EF Core più join a sinistra

Sto usando EF Core in un progetto asp.net mvc core 1.1.0 e ho una query piuttosto complessa.

_context
.Profiles
.Include(p => p.Blog)
 .ThenInclude(b => b.Network)
.Include(p => p.Blog)
 .ThenInclude(i => i.AgeDistributions)
  .ThenInclude(i => i.AgeRange)
.Include(p => p.Blog)
 .ThenInclude(b => b.GenderDistributions)
.Include(p => p.Instagram)
 .ThenInclude(i => i.Network)
.Include(p => p.Instagram)
 .ThenInclude(i => i.AgeDistributions)
  .ThenInclude(i => i.AgeRange)
.Include(p => p.Instagram)
 .ThenInclude(b => b.GenderDistributions)
.Include(p => p.Youtube)
 .ThenInclude(y => y.Network)
.Include(p => p.Youtube)
 .ThenInclude(i => i.AgeDistributions)
  .ThenInclude(i => i.AgeRange)
.Include(p => p.Youtube)
 .ThenInclude(b => b.GenderDistributions)
.Include(p => p.Snapchat)
 .ThenInclude(s => s.Network)
.Include(p => p.Musically)
.Include(p => p.ProfileCategories)
 .ThenInclude(pc => pc.Category)
.Include(p => p.Tags)
 .ThenInclude(tag => tag.Tag)
.Where(p => !p.Deleted);

Ogni piattaforma sociale può avere qualsiasi tipo di statistica. Ad esempio, AgeDistributions viene modellato utilizzando una classe base con PlatformId e ogni {Platform}AgeDistribution specificata specifica la proprietà di navigazione in modo da configurare correttamente le chiavi esterne.

public class AgeInterval {
  public int Id { get; set; }
  // At most five length. -18, 18-24, ..., 65-
  public string Interval { get; set; }
}

public class PlatformAgeStatistics {
  public int PlatformId { get; set; }
  public int IntervalId { get; set; } 
  public AgeInterval Interval { get; set; } 
  public decimal Distribution { get; set; }
}

public class InstagramAgeStatistics : PlatformAgeStatistics  {
  [ForeignKey("PlatformId")]
  public Instagram Platform { get; set; } // 
}

Sopra la query a volte molto tempo (timeout di esecuzione db dopo 30 secondi) e l'ispezione di sql mi fanno pensare che ho un problema di modellazione che EF non è in grado di determinare correttamente o EF sta solo generando SQL subottimale. Il set di risultati viene impaginato utilizzando skip e take e attualmente è possibile recuperare dieci record.

Questo è il primo SQL che viene eseguito

SELECT -- Emitted
FROM [Profiles] AS [p]
LEFT JOIN [BlogChannels] AS [b] ON [b].[ProfileId] = [p].[Id]
LEFT JOIN [InstagramChannels] AS [i] ON [i].[ProfileId] = [p].[Id]
LEFT JOIN [YoutubeChannels] AS [y] ON [y].[ProfileId] = [p].[Id]
LEFT JOIN [BlogChannels] AS [b2] ON [b2].[ProfileId] = [p].[Id]
LEFT JOIN [InstagramChannels] AS [i2] ON [i2].[ProfileId] = [p].[Id]
LEFT JOIN [YoutubeChannels] AS [y2] ON [y2].[ProfileId] = [p].[Id]
LEFT JOIN [BlogChannels] AS [b4] ON [b4].[ProfileId] = [p].[Id]
LEFT JOIN [Networks] AS [n] ON [b4].[NetworkId] = [n].[Id]
LEFT JOIN [InstagramChannels] AS [i4] ON [i4].[ProfileId] = [p].[Id]
LEFT JOIN [Networks] AS [n0] ON [i4].[NetworkId] = [n0].[Id]
LEFT JOIN [YoutubeChannels] AS [y4] ON [y4].[ProfileId] = [p].[Id]
LEFT JOIN [Networks] AS [n1] ON [y4].[NetworkId] = [n1].[Id]
LEFT JOIN [SnapchatChannels] AS [s] ON [s].[ProfileId] = [p].[Id]
LEFT JOIN [Networks] AS [n2] ON [s].[NetworkId] = [n2].[Id]
LEFT JOIN [MusicallyChannels] AS [m] ON [m].[ProfileId] = [p].[Id]
WHERE [p].[Deleted] = 0
ORDER BY [p].[FullName], [p].[Id], [b].[Id], [i].[Id], [y].[Id], [b2].[Id], [i2].[Id], [y2].[Id]
OFFSET @__p_0 ROWS FETCH NEXT @__p_1 ROWS ONLY

Quindi segue più query che non sembrano abbastanza giuste

SELECT [y3].[Gender], [y3].[ChannelId], [y3].[Distribution]
FROM [YoutubeGenderDistribution] AS [y3]
INNER JOIN (
    SELECT DISTINCT [t7].*
    FROM (
        SELECT [p].[FullName], [p].[Id], [b].[Id] AS [Id0], [i].[Id] AS [Id1], [y].[Id] AS [Id2], [b2].[Id] AS [Id3], [i2].[Id] AS [Id4], [y2].[Id] AS [Id5]
        FROM [Profiles] AS [p]
        LEFT JOIN [BlogChannels] AS [b] ON [b].[ProfileId] = [p].[Id]
        LEFT JOIN [InstagramChannels] AS [i] ON [i].[ProfileId] = [p].[Id]
        LEFT JOIN [YoutubeChannels] AS [y] ON [y].[ProfileId] = [p].[Id]
        LEFT JOIN [BlogChannels] AS [b2] ON [b2].[ProfileId] = [p].[Id]
        LEFT JOIN [InstagramChannels] AS [i2] ON [i2].[ProfileId] = [p].[Id]
        LEFT JOIN [YoutubeChannels] AS [y2] ON [y2].[ProfileId] = [p].[Id]
        WHERE [p].[Deleted] = 0
        ORDER BY [p].[FullName], [p].[Id], [b].[Id], [i].[Id], [y].[Id], [b2].[Id], [i2].[Id], [y2].[Id]
        OFFSET @__p_0 ROWS FETCH NEXT @__p_1 ROWS ONLY
    ) AS [t7]
) AS [y20] ON [y3].[ChannelId] = [y20].[Id5]
ORDER BY [y20].[FullName], [y20].[Id], [y20].[Id0], [y20].[Id1], [y20].[Id2], [y20].[Id3], [y20].[Id4], [y20].[Id5]

Un altro che "sembra" più corretto

SELECT [b0].[AgeRangeId], [b0].[ChannelId], [b0].[Distribution], [a].[Id], [a].[Range]
FROM [BlogAgeDistribution] AS [b0]
INNER JOIN (
    SELECT DISTINCT [t2].*
    FROM (
        SELECT [p].[FullName], [p].[Id], [b].[Id] AS [Id0]
        FROM [Profiles] AS [p]
        LEFT JOIN [BlogChannels] AS [b] ON [b].[ProfileId] = [p].[Id]
        WHERE [p].[Deleted] = 0
        ORDER BY [p].[FullName], [p].[Id], [b].[Id]
        OFFSET @__p_0 ROWS FETCH NEXT @__p_1 ROWS ONLY
    ) AS [t2]
) AS [b1] ON [b0].[ChannelId] = [b1].[Id0]
LEFT JOIN [AgeRanges] AS [a] ON [b0].[AgeRangeId] = [a].[Id]
ORDER BY [b1].[FullName], [b1].[Id], [b1].[Id0]

Qualche idea sul perché EF si unisca a tutte le altre piattaforme quando richiede le statistiche per es. Instagram .

Grazie!

Modificare:

È interessante notare che la prima query per Age genera un join con tutti e tre

SELECT [y0].[AgeRangeId], [y0].[ChannelId], [y0].[Distribution], [a1].[Id], [a1].[Range]
FROM [YoutubeAgeDistribution] AS [y0]
INNER JOIN (
    SELECT DISTINCT [t4].*
    FROM (
        SELECT [p].[FullName], [p].[Id], [b].[Id] AS [Id0], [i].[Id] AS [Id1], [y].[Id] AS [Id2]
        FROM [Profiles] AS [p]
        LEFT JOIN [BlogChannels] AS [b] ON [b].[ProfileId] = [p].[Id]
        LEFT JOIN [InstagramChannels] AS [i] ON [i].[ProfileId] = [p].[Id]
        LEFT JOIN [YoutubeChannels] AS [y] ON [y].[ProfileId] = [p].[Id]
        WHERE [p].[Deleted] = 0
        ORDER BY [p].[FullName], [p].[Id], [b].[Id], [i].[Id], [y].[Id]
        OFFSET @__p_0 ROWS FETCH NEXT @__p_1 ROWS ONLY
    ) AS [t4]
) AS [y1] ON [y0].[ChannelId] = [y1].[Id2]
LEFT JOIN [AgeRanges] AS [a1] ON [y0].[AgeRangeId] = [a1].[Id]
ORDER BY [y1].[FullName], [y1].[Id], [y1].[Id0], [y1].[Id1], [y1].[Id2]