Performance Tuning OLAP Reports
Reports that use an Analysis Services cube as a data source can often have performance problems during pre-execution. Before you even see the classic Report is being generated sign the report is slow to start.
The most common reason I’ve found for this performance lag has to do with parameters that are filtering the main dataset. For example, you have a report that uses a sales cube and you want the user to be able to select the date range that the report will return results for. This would mean you would add a filter to the dataset using a date dimension and check the box to make it a parameter.