Report Caching is one of the features of SSRS. When does caching come into the picture, what drives the requirement of having report caching. One of the features of SSRS is that the data is queried each time the report is run, well this could turn out to be disadvantage since the user would be required to wait for the data to re be requeried each time a report is run. SSRS handles this problem by report caching. With many reports it is not essential to have up to the second data. The requirement could be well that the data source is updated once or twice a day. This would require users need data that is accurate as of the end of the previous business period, perhaps a month or a quarter. For the situations mentioned earlier it does not make sense to have data be requeried everytime a user requests a report. Report caching is the answer and the option can be turned on individually for each report on the report server. When the option is turned on the report server saves copy of the report in a temporary location the first time the report is executed. On the second and future executions of the report the same parameter values are used if any and the report server pulls the information necessary to render the report from the report cache rather than requerying the database. In most cases report caching is faster than the reports which are required every time.
In order to enable report caching one needs to get to the SSRS reporting portal and choose the particular report. Choose the Manage option and look for the properties page, in that there would be choice for Processing options. In the processing options page there would be a choice for :
Cache a temporary copy of the report. Expire copy of report after a number of minutes. One needs to check this option and set the number of minutes after which copy of report expires.
There is also an another option where one can set up a schedule after which a temporary copy of the report expires.
Report caching is a powerful feature which when used with the understanding of business needs, this can be very useful.