Bug #115808 Simple "comment" change operation in partition table should be treat as Metadata
Submitted: 9 Aug 2024 9:52 Modified: 9 Aug 2024 10:43
Reporter: ANIL JOSHI Email Updates:
Status: Unsupported Impact on me:
None 
Category:MySQL Server: Partitions Severity:S3 (Non-critical)
Version:8.0.34 OS:Any
Assigned to: CPU Architecture:Any
Tags: feature request

[9 Aug 2024 9:52] ANIL JOSHI
Description:
Feature Request:

Need to make the "comment" change operation in the partition table non-impactful and should be included in the Metadata change only.

mysql [localhost:8038] {msandbox} (test) > alter table t1 REORGANIZE PARTITION t1 INTO (PARTITION t_col VALUES IN (2) COMMENT = 'xxx' ENGINE = InnoDB);
Query OK, 0 rows affected (0.04 sec)
Records: 0  Duplicates: 0  Warnings: 0

As of now, the DMLs are not permitted while the above partition DDL is running.

https://dev.mysql.com/doc/refman/8.4/en/innodb-online-ddl-operations.html#online-ddl-parti...

How to repeat:

Run concurrent DMLs while the below DDL is ongoing. As per the official documentation - https://dev.mysql.com/doc/refman/8.4/en/innodb-online-ddl-operations.html#online-ddl-parti... the DML should be prohibited.

mysql [localhost:8038] {msandbox} (test) > alter table t1 REORGANIZE PARTITION t1 INTO (PARTITION t_col VALUES IN (2) COMMENT = 'xxx' ENGINE = InnoDB);
Query OK, 0 rows affected (0.04 sec)
Records: 0  Duplicates: 0  Warnings: 0

Suggested fix:

Need to add a feature where the "comment" addition task treated as Metadata change and should be completely impactful.
[9 Aug 2024 9:58] ANIL JOSHI
Suggested fix:

Please read as below

Need to add a feature where the "comment" addition task treated as Metadata change and should be completely Non-impactful/blocking.
[9 Aug 2024 10:43] MySQL Verification Team
Hi Mr. Joshi,

Thank you for your feature request.

However, your DDL is not just changing comment.

It is also including other changes.

Also, every single DDL will use MDL locks, by the rule.

We do not see how we can accommodate your request.