In Oracle 10g or higher, the ASH report can be generated using selected time interval. The report can be requested using Main menu Report | Performance | ASH Report. If this menu item is not enabled, then make sure that time interval is selected and the focus is on the screen that has time selection. The ASH report can also be requested using most popup menus, in the Reports submenu. The report can be generated using two formats: text and HTML.
The ASH report is generated by Oracle package dbms_workload_repository, ash_report_html() function. As alternative to this report, you can use Statspack performance report generated by Lab128 natively. The report contains the most important sections - "ASH - Top SQL Statements", "ASH - Top Service/Module" generated from Lab128 own ASH repository. You can also use Activity Explorer for detailed analysis of ASH data.