Why MYSQL doesn't use my indexes? - mysql

Question

I have table karton00 which holds thousands of records. This makes the queries slow. I would like to use indexes, but even though I set them, they are not being used.
Here is my table. and here is the result of using EXPLAIN.
This is my query:
SELECT '' checkbox,
k00_eszkozid,
k00_eszkoznev,
k01_gyariszam,
k01_leltszam,
prsn_name,
k00_status,
tstikon,
k00_startflow,
tstname,
k00_eszkozid,
k01_gyariszam,
k01_leltszam
FROM karton00
LEFT JOIN karton01
ON k00_eszkozid = k01_eszkozid
AND k01_status = 'A'
LEFT JOIN karton02
ON k00_eszkozid = k02_eszkozid
AND k02_status = 'A'
LEFT JOIN karton04
ON k00_eszkozid = k04_eszkozid
AND k04_status = 'A'
LEFT JOIN karton05
ON k00_eszkozid = k05_eszkozid
AND k05_status = 'A'
LEFT JOIN karton06
ON k00_eszkozid = k06_eszkozid
AND k06_status = 'A'
LEFT JOIN karton08
ON k00_eszkozid = k08_eszkozid
AND k08_status = 'A'
LEFT JOIN karton09
ON k00_eszkozid = k09_eszkozid
AND k09_status = 'A'
LEFT JOIN telephely et
ON k06_telephelyid = et.telepid
LEFT JOIN ktghely00 ek
ON k02_ktghid = ek.ktghid
LEFT JOIN person00 us
ON k06_userid = prsn_id
LEFT JOIN ktghely00 fk
ON prsn_ktgh = fk.ktghid
LEFT JOIN telephely ft
ON prsn_telep = ft.telepid
LEFT JOIN tamstatus
ON k02_tamstatusid = tstid
LEFT JOIN szakleltar
ON k02_szakleltarid = szleltid
LEFT JOIN tamszerv
ON k02_tamszervid = tszid
LEFT JOIN ktghely01
ON k02_vgazdaid = vgid
AND vgstatus = 'A'
LEFT JOIN ktghely00 vk
ON vgktghid = vk.ktghid
LEFT JOIN szallitok m
ON k05_mincegid = m.szallid
LEFT JOIN szallitok s
ON k04_szallitoid = s.szallid
LEFT JOIN dctnry00 ym
ON k05_minosit = ym.dctnryname
AND ym.dctnrygrp = 'YESNO'
LEFT JOIN dctnry00 yd
ON k05_check = yd.dctnryname
AND yd.dctnrygrp = 'YESNO'
WHERE k00_status IN ( 'A', 'H' )
AND ( k02_vgazdaid IN ( 7 ) )
AND NOT EXISTS (SELECT *
FROM eszkozkizar
WHERE ez_flid = 0
AND ez_emintaid = k00_eszkozmintaid
AND k00_uzembedatum < ( Date_add(Curdate(),
INTERVAL ez_honap month) )
AND k00_uzembedatum != ''
AND k02_vgazdaid NOT IN ( 7 ))
AND NOT EXISTS(SELECT *
FROM eszkozkizar
WHERE ez_flid = 0
AND ez_emintaid = k00_eszkozmintaid
AND k02_tamszervid = ez_tamszerv
AND k02_tamstatusid = ez_tamsts
AND k00_uzembedatum < ( Date_add(Curdate(),
INTERVAL ez_honap month) )
AND k00_uzembedatum != ''
AND k02_vgazdaid NOT IN ( 7 ))
ORDER BY k00_eszkoznev ASC;

Answer 1

Also you can use USE INDEX (index_list) statement: http://dev.mysql.com/doc/refman/5.5/en/index-hints.html