[TYPO3-dev] DB Performance Problems (fe_sessions table)

[Dmitry Dulepov]

Hi!

Susanne Moog wrote:
> MySQL log shows thousands of the following queries:
> 
> DELETE FROM fe_sessions    WHERE    ses_id =
> '9dd6ed3c54bdf13ea23cb82a7c095831'    AND ses_name = 'fe_typo_user'

This table should be InnoDB. If it is MyISAM, you will have performance problems.

> We do not have frontend users and the table "fe_sessions" is empty. The
> log does not show any inserts for that table.
> 
> Can someone give me a hint where and why those queries are generated
> (and what I can do against it ;))

TYPO3 creates FE sessions even when user is not logged in. Plugins still can save data in session. So TYPO3 saves sessions and cleans them up from time to time.

-- 
Dmitry Dulepov
TYPO3 core team
http://dmitry-dulepov.com/
"Computers are so unreliable... just like people" (Major Cain, "Resident Evil: Apocalypse")