LINQクエリが遅く、タイムアウトを作成します。生成されたSQLは問題ありませんか？

Question

私は非常に遅い、かなり複雑なLINQクエリを持っています。System.Data.SqlClient.SqlException： "待機操作がタイムアウトしました"が作成されます。私は、生成されたSQLを（DataContextのLogにTextWriterを割り当てることで）ログ、およびSQL Server上で直接実行するとき

はしかし、それは大丈夫である、約4秒で完了します。

矛盾はどこから発生し、どのようにデバッグするのですか？

編集：Sql Server Management Studioのアクティビティモニタでは、クエリが.NETから実行されているときに100％になっていますが、生成されたSQLクエリを実行するときには3％ほどしかありませんでした。

私は私のコードを掲示することに役立つかどうかはわかりませんが、それが要求されたことから、ここでは、クエリを含むコードです：

var Db = MyProject.GetDataContext(); 
var statusPaymentSuccess = new string[] { "SUCCESS", "REMBOURS", "AFTERPAY" }; 

var items = Db.Orders.Where(item => 
    (siteid == null || item.SiteId == siteid) && 
    (ls_list.Contains(item.OrderOrderLifeCycles.OrderByDescending(it => it.Id).First().OrderLifeCycleId)) && 
    (item.OrderOrderPaymentStatus.Any(ops => statusPaymentSuccess.Contains(ops.OrderPaymentStatus.Code)) && 
     (CycleID == null || item.OrderOrderLifeCycles.First().OrderLifeCycleId == CycleID) && 
     (LocationID == null || item.SaleLocationId == LocationID) && 
     (string.IsNullOrEmpty(SalesPerson) || item.EmployeeName.ToLower() == SalesPerson.ToLower())) 
); 

var betweenorders = items.Select(it => new OrderBetween() 
{ 
    FirstPayDate = it.OrderOrderPaymentStatus.FirstOrDefault(ops => statusPaymentSuccess.Contains(ops.OrderPaymentStatus.Code)).DateTime, 
    OrderTotal = it.TotalAmount, 
    VatTotal = it.OrderItems.Sum(it2 => it2.BTWAmount ?? 0), 
    Quantity = it.OrderItems.Count, 
    SiteId = it.SiteId 
}); 

return betweenorders.Where(item => item.FirstPayDate >= start && item.FirstPayDate < stop) 
    .GroupBy(item => item.FirstPayDate.Value.Year + "-" + item.FirstPayDate.Value.Month).Select(
     item => 
      new SaleTotal() 
      { 
       Count = item.Sum(sub => sub.Quantity), 
       Month = item.FirstOrDefault().FirstPayDate.Value.Year + "-" + item.FirstOrDefault().FirstPayDate.Value.Month.ToString().PadLeft(2, '0'), 
       Total = item.Sum(sub => sub.OrderTotal), 
       VAT = item.Sum(sub => sub.VatTotal) 
      }).OrderBy(item => item.Month).ToArray(); 

どこls_listがOrderOrderLifeCycles IDを含むList<int>です。

生成されたSQLクエリログから引っ張って：あなたのクエリを改善するための

DECLARE @p0 NVarChar(4000) = 'SUCCESS' 
DECLARE @p1 NVarChar(4000) = 'REMBOURS' 
DECLARE @p2 NVarChar(4000) = 'AFTERPAY' 
DECLARE @p3 Decimal(31,2) = '0' 
DECLARE @p4 NVarChar(4000) = '-' 
DECLARE @p5 DateTime = '2016-06-01' 
DECLARE @p6 DateTime = '2016-09-01' 
DECLARE @p7 Int = '4' 
DECLARE @p8 Int = '5' 
DECLARE @p9 Int = '8' 
DECLARE @p10 NVarChar(4000) = 'SUCCESS' 
DECLARE @p11 NVarChar(4000) = 'REMBOURS' 
DECLARE @p12 NVarChar(4000) = 'AFTERPAY' 
DECLARE @p13 NVarChar(4000) = '-' 
DECLARE @p14 NVarChar(4000) = '-' 
DECLARE @p15 Int = '2' 
DECLARE @p16 NChar(1) = '0' 
SELECT [t64].[value] AS [Month], [t64].[value2] AS [Count], [t64].[value22] AS [Total], [t64].[value3] AS [VAT] 
FROM (
    SELECT ((CONVERT(NVarChar,DATEPART(Year, (
     SELECT [t23].[value] 
     FROM (
      SELECT TOP (1) [t18].[value] 
      FROM (
       SELECT (
        SELECT [t17].[DateTime] 
        FROM (
         SELECT TOP (1) [t15].[DateTime] 
         FROM [dbo].[OrderOrderPaymentStatus] AS [t15] 
         INNER JOIN [dbo].[OrderPaymentStatus] AS [t16] ON [t16].[Id] = [t15].[OrderPaymentStatusId] 
         WHERE ([t16].[Code] IN (@p0, @p1, @p2)) AND ([t15].[OrderId] = [t14].[Id]) 
         ) AS [t17] 
        ) AS [value], [t14].[Id] 
       FROM [dbo].[Order] AS [t14] 
       ) AS [t18] 
      WHERE ((([t13].[value4] IS NULL) AND ((((CONVERT(NVarChar,DATEPART(Year, [t18].[value]))) + @p13) + (CONVERT(NVarChar,DATEPART(Month, [t18].[value])))) IS NULL)) OR (([t13].[value4] IS NOT NULL) AND ((((CONVERT(NVarChar,DATEPART(Year, [t18].[value]))) + @p13) + (CONVERT(NVarChar,DATEPART(Month, [t18].[value])))) IS NOT NULL) AND ([t13].[value4] = (((CONVERT(NVarChar,DATEPART(Year, [t18].[value]))) + @p13) + (CONVERT(NVarChar,DATEPART(Month, [t18].[value]))))))) AND ([t18].[value] >= @p5) AND ([t18].[value] < @p6) AND (((
       SELECT [t20].[OrderLifeCycleId] 
       FROM (
        SELECT TOP (1) [t19].[OrderLifeCycleId] 
        FROM [dbo].[OrderOrderLifeCycle] AS [t19] 
        WHERE [t19].[OrderId] = [t18].[Id] 
        ORDER BY [t19].[Id] DESC 
        ) AS [t20] 
       )) IN (@p7, @p8, @p9)) AND (EXISTS(
       SELECT NULL AS [EMPTY] 
       FROM [dbo].[OrderOrderPaymentStatus] AS [t21] 
       INNER JOIN [dbo].[OrderPaymentStatus] AS [t22] ON [t22].[Id] = [t21].[OrderPaymentStatusId] 
       WHERE ([t22].[Code] IN (@p10, @p11, @p12)) AND ([t21].[OrderId] = [t18].[Id]) 
       )) 
      ) AS [t23] 
     )))) + @p14) + (
     (CASE 
      WHEN (CONVERT(Int,DATALENGTH(CONVERT(NVarChar,DATEPART(Month, (
       SELECT [t63].[value] 
       FROM (
        SELECT TOP (1) [t58].[value] 
        FROM (
         SELECT (
          SELECT [t57].[DateTime] 
          FROM (
           SELECT TOP (1) [t55].[DateTime] 
           FROM [dbo].[OrderOrderPaymentStatus] AS [t55] 
           INNER JOIN [dbo].[OrderPaymentStatus] AS [t56] ON [t56].[Id] = [t55].[OrderPaymentStatusId] 
           WHERE ([t56].[Code] IN (@p0, @p1, @p2)) AND ([t55].[OrderId] = [t54].[Id]) 
           ) AS [t57] 
          ) AS [value], [t54].[Id] 
         FROM [dbo].[Order] AS [t54] 
         ) AS [t58] 
        WHERE ((([t13].[value4] IS NULL) AND ((((CONVERT(NVarChar,DATEPART(Year, [t58].[value]))) + @p13) + (CONVERT(NVarChar,DATEPART(Month, [t58].[value])))) IS NULL)) OR (([t13].[value4] IS NOT NULL) AND ((((CONVERT(NVarChar,DATEPART(Year, [t58].[value]))) + @p13) + (CONVERT(NVarChar,DATEPART(Month, [t58].[value])))) IS NOT NULL) AND ([t13].[value4] = (((CONVERT(NVarChar,DATEPART(Year, [t58].[value]))) + @p13) + (CONVERT(NVarChar,DATEPART(Month, [t58].[value]))))))) AND ([t58].[value] >= @p5) AND ([t58].[value] < @p6) AND (((
         SELECT [t60].[OrderLifeCycleId] 
         FROM (
          SELECT TOP (1) [t59].[OrderLifeCycleId] 
          FROM [dbo].[OrderOrderLifeCycle] AS [t59] 
          WHERE [t59].[OrderId] = [t58].[Id] 
          ORDER BY [t59].[Id] DESC 
          ) AS [t60] 
         )) IN (@p7, @p8, @p9)) AND (EXISTS(
         SELECT NULL AS [EMPTY] 
         FROM [dbo].[OrderOrderPaymentStatus] AS [t61] 
         INNER JOIN [dbo].[OrderPaymentStatus] AS [t62] ON [t62].[Id] = [t61].[OrderPaymentStatusId] 
         WHERE ([t62].[Code] IN (@p10, @p11, @p12)) AND ([t61].[OrderId] = [t58].[Id]) 
         )) 
        ) AS [t63] 
       ))))/2)) >= @p15 THEN CONVERT(NVarChar,DATEPART(Month, (
       SELECT [t63].[value] 
       FROM (
        SELECT TOP (1) [t58].[value] 
        FROM (
         SELECT (
          SELECT [t57].[DateTime] 
          FROM (
           SELECT TOP (1) [t55].[DateTime] 
           FROM [dbo].[OrderOrderPaymentStatus] AS [t55] 
           INNER JOIN [dbo].[OrderPaymentStatus] AS [t56] ON [t56].[Id] = [t55].[OrderPaymentStatusId] 
           WHERE ([t56].[Code] IN (@p0, @p1, @p2)) AND ([t55].[OrderId] = [t54].[Id]) 
           ) AS [t57] 
          ) AS [value], [t54].[Id] 
         FROM [dbo].[Order] AS [t54] 
         ) AS [t58] 
        WHERE ((([t13].[value4] IS NULL) AND ((((CONVERT(NVarChar,DATEPART(Year, [t58].[value]))) + @p13) + (CONVERT(NVarChar,DATEPART(Month, [t58].[value])))) IS NULL)) OR (([t13].[value4] IS NOT NULL) AND ((((CONVERT(NVarChar,DATEPART(Year, [t58].[value]))) + @p13) + (CONVERT(NVarChar,DATEPART(Month, [t58].[value])))) IS NOT NULL) AND ([t13].[value4] = (((CONVERT(NVarChar,DATEPART(Year, [t58].[value]))) + @p13) + (CONVERT(NVarChar,DATEPART(Month, [t58].[value]))))))) AND ([t58].[value] >= @p5) AND ([t58].[value] < @p6) AND (((
         SELECT [t60].[OrderLifeCycleId] 
         FROM (
          SELECT TOP (1) [t59].[OrderLifeCycleId] 
          FROM [dbo].[OrderOrderLifeCycle] AS [t59] 
          WHERE [t59].[OrderId] = [t58].[Id] 
          ORDER BY [t59].[Id] DESC 
          ) AS [t60] 
         )) IN (@p7, @p8, @p9)) AND (EXISTS(
         SELECT NULL AS [EMPTY] 
         FROM [dbo].[OrderOrderPaymentStatus] AS [t61] 
         INNER JOIN [dbo].[OrderPaymentStatus] AS [t62] ON [t62].[Id] = [t61].[OrderPaymentStatusId] 
         WHERE ([t62].[Code] IN (@p10, @p11, @p12)) AND ([t61].[OrderId] = [t58].[Id]) 
         )) 
        ) AS [t63] 
       ))) 
      ELSE REPLICATE(@p16, @p15 - (CONVERT(Int,DATALENGTH(CONVERT(NVarChar,DATEPART(Month, (
       SELECT [t63].[value] 
       FROM (
        SELECT TOP (1) [t58].[value] 
        FROM (
         SELECT (
          SELECT [t57].[DateTime] 
          FROM (
           SELECT TOP (1) [t55].[DateTime] 
           FROM [dbo].[OrderOrderPaymentStatus] AS [t55] 
           INNER JOIN [dbo].[OrderPaymentStatus] AS [t56] ON [t56].[Id] = [t55].[OrderPaymentStatusId] 
           WHERE ([t56].[Code] IN (@p0, @p1, @p2)) AND ([t55].[OrderId] = [t54].[Id]) 
           ) AS [t57] 
          ) AS [value], [t54].[Id] 
         FROM [dbo].[Order] AS [t54] 
         ) AS [t58] 
        WHERE ((([t13].[value4] IS NULL) AND ((((CONVERT(NVarChar,DATEPART(Year, [t58].[value]))) + @p13) + (CONVERT(NVarChar,DATEPART(Month, [t58].[value])))) IS NULL)) OR (([t13].[value4] IS NOT NULL) AND ((((CONVERT(NVarChar,DATEPART(Year, [t58].[value]))) + @p13) + (CONVERT(NVarChar,DATEPART(Month, [t58].[value])))) IS NOT NULL) AND ([t13].[value4] = (((CONVERT(NVarChar,DATEPART(Year, [t58].[value]))) + @p13) + (CONVERT(NVarChar,DATEPART(Month, [t58].[value]))))))) AND ([t58].[value] >= @p5) AND ([t58].[value] < @p6) AND (((
         SELECT [t60].[OrderLifeCycleId] 
         FROM (
          SELECT TOP (1) [t59].[OrderLifeCycleId] 
          FROM [dbo].[OrderOrderLifeCycle] AS [t59] 
          WHERE [t59].[OrderId] = [t58].[Id] 
          ORDER BY [t59].[Id] DESC 
          ) AS [t60] 
         )) IN (@p7, @p8, @p9)) AND (EXISTS(
         SELECT NULL AS [EMPTY] 
         FROM [dbo].[OrderOrderPaymentStatus] AS [t61] 
         INNER JOIN [dbo].[OrderPaymentStatus] AS [t62] ON [t62].[Id] = [t61].[OrderPaymentStatusId] 
         WHERE ([t62].[Code] IN (@p10, @p11, @p12)) AND ([t61].[OrderId] = [t58].[Id]) 
         )) 
        ) AS [t63] 
       ))))/2))) + (CONVERT(NVarChar,DATEPART(Month, (
       SELECT [t63].[value] 
       FROM (
        SELECT TOP (1) [t58].[value] 
        FROM (
         SELECT (
          SELECT [t57].[DateTime] 
          FROM (
           SELECT TOP (1) [t55].[DateTime] 
           FROM [dbo].[OrderOrderPaymentStatus] AS [t55] 
           INNER JOIN [dbo].[OrderPaymentStatus] AS [t56] ON [t56].[Id] = [t55].[OrderPaymentStatusId] 
           WHERE ([t56].[Code] IN (@p0, @p1, @p2)) AND ([t55].[OrderId] = [t54].[Id]) 
           ) AS [t57] 
          ) AS [value], [t54].[Id] 
         FROM [dbo].[Order] AS [t54] 
         ) AS [t58] 
        WHERE ((([t13].[value4] IS NULL) AND ((((CONVERT(NVarChar,DATEPART(Year, [t58].[value]))) + @p13) + (CONVERT(NVarChar,DATEPART(Month, [t58].[value])))) IS NULL)) OR (([t13].[value4] IS NOT NULL) AND ((((CONVERT(NVarChar,DATEPART(Year, [t58].[value]))) + @p13) + (CONVERT(NVarChar,DATEPART(Month, [t58].[value])))) IS NOT NULL) AND ([t13].[value4] = (((CONVERT(NVarChar,DATEPART(Year, [t58].[value]))) + @p13) + (CONVERT(NVarChar,DATEPART(Month, [t58].[value]))))))) AND ([t58].[value] >= @p5) AND ([t58].[value] < @p6) AND (((
         SELECT [t60].[OrderLifeCycleId] 
         FROM (
          SELECT TOP (1) [t59].[OrderLifeCycleId] 
          FROM [dbo].[OrderOrderLifeCycle] AS [t59] 
          WHERE [t59].[OrderId] = [t58].[Id] 
          ORDER BY [t59].[Id] DESC 
          ) AS [t60] 
         )) IN (@p7, @p8, @p9)) AND (EXISTS(
         SELECT NULL AS [EMPTY] 
         FROM [dbo].[OrderOrderPaymentStatus] AS [t61] 
         INNER JOIN [dbo].[OrderPaymentStatus] AS [t62] ON [t62].[Id] = [t61].[OrderPaymentStatusId] 
         WHERE ([t62].[Code] IN (@p10, @p11, @p12)) AND ([t61].[OrderId] = [t58].[Id]) 
         )) 
        ) AS [t63] 
       )))) 
     END)) AS [value], [t13].[value] AS [value2], [t13].[value2] AS [value22], [t13].[value3] 
    FROM (
     SELECT SUM([t8].[value3]) AS [value], SUM([t8].[TotalAmount]) AS [value2], SUM([t8].[value22]) AS [value3], [t8].[value] AS [value4] 
     FROM (
      SELECT ((CONVERT(NVarChar,DATEPART(Year, [t7].[value]))) + @p4) + (CONVERT(NVarChar,DATEPART(Month, [t7].[value]))) AS [value], [t7].[value] AS [value2], [t7].[Id], [t7].[value3], [t7].[TotalAmount], [t7].[value2] AS [value22] 
      FROM (
       SELECT (
        SELECT [t3].[DateTime] 
        FROM (
         SELECT TOP (1) [t1].[DateTime] 
         FROM [dbo].[OrderOrderPaymentStatus] AS [t1] 
         INNER JOIN [dbo].[OrderPaymentStatus] AS [t2] ON [t2].[Id] = [t1].[OrderPaymentStatusId] 
         WHERE ([t2].[Code] IN (@p0, @p1, @p2)) AND ([t1].[OrderId] = [t0].[Id]) 
         ) AS [t3] 
        ) AS [value], [t0].[TotalAmount], (
        SELECT SUM([t5].[value]) 
        FROM (
         SELECT COALESCE([t4].[BTWAmount],@p3) AS [value], [t4].[OrderId] 
         FROM [dbo].[OrderItem] AS [t4] 
         ) AS [t5] 
        WHERE [t5].[OrderId] = [t0].[Id] 
        ) AS [value2], (
        SELECT COUNT(*) 
        FROM [dbo].[OrderItem] AS [t6] 
        WHERE [t6].[OrderId] = [t0].[Id] 
        ) AS [value3], [t0].[Id] 
       FROM [dbo].[Order] AS [t0] 
       ) AS [t7] 
      ) AS [t8] 
     WHERE ([t8].[value2] >= @p5) AND ([t8].[value2] < @p6) AND (((
      SELECT [t10].[OrderLifeCycleId] 
      FROM (
       SELECT TOP (1) [t9].[OrderLifeCycleId] 
       FROM [dbo].[OrderOrderLifeCycle] AS [t9] 
       WHERE [t9].[OrderId] = [t8].[Id] 
       ORDER BY [t9].[Id] DESC 
       ) AS [t10] 
      )) IN (@p7, @p8, @p9)) AND (EXISTS(
      SELECT NULL AS [EMPTY] 
      FROM [dbo].[OrderOrderPaymentStatus] AS [t11] 
      INNER JOIN [dbo].[OrderPaymentStatus] AS [t12] ON [t12].[Id] = [t11].[OrderPaymentStatusId] 
      WHERE ([t12].[Code] IN (@p10, @p11, @p12)) AND ([t11].[OrderId] = [t8].[Id]) 
      )) 
     GROUP BY [t8].[value] 
     ) AS [t13] 
    ) AS [t64] 
ORDER BY [t64].[value] 

Answer 1

1つの明白な方法は、最初の部分で、すぐに目を引く：

var items = Db.Orders.Where(item => 
    (siteid == null || item.SiteId == siteid) 
&& (ls_list.Contains(item.OrderOrderLifeCycles.OrderByDescending(it => it.Id).First().OrderLifeCycleId)) 
&& (item.OrderOrderPaymentStatus.Any(ops => statusPaymentSuccess.Contains(ops.OrderPaymentStatus.Code)) 
&& (CycleID == null || item.OrderOrderLifeCycles.First().OrderLifeCycleId == CycleID) 
&& (LocationID == null || item.SaleLocationId == LocationID) 
&& (string.IsNullOrEmpty(SalesPerson) || item.EmployeeName.ToLower() == SalesPerson.ToLower())) 
); 

は全体のLINQ文のことを覚えておいてくださいこれらすべてのnull検査を含むSQLに変換されます。これにより、SQLクエリは複雑になり、クエリオプティマイザで処理するのが難しくなります。 （ところで、別のLINQ文に属するSQLクエリを表示します）。

IQueryable<Order> items = var items = Db.Orders; 

if(siteid != null) 
{ 
    items = items.Where(item => item.SiteId == siteid); 
} 
if (CycleID != null) 
{ 
    items = items.Where(item => item.OrderOrderLifeCycles.First().OrderLifeCycleId == CycleID); 
} 
// etc. 

もう一つは、検索条件が適用される前に、これはEmployeeNameフィールドの値を変換し

item.EmployeeName.ToLower() == SalesPerson.ToLower() 

です：

NULL可能な条件に対処するための推奨方法は、クエリを構成することです。つまり、EmployeeNameのインデックスは使用できません（はsargableではなくとも呼ばれます）。 I とすれば、ToLower()コールを削除できます。 SQLクエリでは、EmployeeNameフィールドのデータベース照合が使用されており、デフォルトでは大文字小文字を区別しない可能性が非常に高いです（CI）。

最後に、あなたは...グループ化を実行する（オブジェクトへのLINQ）

GroupBy(item => item.FirstPayDate.Value.Year + "-" + item.FirstPayDate.Value.Month) 

...メモリ内を考える代わりに、データベース内にあります。すなわち：

return betweenorders.Where(item => item.FirstPayDate >= start && item.FirstPayDate < stop) 
.AsEnumerable() // Switch to LINQ to objects 
.GroupBy(... 

グルーピングはORDER BY（この回答の範囲を超えた理由のためではないGROUP BY）として翻訳され、再度、データベースフィールドFirstPayDateの変換は、インデックスを無効にしています。また、SQLクエリーの複雑さも緩和され、メモリ内でこれを行うのは多分大した作業ではありません。不一致の

Answer 2

一部はthis SAの答えで説明されています。

SSMSは、一般的にARITHABORT ONを使用し、コードは一般的に ARITHABORTをOFF使用しています - これは基本的に数学的な場合 は何が起こるかをどのように扱うかのオプションですコードの行にエラーがあります。 をゼロで除算します。

ここで重要なのは、どちらの方法も異なる 実行計画を持っていることです。つまり、同じことが（ランダムに）SSMSよりもウェブサイト上で多くの時間がかかることがあります。

実行計画は、あなたがランダムに何を見つけるように使用されて初めて の推定値に基づいてコンパイルされ、実行計画は、あなたの最初のクエリに合ったが、その後のクエリに対して 恐ろしいですひどいやり方で キャッシュされていることです。これはここで起こったことで、 が突然再び働き始めたのですが、ストアドプロシージャの変更後に新しいクエリプランが作成されました。

SET ARITHABORT OFFでSSMSでクエリを実行すると、クエリの実行が大幅に遅くなります。それでもコードではLINQ-to-SQLバージョンよりも少なくとも300％高速ですので、この回答を/見つけた場合にはさらに更新していきます。

編集：SSMSはLINQのようにオブジェクトトラッキングを処理する必要はないので、オブジェクトトラッキングを無効にすることで、LINQからSQLへの実行を高速化できます。どのオブジェクトを読み込むかを手動で指定する必要があります（私が知る限り）試行錯誤によってのみ決定できます。私のクエリのために
は、追跡およびオブジェクトのロードの無効化は、このコードで扱うことができます。

db.ObjectTrackingEnabled = false; 
var lo = new DataLoadOptions(); 
lo.LoadWith<Order>(x => x.OrderOrderPaymentStatus); 
lo.LoadWith<OrderOrderPaymentStatus>(x => x.OrderPaymentStatus); 
db.LoadOptions = lo;