MySQL Bugs: #96904: 'Purge Configuration' of MySQL 5.5 is wrong.

Bug #96904	'Purge Configuration' of MySQL 5.5 is wrong.
Submitted:	17 Sep 2019 12:07	Modified:	18 Sep 2019 22:28
Reporter:	Meiji Kimura	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Server: Documentation	Severity:	S3 (Non-critical)
Version:	5.5	OS:	Any
Assigned to:		CPU Architecture:	Any

Description:
Purge configuration is explained in this page.

https://dev.mysql.com/doc/refman/5.5/en/innodb-purge-configuration.html

But it's wrong about innodb_purge_threads.

"By default, purge operations are performed by the InnoDB master thread. Starting with MySQL 5.5, purge operations can performed by one or more separate purge threads rather than as part of the InnoDB master thread."

is wrong. it's for 5.6. In MySQL 5.5, with master thread, or only one separate purge threads. 

"The maximum number of purge threads is 32." is wrong. it's for 5.6.
In MySQL 5.5, 0 or 1, thus maximum number is 1.

https://dev.mysql.com/doc/refman/5.5/en/innodb-parameters.html#sysvar_innodb_purge_threads

Almost of all description is based on MySQL 5.6. Please check and modify based on MySQL 5.5. 

How to repeat:
See above URLs.

Suggested fix:
Please re-write this page.

https://dev.mysql.com/doc/refman/5.5/en/innodb-purge-configuration.html

Based on MySQL 5.5.

Hello Meiji-San,

Thank you for the report and feedback.

regards,
Umesh

Posted by developer:
 
The 5.5 purge content has been revised. Changes should appear online soon. 
Thank you for the bug report.