diff --git a/src/backend/utils/time/snapmgr.c b/src/backend/utils/time/snapmgr.c
index 92afc32..b0b0a8d 100644
--- a/src/backend/utils/time/snapmgr.c
+++ b/src/backend/utils/time/snapmgr.c
@@ -979,6 +979,14 @@ SnapshotResetXmin(void)
 
 	if (pairingheap_is_empty(&RegisteredSnapshots))
 	{
+		/*
+		 * PgXact->xmin access bottlenecks on larger servers, so we choose
+		 * to skip this if we have reason to believe that the xmin would not
+		 * be long-lived such as when idle_in_transaction_timeout is set.
+		 */
+		if (IdleInTransactionSessionTimeout > 0)
+			return;
+
 		MyPgXact->xmin = InvalidTransactionId;
 		return;
 	}
diff --git a/src/include/utils/snapmgr.h b/src/include/utils/snapmgr.h
index 2618cc4..828a257 100644
--- a/src/include/utils/snapmgr.h
+++ b/src/include/utils/snapmgr.h
@@ -47,7 +47,7 @@
 
 /* GUC variables */
 extern PGDLLIMPORT int old_snapshot_threshold;
-
+extern int	IdleInTransactionSessionTimeout; /* copied from proc.h for convenience */
 
 extern Size SnapMgrShmemSize(void);
 extern void SnapMgrInit(void);