TiDB md5 result is different to MySQL

[breezewish]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

Using the test data from https://github.com/datacharmer/test_db

(Note: This is the sample data provided by MySQL https://dev.mysql.com/doc/employee/en/)

mysql --host 127.0.0.1 --port 4000 -u root < employees.sql
mysql --host 127.0.0.1 --port 4000 -u root -t < test_employees_md5.sql

2. What did you expect to see? (Required)

On MySQL 8.0:

mysql --host 127.0.0.1 --port 3306 -u root < employees.sql
mysql --host 127.0.0.1 --port 3306 -u root -t < test_employees_md5.sql

Result:

+----------------------+
| INFO                 |
+----------------------+
| TESTING INSTALLATION |
+----------------------+
+--------------+------------------+----------------------------------+
| table_name   | expected_records | expected_crc                     |
+--------------+------------------+----------------------------------+
| departments  |                9 | d1af5e170d2d1591d776d5638d71fc5f |
| dept_emp     |           331603 | ccf6fe516f990bdaa49713fc478701b7 |
| dept_manager |               24 | 8720e2f0853ac9096b689c14664f847e |
| employees    |           300024 | 4ec56ab5ba37218d187cf6ab09ce1aa1 |
| salaries     |          2844047 | fd220654e95aea1b169624ffe3fca934 |
| titles       |           443308 | bfa016c472df68e70a03facafa1bc0a8 |
+--------------+------------------+----------------------------------+
+--------------+------------------+----------------------------------+
| table_name   | found_records    | found_crc                        |
+--------------+------------------+----------------------------------+
| departments  |                9 | d1af5e170d2d1591d776d5638d71fc5f |
| dept_emp     |           331603 | ccf6fe516f990bdaa49713fc478701b7 |
| dept_manager |               24 | 8720e2f0853ac9096b689c14664f847e |
| employees    |           300024 | 4ec56ab5ba37218d187cf6ab09ce1aa1 |
| salaries     |          2844047 | fd220654e95aea1b169624ffe3fca934 |
| titles       |           443308 | bfa016c472df68e70a03facafa1bc0a8 |
+--------------+------------------+----------------------------------+
+--------------+---------------+-----------+
| table_name   | records_match | crc_match |
+--------------+---------------+-----------+
| departments  | OK            | ok        |
| dept_emp     | OK            | ok        |
| dept_manager | OK            | ok        |
| employees    | OK            | ok        |
| salaries     | OK            | ok        |
| titles       | OK            | ok        |
+--------------+---------------+-----------+
+------------------+
| computation_time |
+------------------+
| 00:00:21         |
+------------------+
+---------+--------+
| summary | result |
+---------+--------+
| CRC     | OK     |
| count   | OK     |
+---------+--------+

3. What did you see instead (Required)

+----------------------+
| INFO                 |
+----------------------+
| TESTING INSTALLATION |
+----------------------+
+--------------+------------------+----------------------------------+
| table_name   | expected_records | expected_crc                     |
+--------------+------------------+----------------------------------+
| departments  |                9 | d1af5e170d2d1591d776d5638d71fc5f |
| dept_emp     |           331603 | ccf6fe516f990bdaa49713fc478701b7 |
| dept_manager |               24 | 8720e2f0853ac9096b689c14664f847e |
| employees    |           300024 | 4ec56ab5ba37218d187cf6ab09ce1aa1 |
| salaries     |          2844047 | fd220654e95aea1b169624ffe3fca934 |
| titles       |           443308 | bfa016c472df68e70a03facafa1bc0a8 |
+--------------+------------------+----------------------------------+
+--------------+------------------+----------------------------------+
| table_name   | found_records    | found_crc                        |
+--------------+------------------+----------------------------------+
| departments  |                9 | d1af5e170d2d1591d776d5638d71fc5f |
| dept_emp     |           331603 | 26f0a59726fef3d22f7f7fd872595a37 |
| dept_manager |               24 | 8720e2f0853ac9096b689c14664f847e |
| employees    |           300024 | 4ec56ab5ba37218d187cf6ab09ce1aa1 |
| salaries     |          2844047 | 892c9dfa133d6894fb7b66f2051b2103 |
| titles       |           443308 | bfa016c472df68e70a03facafa1bc0a8 |
+--------------+------------------+----------------------------------+
+--------------+---------------+-----------+
| table_name   | records_match | crc_match |
+--------------+---------------+-----------+
| departments  | OK            | ok        |
| dept_emp     | OK            | not ok    |
| dept_manager | OK            | ok        |
| employees    | OK            | ok        |
| salaries     | OK            | not ok    |
| titles       | OK            | ok        |
+--------------+---------------+-----------+
+------------------+
| computation_time |
+------------------+
| 00:00:44         |
+------------------+
+---------+--------+
| summary | result |
+---------+--------+
| CRC     | FAIL   |
| count   | OK     |
+---------+--------+

4. What is your TiDB version? (Required)

Release Version: v7.6.0-alpha-390-ge1b50b2eed-dirty
Edition: Community
Git Commit Hash: e1b50b2eed78012b76bf6ddd4c2083b6d16dfd22
Git Branch: sql_calc_found_rows
UTC Build Time: 2023-12-11 06:16:06
GoVersion: go1.21.0
Race Enabled: false
Check Table Before Drop: false
Store: tikv