From 1ea31af477d66557fdbc5f83a5bdacadd6159a9d Mon Sep 17 00:00:00 2001
From: Nathan Bossart <nathandbossart@gmail.com>
Date: Thu, 1 Sep 2022 11:23:15 -0700
Subject: [PATCH v1 1/2] use optimized linear search in
 TransactionIdIsInProgress

---
 src/backend/storage/ipc/procarray.c | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/src/backend/storage/ipc/procarray.c b/src/backend/storage/ipc/procarray.c
index 0555b02a8d..a8b7b65518 100644
--- a/src/backend/storage/ipc/procarray.c
+++ b/src/backend/storage/ipc/procarray.c
@@ -58,6 +58,7 @@
 #include "commands/dbcommands.h"
 #include "miscadmin.h"
 #include "pgstat.h"
+#include "port/pg_lfind.h"
 #include "storage/proc.h"
 #include "storage/procarray.h"
 #include "storage/spin.h"
@@ -1586,14 +1587,9 @@ TransactionIdIsInProgress(TransactionId xid)
 	 */
 	topxid = SubTransGetTopmostTransaction(xid);
 	Assert(TransactionIdIsValid(topxid));
-	if (!TransactionIdEquals(topxid, xid))
-	{
-		for (int i = 0; i < nxids; i++)
-		{
-			if (TransactionIdEquals(xids[i], topxid))
-				return true;
-		}
-	}
+	if (!TransactionIdEquals(topxid, xid) &&
+		pg_lfind32(topxid, xids, nxids))
+		return true;
 
 	cachedXidIsNotInProgress = xid;
 	return false;
-- 
2.25.1