From bd97130f8eadbe85e34191a26a1990bf255762b6 Mon Sep 17 00:00:00 2001
From: Yuanjia Zhang <zhangyuanjia@pingcap.com>
Date: Tue, 22 Nov 2022 09:03:57 +0800
Subject: [PATCH] Revert "planner: enable cost model2 by default" (#39265)

---
 sessionctx/variable/tidb_vars.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sessionctx/variable/tidb_vars.go b/sessionctx/variable/tidb_vars.go
index d7c05c0a48e88..3511775de08f1 100644
--- a/sessionctx/variable/tidb_vars.go
+++ b/sessionctx/variable/tidb_vars.go
@@ -1079,7 +1079,7 @@ const (
 	DefTiDBForeignKeyChecks                      = false
 	DefTiDBAnalyzePartitionConcurrency           = 1
 	DefTiDBOptRangeMaxSize                       = 64 * int64(size.MB) // 64 MB
-	DefTiDBCostModelVer                          = 2
+	DefTiDBCostModelVer                          = 1
 	DefTiDBServerMemoryLimitSessMinSize          = 128 << 20
 	DefTiDBMergePartitionStatsConcurrency        = 1
 	DefTiDBServerMemoryLimitGCTrigger            = 0.7