title: Can't run Add-Migration on asp.net core Identity + PostgreSQL when change user id type
body: <p>I made a project with <strong>asp.net core 5</strong> and <strong>Identity</strong> and <strong>PostgreSql</strong> for database,
  when i change user id to <code>int</code>, then can't run <code>Add-Migration</code> and show this error below but when use <strong>SqlServer</strong> haven't any error and run correctly.</p>
  <pre><code>System.ArgumentOutOfRangeException: Specified argument was out of the range of valid values.
     at Npgsql.EntityFrameworkCore.PostgreSQL.Design.Internal.NpgsqlAnnotationCodeGenerator.GenerateValueGenerationStrategy(IDictionary`2 annotations, Boolean onModel)
     at Npgsql.EntityFrameworkCore.PostgreSQL.Design.Internal.NpgsqlAnnotationCodeGenerator.GenerateFluentApiCalls(IProperty property, IDictionary`2 annotations)
     at Microsoft.EntityFrameworkCore.Migrations.Design.CSharpSnapshotGenerator.GeneratePropertyAnnotations(IProperty property, IndentedStringBuilder stringBuilder)
     at Microsoft.EntityFrameworkCore.Migrations.Design.CSharpSnapshotGenerator.GenerateProperty(String builderName, IProperty property, IndentedStringBuilder stringBuilder)
     at Microsoft.EntityFrameworkCore.Migrations.Design.CSharpSnapshotGenerator.GenerateProperties(String builderName, IEnumerable`1 properties, IndentedStringBuilder stringBuilder)
     at Microsoft.EntityFrameworkCore.Migrations.Design.CSharpSnapshotGenerator.GenerateEntityType(String builderName, IEntityType entityType, IndentedStringBuilder stringBuilder)
     at Microsoft.EntityFrameworkCore.Migrations.Design.CSharpSnapshotGenerator.GenerateEntityTypes(String builderName, IReadOnlyList`1 entityTypes, IndentedStringBuilder stringBuilder)
     at Microsoft.EntityFrameworkCore.Migrations.Design.CSharpMigrationsGenerator.GenerateMetadata(String migrationNamespace, Type contextType, String migrationName, String migrationId, IModel targetModel)
     at Microsoft.EntityFrameworkCore.Migrations.Design.MigrationsScaffolder.ScaffoldMigration(String migrationName, String rootNamespace, String subNamespace, String language)
     at Microsoft.EntityFrameworkCore.Design.Internal.MigrationsOperations.AddMigration(String name, String outputDir, String contextType, String namespace)
     at Microsoft.EntityFrameworkCore.Design.OperationExecutor.AddMigrationImpl(String name, String outputDir, String contextType, String namespace)
     at Microsoft.EntityFrameworkCore.Design.OperationExecutor.AddMigration.&lt;&gt;c__DisplayClass0_0.&lt;.ctor&gt;b__0()
     at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.&lt;&gt;c__DisplayClass3_0`1.&lt;Execute&gt;b__0()
     at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.Execute(Action action)
  Specified argument was out of the range of valid values.
  </code></pre>
  <p>My code changes for change user id to <code>int</code> is:</p>
  <p>in <code>Startup</code>:</p>
  <pre><code>services.AddIdentity&lt;MyIdentityUser, IdentityRole&lt;int&gt;&gt;()
                  .AddEntityFrameworkStores&lt;MyAppContext&gt;()
                  .AddDefaultTokenProviders();
  </code></pre>
  <p>in <code>data context</code>:</p>
  <pre><code>public class MyAppContext : IdentityDbContext&lt;MyIdentityUser, IdentityRole&lt;int&gt;, int&gt;
  ...
  
  public class MyIdentityUser:IdentityUser&lt;int&gt;
      {}
  </code></pre>
  <p>What is the problem?
  <br>
  I want make this change for improve Database performance in queries because I think  query for integer is faster than default user id which is <code>Guid</code>(which is long string instead integer), is this correct?</p>