Bug #35434 | Many variables stated as static are give an error Unknown System Variable | ||
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Submitted: | 19 Mar 2008 12:18 | Modified: | 4 Dec 2008 11:05 |
Reporter: | Rizwan Maredia | Email Updates: | |
Status: | Verified | Impact on me: | |
Category: | MySQL Server: General | Severity: | S3 (Non-critical) |
Version: | 5.1.22, 5.1.23, 5.0.45 | OS: | Any (Windows XP) |
Assigned to: | CPU Architecture: | Any | |
Tags: | system variable, unknown system variables, unknown variables |
[19 Mar 2008 12:18]
Rizwan Maredia
[19 Mar 2008 12:55]
Valeriy Kravchuk
Thank you for a problem report.
[3 Apr 2008 19:18]
Andrii Nikitin
Added version 5.0.45 Actually this has impact on customers, because e.g. there is no way to detect whether binlog is enabled on server or not.
[10 Apr 2008 9:29]
Georgi Kodinov
We're aware of this problem (see e.g. the related bug #363) and we're working on it.
[10 Jul 2008 1:08]
Ryan Thiessen
I believe this is not strictly related to bug #363 because the variables are not available even to the "show variables" command. For example: mysql> show variables like 'innodb_stats_on_metadata'; Empty set (0.00 sec) As the previous comment suggested this makes it very difficult to audit server settings.
[9 Dec 2008 18:09]
Paul DuBois
The variables listed in the original report and said to be "non static" (that is, dynamic or settable are runtime) are no longer listed in the manual as dynamic. re: the coment about innodb_stats_on_metadata: This is not shown by SHOW VARIABLES because it is a command option only, not a system variable. The same is true of innodb_status_file.
[9 Dec 2008 18:22]
Paul DuBois
Added a note to: http://dev.mysql.com/doc/refman/5.1/en/using-system-variables.html http://dev.mysql.com/doc/refman/5.1/en/set-option.html Some variables displayed by SHOW VARIABLES may not not be available using SELECT @@var_name syntax; an "Unknown system variable" occurs. As a workaround in such cases, you can use SHOW VARIABLES LIKE 'var_name'.
[9 Dec 2008 18:40]
Paul DuBois
As of 5.1.31/6.0.9, the "Unknown system variable" problem was corrected for several of the variables listed here, and they can now be accessed using SELECT @@var_name. These variables still cannot be selected with SELECT @@var_name: have_archive have_blackhole_engine have_example_engine have_federated_engine have_isam have_merge_engine have_raid have_row_based_replication memlock named_pipe ndb_log_orig ndb_use_copying_alter_table shared_memory shared_memory_base_name thread_concurrency Note: I did not test on Windows, so the shared_xxx variables might work on Windows. I did not list innodb_buffer_pool_awe_mem_mb, innodb_log_arch_dir, or innodb_log_archive because these variables has been removed.
[9 Dec 2008 18:41]
Paul DuBois
Changing report to Server:General.