Using Enity Framework 6.1 and initial query VERY slow.

Question

When performing the initial query using EF, it can take up to 9 mins. Though if you rerun it again and again it takes seconds. If I capture the query from the profiler, it always runs in seconds.

If I wait about 10 / 15 mins the slow initial process starts over.

Any way of dealing with this or a setting?

Answer 1

Hi,@Gary Paquette. Welcome to Microsoft Q&A. Optimization

1.For only part of the query available use AsNoTracking().

var items = EFDbContext.MyDbSet.AsNoTracking().ToList();

 

2.Use Ngen to install and generate a local image of EF.

a. Open a cmd window.

b. Switch to the bin directory of the program, such as: cd d:\website\bin.

c. Run the ngen command.

For 32 bit run:

%WINDIR%\Microsoft.NET\Framework\v4.0.30319\ngen install EntityFramework.SqlServer.dll

 

For 64 bit run:

%WINDIR%\Microsoft.NET\Framework64\v4.0.30319\ngen install EntityFramework.SqlServer.dll

 

3.Disabling the first EF query on the table __MigrationHistory(For Code first projects).

Add code

Database.SetInitializer<EFDbContext>(null);

EFDbContext is the EF context class of my project. You need to replace it with your own EF context class according to your project.

 

4.EF Pre-Generated Mapping Views.

Add code

using (var dbcontext = new EFDbContext())

{

var objectContext = ((IObjectContextAdapter)dbcontext).ObjectContext;

var mappingCollection = (StorageMappingItemCollection)objectContext.MetadataWorkspace.GetItemCollection(DataSpace.CSSpace);

mappingCollection.GenerateViews(new List<EdmSchemaError>());

}

5.If access becomes slow after a period of time, you could set the "idle timeout" of the application to make it longer. Or you could create a scheduled task to use EF regularly.

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