create table t (a int primary key, b varchar(255), unique index idx_b_global (b) global) partition by range (a) (partition p1 values less than (200), partition pMax values less than (maxvalue));
insert into t values (1,1),(2,2),(101,101),(102,102),(998,998),(999,999);
select * from information_schema.tidb_indexes where table_name = 't';
select * from mysql.gc_delete_range;
select * from mysql.gc_delete_range_done;
alter table t reorganize partition p1 into (partition p0 values less than (100), partition p1 values less than (200));
select * from mysql.gc_delete_range;
select * from mysql.gc_delete_range_done;
select * from information_schema.tidb_indexes where table_name = 't';

tidb> create table t (a int primary key, b varchar(255), unique index idx_b_global (b) global) partition by range (a) (partition p1 values less than (200), partition pMax values less than (maxvalue));
Query OK, 0 rows affected (0.04 sec)

tidb> insert into t values (1,1),(2,2),(101,101),(102,102),(998,998),(999,999);
Query OK, 6 rows affected (0.00 sec)
Records: 6  Duplicates: 0  Warnings: 0

tidb> select * from information_schema.tidb_indexes where table_name = 't';
+--------------+------------+------------+--------------+--------------+-------------+----------+---------------+------------+----------+------------+-----------+-----------+
| TABLE_SCHEMA | TABLE_NAME | NON_UNIQUE | KEY_NAME     | SEQ_IN_INDEX | COLUMN_NAME | SUB_PART | INDEX_COMMENT | Expression | INDEX_ID | IS_VISIBLE | CLUSTERED | IS_GLOBAL |
+--------------+------------+------------+--------------+--------------+-------------+----------+---------------+------------+----------+------------+-----------+-----------+
| test         | t          |          0 | PRIMARY      |            1 | a           |     NULL |               | NULL       |        0 | YES        | YES       |         0 |
| test         | t          |          0 | idx_b_global |            1 | b           |     NULL |               | NULL       |        1 | YES        | NO        |         1 |
+--------------+------------+------------+--------------+--------------+-------------+----------+---------------+------------+----------+------------+-----------+-----------+
2 rows in set (0.00 sec)

tidb> select * from mysql.gc_delete_range;
Empty set (0.00 sec)

tidb> select * from mysql.gc_delete_range_done;
Empty set (0.00 sec)

tidb> alter table t reorganize partition p1 into (partition p0 values less than (100), partition p1 values less than (200));
Query OK, 0 rows affected, 1 warning (0.73 sec)

tidb> select * from mysql.gc_delete_range;
+--------+------------+--------------------+--------------------+--------------------+
| job_id | element_id | start_key          | end_key            | ts                 |
+--------+------------+--------------------+--------------------+--------------------+
|    116 |          1 | 74800000000000006f | 748000000000000070 | 453456927279808521 |
+--------+------------+--------------------+--------------------+--------------------+
1 row in set (0.00 sec)

tidb> select * from mysql.gc_delete_range_done;
Empty set (0.00 sec)

tidb> select * from information_schema.tidb_indexes where table_name = 't';
+--------------+------------+------------+--------------+--------------+-------------+----------+---------------+------------+----------+------------+-----------+-----------+
| TABLE_SCHEMA | TABLE_NAME | NON_UNIQUE | KEY_NAME     | SEQ_IN_INDEX | COLUMN_NAME | SUB_PART | INDEX_COMMENT | Expression | INDEX_ID | IS_VISIBLE | CLUSTERED | IS_GLOBAL |
+--------------+------------+------------+--------------+--------------+-------------+----------+---------------+------------+----------+------------+-----------+-----------+
| test         | t          |          0 | PRIMARY      |            1 | a           |     NULL |               | NULL       |        0 | YES        | YES       |         0 |
| test         | t          |          0 | idx_b_global |            1 | b           |     NULL |               | NULL       |        2 | YES        | NO        |         1 |
+--------------+------------+------------+--------------+--------------+-------------+----------+---------------+------------+----------+------------+-----------+-----------+
2 rows in set (0.00 sec)