Splunk Search

Which is better NOT or !=

Here are two searches that are the same.

NOT FIELD="value"

FIELD!="value"

Which should be used? Is this just a personal preference or are there any performance differences between the two.

There are lots of cases where the NOT prefixes a much more complex search, but I'm just wondering about this simple case.

1 Solution

Splunk Employee
Splunk Employee

These two searches are not the same.

NOT field="value" will return events where field is undefined (or null). field!="value" will only return events where field exists (and does not have the value "value").

In the case where the value in question is "*", NOT field=* will return events where field is null/undefined. field!=* will never return any events.

View solution in original post

Splunk Employee
Splunk Employee

These searches are not the same. See below.

Splunk Employee
Splunk Employee

These two searches are not the same.

NOT field="value" will return events where field is undefined (or null). field!="value" will only return events where field exists (and does not have the value "value").

In the case where the value in question is "*", NOT field=* will return events where field is null/undefined. field!=* will never return any events.

View solution in original post