Question

How can I reduce time for the following query?

SELECT *
FROM (`ci_session`)
WHERE `session_id` = '8011e978d8692846a22bc8f7f806af4d'
AND `user_agent` = 'Mozilla/5.0 (Windows NT 6.1; rv:2.0) Gecko/2010010' 

This query takes around 0.3 seconds to execute on my MySQL 5.5

This is an very important query as it determines the session of the user (PHP/CodeIgniter)

The table contains 1000 rows.

Answer 1

session_id is a fixed with column, try to change it to CHAR(32) instead of VARCHAR if that’s the case.

And make a UNIQUE INDEX for session_id.

CREATE UNIQUE INDEX idx_session ON ci_session (session_id)

Or an INDEX with prefix

CREATE INDEX idx_session ON ci_session (session_id(8))

and change the length of the prefix to see which one is faster.