Is there any way to optimize this mysql query?
I have about 100K rows in a table.
select komentarai.* FROM (
SELECT MAX(id) AS max_id FROM komentarai WHERE siteid=1 GROUP BY number
) AS tbl
INNER JOIN `komentarai` ON komentarai.id = tbl.max_id ORDER BY komentarai.added DESC LIMIT XX, 10
Here is an explanation of index:
PRIMARY <derived2> ALL NULL NULL NULL NULL 3372 Using temporary; Using filesort
PRIMARY komentarai eq_ref PRIMARY,id PRIMARY 4 tbl.max_id 1 2
DERIVED komentarai ref siteid siteid 1 5695 Using where; Using temporary; Using filesort
Thanks!
Related
I am trying to debug a MYSQL Query for its taking time around 4-5 minutes on one server and it fails on another MYSQL server.
The query is like this:
SELECT
*,
TM.tutor_id as tutor_id,
TIMESTAMPDIFF( YEAR, birthdate, CURDATE( ) ) AS age
from
tutor_master as TM
LEFT JOIN category_master as CM
on TM.category = CM.category_id
LEFT JOIN tutor_expected_rate TER
ON FIND_IN_SET( TER.tutor_id, TM.tutor_id ) > 0
LEFT JOIN admin_shortlist_master SHM
ON TM.tutor_id = SHM.tutor_id
AND (SHM.user_auth_id = 'c84258e9c39059a89ab77d846ddab909')
INNER JOIN level_master LM
ON FIND_IN_SET(LM.level_id, TER.level_id) > 0
WHERE
1=1
GROUP BY
TM.tutor_id
order by
TM.is_priority DESC,
TM.tutor_id DESC
LIMIT
0, 10
and MYSQL explain result is like this:
1 SIMPLE TM NULL ALL PRIMARY,tutor_id NULL NULL NULL 27530 100.00 Using temporary; Using filesort
1 SIMPLE SHM NULL ref tutor_id,user_auth_id user_auth_id 257 const 1 100.00 Using where
1 SIMPLE CM NULL eq_ref PRIMARY PRIMARY 4 toprecru_portal_db.TM.category 1 100.00 NULL
1 SIMPLE LM NULL ALL NULL NULL NULL NULL 11 100.00 Using join buffer (Block Nested Loop)
1 SIMPLE TER NULL ALL NULL NULL NULL NULL 13223 100.00 Using where; Using join buffer (Block Nested Loop)
Now my question is, it there any apparent mistake, which I am overlooking to make the query more efficient.
Thanks.
I have a problem with performance with MySQL. How can i improve it?
The situation is following:
Table “backlogsap„ have about 4 mio entries.
Indexes are created
This table have FK and other tables have FK to this table => can’t
create partitions.
This query need about 140 seconds to complete:
select
idmaterial,
materialgroup,
materialgroupcategory,
name,
dispatchgroup,
idsupplier,
group_concat(distinct sellingorganizationname) as sellingorganizationnames,
group_concat(distinct idordertype) as idordertypes,
group_concat(distinct idpositiontype) as idpositiontypes,
sum(newOrUpdated and isCritical) as classA,
sum(newOrUpdated and not isCritical) as classB,
sum(processingstate <3) as classC,
(select count(innerBacklogsAp.idmaterial)
from backlogsap as innerBacklogsAp
where innerBacklogsAp.idmaterial = src.idmaterial and IsDeleted = 0) as countReplacementVehiclerRequests
from
(select
backlogsap.idmaterial as idmaterial,
backlog.processingstate as processingstate,
material.idsupplier as idsupplier,
backlogsap.sellingorganizationname as sellingorganizationname,
backlogsap.idpositiontype as idpositiontype,
backlogsap.idordertype as idordertype,
materialindistributioncenter.dispatchgroup as dispatchgroup,
material.name as name,
material.idmaterialgroup as materialgroup,
materialgroup.idmaterialgroupcategory as materialgroupcategory,
(processingstate = 0 or processingstate = 1) as newOrUpdated,
((cancellation.state is not null and cancellation.state = 0 ) or
(reminderrequest.state is not null and (reminderrequest.state = 2 or reminderrequest.state = 0))
) as isCritical
from backlogsap
join backlog using (idbacklogsap)
left join cancellation using (idcancellation)
left join reminderrequest on backlog.IdReminderRequest = reminderrequest.idreminder
left join material using (idmaterial)
left join materialindistributioncenter using (idmaterial, iddistributioncenter)
left join materialgroup using (idmaterialgroup)
where (idcancellation is null or cancellation.State not in (1)) and
backlogsap.isdeleted = 0 and
backlogsap.idordertype not in ('ZAP', 'ZAK', 'ZAKO', 'ZAKZ', 'ZAPM') and
iddistributioncenter = 1469990
) as src
group by idmaterial
order by classA desc, classB desc, classC, idmaterial desc
Explain
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY <derived3> ALL 26960 Using temporary; Using filesort
3 DERIVED backlogsap index_merge PRIMARY,fk_BacklogSap_OrderType1_idx,
fk_BacklogSap_MaterialInDistributionCenter1_idx,
perform_backlogsap_isdeleted,
fk_BacklogSap_DistributionCenter_idx perform_backlogsap_isdeleted,fk_BacklogSap_DistributionCenter_idx 1,4 35946 Using intersect(perform_backlogsap_isdeleted,fk_BacklogSap_DistributionCenter_idx); Using where
3 DERIVED backlog eq_ref idBacklogSAP_UNIQUE,
fk_Backlog_BacklogSap1_idx,
fk_Backlog_Cancellation1_idx idBacklogSAP_UNIQUE 4 ...backlogsap.IdBacklogSap 1
3 DERIVED cancellation eq_ref PRIMARY PRIMARY 4 ...backlog.IdCancellation 1 Using where
3 DERIVED reminderrequest eq_ref PRIMARY PRIMARY 4 ...backlog.IdReminderRequest 1
3 DERIVED material eq_ref PRIMARY PRIMARY 45 ...backlogsap.IdMaterial 1
3 DERIVED materialindistributioncenter eq_ref PRIMARY,
unqiue_IdDistributionCenter_IdMaterial,
fk_MaterialDistributionCenter_DistributionCenter1_idx,
fk_MaterialDistributionCenter_Material1_idx PRIMARY 49 const,...backlogsap.IdMaterial 1
3 DERIVED materialgroup eq_ref PRIMARY PRIMARY 137 ....material.IdMaterialGroup 1
2 DEPENDENT SUBQUERY innerBacklogsAp ref perform_backlogsap_isdeleted,
idx_backlogsap_IdMaterial idx_backlogsap_IdMaterial 45 func 8 Using where
Solved: created combined Index (idmaterial, IsDeleted)
Our search is very slow on view. we can't define index on view.. Please help how we can improve this .. Below Query took 33.3993 sec.
SELECT
`v_cat_pro`.`product_id`, `v_cat_pro`.`msrp`,
FROM
`v_prod_cat` AS `v_cat_pro`
WHERE
(product_status="1" and msrp >0 AND (search_text = 'de') )
ORDER BY
`msrp` ASC LIMIT 50
Explain query result
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE cat_product index catproducts_product_id,category_product_index category_product_index 8 NULL 941343 Using index; Using temporary; Using filesort
1 SIMPLE dept eq_ref PRIMARY PRIMARY 4 newdhf.cat_product.category_id 1 Using where
1 SIMPLE team eq_ref PRIMARY PRIMARY 4 newdhf.dept.parent_id 1 Using where
1 SIMPLE league eq_ref PRIMARY PRIMARY 4 newdhf.team.parent_id 1 Using where
1 SIMPLE product eq_ref PRIMARY PRIMARY 4 newdhf.cat_product.product_id 1 Using where
CREATE
ALGORITHM=UNDEFINED VIEW v_prod_cat AS
select
dept.id AS dept_id,team.short_name AS shortteamname,team.url AS team_url,team.id AS team_id,league.id AS league_id,product.product_id AS product_id,product.product_status AS product_status,product.upload_image_l AS upload_image_l,dept.name AS department,team.name AS team,league.name AS league,product.title AS title,cat_product.product_url AS product_url,product.discount AS discount,product.discount_start_date AS discount_start_date,product.discount_end_date AS discount_end_date,product.extra_discount AS extra_discount,product.extra_discount_start_date AS extra_discount_start_date,product.extra_discount_end_date AS extra_discount_end_date,product.global_alt_tag AS global_alt_tag,product.msrp AS msrp,product.cost AS cost,product.vendor_id AS vendor_id,if((cat_product.is_default > 0),1,0) AS is_default,
concat(league.name,_utf8' ',team.name,_utf8' ',dept.name,_utf8' ',replace(replace(replace(replace(product.title,'$leaguename',league.name),'$teamname',team.name),'$shortteamname',team.short_name),'$departmentname',dept.name),' ',product.sku_code,_utf8' ',replace(replace(replace(replace(product.site_search_keyword,'$leaguename',league.name),'$teamname',team.name),'$shortteamname',team.short_name),'$departmentname',dept.name)) AS search_text
from
((((categories dept join categories team on(((team.id = dept.parent_id) and (team.category_type = _utf8'team')))) join categories league on(((league.id = team.parent_id) and (league.category_type = _utf8'league')))) join category_products cat_product on((cat_product.category_id = dept.id))) join products product on((product.product_id = cat_product.product_id))) where (dept.category_type = _utf8'department')
order by
dept.id desc;
If you add an index to your 'v_prod_cat' table on the columns that you are searching on then this should help speed up your view.
I have a really wierd problem in my MySQL InnoDB database. I have following query:
SELECT DISTINCT p.idProject AS idProject, p.name AS name, 0 AS isConfirm
FROM Projects p
JOIN team_project tp ON (p.idProject = tp.idProject)
JOIN projtimes pt ON (p.idProject = pt.idProject)
JOIN CalledTimesTbl ctt ON (p.idProject = ctt.idProject)
LEFT JOIN NextCalls nc ON (ctt.idCustomer = nc.idCustomer
AND ctt.idProject = nc.idProject)
WHERE tp.idTeam = 158
AND p.activated = 1
AND current_date >= p.projStart
AND current_date < p.confirmStart
AND pt.invitesCount < pt.maxPerPresentation
AND (nc.idCustomer IS NULL OR nc.nextCall < now())
ORDER BY p.name
Generally the query runs fine, but sometimes - for example when I set tp.idTeam = 147 it runs really slow (like 10 or 20 seconds). When I create alternative team and adjust proper tables values to have the same result with different idTeam value - the query executes in a fraction of second.
I profiled the query and noticed that when query executes slowly - there is one thing that consumes most of the time:
Copying to tmp table | 12.489197
I was a bit surprised that the query creates a tmp table but ok - it creates it every time the query executes - also when it executes fast.
I just add that db is designed well, there are all needed foreign keys, etc.
How to find the source of the slow executions and eliminate it?
EDIT: EXPLAIN results:
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE tp ref unique_row,idTeam idTeam 4 const 56 Using temporary; Using filesort
1 SIMPLE p eq_ref PRIMARY,projStart,confirmStart PRIMARY 4 xxx.tp.idProject 1 Using where
1 SIMPLE pt ref uniq_projtimes uniq_projtimes 4 xxx.tp.idProject 1 Using where; Distinct
1 SIMPLE ctt ref idProject idProject 4 xxx.tp.idProject 3966 Using index; Distinct
1 SIMPLE nc eq_ref PRIMARY,idProject PRIMARY 8 xxx.ctt.idCustomer,xxx.tp.idProject 1 Using where; Distinct
EDIT2: Results of EXPLAIN EXTENDED first for fast query, second for the slow one.
id select_type table type possible_keys key key_len ref rows filtered Extra 1 SIMPLE tp ref unique_row,idTeam idTeam 4 const 1 100 Using temporary
1 SIMPLE p eq_ref PRIMARY,projStart,confirmStart PRIMARY 4 xxx.tp.idProject 1 100 Using where
1 SIMPLE pt ref uniq_projtimes uniq_projtimes 4 xxx.tp.idProject 1 100 Using where; Distinct
1 SIMPLE ctt ref idProject idProject 4 xxx.tp.idProject 46199 100 Using index; Distinct
1 SIMPLE nc eq_ref PRIMARY,idProject PRIMARY 8 xxx.ctt.idCustomer,xxx.tp.idProject 1 100 Using index; Distinct
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE p eq_ref PRIMARY,projStart,confirmStart PRIMARY 4 xxx.ctt.idProject 1 100 Using where
1 SIMPLE pt ref uniq_projtimes uniq_projtimes 4 xxx.ctt.idProject 1 100 Using where; Distinct
1 SIMPLE tp ref unique_row,idTeam unique_row 8 xxx.pt.idProject,const 1 100 Using where; Using index; Distinct
1 SIMPLE nc eq_ref PRIMARY,idProject PRIMARY 8 xxx.ctt.idCustomer,xxx.tp.idProject 1 100 Using index; Distinct
Try this adjusted query. (It will join less rows)
SELECT DISTINCT p.idProject AS idProject, p.name AS name, 0 AS isConfirm
FROM Projects p
JOIN projtimes pt ON
p.idProject = pt.idProject
AND p.activated = 1
AND current_date >= p.projStart
AND current_date < p.confirmStart
AND pt.invitesCount < pt.maxPerPresentation
JOIN team_project tp ON
p.idProject = tp.idProject
AND tp.idTeam = 158
JOIN CalledTimesTbl ctt ON (p.idProject = ctt.idProject)
LEFT JOIN NextCalls nc ON (ctt.idCustomer = nc.idCustomer
AND ctt.idProject = nc.idProject)
WHERE (nc.idCustomer IS NULL OR nc.nextCall < now())
ORDER BY p.name
Can anyone tell me why this query is not using index idx_accessorieslinkid
I have created index:
CREATE INDEX idx_accessorieslinkid ON `accessorieslink` (actionid);
I am new to indexes and trying to understand how they work (and why sometimes they don't!)
sql
SELECT action.actionid
FROM
ACTION
LEFT JOIN
(SELECT
SUM(accprice) AS accprice,
actionid
FROM
accessorieslink
GROUP BY actionid) AS accprice
ON accprice.actionid = action.actionid
WHERE action.typeid = '2'
AND actiondate2 BETWEEN '20130301' AND '20130301'
ORDER BY actiondate2 DESC
explain results
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY action index_merge idx_actiontypeid,idx_actiondate idx_actiondate,idx_actiontypeid 4,5 141 Using intersect(idx_actiondate,idx_actiontypeid); Using where; Using index; Using temporary; Using filesort
1 PRIMARY <derived2> ALL 7804
2 DERIVED accessorieslink ALL 12175 Using temporary; Using filesort
derived table can not use index on the physical table.
try below query
SELECT SUM(accprice) AS accprice, accessorieslink.actionid FROM accessorieslink
LEFT JOIN `action` ON accessorieslink.actionid = action.actionid
GROUP BY accessorieslink.actionid