Question

There is a book management system web application based on ASP.NET MVC3. When click the book index page, data query is very slow and user has to wait for several seconds for response. The code of Action Index in BookController below:

    public ViewResult Index(string sortOrder, int? page)
    {
        ViewBag.NameSortParam = string.IsNullOrEmpty(sortOrder) ? "desc" : "";
        ViewBag.CurrentSort = sortOrder;

        BookModel books = from b in db.Books select b; // db = new BookContext();
        switch (sortOrder) {
            case "desc":
                books = books.OrderByDescending(b => b.Name);
                break;
            default:
                books = books.OrderBy(b => b.Name);
                break;
        }
        int pageSize = 15;
        int pageNumber = (page ?? 1);

        return View(books.ToPagedList(pageNumber, pageSize));
    }

In my opinion, the main reason of slow is that server does not response to client until all data are ready. This process takes much time.

I do not know how to solve this problem, is there any method to improve data query performance in this case? Thank you!

update:
backend database is SQL Server Compact Edition 4.0

UPDATE
I update my logic code below, orderby is used before skip and take statements. Everything goes well. Thank you all for help.

books = (from b in db.Books
                       orderby b.Name descending
                       select b)
                       .Skip((page - 1) * pageSize)
                       .Take(pageSize)
                       .ToList();

Answer 1

You are loading in all your books before filtering the dataset to just the data you need (by using ToPagedList). Change your query and use the Skip and Take methods instead of ToPagedList.