The configuration in this section is applicable to relational databases in general. The extension methods shown here will become available when you install a relational database provider (due to the shared Microsoft.EntityFrameworkCore.Relational package).

An index in a relational database maps to the same concept as an index in the core of Entity Framework.


By convention, indexes are named IX_<type name>_<property name>. For composite indexes <property name> becomes an underscore separated list of property names.

Data Annotations

Indexes can not be configured using Data Annotations.

Fluent API

You can use the Fluent API to configure the name of an index.

class MyContext : DbContext
    public DbSet<Blog> Blogs { get; set; }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
            .HasIndex(b => b.Url)

public class Blog
    public int BlogId { get; set; }
    public string Url { get; set; }