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Entity Frameworkにはパフォーマンスの低下があります

環境

Entity Framework 6.x関連の問題があるようです。パフォーマンスの問題を特定するために何週間も費やしてきましたが、すべてではないにしても、ほとんどの場合、発見/考えられる問題を修正しました。つまり、Includeを使用すると、パフォーマンスが大幅に低下します。

  • EFCacheの利用。
  • EF 6.2を実行するdbモデルキャッシュを有効にしました。
  • キャッシュされたビューを利用する。
  • 可能な場合はレイジーロードなしのコンテキストを使用して、正しい（および最小限の）インクルードを利用します。
  • 読み取り専用データにはAsNoTrackingを使用します。
  • プロキシの生成も自動検出の変更もないコンテキストの使用（後者は最小限の改善であるように見えますが）。
  • コンテキストの有効期間は、可能な場合は使用ブロック内の最小限の単一クエリです。
  • オブジェクトのコンストラクターをクリーンアップして、EFがデータをオブジェクトにマッピングする際のオーバーヘッドを最小限に抑える必要があります。
  • "Async all the way"これは確かに応答性を向上させますが、実行される作業を減らしません。

影響を与える可能性のある、私たちがまだ抱えている現在の（推定される）問題：

  • 主キー、クラスター化されたGUID。
  • エンティティがその一部であり、二重結合を引き起こす、タイプ階層ごとのテーブル。

私たちがすでに焼き尽くしてきた関連トピックのほとんどは、大きな影響はありません。私たちが知る限り、データベースは「大丈夫」です。クエリがデータベースに到達する前にlog4netインターセプターを利用したところ、3〜7のインクルードを使用したクエリの一部は巨大なものですが、非常に遅くないことがわかりました。時間は0ミリ秒から100ミリ秒です。オブジェクトが「使用可能」になるまでは、2000ミリ秒から8000ミリ秒になる傾向があります。

現在、データベースには最大で50.000のエンティティがあります。ただし、ほぼクリーンなデータベースであっても、違いは最小限です。

コード

（簡略化、抽出）モデル構造：

_public class Entity
{
    public virtual Guid Id { get; set; }
    public virtual long Version { get; set; }
    public virtual string EntityType { get; set; }
}

public class User : Entity
{
    public virtual Guid Id { get; set; }
    public virtual string Username { get; set; }
    public virtual string Password { get; set; }

    public virtual Person Person { get; set; }
}

public class Person : Entity
{
    public virtual Guid Id { get; set; }
    public virtual DateTime DateOfBirth { get; set; }
    public virtual string Name { get; set; }

    public virtual Employee Employee { get; set; }
}

public class Employee : Entity
{
    public virtual Guid Id { get; set; }
    public virtual string EmployeeCode { get; set; }
}
_

（簡略化）遅いクエリ。 Stopwatchをラップして監視すると、平均時間は2秒になりますが、クエリ自体はlog4netの生成されたログファイルに数ミリ秒しかリストしません。

_var userId = .... // Obtained elsewhere
using (var context = new DbContext())
{
    var user =
        context.Set<User>()
            .Include(u => u.Person.Employee)
            .FirstOrDefault(u => u.Id == userId);
}
_

私たちは別のアプローチを試しました：

_context.Set<User>().Where(u => u.Id == userId).Load();
context.Set<Person>().Where(p => p.User.Id == userId).Load();
context.Set<Employee>().Where(e => e.Person.User.Id == userId).Load();

var user = context.Set<User>().Local.FirstOrDefault(u => u.Id == userId);
_

概要

提供された情報に基づいて、見落としている可能性のある明確な問題を誰かが見たり、他に試すことができる提案をしていますか？

前述の2つの「問題」がまだ存在しているという事実は、EFを半高速で構築することからのEFのデザイアーですか？

おそらく関連します。FirstOrDefaultブロックの代わりにFind(userId)を使用すると、妥当な期間内に終了しないようです。

アップデート1

@Ivan Stoevへの応答-上記のクエリを実行すると、98ミリ秒（2968ミリ秒）実行され、次の（完全な）SQLステートメントが生成されました。

_SELECT 
    [Limit1].[CheckSum] AS [CheckSum], 
    [Limit1].[C1] AS [C1], 
    [Limit1].[Id] AS [Id], 
    [Limit1].[Version] AS [Version], 
    [Limit1].[EntityType] AS [EntityType], 
    [Limit1].[Deleted] AS [Deleted], 
    [Limit1].[UpdatedBy] AS [UpdatedBy], 
    [Limit1].[UpdatedAt] AS [UpdatedAt], 
    [Limit1].[CreatedBy] AS [CreatedBy], 
    [Limit1].[CreatedAt] AS [CreatedAt], 
    [Limit1].[LastRevision] AS [LastRevision], 
    [Limit1].[AccessControlListId] AS [AccessControlListId], 
    [Limit1].[EntityStatus] AS [EntityStatus], 
    [Limit1].[Username] AS [Username], 
    [Limit1].[Password] AS [Password], 
    [Limit1].[Email] AS [Email], 
    [Limit1].[ResetHash] AS [ResetHash], 
    [Limit1].[Flag] AS [Flag], 
    [Limit1].[CryptoKey] AS [CryptoKey], 
    [Limit1].[FailedPasswordTries] AS [FailedPasswordTries], 
    [Limit1].[LastPasswordTry] AS [LastPasswordTry], 
    [Limit1].[UXConfigId] AS [UXConfigId], 
    [Limit1].[LastActivity] AS [LastActivity], 
    [Limit1].[C2] AS [C2], 
    [Limit1].[C3] AS [C3], 
    [Limit1].[C4] AS [C4], 
    [Limit1].[C5] AS [C5], 
    [Limit1].[C6] AS [C6], 
    [Limit1].[C7] AS [C7], 
    [Limit1].[C8] AS [C8], 
    [Limit1].[C9] AS [C9], 
    [Limit1].[C10] AS [C10], 
    [Limit1].[C11] AS [C11], 
    [Limit1].[C12] AS [C12], 
    [Limit1].[C13] AS [C13], 
    [Limit1].[C14] AS [C14], 
    [Limit1].[C15] AS [C15], 
    [Limit1].[C16] AS [C16], 
    [Limit1].[Id1] AS [Id1], 
    [Limit1].[Version1] AS [Version1], 
    [Limit1].[EntityType1] AS [EntityType1], 
    [Limit1].[Deleted1] AS [Deleted1], 
    [Limit1].[UpdatedBy1] AS [UpdatedBy1], 
    [Limit1].[UpdatedAt1] AS [UpdatedAt1], 
    [Limit1].[CreatedBy1] AS [CreatedBy1], 
    [Limit1].[CreatedAt1] AS [CreatedAt1], 
    [Limit1].[LastRevision1] AS [LastRevision1], 
    [Limit1].[AccessControlListId1] AS [AccessControlListId1], 
    [Limit1].[EntityStatus1] AS [EntityStatus1], 
    [Limit1].[CheckSum1] AS [CheckSum1], 
    [Limit1].[C17] AS [C17], 
    [Limit1].[C18] AS [C18], 
    [Limit1].[C19] AS [C19], 
    [Limit1].[C20] AS [C20], 
    [Limit1].[C21] AS [C21], 
    [Limit1].[C22] AS [C22], 
    [Limit1].[C23] AS [C23], 
    [Limit1].[C24] AS [C24], 
    [Limit1].[C25] AS [C25], 
    [Limit1].[C26] AS [C26], 
    [Limit1].[Name_Firstname] AS [Name_Firstname], 
    [Limit1].[Name_Surname] AS [Name_Surname], 
    [Limit1].[Name_Prefix] AS [Name_Prefix], 
    [Limit1].[Name_Title] AS [Name_Title], 
    [Limit1].[Name_Middle] AS [Name_Middle], 
    [Limit1].[Name_Suffix] AS [Name_Suffix], 
    [Limit1].[Sex] AS [Sex], 
    [Limit1].[DateOfBirth] AS [DateOfBirth], 
    [Limit1].[State] AS [State], 
    [Limit1].[C27] AS [C27], 
    [Limit1].[C28] AS [C28], 
    [Limit1].[C29] AS [C29], 
    [Limit1].[C30] AS [C30], 
    [Limit1].[C31] AS [C31], 
    [Limit1].[Id2] AS [Id2], 
    [Limit1].[Version2] AS [Version2], 
    [Limit1].[EntityType2] AS [EntityType2], 
    [Limit1].[Deleted2] AS [Deleted2], 
    [Limit1].[UpdatedBy2] AS [UpdatedBy2], 
    [Limit1].[UpdatedAt2] AS [UpdatedAt2], 
    [Limit1].[CreatedBy2] AS [CreatedBy2], 
    [Limit1].[CreatedAt2] AS [CreatedAt2], 
    [Limit1].[LastRevision2] AS [LastRevision2], 
    [Limit1].[AccessControlListId2] AS [AccessControlListId2], 
    [Limit1].[EntityStatus2] AS [EntityStatus2], 
    [Limit1].[CheckSum2] AS [CheckSum2], 
    [Limit1].[C32] AS [C32], 
    [Limit1].[C33] AS [C33], 
    [Limit1].[C34] AS [C34], 
    [Limit1].[C35] AS [C35], 
    [Limit1].[C36] AS [C36], 
    [Limit1].[C37] AS [C37], 
    [Limit1].[C38] AS [C38], 
    [Limit1].[C39] AS [C39], 
    [Limit1].[C40] AS [C40], 
    [Limit1].[C41] AS [C41], 
    [Limit1].[C42] AS [C42], 
    [Limit1].[C43] AS [C43], 
    [Limit1].[C44] AS [C44], 
    [Limit1].[C45] AS [C45], 
    [Limit1].[C46] AS [C46], 
    [Limit1].[C47] AS [C47], 
    [Limit1].[C48] AS [C48], 
    [Limit1].[C49] AS [C49], 
    [Limit1].[C50] AS [C50], 
    [Limit1].[C51] AS [C51], 
    [Limit1].[Ssn] AS [Ssn], 
    [Limit1].[Employeenumber] AS [Employeenumber], 
    [Limit1].[Bankaccount] AS [Bankaccount], 
    [Limit1].[PersonId] AS [PersonId]
    FROM ( SELECT TOP (1) 
        [Extent1].[Id] AS [Id], 
        [Extent1].[Username] AS [Username], 
        [Extent1].[Password] AS [Password], 
        [Extent1].[Email] AS [Email], 
        [Extent1].[ResetHash] AS [ResetHash], 
        [Extent1].[Flag] AS [Flag], 
        [Extent1].[CryptoKey] AS [CryptoKey], 
        [Extent1].[FailedPasswordTries] AS [FailedPasswordTries], 
        [Extent1].[LastPasswordTry] AS [LastPasswordTry], 
        [Extent1].[UXConfigId] AS [UXConfigId], 
        [Extent1].[LastActivity] AS [LastActivity], 
        [Extent2].[Version] AS [Version], 
        [Extent2].[EntityType] AS [EntityType], 
        [Extent2].[Deleted] AS [Deleted], 
        [Extent2].[UpdatedBy] AS [UpdatedBy], 
        [Extent2].[UpdatedAt] AS [UpdatedAt], 
        [Extent2].[CreatedBy] AS [CreatedBy], 
        [Extent2].[CreatedAt] AS [CreatedAt], 
        [Extent2].[LastRevision] AS [LastRevision], 
        [Extent2].[AccessControlListId] AS [AccessControlListId], 
        [Extent2].[EntityStatus] AS [EntityStatus], 
        [Extent2].[CheckSum] AS [CheckSum], 
        '0X0X' AS [C1], 
        CAST(NULL AS int) AS [C2], 
        CAST(NULL AS varchar(1)) AS [C3], 
        CAST(NULL AS varchar(1)) AS [C4], 
        CAST(NULL AS varchar(1)) AS [C5], 
        CAST(NULL AS varchar(1)) AS [C6], 
        CAST(NULL AS varchar(1)) AS [C7], 
        CAST(NULL AS varchar(1)) AS [C8], 
        CAST(NULL AS bigint) AS [C9], 
        CAST(NULL AS datetime2) AS [C10], 
        CAST(NULL AS bigint) AS [C11], 
        CAST(NULL AS varchar(1)) AS [C12], 
        CAST(NULL AS varchar(1)) AS [C13], 
        CAST(NULL AS varchar(1)) AS [C14], 
        CAST(NULL AS uniqueidentifier) AS [C15], 
        [Join3].[Id1] AS [Id1], 
        [Join3].[Name_Firstname] AS [Name_Firstname], 
        [Join3].[Name_Surname] AS [Name_Surname], 
        [Join3].[Name_Prefix] AS [Name_Prefix], 
        [Join3].[Name_Title] AS [Name_Title], 
        [Join3].[Name_Middle] AS [Name_Middle], 
        [Join3].[Name_Suffix] AS [Name_Suffix], 
        [Join3].[Sex] AS [Sex], 
        [Join3].[DateOfBirth] AS [DateOfBirth], 
        [Join3].[State] AS [State], 
        [Join3].[Version] AS [Version1], 
        [Join3].[EntityType] AS [EntityType1], 
        [Join3].[Deleted] AS [Deleted1], 
        [Join3].[UpdatedBy] AS [UpdatedBy1], 
        [Join3].[UpdatedAt] AS [UpdatedAt1], 
        [Join3].[CreatedBy] AS [CreatedBy1], 
        [Join3].[CreatedAt] AS [CreatedAt1], 
        [Join3].[LastRevision] AS [LastRevision1], 
        [Join3].[AccessControlListId] AS [AccessControlListId1], 
        [Join3].[EntityStatus] AS [EntityStatus1], 
        [Join3].[CheckSum] AS [CheckSum1], 
        CASE WHEN ([Join3].[Id1] IS NULL) THEN CAST(NULL AS varchar(1)) ELSE '0X1X' END AS [C16], 
        CAST(NULL AS varchar(1)) AS [C17], 
        CAST(NULL AS varchar(1)) AS [C18], 
        CAST(NULL AS varchar(1)) AS [C19], 
        CAST(NULL AS varchar(1)) AS [C20], 
        CAST(NULL AS bigint) AS [C21], 
        CAST(NULL AS varchar(1)) AS [C22], 
        CAST(NULL AS smallint) AS [C23], 
        CAST(NULL AS datetime2) AS [C24], 
        CAST(NULL AS uniqueidentifier) AS [C25], 
        CAST(NULL AS datetime2) AS [C26], 
        CAST(NULL AS varchar(1)) AS [C27], 
        CAST(NULL AS varchar(1)) AS [C28], 
        CAST(NULL AS varchar(1)) AS [C29], 
        CAST(NULL AS uniqueidentifier) AS [C30], 
        [Join6].[Id2] AS [Id2], 
        [Join6].[Ssn1] AS [Ssn], 
        [Join6].[Employeenumber1] AS [Employeenumber], 
        [Join6].[Bankaccount1] AS [Bankaccount], 
        [Join6].[PersonId1] AS [PersonId], 
        [Join6].[Version] AS [Version2], 
        [Join6].[EntityType] AS [EntityType2], 
        [Join6].[Deleted] AS [Deleted2], 
        [Join6].[UpdatedBy] AS [UpdatedBy2], 
        [Join6].[UpdatedAt] AS [UpdatedAt2], 
        [Join6].[CreatedBy] AS [CreatedBy2], 
        [Join6].[CreatedAt] AS [CreatedAt2], 
        [Join6].[LastRevision] AS [LastRevision2], 
        [Join6].[AccessControlListId] AS [AccessControlListId2], 
        [Join6].[EntityStatus] AS [EntityStatus2], 
        [Join6].[CheckSum] AS [CheckSum2], 
        CASE WHEN ([Join6].[Id2] IS NULL) THEN CAST(NULL AS varchar(1)) ELSE '0X2X' END AS [C31], 
        CAST(NULL AS varchar(1)) AS [C32], 
        CAST(NULL AS varchar(1)) AS [C33], 
        CAST(NULL AS varchar(1)) AS [C34], 
        CAST(NULL AS varchar(1)) AS [C35], 
        CAST(NULL AS bigint) AS [C36], 
        CAST(NULL AS varchar(1)) AS [C37], 
        CAST(NULL AS smallint) AS [C38], 
        CAST(NULL AS datetime2) AS [C39], 
        CAST(NULL AS uniqueidentifier) AS [C40], 
        CAST(NULL AS datetime2) AS [C41], 
        CAST(NULL AS int) AS [C42], 
        CAST(NULL AS varchar(1)) AS [C43], 
        CAST(NULL AS varchar(1)) AS [C44], 
        CAST(NULL AS varchar(1)) AS [C45], 
        CAST(NULL AS varchar(1)) AS [C46], 
        CAST(NULL AS varchar(1)) AS [C47], 
        CAST(NULL AS varchar(1)) AS [C48], 
        CAST(NULL AS bigint) AS [C49], 
        CAST(NULL AS datetime2) AS [C50], 
        CAST(NULL AS bigint) AS [C51]
        FROM    [dbo].[Users] AS [Extent1]
        INNER JOIN  (SELECT [Var_27].[Id] AS [Id], [Var_27].[Version] AS [Version], [Var_27].[EntityType] AS [EntityType], [Var_27].[Deleted] AS [Deleted], [Var_27].[UpdatedBy] AS [UpdatedBy], [Var_27].[UpdatedAt] AS [UpdatedAt], [Var_27].[CreatedBy] AS [CreatedBy], [Var_27].[CreatedAt] AS [CreatedAt], [Var_27].[LastRevision] AS [LastRevision], [Var_27].[AccessControlListId] AS [AccessControlListId], [Var_27].[EntityStatus] AS [EntityStatus], [Var_27].[CheckSum] AS [CheckSum]
            FROM [dbo].[Entities] AS [Var_27]
            WHERE [Var_27].[Deleted] <> 1 ) AS [Extent2] ON [Extent1].[Id] = [Extent2].[Id]
        LEFT OUTER JOIN  (SELECT [Extent3].[Id] AS [Id1], [Extent3].[Name_Firstname] AS [Name_Firstname], [Extent3].[Name_Surname] AS [Name_Surname], [Extent3].[Name_Prefix] AS [Name_Prefix], [Extent3].[Name_Title] AS [Name_Title], [Extent3].[Name_Middle] AS [Name_Middle], [Extent3].[Name_Suffix] AS [Name_Suffix], [Extent3].[Sex] AS [Sex], [Extent3].[DateOfBirth] AS [DateOfBirth], [Extent3].[State] AS [State], [Extent4].[Id] AS [Id3], [Extent4].[Version] AS [Version], [Extent4].[EntityType] AS [EntityType], [Extent4].[Deleted] AS [Deleted], [Extent4].[UpdatedBy] AS [UpdatedBy], [Extent4].[UpdatedAt] AS [UpdatedAt], [Extent4].[CreatedBy] AS [CreatedBy], [Extent4].[CreatedAt] AS [CreatedAt], [Extent4].[LastRevision] AS [LastRevision], [Extent4].[AccessControlListId] AS [AccessControlListId], [Extent4].[EntityStatus] AS [EntityStatus], [Extent4].[CheckSum] AS [CheckSum]
            FROM   [dbo].[People] AS [Extent3]
            INNER JOIN  (SELECT [Var_28].[Id] AS [Id], [Var_28].[Version] AS [Version], [Var_28].[EntityType] AS [EntityType], [Var_28].[Deleted] AS [Deleted], [Var_28].[UpdatedBy] AS [UpdatedBy], [Var_28].[UpdatedAt] AS [UpdatedAt], [Var_28].[CreatedBy] AS [CreatedBy], [Var_28].[CreatedAt] AS [CreatedAt], [Var_28].[LastRevision] AS [LastRevision], [Var_28].[AccessControlListId] AS [AccessControlListId], [Var_28].[EntityStatus] AS [EntityStatus], [Var_28].[CheckSum] AS [CheckSum]
                FROM [dbo].[Entities] AS [Var_28]
                WHERE [Var_28].[Deleted] <> 1 ) AS [Extent4] ON [Extent3].[Id] = [Extent4].[Id]
            LEFT OUTER JOIN [dbo].[Employees] AS [Extent5] ON [Extent3].[Id] = [Extent5].[Person_Id] ) AS [Join3] ON [Join3].[Id1] = [Extent1].[Person_Id]
        LEFT OUTER JOIN  (SELECT [Extent6].[Id] AS [Id2], [Extent6].[Person_Id] AS [Person_Id1], [Extent6].[Ssn] AS [Ssn1], [Extent6].[Employeenumber] AS [Employeenumber1], [Extent6].[Bankaccount] AS [Bankaccount1], [Extent6].[PersonId] AS [PersonId1], [Extent7].[Id] AS [Id4], [Extent7].[Version] AS [Version], [Extent7].[EntityType] AS [EntityType], [Extent7].[Deleted] AS [Deleted], [Extent7].[UpdatedBy] AS [UpdatedBy], [Extent7].[UpdatedAt] AS [UpdatedAt], [Extent7].[CreatedBy] AS [CreatedBy], [Extent7].[CreatedAt] AS [CreatedAt], [Extent7].[LastRevision] AS [LastRevision], [Extent7].[AccessControlListId] AS [AccessControlListId], [Extent7].[EntityStatus] AS [EntityStatus], [Extent7].[CheckSum] AS [CheckSum], [Extent8].[Person_Id] AS [Person_Id2]
            FROM   [dbo].[Employees] AS [Extent6]
            INNER JOIN  (SELECT [Var_29].[Id] AS [Id], [Var_29].[Version] AS [Version], [Var_29].[EntityType] AS [EntityType], [Var_29].[Deleted] AS [Deleted], [Var_29].[UpdatedBy] AS [UpdatedBy], [Var_29].[UpdatedAt] AS [UpdatedAt], [Var_29].[CreatedBy] AS [CreatedBy], [Var_29].[CreatedAt] AS [CreatedAt], [Var_29].[LastRevision] AS [LastRevision], [Var_29].[AccessControlListId] AS [AccessControlListId], [Var_29].[EntityStatus] AS [EntityStatus], [Var_29].[CheckSum] AS [CheckSum]
                FROM [dbo].[Entities] AS [Var_29]
                WHERE [Var_29].[Deleted] <> 1 ) AS [Extent7] ON [Extent6].[Id] = [Extent7].[Id]
            INNER JOIN [dbo].[Employees] AS [Extent8] ON 1 = 1 ) AS [Join6] ON ([Join6].[Person_Id1] = [Extent1].[Person_Id]) AND ([Extent1].[Person_Id] = [Join6].[Person_Id2])
        WHERE [Extent1].[Id] = @p__linq__0
    )  AS [Limit1]
_

アップデート2

@ grek40への応答-所定のインターセプターが各選択クエリに追加され、受信しているエンティティにフラグ_Deleted == true_がないことを確認します。すべてのオブジェクト+インクルードのEntitiesテーブルを結合しているため、上記のクエリはさらに3つの結合を示しています。インターセプターを無効にすると、7ではなく4つの結合が残ります。ほとんど考えていませんでしたが、無効にしたので、Entity Frameworkを介した上記のクエリの計算時間は〜3になりました秒から2秒まで。私たちが目にしているパフォーマンスの問題の3分の1を説明できたようです。

アップデート3

@GertArnoldへの応答として、上記のクエリに一致するEntity基本クラスのマッピングコードを次に示します。

_modelBuilder.Entity<Entity>()
            .HasKey(p => new { p.Id })
            // Table Per Type (TPT) inheritance root class
            .ToTable("Entities", "dbo");
        // Properties:
        modelBuilder.Entity<Entity>()
            .Property(p => p.Id)
                .IsRequired()
                .HasDatabaseGeneratedOption(System.ComponentModel.DataAnnotations.Schema.DatabaseGeneratedOption.None)
                .HasColumnType("uniqueidentifier");
        modelBuilder.Entity<Entity>()
            .Property(p => p.Version)
                .IsRequired()
                .IsConcurrencyToken()
                .HasColumnType("bigint");
        modelBuilder.Entity<Entity>()
            .Property(p => p.EntityType)
                .IsRequired()
                .HasColumnType("varchar");
        modelBuilder.Entity<Entity>()
            .Property(p => p.Deleted)
                .IsRequired()
                .HasColumnType("bit");
        modelBuilder.Entity<Entity>()
            .Property(p => p.UpdatedBy)
                .HasColumnType("uniqueidentifier");
        modelBuilder.Entity<Entity>()
            .Property(p => p.UpdatedAt)
                .HasColumnType("datetime");
        modelBuilder.Entity<Entity>()
            .Property(p => p.CreatedBy)
                .HasColumnType("uniqueidentifier");
        modelBuilder.Entity<Entity>()
            .Property(p => p.CreatedAt)
                .HasColumnType("datetime");
        modelBuilder.Entity<Entity>()
            .Property(p => p.LastRevision)
                .IsRequired()
                .HasColumnType("bigint");
        modelBuilder.Entity<Entity>()
            .Property(p => p.AccessControlListId)
                .HasColumnType("uniqueidentifier");
        modelBuilder.Entity<Entity>()
            .Property(p => p.EntityStatus)
                .IsRequired()
                .HasColumnType("bigint");
        modelBuilder.Entity<Entity>()
            .Property(p => p.CheckSum)
                .IsRequired()
                .HasDatabaseGeneratedOption(System.ComponentModel.DataAnnotations.Schema.DatabaseGeneratedOption.Computed)
                .IsConcurrencyToken()
                .HasColumnType("int");
_
c#sql-serverentity-frameworkquery-performance
22
TVisser

ユーザー情報を取得するなどの単純な操作では、クエリが複雑すぎる（結合が多すぎる）ようです。

最大のパフォーマンスを得るには、@ userIdパラメータを使用してストアドプロシージャを記述し、Entity FrameworkなしでこのストアドプロシージャでSQLクエリを最適化し（SSMSで実際のクエリプランを確認）、Entity Frameworkでラッパーを記述してこのプロシージャを呼び出します。

十分でない場合は、このクエリに対して インデックス付きビューの作成 を使用します。

それでも不十分な場合は、データベース構造をより簡単に再設計する必要があり、一時テーブルにVIEWSをキャッシュし、ユーザーテーブルまたは従業員テーブルが変更された場合にトリガーによってこれらのキャッシュビューを更新する場合があります。これは非常に役立ちます。

7
Tomas Kubes

してみてください

var userId = .... // Obtained elsewhere
using (var context = new DbContext())
{
    var user =
        context.Set<User>()
            .Include(u => u.Person.Employee)
            .Where(u => u.Id == userId)
            .ToList()
            .FirstOrDefault();
}

それが役立つ場合、考えられる理由は、IQueryableのFirstOrDefaultがSQLのTOP 1を生成するため、SQLオプティマイザがハッシュ一致ではなくネストされたループを使用する可能性があります。

2
casperbear

これまでに見つけた最良の方法は、EntityFramework Plus拡張機能を使用することです。これを読んでください https://entityframework-plus.net/query-include-optimized 、興味がすぐにわかります

1
olivier houssin

ほとんどの場合、テーブルのインデックス作成の問題またはインデックスの欠落である可能性があります。MicrosoftSQLサーバーのチューニングアドバイザーで遅いクエリを実行してみてください。クエリとテーブルに関する推奨事項が表示されます。

このリンクは役に立ちます： https://docs.Microsoft.com/en-us/sql/relational-databases/performance/start-and-use-the-database-engine-tuning-advisor

0
MohamedHamza