Professional ASP.NET 3.5 SP1 Edition: In C# and VB

Chapter 23. Caching

Performance is a key requirement for any application or piece of code that you develop. The browser helps with client-side caching of text and images, whereas the server-side caching you choose to implement is vital for creating the best possible performance. Caching is the process of storing frequently used data on the server to fulfill subsequent requests. You will discover that grabbing objects from memory is much faster than re-creating the Web pages or items contained in them from scratch each time they are requested. Caching increases your application's performance, scalability, and availability. The more you fine-tune your application's caching approach, the better it performs.

This chapter focuses on caching, including the SQL invalidation caching capabilities that ASP.NET provides. This chapter takes a close look at this unique aspect of caching. When you are using SQL cache invalidation, if the result set from SQL Server changes, the output cache can be triggered to change automatically. This ensures that the end user always sees the latest result set, and the data presented is never stale. After introducing SQL cache invalidation, this chapter also covers other performance enhancements. It discusses the new Post-Cache Substitution feature, which caches entire pages while dynamically replacing specified bits of content. Lastly, this chapter covers a new capability that enables a developer to create custom dependencies.

Caching

There are several ways to ...