MGR 需要使用主键

mysql> show tables;
+--------------+
| Tables_in_dd |
+--------------+
| a            |
+--------------+
1 row in set (0.00 sec)

mysql> desc a;
+-------+---------+------+-----+---------+-------+
| Field | Type    | Null | Key | Default | Extra |
+-------+---------+------+-----+---------+-------+
| id    | int(11) | YES  |     | NULL    |       |
+-------+---------+------+-----+---------+-------+
1 row in set (0.00 sec)

mysql> insert into a values(1);
ERROR 3098 (HY000): The table does not comply with the requirements by an external plugin.

mysql> alter table a add primary key (id);
Query OK, 0 rows affected (0.02 sec)
Records: 0  Duplicates: 0  Warnings: 0

mysql> desc a;
+-------+---------+------+-----+---------+-------+
| Field | Type    | Null | Key | Default | Extra |
+-------+---------+------+-----+---------+-------+
| id    | int(11) | NO   | PRI | NULL    |       |
+-------+---------+------+-----+---------+-------+
1 row in set (0.01 sec)

mysql> insert into a values(1);
Query OK, 1 row affected (0.00 sec)
mysql> insert into a values(1);
Query OK, 1 row affected (0.00 sec)

mysql> select * from a;
+----+
| id |
+----+
|  1 |
+----+
1 row in set (0.00 sec)