From 08420b6404fee34dce094ef76b442f86cf74c289 Mon Sep 17 00:00:00 2001
From: Andrew Kane <andrew@ankane.org>
Date: Sun, 22 Sep 2024 10:10:55 -0700
Subject: [PATCH] Updated comment [skip ci]

---
 src/hnswscan.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/hnswscan.c b/src/hnswscan.c
index ce1a5fc..92913ac 100644
--- a/src/hnswscan.c
+++ b/src/hnswscan.c
@@ -235,8 +235,12 @@ hnswgettuple(IndexScanDesc scan, ScanDirection dir)
 			{
 				/*
 				 * Locking ensures when neighbors are read, the elements they
-				 * reference will not be marked as deleted (and replaced)
-				 * during the iteration
+				 * reference will not be deleted (and replaced) during the
+				 * iteration.
+				 *
+				 * Elements loaded into memory on previous iterations may have
+				 * been deleted (and replaced), so when reading neighbors, the
+				 * element version must be checked.
 				 */
 				LockPage(scan->indexRelation, HNSW_SCAN_LOCK, ShareLock);