From 26637bcb28be0add60d0136ed7ffc2f4cfbf6f53 Mon Sep 17 00:00:00 2001
From: wshwsh12 <793703860@qq.com>
Date: Mon, 8 Jan 2024 16:15:03 +0800
Subject: [PATCH] pick

---
 executor/aggregate.go                     |  4 ++--
 executor/issuetest/executor_issue_test.go | 17 +++++++++++++++++
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/executor/aggregate.go b/executor/aggregate.go
index 561bd4dcd9502..d34d7be17731c 100644
--- a/executor/aggregate.go
+++ b/executor/aggregate.go
@@ -1509,12 +1509,12 @@ func (e *vecGroupChecker) splitIntoGroups(chk *chunk.Chunk) (isFirstGroupSameAsP
 			return false, err
 		}
 	}
-	e.firstGroupKey, err = codec.EncodeValue(e.ctx.GetSessionVars().StmtCtx, e.firstGroupKey, e.firstRowDatums...)
+	e.firstGroupKey, err = codec.EncodeKey(e.ctx.GetSessionVars().StmtCtx, e.firstGroupKey, e.firstRowDatums...)
 	if err != nil {
 		return false, err
 	}
 
-	e.lastGroupKey, err = codec.EncodeValue(e.ctx.GetSessionVars().StmtCtx, e.lastGroupKey, e.lastRowDatums...)
+	e.lastGroupKey, err = codec.EncodeKey(e.ctx.GetSessionVars().StmtCtx, e.lastGroupKey, e.lastRowDatums...)
 	if err != nil {
 		return false, err
 	}
diff --git a/executor/issuetest/executor_issue_test.go b/executor/issuetest/executor_issue_test.go
index 91664bfcece4a..0a52238c4ef65 100644
--- a/executor/issuetest/executor_issue_test.go
+++ b/executor/issuetest/executor_issue_test.go
@@ -1477,3 +1477,20 @@ func TestIssue49369(t *testing.T) {
 	tk.MustQuery("select * from issue49369").Check(testkit.Rows("999999999999999999000000000000"))
 	tk.MustExec("set @@sql_mode = default")
 }
+
+func TestIssue49902(t *testing.T) {
+	store := testkit.CreateMockStore(t)
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec("use test")
+	tk.MustExec("set @@tidb_max_chunk_size = 32;")
+	tk.MustExec("drop table if exists t, s;")
+	tk.MustExec("CREATE TABLE `t` (`c` char(1)) COLLATE=utf8_general_ci ;")
+	tk.MustExec("insert into t values(\"V\"),(\"v\");")
+	tk.MustExec("insert into t values(\"V\"),(\"v\"),(\"v\");")
+	tk.MustExec("CREATE TABLE `s` (`col_61` int);")
+	tk.MustExec("insert into s values(1),(1),(1),(1),(1),(1),(1),(1),(1),(1),(1),(1),(1),(1),(1),(1),(1);")
+	tk.MustExec("insert into s values(1),(1),(1),(1),(1),(1),(1),(1),(1),(1),(1),(1),(1),(1),(1),(1),(1);")
+	tk.MustQuery("SELECT /*+ stream_agg()*/ count(`t`.`c`) FROM (`s`) JOIN `t` GROUP BY `t`.`c`;").Check(testkit.Rows("170"))
+	tk.MustQuery("SELECT count(`t`.`c`) FROM (`s`) JOIN `t` GROUP BY `t`.`c`;").Check(testkit.Rows("170"))
+	tk.MustExec("set @@tidb_max_chunk_size = default;")
+}