gistfile1.txt

    public class Employee
    {
        [Key]
        public virtual int EmployeeId { get; protected set; }

        [StringLength(100)]
        public virtual string FirstName { get; set; }

        [StringLength(100)]
        public virtual string LastName { get; set; }

    }

    public class EmployeeMap : ClassMap<Employee>
    {
        public EmployeeMap()
        {
            Id(x => x.EmployeeId);

            Map(x => x.FirstName)
                .Length(100);

            Map(x => x.LastName)
                .Length(100);

            Table("Employees");
         
        }
    }

        static void EF_Select()
        {
            using (var context = new MyContext())
            {
                var pppp = context.Persons.Where(p => p.EmployeeId == 0).SingleOrDefault();

                DateTime start = DateTime.Now;

                int aggr = 0;
                foreach (var pp in context.Persons.Where(p => p.EmployeeId > 1)
                    .Select(p => new { p.EmployeeId, p.FirstName, p.LastName }))
                {
                    aggr += pp.EmployeeId;
                }

                Console.WriteLine(string.Format("EF select {0};", DateTime.Now - start));
            }
        }

        private static void NHibernate_Select()
        {
            var sessionFactory = CreateSessionFactory();

            using (var session = sessionFactory.OpenStatelessSession())
            {

                var pppp = session.Query<Employee>().Where(p => p.EmployeeId == 0).SingleOrDefault();

                DateTime start = DateTime.Now;

                int aggr = 0;
                foreach (var pp in session.Query<Employee>().Where(p => p.EmployeeId > 1)
                    .Select(p => new { p.EmployeeId, p.FirstName, p.LastName }))
                {
                    aggr += pp.EmployeeId;
                }

                Console.WriteLine(string.Format("NH select {0};", DateTime.Now - start));
            }
        }