maria-developers team mailing list archive

[Jean Weisbuch <jean@xxxxxxxxxx>]

In my opinion many of the new features of MariaDB lacks some proper 
documentation/benchmarks and sometimes even testing, there are many 
features and new variables that could be used but almost nobody knows 
about these or the possible usecases/downsides are not clear and users 
will just keep it safe and not try these unless they are sure of what 
they are playing with.
It might be better for the end-user to have less new features but more 
knowledge/clarity about what he can do with the already available ones.

In that matter, creating tasks on Jira to follow up features/tools that 
has been added/modified and putting milestones on the task such as 
"Create KB page on this", "Do a benchmark for this on this case" or 
"Document the possible downsides and usecases of that feature" might be 
a good idea as you can follow up the advancement and other peoples might 
contribute as well.
It might also avoid certain questions on the KB which is IMO poorly 
designed in that aspect (answers are put in comments).

A very short list of examples of these features/options that would 
benefit from a better documentation/visibility :
    - The optimize_join_buffer_size optimizer switch is not documented 
at all and is disabled by default, what is its purpose and why isnt it 
activated by default (lack of testing of downsides?).
    - Its not clear on what these variables do and which engine they 
apply to (there is a bug about that 
https://mariadb.atlassian.net/browse/MDEV-4395) : 
deadlock_search_depth_long, deadlock_search_depth_short, 
deadlock_timeout_long, deadlock_timeout_short.
    - The default value of aria_repair_threads is 1, are there any 
downsides if an higher value is set, benchmarks might also come in 
interest if this value can make great performance differences.
    - What is the use/action (if any) of the thread_cache_size variable 
when the threadpool is activated.
    - More thorough benchmarks on Aria, especially with TRANSACTIONAL = 
0 & 1 compaired to MyISAM and InnoDB.
    - Document how to define a correct value for the segmented key 
cache of MyISAM (knowing that it is not working like the innodb buffer 
pool instances) and is there any possible downside on its usage as its 
deactivated by default (except for some critical bug on it such as 
MDEV-4409).


Le 14/06/2013 17:30, Roberto Spadim a écrit :
> about quality assurance process, what should be done? unit tests? test 
> team?