MySQL Bugs: #69976: No deprecation warning on innodb_stats_sample

Bug #69976	No deprecation warning on innodb_stats_sample_pages
Submitted:	9 Aug 2013 19:44	Modified:	13 Jan 2015 14:41
Reporter:	Elena Stepanova	Email Updates:
Status:	Verified	Impact on me:	None
Category:	MySQL Server: Options	Severity:	S3 (Non-critical)
Version:	5.6.13	OS:	Any
Assigned to:		CPU Architecture:	Any

Description:
http://dev.mysql.com/doc/refman/5.6/en/innodb-parameters.html#sysvar_innodb_stats_sample_p...

The manual says that innodb_stats_sample_pages is deprecated, but when it's provided on server startup, no warning is written into the error log.

How to repeat:
- start server with --innodb-stats-sample-pages=20
- check the error log for warnings, don't find one about the variable/option.

Thank you for the bug report.

What is it a duplicate of?

Closed by mistake, sorry. Reopened. -Stefan

An update on this one. It's accepted that a deprecation warning would be useful but there's a problem doing that related to the way the code is structured. Within the server innodb_stats_sample_pages and innodb_stats_transient_pages have the same meaning and effect. At the point where InnoDB checks for deprecation it doesn't have a way to know which version of the variable name was used, it could have been either.

If the setting is changed while the server is in normal operation it is possible to give the deprecation warning and that does happen.

A related problem is if there is a variable set to true and the default is true. At startup InnoDB has no way to know whether it's been set to true with an explicit option setting and a deprecation warning should be given or it's set to true because that is the default value.

That is undesirable so at some point the issues will probably be fixed but there is currently no specific timeline for when to fix it. Elena, that work is being tracked in the internal bug 13986020.

James Day, MySQL Senior Principal Support Engineer, Oracle