TiDB can not update stats correctly after exchange a partition

[Rustin170506]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

1. Create a table: create table pt(a int, b varchar(10), index idx_b (b)) partition by range(a) (partition p0 values less than (10), partition p1 values less than (20), partition p2 values less than (30));
2. Insert some data: insert into pt(a, b) values(1,'a'); insert into pt(a, b) values(5,'a');
3. Check the meta:

mysql> select * from mysql.stats_meta;
+--------------------+----------+--------------+-------+----------+
| version            | table_id | modify_count | count | snapshot |
+--------------------+----------+--------------+-------+----------+
| 444565530978025482 |      103 |            2 |     2 |        0 |
| 444565516821987331 |      104 |            0 |     0 |        0 |
| 444565516821987336 |      105 |            0 |     0 |        0 |
| 444565530978025482 |      102 |            2 |     2 |        0 |
+--------------------+----------+--------------+-------+----------+
4 rows in set (0.00 sec)

4. Create a new table: create table t1(a int, b varchar(10), index idx_b (b));
5. Insert data to t1: insert into t1(a, b) values(1,'a');
6. Check the meta again:

mysql> select * from mysql.stats_meta;
+--------------------+----------+--------------+-------+----------+
| version            | table_id | modify_count | count | snapshot |
+--------------------+----------+--------------+-------+----------+
| 444565530978025482 |      103 |            2 |     2 |        0 |
| 444565516821987331 |      104 |            0 |     0 |        0 |
| 444565516821987336 |      105 |            0 |     0 |        0 |
| 444565530978025482 |      102 |            2 |     2 |        0 |
| 444565546707976206 |      107 |            1 |     1 |        0 |
+--------------------+----------+--------------+-------+----------+
5 rows in set (0.00 sec)

7. Exchange the partition: alter table pt exchange partition p0 with table t1;
8. Check the meta:

mysql> show stats_meta;
+---------+------------+----------------+---------------------+--------------+-----------+
| Db_name | Table_name | Partition_name | Update_time         | Modify_count | Row_count |
+---------+------------+----------------+---------------------+--------------+-----------+
| test    | t1         |                | 2023-09-28 14:35:15 |            2 |         2 |
| test    | pt         | global         | 2023-09-28 14:35:15 |            2 |         2 |
| test    | pt         | p0             | 2023-09-28 14:36:15 |            1 |         1 |
| test    | pt         | p1             | 2023-09-28 14:34:21 |            0 |         0 |
| test    | pt         | p2             | 2023-09-28 14:34:21 |            0 |         0 |
+---------+------------+----------------+---------------------+--------------+-----------+
5 rows in set (0.00 sec)

2. What did you expect to see? (Required)

mysql> show stats_meta;
+---------+------------+----------------+---------------------+--------------+-----------+
| Db_name | Table_name | Partition_name | Update_time         | Modify_count | Row_count |
+---------+------------+----------------+---------------------+--------------+-----------+
| test    | t1         |                | 2023-09-28 14:35:15 |            2 |         2 |
- | test    | pt         | global         | 2023-09-28 14:35:15 |            2 |         2 |
+ | test    | pt         | global         | 2023-09-28 14:35:15 |            1 |         1 |
| test    | pt         | p0             | 2023-09-28 14:36:15 |            1 |         1 |
| test    | pt         | p1             | 2023-09-28 14:34:21 |            0 |         0 |
| test    | pt         | p2             | 2023-09-28 14:34:21 |            0 |         0 |
+---------+------------+----------------+---------------------+--------------+-----------+
5 rows in set (0.00 sec)

3. What did you see instead (Required)

mysql> show stats_meta;
+---------+------------+----------------+---------------------+--------------+-----------+
| Db_name | Table_name | Partition_name | Update_time         | Modify_count | Row_count |
+---------+------------+----------------+---------------------+--------------+-----------+
| test    | t1         |                | 2023-09-28 14:35:15 |            2 |         2 |
| test    | pt         | global         | 2023-09-28 14:35:15 |            2 |         2 |
| test    | pt         | p0             | 2023-09-28 14:36:15 |            1 |         1 |
| test    | pt         | p1             | 2023-09-28 14:34:21 |            0 |         0 |
| test    | pt         | p2             | 2023-09-28 14:34:21 |            0 |         0 |
+---------+------------+----------------+---------------------+--------------+-----------+
5 rows in set (0.00 sec)

4. What is your TiDB version? (Required)

mysql> SELECT tidb_version();
+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| tidb_version()                                                                                                                                                                                                                                                     |
+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Release Version: v7.5.0-alpha-1-g22e9be7d4e
Edition: Community
Git Commit Hash: 22e9be7d4e440ec87cf5c8407866ca0a9b49c91a
Git Branch: master
UTC Build Time: 2023-09-28 06:24:13
GoVersion: go1.21.1
Race Enabled: false
Check Table Before Drop: false
Store: tikv |
+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)