title: How to search for logs where "only certain fields exist" in Kibana?
body: <p>I have multiple grok patterns configured to match the input in the Logstash config file. It starts detailed with multiple fields at the top and all encompassing just one {GREEDYDATA:message} at last. So some records might match just the last one or the one that has only certain fields. Is there a way to search for logs that have only &quot;message&quot; field, for example? I am able to search if certain fields exist in a record but not if only those fields exist.
  Also, is having multiple grok patterns the best way to handle different kinds of logs?</p>
  <p>I have around 100 fields so filtering with every thing else NOT EXISTS is not optimum.</p>