set @@global.tidb_enable_foreign_key=1;
set @@foreign_key_checks=1;
create table t1 (id int key);
create table t2 (id int key, foreign key fk(id) references t1(id) ON UPDATE CASCADE ON DELETE CASCADE);
insert into t1 values (1),(2),(3),(4),(5),(6),(7),(8),(9),(10);

test2> explain analyze insert into t2 values (1);
+-----------------------+---------+---------+------+---------------+---------------------------------------------------------+-----------------------------+----------+------+
| id                    | estRows | actRows | task | access object | execution info                                          | operator info               | memory   | disk |
+-----------------------+---------+---------+------+---------------+---------------------------------------------------------+-----------------------------+----------+------+
| Insert_1              | N/A     | 0       | root |               | time:97µs, loops:1, prepare: 28.8µs, insert:68.3µs      | N/A                         | 97 Bytes | N/A  |
| └─Foreign_Key_Check_3 | 0.00    | 0       | root | table:t1      | total:163.5µs, check:151µs, lock:12.4µs, foreign_keys:1 | foreign_key:fk, check_exist | N/A      | N/A  |
+-----------------------+---------+---------+------+---------------+---------------------------------------------------------+-----------------------------+----------+------+
2 rows in set
Time: 0.012s
test2> explain analyze update t2 set id=id+1 where id = 1;
+-----------------------+---------+---------+------+---------------+---------------------------------------------------------------------------------------------------+-----------------------------+-----------+------+
| id                    | estRows | actRows | task | access object | execution info                                                                                    | operator info               | memory    | disk |
+-----------------------+---------+---------+------+---------------+---------------------------------------------------------------------------------------------------+-----------------------------+-----------+------+
| Update_3              | N/A     | 0       | root |               | time:240.8µs, loops:1, Get:{num_rpc:1, total_time:14.3µs},BatchGet:{num_rpc:1, total_time:11.3µs} | N/A                         | 380 Bytes | N/A  |
| ├─Point_Get_1         | 1.00    | 1       | root | table:t2      | time:82.2µs, loops:2, Get:{num_rpc:1, total_time:36.1µs}                                          | handle:1                    | N/A       | N/A  |
| └─Foreign_Key_Check_4 | 0.00    | 0       | root | table:t1      | total:49.2µs, check:39µs, lock:10.2µs, foreign_keys:1                                             | foreign_key:fk, check_exist | N/A       | N/A  |
+-----------------------+---------+---------+------+---------------+---------------------------------------------------------------------------------------------------+-----------------------------+-----------+------+
3 rows in set
Time: 0.006s
test2> explain analyze delete from t1 where id > 1;
+-------------------------+---------+---------+-----------+---------------+-------------------------------------------------------------------------------------------------------------------------------------------------------+-----------------------------------------------------------+-----------+------+
| id                      | estRows | actRows | task      | access object | execution info                                                                                                                                        | operator info                                             | memory    | disk |
+-------------------------+---------+---------+-----------+---------------+-------------------------------------------------------------------------------------------------------------------------------------------------------+-----------------------------------------------------------+-----------+------+
| Delete_4                | N/A     | 0       | root      |               | time:373.3µs, loops:1                                                                                                                                 | N/A                                                       | 551 Bytes | N/A  |
| ├─TableReader_7         | 3333.33 | 9       | root      |               | time:319µs, loops:2, cop_task: {num: 1, max: 256µs, proc_keys: 0, rpc_num: 1, rpc_time: 229.5µs, copr_cache_hit_ratio: 0.00, distsql_concurrency: 15} | data:TableRangeScan_6                                     | 250 Bytes | N/A  |
| │ └─TableRangeScan_6    | 3333.33 | 9       | cop[tikv] | table:t1      | tikv_task:{time:211.4µs, loops:0}                                                                                                                     | range:(1,+inf], keep order:false, stats:pseudo            | N/A       | N/A  |
| └─Foreign_Key_Cascade_8 | 0.00    | 0       | root      | table:t2      | total:92.8µs, foreign_keys:9                                                                                                                          | foreign_key:fk, on_delete:CASCADE                         | N/A       | N/A  |
|   └─Delete_10           | N/A     | 0       | root      |               | time:54.8µs, loops:1                                                                                                                                  | N/A                                                       | 213 Bytes | N/A  |
|     └─Batch_Point_Get_9 | 9.00    | 1       | root      | table:t2      | time:50.7µs, loops:2, BatchGet:{num_rpc:1, total_time:26µs}                                                                                           | handle:[2 3 4 5 6 7 8 9 10], keep order:false, desc:false | N/A       | N/A  |
+-------------------------+---------+---------+-----------+---------------+-------------------------------------------------------------------------------------------------------------------------------------------------------+-----------------------------------------------------------+-----------+------+
6 rows in set
Time: 0.006s
test2> explain analyze update t1 set id=id+1 where id = 1;
+---------------------------+---------+---------+------+---------------+---------------------------------------------------------------+------------------------------------------+-----------+------+
| id                        | estRows | actRows | task | access object | execution info                                                | operator info                            | memory    | disk |
+---------------------------+---------+---------+------+---------------+---------------------------------------------------------------+------------------------------------------+-----------+------+
| Update_3                  | N/A     | 0       | root |               | time:69.6µs, loops:1, Get:{num_rpc:1, total_time:1.5µs}       | N/A                                      | 194 Bytes | N/A  |
| ├─Point_Get_1             | 1.00    | 1       | root | table:t1      | time:28.8µs, loops:2, Get:{num_rpc:1, total_time:12µs}        | handle:1                                 | N/A       | N/A  |
| └─Foreign_Key_Cascade_4   | 0.00    | 0       | root | table:t2      | total:45.7µs, foreign_keys:1                                  | foreign_key:fk, on_update:CASCADE        | N/A       | N/A  |
|   └─Update_7              | N/A     | 0       | root |               | time:13.5µs, loops:1                                          | N/A                                      | 0 Bytes   | N/A  |
|     ├─Batch_Point_Get_5   | 1.00    | 0       | root | table:t2      | time:12.8µs, loops:1, BatchGet:{num_rpc:1, total_time:3.58µs} | handle:[1], keep order:false, desc:false | N/A       | N/A  |
|     └─Foreign_Key_Check_8 | 0.00    | 0       | root | table:t1      | total:0s                                                      | foreign_key:fk, check_exist              | N/A       | N/A  |
+---------------------------+---------+---------+------+---------------+---------------------------------------------------------------+------------------------------------------+-----------+------+
6 rows in set