Report caches

A report cache is a special data store within MicroStrategy software that holds information that was recently requested from the data source to be displayed on a report. A cache is created when a report is executed for the first time and the request is submitted to the database to gather the latest data. The report's results are then cached, or stored, in MicroStrategy.

Generally, frequently requested reports are cached because future requests for the same reports return data faster if the report has been cached. The execution time is quicker because cached reports do not need to run against the data source. In a cache, results from your data source are stored and can be used by new job requests that require the same data.

Caching is a useful strategy your administrator can use to reduce demands on your database and improve the speed of MicroStrategy's reporting performance. However, cached data is not always the most up-to-date, because it has not been run through your data source since the cache was created.

You can get new data for a report that has been cached, by deleting the report's cache before you execute the report. (There are other ways to refresh data on a report, which are discussed in this chapter.) Deleting the report's cache forces the report to be executed through your data source again, thus returning the most recent data from your data source. You must have administrative privileges to delete a report cache.

You can see whether the results on a report have come from a MicroStrategy cache in two ways:

• Look at the Report Details for the report. To do this, open a report and, from the View menu, select Report Details. An example image of the Report Details pane and its related report is shown below:

In the Report Details pane above, the last line shows whether the cache was used to populate the report with data. For this report, the answer is Cache Used: No.

• Look at a report in SQL view. To do this, from the View menu select SQL View. As shown in the image below, for this report the 5th line says Cache Used: Yes.

Cached data and OLAP Services

MicroStrategy OLAP Services lets MicroStrategy Developer, Web, and Office users make use of features that slice and dice data in reports to create new reports, without re-executing SQL against the data source. These reports are called view reports. This improves performance by resulting in quicker data display within a report as users analyze and manipulate the data. OLAP Services view reports are populated from the original report's cache rather than being run against the data source.

The Report Objects pane is an OLAP Services feature that lets users create mini-reports based on an original report, by dragging objects on and off the report. When report objects are dragged to or from the Report Objects pane, the report results are recalculated based on the cached data rather than being submitted through the data source again.

To determine whether you have OLAP Services, and for details on other OLAP Services features, see OLAP Services.