The Kusto Query Language (KQL) is the language you use to query data in Azure Data Explorer [1]. It's a powerful language that allows you to perform advanced queries and extract meaningful insights from your data.

To query for events that match the criteria you specified, you would use the following KQL query:

index==main NOT status==200

This query will return all events that are inside the main index and have a status field, but the value of the status field does not equal 200. It is important to note that the "NOT" operator must be used in order to exclude events with a status value of 200.

By using the "NOT" operator, the query will return only events that do not match the specified criteria. This is useful for narrowing down search results to only those events that are relevant to the query.

The fields sidebar in Splunk shows the default fields and the interesting fields for the events that match your search. The default fields are host, source, and sourcetype, which are extracted for every event at index time. The interesting fields are fields that appear in at least 20% of the events in your search results. You can also select additional fields to display in the fields sidebar1.

By default, the index field is not listed in the fields sidebar, because it is not a default field nor an interesting field. The index field is a metadata field that indicates which index the event belongs to. Metadata fields are not extracted from the event data, but are added by the indexer as part of the indexing process. Metadata fields are not shown in the fields sidebar, but you can use them in your search queries2.

Therefore, among the four options, only sourcetype would be listed in the fields sidebar under interesting fields by default.

References

• Use fields to search
• About default fields