From f8a207ce906e433bb5ca8d07c90cc440e8f582df Mon Sep 17 00:00:00 2001
From: Weizhen Wang <wangweizhen@pingcap.com>
Date: Thu, 9 Oct 2025 17:59:45 +0800
Subject: [PATCH] expression: don't allocate column every time when to
 newLocalColumnPool (#63864)

ref pingcap/tidb#63809
---
 pkg/expression/builtin_vectorized.go | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/pkg/expression/builtin_vectorized.go b/pkg/expression/builtin_vectorized.go
index 1a37f16dbf..78480bbdfb 100644
--- a/pkg/expression/builtin_vectorized.go
+++ b/pkg/expression/builtin_vectorized.go
@@ -40,12 +40,13 @@ type localColumnPool struct {
 	sync.Pool
 }
 
+var columnTempl = chunk.NewColumn(types.NewFieldType(mysql.TypeLonglong), chunk.InitialCapacity)
+
 func newLocalColumnPool() *localColumnPool {
-	newColumn := chunk.NewColumn(types.NewFieldType(mysql.TypeLonglong), chunk.InitialCapacity)
 	return &localColumnPool{
 		sync.Pool{
 			New: func() any {
-				return newColumn.CopyConstruct(nil)
+				return columnTempl.CopyConstruct(nil)
 			},
 		},
 	}