From 271a46b3dfc6449db529e5815419ab248b9fc20c Mon Sep 17 00:00:00 2001
From: wshwsh12 <793703860@qq.com>
Date: Tue, 7 Jun 2022 14:19:52 +0800
Subject: [PATCH] add comments

---
 executor/join.go | 1 +
 1 file changed, 1 insertion(+)

diff --git a/executor/join.go b/executor/join.go
index dd80cb457ec72..b2076d459d82c 100644
--- a/executor/join.go
+++ b/executor/join.go
@@ -95,6 +95,7 @@ type HashJoinExec struct {
 
 	stats *hashJoinRuntimeStats
 
+	// We pre-alloc and reuse the Rows and RowPtrs for each probe goroutine, to avoid allocation frequently
 	buildSideRows    [][]chunk.Row
 	buildSideRowPtrs [][]chunk.RowPtr
 }