In Chapter 10, Summary Indexes and CSV Files, we edited transforms.conf but did not explain what was happening. Let's take another look. Our transform stanza looks like this:
[flatten_summary_lookup] filename = flatten_summary_lookup.csv match_type = WILDCARD(url) max_matches = 1
Walking through what we added, we have the following terms and their descriptions:
- match_type = WILDCARD(url): This says that the value of the url field in the lookup file may contain wildcards. In our example, the URL might look like / contact/* in our CSV file.
- max_matches = 1: By default, up to 10 entries that match in the lookup file will be added to an event, with the values in each field being added to a multivalue field. In this case, we only want the first match to be applied.