From ef480ff0b995af1f459a202294f6047b177b79bd Mon Sep 17 00:00:00 2001
From: Andrew Kane <andrew@ankane.org>
Date: Sun, 13 Aug 2023 17:22:25 -0700
Subject: [PATCH] Added comment [skip ci]

---
 src/hnswinsert.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/hnswinsert.c b/src/hnswinsert.c
index b397941..e20a041 100644
--- a/src/hnswinsert.c
+++ b/src/hnswinsert.c
@@ -311,6 +311,13 @@ UpdateNeighborPages(Relation index, FmgrInfo *procinfo, Oid collation, HnswEleme
 			/* Do not lock yet since selecting neighbors can take time */
 			HnswLoadNeighbors(hc->element, index);
 
+			/*
+			 * Could improve performance for vacuuming by checking neighbors
+			 * against list of elements being deleted. It's important to
+			 * exclude already deleted elements for this since they can be
+			 * replaced at any time.
+			 */
+
 			/* Select neighbors */
 			HnswUpdateConnection(e, hc, lm, lc, &idx, index, procinfo, collation);