Chapter 23. Caching Application Pages and Data

In this Chapter

• Overview of Caching

• Using Page Output Caching

• Using Partial Page Caching

• Using DataSource Caching

• Using Data Caching

• Using SQL Cache Dependencies

• Summary

If someone put a gun to my head and told me that I had 5 minutes to improve the performance of a website, then I would immediately think of caching. By taking advantage of caching, you can dramatically improve the performance of your web applications.

The slowest operation that you can perform in an ASP.NET page is database access. Opening a database connection and retrieving data is a slow operation. The best way to improve the performance of your data access code is not to access the database at all.

By taking advantage of caching, you can cache your database records in memory. Retrieving data from a database is dog slow. Retrieving data from the cache, on the other hand, is lightning fast.

In this chapter, you learn about the different caching mechanisms supported by the ASP.NET Framework. The ASP.NET 2.0 Framework provides you with an (almost) overwhelming number of caching options. I attempt to clarify all these caching options over the course of this chapter.

In the final section of this chapter, you learn how to use SQL Cache Dependencies. A SQL Cache Dependency enables you to reload cached data automatically when data changes in a database table. You learn how to use both polling and push SQL Cache Dependencies.