diff --git a/src/backend/access/heap/heapam_indexscan.c b/src/backend/access/heap/heapam_indexscan.c
index bbd8a165ddc..33d14f1de7d 100644
--- a/src/backend/access/heap/heapam_indexscan.c
+++ b/src/backend/access/heap/heapam_indexscan.c
@@ -41,20 +41,13 @@ heapam_index_fetch_begin(Relation rel, uint32 flags)
 void
 heapam_index_fetch_reset(IndexFetchTableData *scan)
 {
-	IndexFetchHeapData *hscan = (IndexFetchHeapData *) scan;
-
-	if (BufferIsValid(hscan->xs_cbuf))
-	{
-		ReleaseBuffer(hscan->xs_cbuf);
-		hscan->xs_cbuf = InvalidBuffer;
-		hscan->xs_blk = InvalidBlockNumber;
-	}
-
-	if (BufferIsValid(hscan->xs_vmbuffer))
-	{
-		ReleaseBuffer(hscan->xs_vmbuffer);
-		hscan->xs_vmbuffer = InvalidBuffer;
-	}
+	/*
+	 * Resets are a no-op.
+	 *
+	 * Deliberately avoid dropping pins now held in xs_cbuf and xs_vmbuffer.
+	 * This saves cycles during certain tight nested loop joins (it can avoid
+	 * repeated pinning and unpinning of the same buffer across rescans).
+	 */
 }
 
 void
@@ -62,7 +55,13 @@ heapam_index_fetch_end(IndexFetchTableData *scan)
 {
 	IndexFetchHeapData *hscan = (IndexFetchHeapData *) scan;
 
-	heapam_index_fetch_reset(scan);
+	/* drop pin if there's a pinned heap page */
+	if (BufferIsValid(hscan->xs_cbuf))
+		ReleaseBuffer(hscan->xs_cbuf);
+
+	/* drop pin if there's a pinned visibility map page */
+	if (BufferIsValid(hscan->xs_vmbuffer))
+		ReleaseBuffer(hscan->xs_vmbuffer);
 
 	pfree(hscan);
 }
diff --git a/src/backend/access/index/indexam.c b/src/backend/access/index/indexam.c
index 44496ae0963..23288a4f994 100644
--- a/src/backend/access/index/indexam.c
+++ b/src/backend/access/index/indexam.c
@@ -375,7 +375,7 @@ index_rescan(IndexScanDesc scan,
 	Assert(nkeys == scan->numberOfKeys);
 	Assert(norderbys == scan->numberOfOrderBys);
 
-	/* Release resources (like buffer pins) from table accesses */
+	/* reset table AM state for rescan */
 	if (scan->xs_heapfetch)
 		table_index_fetch_reset(scan->xs_heapfetch);
 
@@ -452,7 +452,7 @@ index_restrpos(IndexScanDesc scan)
 	SCAN_CHECKS;
 	CHECK_SCAN_PROCEDURE(amrestrpos);
 
-	/* release resources (like buffer pins) from table accesses */
+	/* reset table AM state for restoring the marked position */
 	if (scan->xs_heapfetch)
 		table_index_fetch_reset(scan->xs_heapfetch);
 
@@ -578,6 +578,7 @@ index_parallelrescan(IndexScanDesc scan)
 {
 	SCAN_CHECKS;
 
+	/* reset table AM state for rescan */
 	if (scan->xs_heapfetch)
 		table_index_fetch_reset(scan->xs_heapfetch);
 
@@ -659,7 +660,7 @@ index_getnext_tid(IndexScanDesc scan, ScanDirection direction)
 	/* If we're out of index entries, we're done */
 	if (!found)
 	{
-		/* release resources (like buffer pins) from table accesses */
+		/* reset table AM state */
 		if (scan->xs_heapfetch)
 			table_index_fetch_reset(scan->xs_heapfetch);