Update Statistics (Model Designer)
Use the Update Statistics page to generate report model statistics. Report Model Designer collects counts on the unique instances of each entity. When you create a report model for the first time, it is recommended that you update the statistics. These statistics are not the same as database statistics. These statistics are used only to generate and set properties in the report model, and are stored within the data source view.
Update statistics before generating
Select to create or update the statistics for a report model. By default, this option is selected; however, it is recommended that you only update the statistical information when the data source is changed.
Use current statistics in the data source view
Select to use the current available statistics.