MySQL Bugs: #71524: manual isn't clear with setting default variable with -1

Bug #71524	manual isn't clear with setting default variable with -1
Submitted:	30 Jan 2014 11:53	Modified:	3 Mar 2014 13:33
Reporter:	martin fuxa	Email Updates:
Status:	Duplicate	Impact on me:	None
Category:	MySQL Server: Options	Severity:	S3 (Non-critical)
Version:	5.6	OS:	Any
Assigned to:		CPU Architecture:	Any

Description:
docs says: table_definition_cache have Default	-1 (autosized)
http://dev.mysql.com/doc/refman/5.6/en/server-system-variables.html#sysvar_table_definitio...

ok, lets try set it to default
set global table_definition_cache=-1;
Query OK, 0 rows affected, 1 warning (0.00 sec)
Warning (Code 1292): Truncated incorrect table_definition_cache value: '-1'

doesn't work. according to code and I found it in documentation too, DEFAULT works
set global table_definition_cache=DEFAULT;
Query OK, 0 rows affected (0.00 sec)

And again doc, in http://dev.mysql.com/doc/refman/5.6/en/dynamic-system-variables.html ... type of “numeric” take a numeric value ...
table_definition_cache IS numeric and -1 IS number. There isn't note about ilegal use of -1.

see my opinion in Suggested fix.

How to repeat:
set global table_definition_cache=-1;

Suggested fix:
- use DEFAULT as default value instead of -1
- make -1 working. who reads doc? ;)
- add to documentation note that -1 doesn't work and DEFAULT magic-word must be used.

Hello Martin,

Thank you for the bug report.
Verified as described.

Thanks,
Umesh

This is actually a software issue, not a documentation bug, and is a duplicate of another bug currently being worked on. This bug is closed as a duplicate, but will be updated when the primary issue has been fixed. Thanks.