Parallel EntityFramework

Is it possible to make some work in parallel with entity framework for following example?

using (var dbContext = new DB())
{
var res = (from c in dbContext.Customers
           orderby c.Name
           select new
                    {
                    c.Id, 
                    c.Name,
                    c.Role
                    }
          ).ToDictionary(c => c.Id,
                         c => new Dictionary<string, object> {
                                                               { "Name",c.Name },
                                                               { "Role", c.Role }
                                                             });
}

For exampe what will be changed if I add AsParrallel?

using (var dbContext = new DB())
{
var res = (from c in dbContext.Customers
           orderby c.Name
           select new
                    {
                    c.Id, 
                    c.Name,
                    c.Role
                    }
          ).AsParallel().ToDictionary(c => c.Id,
                         c => new Dictionary<string, object> {
                                                               { "Name",c.Name },
                                                               { "Role", c.Role }
                                                             });
}

And one more example. The question is same what are the differences in 3 examples.

using (var dbContext = new DB()) 
{ 
var res = (from c in dbContext.Customers.AsParallel() 
           orderby c.Name 
           select new 
                    { 
                    c.Id,  
                    c.Name, 
                    c.Role 
                   } 
          ).AsParallel().ToDictionary(c => c.Id, 
                         c => new Dictionary<string, object> { 
                                                               { "Name",c.Name }, 
                                                               { "Role", c.Role } 
                                                             }); 
}