Entity Framework Improve Include Performance Discover Why it is Slow

How to Improve Entity Framework Include Performance?

Entity Framework does a great job to generate SQL. However, they are often very far to be optimized.

using (var ctx = new CustomerContext())
{
    var customers = ctx.Customers
        .Include(x => x.Orders.Select(y => y.Items.Select(z => z.Product))
        .Include(x => x.Payments.Select(y => y.Items)
        .Include(x => x.Shippings.Select(y => y.Items)
        .ToList();
}

Answer

SPLIT the LINQ query in multiple queries
USE EF+ Query IncludeOptimized (Recommended)

SPLIT the LINQ query into multiple queries

You don't have to include everything in the same query, the divide and conquer strategy can apply here also!

Pros

Convert the BIG monster query generated by Entity Framework into multiple tiny monsters
Return less NULL value

Cons

Can sometimes be slower than Include
Cannot be used with AsNoTracking()
Multiple database round-trips is required

How?

SPLIT the queries in multiple smaller queries
Done!

using (var ctx = new CustomerContext())
{
    // 1. SPLIT the queries into multiple smaller queries
    var customers = ctx.Customers
            .Include(x => x.Orders.Select(y => y.Items.Select(z => z.Product))
            .ToList();
                    
    var customers = ctx.Customers
            .Include(x => x.Payments.Select(y => y.Items)
            .ToList();
                       
    var customers = ctx.Customers
            .Include(x => x.Shippings.Select(y => y.Items)
            .ToList();
                     
    // 2. Done!
}

USE EF+ Query IncludeOptimized (Recommended)

Entity Framework Plus library contains IncludeOptimized extension method which under the hood also split the query into multiples queries but way more:

Easier
Faster
Flexible

Pros

Easier to use than splitting queries
One database round-trip is required
Bonus: Allow to filter related entities

Cons

Can sometimes be slower than Include
Cannot be used with AsNoTracking()
Cannot be mixed with Include

How?

CHANGE all Include by IncludeOptimized
Done!

using (var ctx = new CustomerContext())
{
    // 1. CHANGE all Include by IncludeOptimized
    var customers = ctx.Customers
            .IncludeOptimized(x => x.Orders.Select(y => y.Items.Select(z => z.Product))
            .IncludeOptimized(x => x.Payments.Select(y => y.Items)
            .IncludeOptimized(x => x.Shippings.Select(y => y.Items)
            .ToList();
                       
    // 2. Done!
}

SQL Generated for Include vs IncludeOptimized

People looking at the SQL generated often become speechless.

SELECT
[UnionAll2].[ID] AS [C1],
[UnionAll2].[ID1] AS [C2],
[UnionAll2].[Code] AS [C3],
[UnionAll2].[CreatedDate] AS [C4],
[UnionAll2].[C1] AS [C5],
[UnionAll2].[ID2] AS [C6],
[UnionAll2].[ID3] AS [C7],
[UnionAll2].[Code1] AS [C8],
[UnionAll2].[Customer_ID] AS [C9],
[UnionAll2].[C2] AS [C10],
[UnionAll2].[ID4] AS [C11],
[UnionAll2].[ID5] AS [C12],
[UnionAll2].[Code2] AS [C13],
[UnionAll2].[ID6] AS [C14],
[UnionAll2].[Code3] AS [C15],
[UnionAll2].[Order_ID] AS [C16],
[UnionAll2].[C3] AS [C17],
[UnionAll2].[C4] AS [C18],
[UnionAll2].[C5] AS [C19],
[UnionAll2].[C6] AS [C20],
[UnionAll2].[C7] AS [C21],
[UnionAll2].[C8] AS [C22],
[UnionAll2].[C9] AS [C23],
[UnionAll2].[C10] AS [C24],
[UnionAll2].[C11] AS [C25],
[UnionAll2].[C12] AS [C26],
[UnionAll2].[C13] AS [C27],
[UnionAll2].[C14] AS [C28],
[UnionAll2].[C15] AS [C29],
[UnionAll2].[C16] AS [C30],
[UnionAll2].[C17] AS [C31],
[UnionAll2].[C18] AS [C32],
[UnionAll2].[C19] AS [C33],
[UnionAll2].[C20] AS [C34]
FROM (SELECT
CASE WHEN ([Join2].[ID1] IS NULL) THEN CAST(NULL AS int) ELSE 1 END AS [C1],
[Extent1].[ID] AS [ID],
[Extent1].[ID] AS [ID1],
[Extent1].[Code] AS [Code],
[Extent1].[CreatedDate] AS [CreatedDate],
[Join2].[ID1] AS [ID2],
[Join2].[ID1] AS [ID3],
[Join2].[Code1] AS [Code1],
[Join2].[Customer_ID] AS [Customer_ID],
CASE WHEN ([Join2].[ID1] IS NULL) THEN CAST(NULL AS int) WHEN ([Join2].[ID2] IS NULL) THEN CAST(NULL AS int) ELSE 1 END AS [C2],
[Join2].[ID2] AS [ID4],
[Join2].[ID2] AS [ID5],
[Join2].[Code2] AS [Code2],
[Join2].[ID3] AS [ID6],
[Join2].[Code3] AS [Code3],
[Join2].[Order_ID] AS [Order_ID],
CAST(NULL AS int) AS [C3],
CAST(NULL AS int) AS [C4],
CAST(NULL AS varchar(1)) AS [C5],
CAST(NULL AS int) AS [C6],
CAST(NULL AS int) AS [C7],
CAST(NULL AS int) AS [C8],
CAST(NULL AS int) AS [C9],
CAST(NULL AS varchar(1)) AS [C10],
CAST(NULL AS int) AS [C11],
CAST(NULL AS int) AS [C12],
CAST(NULL AS int) AS [C13],
CAST(NULL AS varchar(1)) AS [C14],
CAST(NULL AS int) AS [C15],
CAST(NULL AS int) AS [C16],
CAST(NULL AS int) AS [C17],
CAST(NULL AS int) AS [C18],
CAST(NULL AS varchar(1)) AS [C19],
CAST(NULL AS int) AS [C20]
FROM [dbo].[EF6_Performance_Include_IncludeOptimized_Customer] AS [Extent1]
LEFT OUTER JOIN (SELECT [Extent2].[ID] AS [ID1], [Extent2].[Code] AS [Code1], [Extent2].[Customer_ID] AS [Customer_ID], [Join1].[ID2], [Join1].[Code2], [Join1].[Order_ID], [Join1].[ID3], [Join1].[Code3]
FROM [dbo].[EF6_Performance_Include_IncludeOptimized_Order] AS [Extent2]
LEFT OUTER JOIN (SELECT [Extent3].[ID] AS [ID2], [Extent3].[Code] AS [Code2], [Extent3].[Order_ID] AS [Order_ID], [Extent4].[ID] AS [ID3], [Extent4].[Code] AS [Code3]
FROM [dbo].[EF6_Performance_Include_IncludeOptimized_OrderItem] AS [Extent3]
LEFT OUTER JOIN [dbo].[EF6_Performance_Include_IncludeOptimized_Product] AS [Extent4] ON [Extent3].[Product_ID] = [Extent4].[ID] ) AS [Join1] ON [Extent2].[ID] = [Join1].[Order_ID] ) AS [Join2] ON [Extent1].[ID] = [Join2].[Customer_ID]
UNION ALL
SELECT
2 AS [C1],
[Extent5].[ID] AS [ID],
[Extent5].[ID] AS [ID1],
[Extent5].[Code] AS [Code],
[Extent5].[CreatedDate] AS [CreatedDate],
CAST(NULL AS int) AS [C2],
CAST(NULL AS int) AS [C3],
CAST(NULL AS varchar(1)) AS [C4],
CAST(NULL AS int) AS [C5],
CAST(NULL AS int) AS [C6],
CAST(NULL AS int) AS [C7],
CAST(NULL AS int) AS [C8],
CAST(NULL AS varchar(1)) AS [C9],
CAST(NULL AS int) AS [C10],
CAST(NULL AS varchar(1)) AS [C11],
CAST(NULL AS int) AS [C12],
[Join4].[ID4] AS [ID2],
[Join4].[ID4] AS [ID3],
[Join4].[Code4] AS [Code1],
[Join4].[Customer_ID] AS [Customer_ID],
CASE WHEN ([Join4].[ID5] IS NULL) THEN CAST(NULL AS int) ELSE 1 END AS [C13],
[Join4].[ID5] AS [ID4],
[Join4].[ID5] AS [ID5],
[Join4].[Code5] AS [Code2],
[Join4].[Payment_ID] AS [Payment_ID],
CAST(NULL AS int) AS [C14],
CAST(NULL AS int) AS [C15],
CAST(NULL AS varchar(1)) AS [C16],
CAST(NULL AS int) AS [C17],
CAST(NULL AS int) AS [C18],
CAST(NULL AS int) AS [C19],
CAST(NULL AS int) AS [C20],
CAST(NULL AS varchar(1)) AS [C21],
CAST(NULL AS int) AS [C22]
FROM [dbo].[EF6_Performance_Include_IncludeOptimized_Customer] AS [Extent5]
INNER JOIN (SELECT [Extent6].[ID] AS [ID4], [Extent6].[Code] AS [Code4], [Extent6].[Customer_ID] AS [Customer_ID], [Extent7].[ID] AS [ID5], [Extent7].[Code] AS [Code5], [Extent7].[Payment_ID] AS [Payment_ID]
FROM [dbo].[EF6_Performance_Include_IncludeOptimized_Payment] AS [Extent6]
LEFT OUTER JOIN [dbo].[EF6_Performance_Include_IncludeOptimized_PaymentItem] AS [Extent7] ON [Extent6].[ID] = [Extent7].[Payment_ID] ) AS [Join4] ON [Extent5].[ID] = [Join4].[Customer_ID]
UNION ALL
SELECT
3 AS [C1],
[Extent8].[ID] AS [ID],
[Extent8].[ID] AS [ID1],
[Extent8].[Code] AS [Code],
[Extent8].[CreatedDate] AS [CreatedDate],
CAST(NULL AS int) AS [C2],
CAST(NULL AS int) AS [C3],
CAST(NULL AS varchar(1)) AS [C4],
CAST(NULL AS int) AS [C5],
CAST(NULL AS int) AS [C6],
CAST(NULL AS int) AS [C7],
CAST(NULL AS int) AS [C8],
CAST(NULL AS varchar(1)) AS [C9],
CAST(NULL AS int) AS [C10],
CAST(NULL AS varchar(1)) AS [C11],
CAST(NULL AS int) AS [C12],
CAST(NULL AS int) AS [C13],
CAST(NULL AS int) AS [C14],
CAST(NULL AS varchar(1)) AS [C15],
CAST(NULL AS int) AS [C16],
CAST(NULL AS int) AS [C17],
CAST(NULL AS int) AS [C18],
CAST(NULL AS int) AS [C19],
CAST(NULL AS varchar(1)) AS [C20],
CAST(NULL AS int) AS [C21],
[Join6].[ID6] AS [ID2],
[Join6].[ID6] AS [ID3],
[Join6].[Code6] AS [Code1],
[Join6].[Customer_ID] AS [Customer_ID],
CASE WHEN ([Join6].[ID7] IS NULL) THEN CAST(NULL AS int) ELSE 1 END AS [C22],
[Join6].[ID7] AS [ID4],
[Join6].[ID7] AS [ID5],
[Join6].[Code7] AS [Code2],
[Join6].[Shipping_ID] AS [Shipping_ID]
FROM [dbo].[EF6_Performance_Include_IncludeOptimized_Customer] AS [Extent8]
INNER JOIN (SELECT [Extent9].[ID] AS [ID6], [Extent9].[Code] AS [Code6], [Extent9].[Customer_ID] AS [Customer_ID], [Extent10].[ID] AS [ID7], [Extent10].[Code] AS [Code7], [Extent10].[Shipping_ID] AS [Shipping_ID]
FROM [dbo].[EF6_Performance_Include_IncludeOptimized_Shipping] AS [Extent9]
LEFT OUTER JOIN [dbo].[EF6_Performance_Include_IncludeOptimized_ShippingItem] AS [Extent10] ON [Extent9].[ID] = [Extent10].[Shipping_ID] ) AS [Join6] ON [Extent8].[ID] = [Join6].[Customer_ID]) AS [UnionAll2]
ORDER BY [UnionAll2].[ID1] ASC, [UnionAll2].[C1] ASC, [UnionAll2].[ID3] ASC, [UnionAll2].[C2] ASC, [UnionAll2].[C4] ASC, [UnionAll2].[C7] ASC, [UnionAll2].[C13] ASC, [UnionAll2].[C16] ASC

Did you really scroll down all the code to see all the SQL generated to execute this query?

Suprised? Astonished? Flabbergasted?

Yes, this is what I call a monster SQL, and if you execute it, most columns will contains a NULL value which makes it even worse.

Let's now look what's the SQL generated by IncludeOptimized method

//EF+ Query Future: 1 of 4

SELECT
[Project2].[ID] AS [ID],
[Project2].[C2] AS [C1],
[Project2].[ID1] AS [ID1],
[Project2].[C1] AS [C2],
[Project2].[ID2] AS [ID2],
[Project2].[Code] AS [Code]
FROM ( SELECT
[Extent1].[ID] AS [ID],
[Join2].[ID1] AS [ID1],
[Join2].[ID2] AS [ID2],
[Join2].[Code1] AS [Code],
[Join2].[C1] AS [C1],
CASE WHEN ([Join2].[ID1] IS NULL) THEN CAST(NULL AS int) ELSE 1 END AS [C2]
FROM [dbo].[EF6_Performance_Include_IncludeOptimized_Customer] AS [Extent1]
LEFT OUTER JOIN (SELECT [Extent2].[ID] AS [ID1], [Extent2].[Customer_ID] AS [Customer_ID], [Project1].[ID] AS [ID2], [Project1].[Code] AS [Code1], [Project1].[C1] AS [C1]
FROM [dbo].[EF6_Performance_Include_IncludeOptimized_Order] AS [Extent2]
LEFT OUTER JOIN (SELECT
[Extent3].[Order_ID] AS [Order_ID],
[Extent4].[ID] AS [ID],
[Extent4].[Code] AS [Code],
1 AS [C1]
FROM [dbo].[EF6_Performance_Include_IncludeOptimized_OrderItem] AS [Extent3]
LEFT OUTER JOIN [dbo].[EF6_Performance_Include_IncludeOptimized_Product] AS [Extent4] ON [Extent3].[Product_ID] = [Extent4].[ID] ) AS [Project1] ON [Extent2].[ID] = [Project1].[Order_ID] ) AS [Join2] ON [Extent1].[ID] = [Join2].[Customer_ID]
) AS [Project2]
ORDER BY [Project2].[ID] ASC, [Project2].[C2] ASC, [Project2].[ID1] ASC, [Project2].[C1] ASC
;

// EF+ Query Future: 2 of 4

SELECT
[Project1].[ID] AS [ID],
[Project1].[C2] AS [C1],
[Project1].[ID1] AS [ID1],
[Project1].[C1] AS [C2],
[Project1].[ID2] AS [ID2],
[Project1].[Code] AS [Code],
[Project1].[Payment_ID] AS [Payment_ID]
FROM ( SELECT
[Extent1].[ID] AS [ID],
[Join1].[ID1] AS [ID1],
[Join1].[ID2] AS [ID2],
[Join1].[Code1] AS [Code],
[Join1].[Payment_ID] AS [Payment_ID],
CASE WHEN ([Join1].[ID1] IS NULL) THEN CAST(NULL AS int) WHEN ([Join1].[ID2] IS NULL) THEN CAST(NULL AS int) ELSE 1 END AS [C1],
CASE WHEN ([Join1].[ID1] IS NULL) THEN CAST(NULL AS int) ELSE 1 END AS [C2]
FROM [dbo].[EF6_Performance_Include_IncludeOptimized_Customer] AS [Extent1]
LEFT OUTER JOIN (SELECT [Extent2].[ID] AS [ID1], [Extent2].[Customer_ID] AS [Customer_ID], [Extent3].[ID] AS [ID2], [Extent3].[Code] AS [Code1], [Extent3].[Payment_ID] AS [Payment_ID]
FROM [dbo].[EF6_Performance_Include_IncludeOptimized_Payment] AS [Extent2]
LEFT OUTER JOIN [dbo].[EF6_Performance_Include_IncludeOptimized_PaymentItem] AS [Extent3] ON [Extent2].[ID] = [Extent3].[Payment_ID] ) AS [Join1] ON [Extent1].[ID] = [Join1].[Customer_ID]
) AS [Project1]
ORDER BY [Project1].[ID] ASC, [Project1].[C2] ASC, [Project1].[ID1] ASC, [Project1].[C1] ASC
;

//EF+ Query Future: 3 of 4

SELECT
[Project1].[ID] AS [ID],
[Project1].[C2] AS [C1],
[Project1].[ID1] AS [ID1],
[Project1].[C1] AS [C2],
[Project1].[ID2] AS [ID2],
[Project1].[Code] AS [Code],
[Project1].[Shipping_ID] AS [Shipping_ID]
FROM ( SELECT
[Extent1].[ID] AS [ID],
[Join1].[ID1] AS [ID1],
[Join1].[ID2] AS [ID2],
[Join1].[Code1] AS [Code],
[Join1].[Shipping_ID] AS [Shipping_ID],
CASE WHEN ([Join1].[ID1] IS NULL) THEN CAST(NULL AS int) WHEN ([Join1].[ID2] IS NULL) THEN CAST(NULL AS int) ELSE 1 END AS [C1],
CASE WHEN ([Join1].[ID1] IS NULL) THEN CAST(NULL AS int) ELSE 1 END AS [C2]
FROM [dbo].[EF6_Performance_Include_IncludeOptimized_Customer] AS [Extent1]
LEFT OUTER JOIN (SELECT [Extent2].[ID] AS [ID1], [Extent2].[Customer_ID] AS [Customer_ID], [Extent3].[ID] AS [ID2], [Extent3].[Code] AS [Code1], [Extent3].[Shipping_ID] AS [Shipping_ID]
FROM [dbo].[EF6_Performance_Include_IncludeOptimized_Shipping] AS [Extent2]
LEFT OUTER JOIN [dbo].[EF6_Performance_Include_IncludeOptimized_ShippingItem] AS [Extent3] ON [Extent2].[ID] = [Extent3].[Shipping_ID] ) AS [Join1] ON [Extent1].[ID] = [Join1].[Customer_ID]
) AS [Project1]
ORDER BY [Project1].[ID] ASC, [Project1].[C2] ASC, [Project1].[ID1] ASC, [Project1].[C1] ASC
;

//EF+ Query Future: 4 of 4

SELECT
[Extent1].[ID] AS [ID],
[Extent1].[Code] AS [Code],
[Extent1].[CreatedDate] AS [CreatedDate]
FROM [dbo].[EF6_Performance_Include_IncludeOptimized_Customer] AS [Extent1]
ORDER BY [Extent1].[ID] ASC;

That's for sure not the most optimized SQL, but it's already way more readable.

Last updated: 2023-02-26
Author: ZZZ Projects

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#query

#performance

#query

#performance

Fastest Entity Framework Extensions

Entity Framework Improve Include Performance Discover Why it is Slow

How to Improve Entity Framework Include Performance?

Answer

SPLIT the LINQ query into multiple queries

Pros

Cons

How?

USE EF+ Query IncludeOptimized (Recommended)

Pros

Cons

How?

SQL Generated for Include vs IncludeOptimized

Got any EF6 Question?

Performance

Expression Evaluator

Code AI

Related

#query

#performance

#query

#performance

Fastest Entity Framework Extensions

Entity Framework Improve Include Performance Discover Why it is Slow

How to Improve Entity Framework Include Performance?

StackOverflow Related Questions

Answer

SPLIT the LINQ query into multiple queries

Pros

Cons

How?

USE EF+ Query IncludeOptimized (Recommended)

Pros

Cons

How?

SQL Generated for Include vs IncludeOptimized

Got any EF6 Question?

Performance

Expression Evaluator

Code AI

Related