INSERT INTO ON DUPLICATE KEY UPDATE失效问题

在TiDB v5.3.0按楼主步骤测试未发现问题，楼主能否使用测试数据复现？

我的测试如下：

###################################
#     建表及准备测试数据          #
###################################
mysql> create table t3(id int not null auto_increment primary key, name varchar(30) not null , sex tinyint);
Query OK, 0 rows affected (0.14 sec)

mysql> create unique index uniq_name on t3(name);
Query OK, 0 rows affected (2.92 sec)

mysql> insert into t3 values(1, 'a1', 0), (2,'a2', 1), (3,'a3',0);
Query OK, 3 rows affected (0.02 sec)
Records: 3  Duplicates: 0  Warnings: 0

mysql> select * from t3;
+----+------+------+
| id | name | sex  |
+----+------+------+
|  1 | a1   |    0 |
|  2 | a2   |    1 |
|  3 | a3   |    0 |
+----+------+------+
3 rows in set (0.01 sec)


###################################
#     按楼主的测试步骤测试        #
###################################

# 1、新开启一个事务，并通过select记录当前数据
mysql> begin;
Query OK, 0 rows affected (0.01 sec)

mysql> select * from t3;
+----+------+------+
| id | name | sex  |
+----+------+------+
|  1 | a1   |    0 |
|  2 | a2   |    0 |
|  3 | a3   |    0 |
+----+------+------+
3 rows in set (0.00 sec)


# 2、执行INSERT INTO ON DUPLICATE KEY UPDATE（提示了Query OK, 2 rows affected）
mysql> insert into t3(name, sex) values('a2', 1) ON DUPLICATE KEY UPDATE name=values(name), sex=values(sex); 
Query OK, 2 rows affected (0.01 sec)


# 3、再次查询，可以发现和预期的一致（update部分被执行，数据被更新了）
mysql> select * from t3;
+----+------+------+
| id | name | sex  |
+----+------+------+
|  1 | a1   |    0 |
|  2 | a2   |    1 |
|  3 | a3   |    0 |
+----+------+------+
3 rows in set (0.01 sec)

# 4、提交事务（Query OK, 0 rows affected ）
mysql> commit;
Query OK, 0 rows affected (0.01 sec)


# 5、再次查询，数据是【有落盘】，此处与楼主的不一致（楼主测试结论为：5、再次查询，发现数据没有落盘，即：还是原来的数据。）
mysql> select * from t3;
+----+------+------+
| id | name | sex  |
+----+------+------+
|  1 | a1   |    0 |
|  2 | a2   |    1 |
|  3 | a3   |    0 |
+----+------+------+
3 rows in set (0.00 sec)


# 测试环境
mysql> select version();
+--------------------+
| version()          |
+--------------------+
| 5.7.25-TiDB-v5.3.0 |
+--------------------+
1 row in set (0.00 sec)