确实如此，不然这个表就是空的。
mysql> select * from metrics_schema.resource_manager_resource_unit;
+----------------------------+----------------------+
| time | value |
+----------------------------+----------------------+
| 2023-06-28 00:35:16.666000 | 0 |
| 2023-06-28 00:36:16.666000 | 0.004957504103305845 |
+----------------------------+----------------------+
2 rows in set (0.01 sec)