Analysis using a regular expression does not match the results of the regular expression tester


Webtrends Analytics 9.x
Webtrends Analytics 8.x


A filter using a regular expression successfully passes the regular expression test, yet when the profile is analyzed, the report which should display data defined by the regular expression does not produce the expected results.


The tester works using a method considered a “non-greedy match,” in which it is evaluated from right to left. The Webtrends analysis engine performs a “greedy match,” evaluating the entire expression in one pass. A properly crafted greedy statement will work in both cases, so the regular expression must be built as a greedy match to guarantee results.

The following article provides additional information about greedy vs non-greedy statements: