There are two main ways to implement paging:

• Paging at the database level: In this case, the database returns only the page of products
the visitor wants to see.
• Paging at the application level: In this scenario, the data tier always returns the complete
list of products for a certain section of the site, and the presentation tier objects (such as
the GridView control) extract the requested page of products from the complete list. This
method has potential performance problems especially when dealing with large result
sets, because it transfers unnecessarily large quantities of data from the database to the
presentation tier. Additional data also needs to be stored on the server’s memory, unneces-
sarily consuming server resources.

Not original,copied from, :Beginning ASP.NET E-Commerce in C# From Novice to Professional.