*: add foreign key check/cascade information in explain result

[crazycs520]

Signed-off-by: crazycs520 [email protected]

What problem does this PR solve?

Issue Number: close #39166

Problem Summary: Add foreign key check/cascade executor information in explain statement.

What is changed and how it works?

Here is an example:

prepare:

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);

Here is some explain results:

test> explain insert into t2 values (1);
+-----------------------+---------+------+---------------+-----------------------------+
| id                    | estRows | task | access object | operator info               |
+-----------------------+---------+------+---------------+-----------------------------+
| Insert_1              | N/A     | root |               | N/A                         |
| └─Foreign_Key_Check_3 | 0.00    | root | table:t1      | foreign_key:fk, check_exist |
+-----------------------+---------+------+---------------+-----------------------------+
2 rows in set
Time: 0.019s
test> explain update t2 set id=id+1 where id = 1;
+-----------------------+---------+------+---------------+-----------------------------+
| id                    | estRows | task | access object | operator info               |
+-----------------------+---------+------+---------------+-----------------------------+
| Update_3              | N/A     | root |               | N/A                         |
| └─Point_Get_1         | 1.00    | root | table:t2      | handle:1                    |
| └─Foreign_Key_Check_4 | 0.00    | root | table:t1      | foreign_key:fk, check_exist |
+-----------------------+---------+------+---------------+-----------------------------+
3 rows in set
Time: 0.017s
test> explain delete from t1 where id > 1;
+-------------------------+---------+-----------+---------------+------------------------------------------------+
| id                      | estRows | task      | access object | operator info                                  |
+-------------------------+---------+-----------+---------------+------------------------------------------------+
| Delete_4                | N/A     | root      |               | N/A                                            |
| └─TableReader_7         | 3333.33 | root      |               | data:TableRangeScan_6                          |
|   └─TableRangeScan_6    | 3333.33 | cop[tikv] | table:t1      | range:(1,+inf], keep order:false, stats:pseudo |
| └─Foreign_Key_Cascade_8 | 0.00    | root      | table:t2      | foreign_key:fk, on_delete:CASCADE              |
+-------------------------+---------+-----------+---------------+------------------------------------------------+
4 rows in set
Time: 0.013s
test> explain update t1 set id=id+1 where id = 1;
+-------------------------+---------+------+---------------+-----------------------------------+
| id                      | estRows | task | access object | operator info                     |
+-------------------------+---------+------+---------------+-----------------------------------+
| Update_3                | N/A     | root |               | N/A                               |
| └─Point_Get_1           | 1.00    | root | table:t1      | handle:1                          |
| └─Foreign_Key_Cascade_4 | 0.00    | root | table:t2      | foreign_key:fk, on_update:CASCADE |
+-------------------------+---------+------+---------------+-----------------------------------+

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
• No code

Side effects

• Performance regression: Consumes more CPU
• Performance regression: Consumes more Memory
• Breaking backward compatibility

Documentation

• Affects user behaviors
• Contains syntax changes
• Contains variable changes
• Contains experimental features
• Changes MySQL compatibility

Release note

Please refer to Release Notes Language Style Guide to write a quality release note.

None

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• AilinKid
• time-and-fate

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[time-and-fate]

To make the result of EXPLAIN has a reasonable tree-like structure, we need to make sure that we set isLastChild to true only for the last "child" of an operator in flattenRecursively.

[AilinKid]

Rest LGTM

[crazycs520]

/run-all-tests

[crazycs520]

/run-all-tests

[crazycs520]

/merge

[ti-chi-bot]

This pull request has been accepted and is ready to merge.

Commit hash: c4d4ed8

[crazycs520]

/run-all-tests

[sre-bot]

TiDB MergeCI notify

✅ Well Done! New fixed [2] after this pr merged.

CI Name	Result	Duration	Compare with Parent commit
idc-jenkins-ci-tidb/mybatis-test	🔴 failed 1, success 0, total 1	11 min	Existing failure
idc-jenkins-ci/integration-cdc-test	✅ all 39 tests passed	22 min	Fixed
idc-jenkins-ci-tidb/common-test	✅ all 11 tests passed	10 min	Fixed
idc-jenkins-ci-tidb/integration-common-test	🟢 all 17 tests passed	14 min	Existing passed
idc-jenkins-ci-tidb/tics-test	🟢 all 1 tests passed	6 min 12 sec	Existing passed
idc-jenkins-ci-tidb/sqllogic-test-1	🟢 all 26 tests passed	5 min 24 sec	Existing passed
idc-jenkins-ci-tidb/sqllogic-test-2	🟢 all 28 tests passed	5 min 12 sec	Existing passed
idc-jenkins-ci-tidb/integration-ddl-test	🟢 all 6 tests passed	4 min 14 sec	Existing passed
idc-jenkins-ci-tidb/integration-compatibility-test	🟢 all 1 tests passed	3 min 4 sec	Existing passed
idc-jenkins-ci-tidb/plugin-test	🟢 build success, plugin test success	4min	Existing passed