← Back to team overview

maria-discuss team mailing list archive

Re: default_tmp_storage_engine=NULL


This is indeed odd.  The point of the variable is to use myisam temporary
tables when innodb storage is used because there is a huge performance hit
to using innodb temporary tables.  The default of null makes MariaDB use
innodb temp tables which will cause a performance degradation.  I'd expect
the variable to default to myisam or aria.

On Feb 9, 2017 3:59 AM, "Ian Gilfillan" <ian@xxxxxxxxxxx> wrote:

> On 09/02/2017 11:58, Sergei Golubchik wrote:
>> Hi, Ian!
>> On Feb 09, Ian Gilfillan wrote:
>>> What is the purpose/effect of having MariaDB's
>>> default_tmp_storage_engine setting default to NULL instead of the
>>> default used in MySQL, Innodb? I can't see any obvious differences in
>>> behaviour.
>> NULL means "same as default_storage_engine"
>> That is, no matter what you change your default_storage_engine to be,
>> temporary tables will always use the same engine.
> Thanks, but I'm also trying to understand why this decision was made. It's
> an odd obscure difference to the MySQL behaviour, and I'm sure someone is
> going to run up against it some day, and I'd like to try document the
> reasoning behind it.
> _______________________________________________
> Mailing list: https://launchpad.net/~maria-discuss
> Post to     : maria-discuss@xxxxxxxxxxxxxxxxxxx
> Unsubscribe : https://launchpad.net/~maria-discuss
> More help   : https://help.launchpad.net/ListHelp