If the saved search populating a summary index produces too many results, the summary index is less effective at speeding up searches. This usually occurs because one or more of the fields used for grouping has more unique values than expected.
One common example of a field that can have many unique values is the URL in a web access log. The number of URL values might increase in instances where:
On top of this, multiple URLs can represent exactly the same resource, as follows:
We will cover a few approaches ...