ASP.Net Caching, Caching Concept

ASP.NET Caching:

Caching is process of storing frequently used data for reuse. Generally it stores data in memory becuase accessing data from memory is more efficient way rather that generate it again.

ASP.NET provides two types of catching:
1. Output Caching
2. Application Data Caching

Page Output Caching:
 Output caching is done with entire page or with the fragment/part of the page.
 a. Page Output Caching: ASP.Net allows caching entire contents of the page. This is good for caching static pages.

<%@ OutputCache Duration="60" VaryByParam="None" %>

Fragement/Pratial Page Caching:
  This is same as page output caching, but instead it uses to store part or fragment of the page in cache. This is done by caching user controls (.ascx) used in page.

<%@ OutputCache Duration="300" VaryByParam="*" Shared="true" %>

Here shared="true" is used to share same HTML if the user control is used in more than one pages, and to avoid caching same output/HTML of user control multiple time.

Application Data Caching: 

This is used to store data in cache like dataset or any collection objects, or any object that need to be cached:

Item can be added to cache using Cache.Insert(param, param) with expiration parameter. Also Item can be added to cache using Cache.add(param, param) with priority.

Data set can be added to cache like Cache["MyDataSet"] = MyDataSet; and retrived like ds = (DataSet) Cache["MyDataSet"].