EF - 从投影到域映射需要7分钟

Question

EntityFramework生成此查询：

SELECT 
[Project1].[Ocr_Status] AS [Ocr_Status], 
[Project1].[Id] AS [Id], 
[Project1].[Caption] AS [Caption], 
[Project1].[Name] AS [Name], 
[Project1].[Description] AS [Description], 
[Project1].[Url] AS [Url], 
[Project1].[PictureUri] AS [PictureUri], 
[Project1].[ThumbnailUri] AS [ThumbnailUri], 
[Project1].[ValidFrom] AS [ValidFrom], 
[Project1].[ValidTo] AS [ValidTo], 
[Project1].[VisibleFrom] AS [VisibleFrom], 
[Project1].[VisibleTo] AS [VisibleTo], 
[Project1].[Ocr_Id] AS [Ocr_Id], 
[Project1].[Status] AS [Status], 
[Project1].[Gradient_Width] AS [Gradient_Width], 
[Project1].[Gradient_Color] AS [Gradient_Color], 
[Project1].[BrandId] AS [BrandId], 
[Project1].[StoreOfflineJson] AS [StoreOfflineJson], 
[Project1].[CreatedBy] AS [CreatedBy], 
[Project1].[CreatedOn] AS [CreatedOn], 
[Project1].[LastModifiedBy] AS [LastModifiedBy], 
[Project1].[LastModifiedOn] AS [LastModifiedOn], 
[Project1].[RowVersion] AS [RowVersion], 
[Project1].[C1] AS [C1], 
[Project1].[Id1] AS [Id1], 
[Project1].[PictureUri1] AS [PictureUri1], 
[Project1].[Page] AS [Page], 
[Project1].[Text] AS [Text], 
[Project1].[FlyerId] AS [FlyerId], 
[Project1].[CreatedBy1] AS [CreatedBy1], 
[Project1].[CreatedOn1] AS [CreatedOn1], 
[Project1].[LastModifiedBy1] AS [LastModifiedBy1], 
[Project1].[LastModifiedOn1] AS [LastModifiedOn1], 
[Project1].[RowVersion1] AS [RowVersion1]
FROM ( SELECT 
    [Extent1].[Id] AS [Id], 
    [Extent1].[Caption] AS [Caption], 
    [Extent1].[Name] AS [Name], 
    [Extent1].[Description] AS [Description], 
    [Extent1].[Url] AS [Url], 
    [Extent1].[PictureUri] AS [PictureUri], 
    [Extent1].[ThumbnailUri] AS [ThumbnailUri], 
    [Extent1].[ValidFrom] AS [ValidFrom], 
    [Extent1].[ValidTo] AS [ValidTo], 
    [Extent1].[VisibleFrom] AS [VisibleFrom], 
    [Extent1].[VisibleTo] AS [VisibleTo], 
    [Extent1].[Ocr_Id] AS [Ocr_Id], 
    [Extent1].[Ocr_Status] AS [Ocr_Status], 
    [Extent1].[Status] AS [Status], 
    [Extent1].[Gradient_Width] AS [Gradient_Width], 
    [Extent1].[Gradient_Color] AS [Gradient_Color], 
    [Extent1].[BrandId] AS [BrandId], 
    [Extent1].[StoreOfflineJson] AS [StoreOfflineJson], 
    [Extent1].[CreatedBy] AS [CreatedBy], 
    [Extent1].[CreatedOn] AS [CreatedOn], 
    [Extent1].[LastModifiedBy] AS [LastModifiedBy], 
    [Extent1].[LastModifiedOn] AS [LastModifiedOn], 
    [Extent1].[RowVersion] AS [RowVersion], 
    [Extent2].[Id] AS [Id1], 
    [Extent2].[PictureUri] AS [PictureUri1], 
    [Extent2].[Page] AS [Page], 
    [Extent2].[Text] AS [Text], 
    [Extent2].[FlyerId] AS [FlyerId], 
    [Extent2].[CreatedBy] AS [CreatedBy1], 
    [Extent2].[CreatedOn] AS [CreatedOn1], 
    [Extent2].[LastModifiedBy] AS [LastModifiedBy1], 
    [Extent2].[LastModifiedOn] AS [LastModifiedOn1], 
    [Extent2].[RowVersion] AS [RowVersion1], 
    CASE WHEN ([Extent2].[Id] IS NULL) THEN CAST(NULL AS int) ELSE 1 END AS [C1]
    FROM  [Flyers].[Flyers] AS [Extent1]
    LEFT OUTER JOIN [Flyers].[Pages] AS [Extent2] ON [Extent1].[Id] = [Extent2].[FlyerId]
    WHERE ( NOT (((( CAST( [Extent1].[Status] AS int)) & ( CAST( 4 AS int))) = 4) AND ((CASE WHEN (( CAST( [Extent1].[Status] AS int)) & ( CAST( 4 AS int)) IS NULL) THEN cast(1 as bit) ELSE cast(0 as bit) END) = 0))) AND ( NOT (((( CAST( [Extent1].[Status] AS int)) & ( CAST( 1 AS int))) = 1) AND ((CASE WHEN (( CAST( [Extent1].[Status] AS int)) & ( CAST( 1 AS int)) IS NULL) THEN cast(1 as bit) ELSE cast(0 as bit) END) = 0))) AND ((( CAST( [Extent1].[Status] AS int)) & ( CAST( 2 AS int))) = 2) AND (3 = [Extent1].[Ocr_Status])
)  AS [Project1]
ORDER BY [Project1].[Id] ASC, [Project1].[C1] ASC

在MSSMS中，此查询在 1-3s 中完成，但在app中：

-- Executing asynchronously at 30.05.2017 11:19:40 +02:00
-- Completed in **525 ms** with result: SqlDataReader

所以查询在 0.5s 中完成了吗？

然后是投影时间。需要 6-10分钟。

return await Context.Flyers.Where(predicate).Include(f => f.Pages).ToListAsync();

发生了什么事？大约有300行。

编辑：添加谓词

谓词看起来像这样：

Expression<Func<BackOfficeFlyer, bool>> exsp = flyer =>
                !flyer.Status.HasFlag(FlyerStatus.Active) &&
                !flyer.Status.HasFlag(FlyerStatus.Deleted) &&
                flyer.Status.HasFlag(FlyerStatus.Validated) &&
                flyer.Ocr.Status == OcrStatus.Finished;