index b56febd24e4..149a1c0d0f0 100644
--- a/src/backend/replication/logical/reorderbuffer.c
+++ b/src/backend/replication/logical/reorderbuffer.c
@@ -2409,7 +2409,10 @@ ReorderBufferProcessTXN(ReorderBuffer *rb, ReorderBufferTXN *txn,
 								elog(ERROR, "could not open relation with OID %u", relid);
 
 							if (!RelationIsLogicallyLogged(rel))
+							{
+								RelationClose(rel);
 								continue;
+							}
 
 							relations[nrelations++] = rel;
 						}


[parent: 7f92983dcd76]