Webtrends Analytics 9 Adminstration Guide, November 2012
Typically, table limiting problems manifest themselves in one of two ways: slowed Webtrends performance due to insufficient system resources, or missing items in reports. As of Webtrends v7.5, reports also provide a message indicating when analysis or report tables have been trimmed to maintain table limits.
Very large analysis tables can cause performance degradation. The scope of this problem is not necessarily limited to the adjustment of table limits. It can also be a function of your web activity data and your report structure.
If significant items that you know were logged do not show up in reports, your table limits may be causing Webtrends to trim significant data. For example, you create a report using Pages as the primary dimension and Geographical Drilldown as the secondary dimension. When looking at daily reports, you see data for several regions that do not appear in the weekly reports. This scenario probably indicates that your weekly reports have reached their limits, and the missing regions have been rolled up in aggregate data. When you consider the combination of dimensions in this report, you can see that each one has the potential to contain many unique items, creating the possibility of very large reports. When Webtrends limits the tables for these reports, some unique items become part of aggregate data and are not shown individually.