When should I use a CompiledQuery?

You should use a CompiledQuery when all of the following are true:

The query will be executed more than once, varying only by parameter values.
The query is complex enough that the cost of expression evaluation and view generation is "significant" (trial and error)
You are not using a LINQ feature like IEnumerable<T>.

Also to know is, how we can increase the performance of Entity Framework?

Tips to improve Entity Framework Performance

Avoid to put all the DB Objects into One Single Entity Model.
Disable change tracking for entity if not needed.
Use Pre-Generating Views to reduce response time for first request.
Avoid fetching all the fields if not required.
Choose appropriate Collection for data manipulation.
Use Compiled Query wherever needed.

Also, what is compiled query? A compiled query is an object that keeps a prepared SQL statement and a delegate to a materializing function. The first one is to be executed at the server to get rows related to the query, the second one transforms a result set into a sequence of entity objects.

Also to know, what are the benefits of a deferred execution in Linq?

Deferred Execution returns the Latest Data As you can see, the second foreach loop executes the query again and returns the latest data. Deferred execution re-evaluates on each execution; this is called lazy evaluation. This is one of the major advantages of deferred execution: it always gives you the latest data.

What is compiled query in Entity Framework?

A compiled query is a cached version of the actual query, that we use to get the results. We write the query. For the first time it is parsed or verified for any kind of syntax error in LINQ, then converted into SQL version and is added into cache.

Why is Entity Framework so slow?

The fact of the matter is that products such as Entity Framework will ALWAYS be slow and inefficient, because they are executing lot more code. Remove layers such as LINQ, EF and others, and your code will run efficiently, will scale, and yes, it will still be easy to maintain. Too much abstraction is a bad 'pattern'.

Why do we use Entity Framework?

Entity Framework is an open-source ORM framework for . NET applications supported by Microsoft. It enables developers to work with data using objects of domain specific classes without focusing on the underlying database tables and columns where this data is stored.

How does Entity Framework work?

The Entity Framework uses information in the model and mapping files to translate object queries against entity types represented in the conceptual model into data source-specific queries. Query results are materialized into objects that the Entity Framework manages. For more information, see LINQ to Entities.

Is Entity Framework faster than stored procedures?

The overall winner is Stored Procedure, where Stored Procedure won 3 times while Entity Framework won 2 times. A few interesting insight from the profiling: Stored Procedure performed marginally better in overall. Entity Framework is marginally slower but it is not as slow as making Stored Procedure a clear winner.

Is Entity Framework slower than ado net?

As we can see in the data above Entity Framework is markedly slower than either ADO.NET or Dapper.NET, on the order of 3-10 times slower. The data shows that, at least in terms of raw speed and with these queries, Entity Framework will be the slowest option, and Dapper.NET will (narrowly) be the fastest.

What is AsNoTracking in Entity Framework?

The AsNoTracking() extension method returns a new query and the returned entities will not be cached by the context (DbContext or Object Context). This means that the Entity Framework does not perform any additional processing or storage of the entities that are returned by the query.

How LINQ queries improve performance?

Five Tips to Improve LINQ to SQL Performance

Tip #1: Ditch the Extra Baggage with ObjectTrackingEnabled.
Tip #2: Slim Down Your Queries with Projections.
Tip #3: Optimize Your Optimistic Concurrency Checking.
Tip #4: Keep the Number of Parameters Down.
Tip #5: Debug and Optimize Your Queries.
Conclusion.

Is EF core production ready?

Entity Framework Core 2.1: Heck Yes, It's Production Ready!

What is deferred execution in C#?

In Deferred Execution, the query is not executed when declared. It is executed when the query object is iterated over a loop. In Immediate Execution, the query is executed when it is declared. Deferred Execution: Now we will see both the executions using an example.

What is lambda expression in C#?

Background Topics - Lambda expressions A lambda expression is a convenient way of defining an anonymous (unnamed) function that can be passed around as a variable or as a parameter to a method call. Many LINQ methods take a function (called a delegate) as a parameter. The => operator is called the "lambda operator".

What is the use of expression tree in C#?

Expression Trees. Expression Trees was first introduced in C# 3.0 (Visual Studio 2008), where they were mainly used by LINQ providers. Expression trees represent code in a tree-like format, where each node is an expression (for example, a method call or a binary operation such as x < y).

How LINQ query execute?

At what point query expressions are executed can vary. LINQ queries are always executed when the query variable is iterated over, not when the query variable is created. This is called deferred execution. You can also force a query to execute immediately, which is useful for caching query results.

What is SQL compile?

When the documentation refers to recompiling a stored procedure or the SQL Server Profiler records a compilation event, compilation means the process of compiling the special T-SQL statements and optimizing the SELECT, INSERT, UPDATE, and DELETE statements.