Bug #113640 no need to judge rseg in while loop

• Submitted: 15 Jan 3:46
• Modified: 21 May 20:46
• Reporter: alex xing (OCA)
• Status: Closed
• Category: MySQL Server: InnoDB storage engine
• Severity: S5 (Performance)
• Version: 8.0.32
• OS: Any
• CPU Architecture: Any
• Tags: Contribution

[15 Jan 3:46] alex xing

Description:
for get_next_redo_rseg_from_undo_spaces,no need to judge rseg in while loop 

How to repeat:
just read the code

Suggested fix:
just as the below patch based on  8.0.32

[15 Jan 3:46] alex xing

a simple patch to describe the optimization

(*) I confirm the code being submitted is offered under the terms of the OCA, and that I am authorized to contribute it.

Contribution: optimize.patch (text/plain), 454 bytes.

[15 Jan 5:41] MySQL Verification Team

Hello Alex Xing,

Thank you for the report and contribution.

regards,
umesh

[16 Jan 4:17] Rahul Sisondia

Hi Alex, 
Thank you for contributing to MySQL. 
I understand the check is completely redundant and must be removed. 
However, I am curious to know what made you find it ?

Was it just reading the code or you had some performance issue because of this check?

[16 Jan 4:29] alex xing

hi Rahul,
I find this by reading the code

[21 May 20:46] Philip Olson

Posted by developer:
 
Fixed as of the upcoming MySQL Server 9.0.0 release, and here's the proposed changelog entry from the documentation team:

Removed an unnecessary conditional check from
get_next_redo_rseg_from_undo_spaces().

Our thanks to Alex Xing for the contribution.

Thank you for the bug report.