Changing the tmp folder of mysql

Question

Our Mysql queries use temporary tables which creates temporary files in the process. Currently the files are written to /tmp. How exactly can the path of the temp folder to which mysql writes to be changed?

Answer 1

You should edit your my.cnf

tmpdir = /whatewer/you/want 

and after that restart mysql

P.S. Don't forget give write permissions to /whatewer/you/want for mysql user

Answer 2

Here is an example to move the mysqld tmpdir from /tmp to /run/mysqld which already exists on Ubuntu 13.04 and is a tmpfs (memory/ram):

sudo vim /etc/mysql/conf.d/local.cnf 

Add:

[mysqld] tmpdir = /run/mysqld 

Then:

sudo service mysql restart 

Verify:

SHOW VARIABLES LIKE 'tmpdir'; 

==================================================================

If you get an error on MySQL restart, you may have AppArmor enabled:

sudo vim /etc/apparmor.d/local/usr.sbin.mysqld 

Add:

# Site-specific additions and overrides for usr.sbin.mysqld. # For more details, please see /etc/apparmor.d/local/README. /run/mysqld/ r, /run/mysqld/** rwk, 

Then:

sudo service apparmor reload  

sources: http://2bits.com/articles/reduce-your-servers-resource-usage-moving-mysql-temporary-directory-ram-disk.html, https://blogs.oracle.com/jsmyth/entry/apparmor_and_mysql