MySQL Bugs: #116849: Missing documentation (or link) for setting global variable attributes.

Bug #116849	Missing documentation (or link) for setting global variable attributes.
Submitted:	2 Dec 2024 18:26	Modified:	2 Dec 2024 19:16
Reporter:	Jean-François Gagné	Email Updates:
Status:	Verified	Impact on me:	None
Category:	MySQL Server: Documentation	Severity:	S2 (Serious)
Version:	9.0	OS:	Any
Assigned to:		CPU Architecture:	Any

Description:
Hi,

the offline_mode global variable documentation [1] is referring to the global variable attribute named reason.

[1]: https://dev.mysql.com/doc/refman/9.1/en/server-system-variables.html#sysvar_offline_mode

Above documentation is referring to the P_S table global_variable_attributes to query global variable attributes (and to the P_S table schema_variables_info), but it is not referring to any ways of setting a global variable attribute.

I would expect a documentation mentioning global variable attributes to refer to how it is possible to set such global variable attributes.

Other places where I would expect a link to a pages explaining how to set global variable attributes:

1. Performance Schema global_variable_attributes Table [2];

2. read_only global variable documentation [3];

3. SET Syntax for Variable Assignment [4];

4. Using System Variables [5].

[2]: https://dev.mysql.com/doc/refman/9.1/en/performance-schema-global-variable-attributes-tabl...

[3]: https://dev.mysql.com/doc/refman/9.1/en/server-system-variables.html#sysvar_read_only

[4]: https://dev.mysql.com/doc/refman/9.1/en/set-variable.html

[5]: https://dev.mysql.com/doc/refman/9.1/en/using-system-variables.html

Somehow related to this report: the documentation about the Performance Schema global_variable_attributes Table mentions the read_only global variable having attributes, but the documentation for this variable [3] does not mention an attribue.  Either [2] is wrong or something is missing in [3].

Note: my attention was brought to this subject via the Oracle MySQL blog post "Offline mode error improvement" [6].  The link to the documentation is broken in this post (see the documentation here), it probably deserves fixing.

[6]: https://blogs.oracle.com/mysql/post/offline-mode-error-improvement

Many thanks for looking into this,

Jean-François Gagné

How to repeat:
Check the docs, all detail in Description.

Suggested fix:
Add a page describing how to set global variable attributes (if it does not exist, I was not able to find it).

Add a link to above where it is missing (5 places listed in Description).

Fix broken link in post on Oracle MySQL Blog "Offline mode error improvement" (link in Description).

Salut, Monsieur Gagne,

Thank you for your Documentation report.

This is now a verified bug in our Reference Manual for 9.0 and higher.