超大查询导致系统oom

MySQL [(none)]> show variables like 'tidb_mem_quota_query%';
+----------------------+-----------+
| Variable_name        | Value     |
+----------------------+-----------+
| tidb_mem_quota_query | 524288000 |
+----------------------+-----------+
1 row in set (0.020 sec)

MySQL [(none)]> show config where name like '%oom_action%';
+------+-----------------+------------+--------+
| Type | Instance        | Name       | Value  |
+------+-----------------+------------+--------+
| tidb | 10.0.8.183:4000 | oom-action | cancel |
| tidb | 10.0.8.45:4000  | oom-action | cancel |
| tidb | 10.0.8.39:4000  | oom-action | cancel |
+------+-----------------+------------+--------+
3 rows in set (0.019 sec)

MySQL [(none)]> show config where name like '%tmp-storage%';
+------+-----------------+---------------------+--------------------------------------------------------------+
| Type | Instance        | Name                | Value                                                        |
+------+-----------------+---------------------+--------------------------------------------------------------+
| tidb | 10.0.8.183:4000 | oom-use-tmp-storage | true                                                         |
| tidb | 10.0.8.183:4000 | tmp-storage-path    | /tmp/0_tidb/MC4wLjAuMDo0MDAwLzAuMC4wLjA6MTAwODA=/tmp-storage |
| tidb | 10.0.8.183:4000 | tmp-storage-quota   | -1                                                           |
| tidb | 10.0.8.45:4000  | oom-use-tmp-storage | true                                                         |
| tidb | 10.0.8.45:4000  | tmp-storage-path    | /tmp/0_tidb/MC4wLjAuMDo0MDAwLzAuMC4wLjA6MTAwODA=/tmp-storage |
| tidb | 10.0.8.45:4000  | tmp-storage-quota   | -1                                                           |
| tidb | 10.0.8.39:4000  | oom-use-tmp-storage | true                                                         |
| tidb | 10.0.8.39:4000  | tmp-storage-path    | /tmp/0_tidb/MC4wLjAuMDo0MDAwLzAuMC4wLjA6MTAwODA=/tmp-storage |
| tidb | 10.0.8.39:4000  | tmp-storage-quota   | -1                                                           |
+------+-----------------+---------------------+--------------------------------------------------------------+
9 rows in set (0.022 sec)

MySQL [(none)]>