Entity Framework 6クエリパフォーマンス（M-M関係）

Question

EFを使用して複数のテーブルから複数の列を照会する必要があります。選択クエリにM-M関係を含めないと、すべてうまくいって素晴らしいパフォーマンスが得られます。 MM関係に

クエリ：

result = (from s in db.Member 
         .Include(i => i.Category) 
         .Include(i => i.MemberWorkEntity) 
         .Include(i => i.Status) 
         .Include(i => i.DiscountMethod) 
         .Where(i => i.C_deleted == null) 
     select new MemberDTO 
     { 
      memberNumber = s.memberNumber, 
      name = s.name, 
      status = s.Status.name, 
      email = s.email, 
      phone = s.phone, 
      mobile = s.mobile, 
      fax = s.fax, 
      workEntity = (from e in db.WorkEntity.Where(i => i.workEntityLevelID == 2) 
         join sc in s.MemberWorkEntity on e.workEntityID equals sc.workEntityID 
         select e.name).FirstOrDefault(), 
      category = s.Category.name, 
      discountMethod = s.DiscountMethod.name, 
      delegate = s.delegate ? "Yes" : "No", 
      leader = s.leader ? "Yes" : "No" 

     }).AsNoTracking().ToList<MemberDTO>(); 

30000レコードの実行時間（ミリ秒）：MM関係せず

|1st Execution: 1376 
|2nd Execution: 160 
|3rd Execution: 145 

クエリ：

result = (from s in db.Member 
         .Include(i => i.Category) 
         .Include(i => i.MemberWorkEntity) 
         .Include(i => i.Status) 
         .Include(i => i.DiscountMethod) 
         .Where(i => i.C_deleted == null) 
     select new MemberDTO 
     { 
      memberNumber = s.memberNumber, 
      name = s.name, 
      status = s.Status.name, 
      email = s.email, 
      phone = s.phone, 
      mobile = s.mobile, 
      fax = s.fax, 
      //removed M-M Relationship Query 
      category = s.Category.name, 
      discountMethod = s.DiscountMethod.name, 
      delegate = s.delegate ? "Yes" : "No", 
      leader = s.leader ? "Yes" : "No" 

     }).AsNoTracking().ToList<MemberDTO>(); 

30000レコードの実行時間（ミリ秒） ：

|1st Execution: 1286 
|2nd Execution: 79 
|3rd Execution: 67 

なぜこのような違いが（平均2倍遅いのですか）？どのようにしてクエリのパフォーマンスを向上させることができますか？

UPDATE：

IEnumerable<WorkEntity> workEntities = db.WorkEntity.AsNoTracking().Where(i => i.workEntityLevelID == 2); 

result = (from s in db.Member 
         .Include(i => i.Category)       
         .Include(i => i.Status) 
         .Include(i => i.DiscountMethod) 
         .Where(i => i.C_deleted == null) 
     select new MemberDTO 
     { 
      memberNumber = s.memberNumber, 
      name = s.name, 
      status = s.Status.name, 
      email = s.email, 
      phone = s.phone, 
      mobile = s.mobile, 
      fax = s.fax, 
      workEntity = (from e in workEntities 
         join sc in s.MemberWorkEntity on e.workEntityID equals sc.workEntityID 
         select e.name).FirstOrDefault(), 
      category = s.Category.name, 
      discountMethod = s.DiscountMethod.name, 
      delegate = s.delegate ? "Yes" : "No", 
      leader = s.leader ? "Yes" : "No" 

     }).AsNoTracking().ToList<MemberDTO>(); 

30000レコードの実行時間（ミリ秒）：

@ AndreFilimonの提案に基づいて、私のクエリを更新：メンバーとWorkEntity

UPDATEとの関係

|1st Execution: 1364 |2nd Execution: 122 |3rd Execution: 120 

UPDATE：@agfcが示唆したように、私のメンバー表に単純なインデックスを追加しました：

IEnumerable<WorkEntity> workEntities = db.WorkEntity.AsNoTracking().Where(i => i.workEntityLevelID == 2); 

result = (from s in db.Member 
         .Include(i => i.Category)       
         .Include(i => i.Status) 
         .Include(i => i.DiscountMethod) 
         .Where(i => i.C_deleted == null) 
     select new MemberDTO 
     { 
      memberNumber = s.memberNumber, 
      name = s.name, 
      status = s.Status.name, 
      email = s.email, 
      phone = s.phone, 
      mobile = s.mobile, 
      fax = s.fax, 
      workEntity = (from e in workEntities 
         join sc in s.MemberWorkEntity on e.workEntityID equals sc.workEntityID 
         select e.name).FirstOrDefault(), 
      category = s.Category.name, 
      discountMethod = s.DiscountMethod.name, 
      delegate = s.delegate ? "Yes" : "No", 
      leader = s.leader ? "Yes" : "No" 

     }).AsNoTracking().ToList<MemberDTO>(); 

30000レコードの実行時間（ミリ秒）：

|1st Execution: 1544 
|2nd Execution: 109 
|3rd Execution: 105 

UPDATE：クリンガーの答え@に基づいて変更クエリ：

result = db.MemberWorkEntity.Where(mw => mw.WorkEntity.workEntityLevelID == 2 && mw.Member.C_deleted == null) 
     .Select(s => new MemberDTO 
     { 
      memberNumber = mw.Member.memberNumber, 
      name = mw.Member.name, 
      status = mw.Member.Status.name, 
      email = mw.Member.email, 
      phone = mw.Member.phone, 
      mobile = mw.Member.mobile, 
      fax = mw.Member.fax, 
      workEntity = mw.WorkEntity.name, 
      category = mw.Member.Category.name, 
      discountMethod = mw.Member.DiscountMethod.name, 
      @delegate = mw.Member.@delegate ? "Yes" : "No", 
      leader = mw.Member.leader ? "Yes" : "No" 
     }).ToList(); 

30000レコードの実行時間（ミリ秒）：

|1st Execution: 1427 
|2nd Execution: 80 
|3rd Execution: 76 

Answer 1

なし： はまた、怒鳴る加入を避けるために、メイン・クエリのうち、内側のクエリを移動あなたのエンティティの正確な形状を見ていない、次のようなものが何をすべき：

result = db.MemberWorkEntity.Where(mw => mw.WorkEntity.workEntityLevelID == 2 && mw.Member.C_deleted == null) 
     .Select(s => new MemberDTO 
{ 
    memberNumber = mw.Member.memberNumber, 
    name = mw.Member.name, 
    status = mw.Member.Status.name, 
    email = mw.Member.email, 
    phone = mw.Member.phone, 
    mobile = mw.Member.mobile, 
    fax = mw.Member.fax, 
    workEntity = mw.WorkEntity.name, 
    category = mw.Member.Category.name, 
    discountMethod = mw.Member.DiscountMethod.name, 
    @delegate = mw.Member.@delegate ? "Yes" : "No", 
    leader = mw.Member.leader ? "Yes" : "No" 
}).ToList(); 

あなたはDTOないエンティティ内に突出しているのでIncludeを使用する必要はありません。 DTOには、あなたが含むエンティティへのナビゲーションプロパティはありません。 Includeは、エンティティが返されたときに熱心な読み込みに使用されます。

Answer 2

where句の後に含まれて移動しようと、あなたはまた、ここでいくつかの全体的なパフォーマンスを得る必要があります。

var workEntities=(from e in db.WorkEntity).Where(e=>e.workEntityLevelID==2).ToList(); 
var result = (from s in db.Member.Where(i => i.C_deleted == null).Include(i => i.Category).Include(i => i.MemberWorkEntity).Include(i => i.Status).Include(i => i.DiscountMethod) 
      select new MemberDTO 
      { 
       memberNumber = s.memberNumber, 
       name = s.name, 
       status = s.Status.name, 
       email = s.email, 
       phone = s.phone, 
       mobile = s.mobile, 
       fax = s.fax, 
       workEntity = workEntities.Where(e=>e.workEntityID ==sc.workEntityID).DefaultIfEmpty().Select(e=>e.name).FirstOrDefault(), 
       category = s.Category.name, 
       discountMethod = s.DiscountMethod.name, 
       delegate = s.delegate ? "Yes" : "No", 
       leader = s.leader ? "Yes" : "No" 

      }).AsNoTracking().ToList<MemberDTO>();