From: Peter Geoghegan <pg@bowt.ie>
Date: Thu, 16 Jul 2026 22:08:41 +0000 (-0400)
Subject: Use fake LSNs consistently in hash index AM.
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=048067c04c6c0c0862f0e00c4ebe158ac41bda19;p=thirdparty%2Fpostgresql.git

Use fake LSNs consistently in hash index AM.

Defensively make sure that all hash index atomic actions use a fake LSN
with an unlogged relation.

Oversight in commit e5836f7b, which added fake LSN support to the hash
index AM, but missed log_split_page.

Author: Peter Geoghegan <pg@bowt.ie>
Reviewed-by: Ewan Young <kdbase.hack@gmail.com>
Discussion: https://postgr.es/m/CAH2-WzkC-opX8iS6X=a470DDC31er_x5rzPw=HjRxha9N8brZw@mail.gmail.com
Backpatch-through: 19
---

diff --git a/src/backend/access/hash/hashpage.c b/src/backend/access/hash/hashpage.c
index 8099b0d021f..c50f9a48520 100644
--- a/src/backend/access/hash/hashpage.c
+++ b/src/backend/access/hash/hashpage.c
@@ -1477,18 +1477,20 @@ _hash_finish_split(Relation rel, Buffer metabuf, Buffer obuf, Bucket obucket,
 static void
 log_split_page(Relation rel, Buffer buf)
 {
+	XLogRecPtr	recptr;
+
 	if (RelationNeedsWAL(rel))
 	{
-		XLogRecPtr	recptr;
-
 		XLogBeginInsert();
 
 		XLogRegisterBuffer(0, buf, REGBUF_FORCE_IMAGE | REGBUF_STANDARD);
 
 		recptr = XLogInsert(RM_HASH_ID, XLOG_HASH_SPLIT_PAGE);
-
-		PageSetLSN(BufferGetPage(buf), recptr);
 	}
+	else
+		recptr = XLogGetFakeLSN(rel);
+
+	PageSetLSN(BufferGetPage(buf), recptr);
 }
 
 /*