Introduction

Data caching was introduced with Internet Information Server (IIS) in order to optimize the transfer of Web pages and speed up the user s access to these pages. ASP 2. x did not have any native caching ability and simply made use of the caching provided by IIS. Third-party utilities could also be used to increase the caching abilities of ASP 2. x and provide a greater level of control over the IIS cache.

Caching is now available natively within ASP.NET and has three new faces: output, data, and fragment caching. Each of these methods provides new and powerful methods of optimizing the utilization of system resources and increasing application performance.

Output caching is more like the old method of caching provided by IIS; a single page is stored within memory for a small period of time, for any reason that the programmer sees fit. While this model is troublesome in some instances, it can be helpful to the end-user at times. This allows for faster access to pages that contain some dynamic content without having to regenerate the entire page.

Fragment caching is an innovation to output caching; it enables the programmer to determine which parts of a page should be cached for future reference. This is done by breaking the code into separate user controls and then caching the control. This new feature greatly expands on our caching options.

Data caching enables the programmer to have full control over the caching at the...