1. Splunk Enterprise Documentation
Search Manual
Version 9.2.1
"Use comparison operators": This section explicitly states
"The != and operators return true if the field does not have the specified value. This comparison does not return events that do not have the field." This confirms that status != 100 requires the status field to be present in the event.
2. Splunk Enterprise Documentation
Search Manual
Version 9.2.1
"Boolean expressions": This section describes the NOT operator's function to negate the expression that follows. The search NOT status=100 is interpreted as "return events where the statement 'status equals 100' is not true." This condition is met by events lacking a status field
thus including them in the results.
3. Splunk Education
Splunk Core Certified User course materials
Module 5: Filtering and Formatting Results: This official training module for the SPLK-1001 certification covers the fundamental differences in filtering logic between comparison operators like != and boolean operators like NOT
emphasizing this exact scenario as a key concept for users to understand.