Webtrends Analytics 9 Adminstration Guide, November 2012
Typically, you use SmartView to answer immediate questions about how your website is currently performing. Because websites change constantly, it makes sense to collect daily or weekly period data for SmartView profiles.
Focus reporting on short-term time periods to collect more of the data that is most important for SmartView reports and optimize the disk space, processing speed, and memory needed to create these reports.
As a best practice, configure your SmartView profiles to collect one of these period sets:
Collecting and storing only the report periods that make sense for SmartView means that as your website changes, there should be room in the internal tables that store analysis data to track those new links and pages.