When you create a report that organizes data in groups or sections, you can change the appearance of the report to a summary report by hiding the details of a group or section. Hiding details, particularly for a report that runs into hundreds of pages, shows key information at a glance. For reports containing large amounts of aggregate data, you can also create a summary table design, where the aggregate calculations are performed at the data set level. Figure 9‑3 shows two BIRT designs that contain the same data. The first design shows all details. The next design hides the details in each product line section.

Select and right‑click the grouped column or section heading. Choose Group➛Show Detail, or Section➛Show Detail.