Bug #104606 JSON type table leads to CHECKSUM result incorrect

• Submitted: 12 Aug 2021 11:29
• Modified: 12 Aug 2021 12:13
• Reporter: xing ye
• Status: Duplicate
• Category: MySQL Server
• Severity: S2 (Serious)
• Version: 5.7
• OS: Any
• CPU Architecture: Any
• Tags: JSON CHECKSUM

[12 Aug 2021 11:29] xing ye

Description:
when a table create with  some JSON type columns，each time I login in mysql ,CHECKSUM table to  check data changes，the checksum result vary every time even if the table rows doesn't change. 

How to repeat:
create a table t1  on database d1:
1、create table t1(id int ,t1 JSON default NULL);

2、insert into t1 values(1,'[]');

3、login  mysql:
mysql>checksum table d1.t1;
I can get some checksum reusult  XX
then quit
4、login in mysql  and checksum again:
mysql>checksum table d1.t1;
the checksum result is different

[12 Aug 2021 12:13] MySQL Verification Team

Hi Mr. ye,

Thank you for your bug report.

We found out that your bug is a duplicate of the following bug:

https://bugs.mysql.com/bug.php?id=87847

This bug is already fixed in 8.0 and it will not be fixed in 5.7, due to the very large amount of coded that was added to 8.0 for that purpose.

Duplicate.