mysqlクエリが非常に遅く実行されています。インデックスを手伝ってください

Question

私は100000行で実行するのに5秒かかるクエリを実行しようとしています。以下にクエリを示します。私は可能なすべてのインデックスを試しました。何が欠けているか教えてください。

select distinct db_books.bookid as id 
, request_type.name as book_type 
, request_type.id as book_type_id 
, db_books.subject as subject 
, sender_user.uid as sender_user_id 
, sender_user.username as sender_user 
, sender_company.companyid as sender_company_id 
, sender_company.companyname as sender_company 
, sender_team_id.teamid as sender_team_id 
, sender_team_id.name as sender_team 
, GROUP_CONCAT(distinct receiver_user_details.uid separator '|') as receiver_user_id 
, GROUP_CONCAT(distinct receiver_user_details.username separator '|') as receiver_user 
, GROUP_CONCAT(distinct receiver_company.companyid separator '|') as receiver_company_id 
, GROUP_CONCAT(distinct receiver_company.companyname separator '|') as receiver_company 
, GROUP_CONCAT(distinct receiver_team_details.teamid separator '|') as receiver_team_id 
, GROUP_CONCAT(distinct receiver_team_details.name separator '|') as receiver_team 
, status.id as statusid 
, status.name as status 
, db_books.modifydate as modified_date 
, db_books.createddate as creation_date 
, state.id as stateid 
, state.name as state 
, assignee.uid as assignee_user_id 
, assignee.username as assignee_user 
, purpose.name as purpose 
, purpose.id as purposeid 
, g.name as entityname 
, g.entityid as entityid 
from db_books db_books 
inner join db_users sender_user on (sender_user.deleted=0 and sender_user.uid=db_books.sndrUserid) 
inner join db_companies sender_company on (sender_company.deleted=0 and sender_company.companyid=db_books.sndrCompanyid) 
inner join db_companies receiver_company on (receiver_company.deleted=0 and receiver_company.companyid=db_books.target_company_id) 
inner join db_request_types request_type on (request_type.id=db_books.book_type_id) 
left outer join db_teams sender_team_id on (sender_team_id.deleted=0 and sender_team_id.teamid=db_books.sender_team_id) 
left outer join db_books_to_users receiver_user on (receiver_user.bookid=db_books.bookid) 
left outer join db_users receiver_user_details on (receiver_user_details.uid=receiver_user.userid) 
left outer join db_books_to_teams receiver_teams on (receiver_teams.bookid=db_books.bookid) 
left outer join db_teams receiver_team_details on (receiver_team_details.teamid=receiver_teams.teamid) 
left outer join db_request_status status on (status.id=db_books.statusid) 
left outer join db_request_state_types state on (state.id=db_books.request_state_id) 
left outer join db_request_purpose purpose on (purpose.id=db_books.request_purpose_id) 
left outer join db_users assignee on (assignee.uid=db_books.assignee) 
left outer join db_books_details mdtl on (mdtl.deleted=0 and mdtl.bookid=db_books.bookid) 
left outer join db_entities g on (g.deleted=0 and g.entityid=mdtl.entityid) 
where 1=1 
and 
(db_books.sndrUserid=25000000003265 
or db_books.sender_team_id in (
      select a.teamid from db_team_users a 
      inner join db_teams b on (b.teamid=a.teamid and b.deleted=0) 
      where a.userid=25000000003265 
     ) 
or db_books.bookid in (
    select distinct bookid from db_books_to_users where userid=25000000003265 
    union 
    select distinct bookid from db_books_to_teams where teamid in 
     (
      select a.teamid from db_team_users a 
      inner join db_teams b on (b.teamid=a.teamid and b.deleted=0) 
      where a.deleted=0 AND a.userid=25000000003265 
     ) 
    ) 
) 
group by db_books.bookid 
limit 20 

説明は以下の通りです。あなたが実行計画の最初の行が表示された場合

id select_type table type possible_keys key key_len ref rows Extra 
1 PRIMARY sender_user ALL PRIMARY,u2    14573 Using where; Using temporary; Using filesort 
1 PRIMARY db_books ref i_db_books_target_company_id,i_db_books_sndrUserid,i_db_books_sndrCompanyid,i_sndrUserid_sender_team_idbookid i_db_books_sndrUserid 7 mde_staging.sender_user.uid 41 Using where 
1 PRIMARY sender_company eq_ref PRIMARY,db_companies_icd PRIMARY 7 mde_staging.db_books.sndrCompanyid 1 Using where 
1 PRIMARY receiver_company eq_ref PRIMARY,db_companies_icd PRIMARY 7 mde_staging.db_books.target_company_id 1 Using where 
1 PRIMARY sender_team_id eq_ref PRIMARY,db_teams_i PRIMARY 7 mde_staging.db_books.sender_team_id 1 
1 PRIMARY receiver_user ref i_db_books_to_users_bookid i_db_books_to_users_bookid 7 mde_staging.db_books.bookid 1 
1 PRIMARY receiver_user_details eq_ref PRIMARY,u2 PRIMARY 7 mde_staging.receiver_user.userid 1 
1 PRIMARY receiver_teams ref i_db_books_to_teams_bookid i_db_books_to_teams_bookid 7 mde_staging.db_books.bookid 1 
1 PRIMARY receiver_team_details eq_ref PRIMARY,db_teams_i PRIMARY 7 mde_staging.receiver_teams.teamid 1 
1 PRIMARY status eq_ref PRIMARY PRIMARY 4 mde_staging.db_books.statusid 1 
1 PRIMARY state eq_ref PRIMARY PRIMARY 4 mde_staging.db_books.request_state_id 1 
1 PRIMARY purpose eq_ref PRIMARY PRIMARY 4 mde_staging.db_books.request_purpose_id 1 
1 PRIMARY assignee eq_ref PRIMARY,u2 PRIMARY 7 mde_staging.db_books.assignee 1 
1 PRIMARY mdtl ref db_books_details_bookid db_books_details_bookid 7 mde_staging.db_books.bookid 1 
1 PRIMARY request_type ALL PRIMARY    4 Using where; Using join buffer 
1 PRIMARY g eq_ref PRIMARY,db_entities7 PRIMARY 7 mde_staging.mdtl.entityid 1 
3 DEPENDENT SUBQUERY db_books_to_users ref i_db_books_to_users_bookid i_db_books_to_users_bookid 7 func 1 Using where; Using temporary 
4 DEPENDENT UNION db_books_to_teams ref i_db_books_to_teams_bookid i_db_books_to_teams_bookid 7 func 1 Using where; Using temporary 
5 DEPENDENT SUBQUERY b eq_ref PRIMARY,db_teams_i PRIMARY 7 func 1 Using where 
5 DEPENDENT SUBQUERY a ref db_team_users_i db_team_users_i 11 func,const 1 Using where 
    UNION RESULT <union3,4> ALL      
2 DEPENDENT SUBQUERY b eq_ref PRIMARY,db_teams_i PRIMARY 7 func 1 Using where 
2 DEPENDENT SUBQUERY a ref db_team_users_i db_team_users_i 7 func 1 Using where 

、それは可能なインデックスを使用して、ファイルのソートなどそれが問題であるかどうかわからないを使用していません。これを修正する方法を教えてください。

Answer 1

私が見ている最大の問題はサブクエリ修飾子です。テストされた各行ごとのヒット数。私はその後、WHERE句の部分を最初のテーブルとしてのプリクエリに変更し、それらの結果の本を手に入れて本に参加させ、残りはうまくいくはずです。さらに、「STRAIGHT_JOIN」という句は、あなたが言った順序でクエリを実行するようにエンジンに指示します。時には、あなたを先取りして、 "ルックアップ"参照テーブルの1つに基づいて最適化を試み、残りの部分をバックフィルで見つけようとします。 、

select STRAIGHT_JOIN distinct 

、その後、あなたの句から

from 
     db_books db_books 

から

from 
     (SELECT distinct db.bookid 
      from 
       db_books db 
       left join db_team_users TeamA 
        ON db.sndrUserID = TeamA.userID 
        AND db.Sender_Team_ID = TeamA.TeamID 
        LEFT JOIN db_teams TeamB 
         ON TeamA.TeamID = TeamB.TeamID 
         AND TeamB.Deleted = 0 
       left join db_books_to_users ToUser 
        ON db.BookID = ToUser.BookID 
        AND db.sndrUserID = ToUser.userID 
       left join db_books_to_teams ToTeamA 
        ON db.TeamID = ToTeamA.TeamID 
        AND db.sndrUserID = ToTeamA.UserID 
        AND a.Deleted = 0 
        left join db_teams ToTeamsB 
         ON ToTeamA.TeamID = ToTeamB.TeamID 
         AND b.Deleted = 0 
      where 
       db.sndrUserID = 25000000003265 
       OR NOT TeamB.TeamID IS NULL 
       OR NOT ToUser.BookID IS NULL 
       OR NOT ToTeamB.TeamID IS NULL 
      limit 
       20) PreQualBooks 
     JOIN db_books 
     ON PreQualBooks.BookID = db_Books.BookID 

への一番上のSELECT

CHANGEを言っているすべてのそして、あなたはWHERE決勝を削除することができますこのプレクエリは、ユーザまたはチームに基づいてすべての可能性のある本IDを事前に認定するために一番前に行われますJOINとの関係。 LEFT JOINを許可することにより、booksテーブルはONCEを通過し、それぞれの関係がチーム/ユーザーステータスになり、送信ユーザーまたはそれぞれLEFT JOIN（TeamB、ToUserおよびToTeamB）の最低レベルに基づいてレコードが返されます。このプレクエリーでは20冊までの制限が適用されるため、問合せの最後にLIMIT句が必要なく、20冊しか使用できません。

group_concatのために外部GROUP BYを残してください。