Will lose rows after execute remove partitioning on a partition table with exchange partition

[Defined2014]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

create table t (id int not null, store_id int not null )  partition by range (store_id) (partition p0 values less than (6), partition p1 values less than (11), partition p2 values less than (16), partition p3 values less than (21) );
create table t1(id int not null, store_id int not null);
insert into t values (1, 1);
insert into t values (2, 17);
insert into t1 values (0, 18);
alter table t exchange partition p3 with table t1;
alter table t remove partitioning;
select * from t;

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

mysql> select * from t;
+----+----------+
| id | store_id |
+----+----------+
|  1 |        1 |
|  0 |       18 |
+----+----------+
2 rows in set (0.00 sec)

3. What did you see instead (Required)

mysql> select * from t;
+----+----------+
| id | store_id |
+----+----------+
|  0 |       18 |
+----+----------+
1 row in set (0.01 sec)

4. What is your TiDB version? (Required)

mysql> select tidb_version();
+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| tidb_version()                                                                                                                                                                                                                                                           |
+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Release Version: v8.2.0-alpha-192-g397a460dd0
Edition: Community
Git Commit Hash: 397a460dd067986d585d71a729a51b9e77a4c7ac
Git Branch: master
UTC Build Time: 2024-05-20 06:27:50
GoVersion: go1.21.5
Race Enabled: false
Check Table Before Drop: false
Store: unistore |
+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.04 sec)

[Defined2014]

The problem is caused by duplicate _tidb_rowid after exchange partition. We should seriously think about how to deal with this situation.

[mjonss]

For v7.1 REMOVE PARTITTIONING is not supported, but REORGANIZE PARTITION is, so the bug is still affecting v7.1 with:

alter table t reorganize partition p0, p1, p2, p3 into (partition p3 values less than (21));