Null Operators

Null operators return true or false.

Use is null and is not null in projections and in post-projection filters. You can't use them in pre-projection filters.

For example, display all the accounts that your reps have met with at least once.

Or, you can use case to replace null values with a value of your choice.

This example is not valid because you can't use is not null or is null before a projection:

Use is null with cogroup

A left outer cogroup combines the right data stream with the left data stream. If a record on the left side does not have a match on the right, the missing right value is null in the resulting data stream.

For example, suppose that you have a Meeting data set containing information about your rep's meetings with each account. You want to see all accounts that reps have not met with. Use a left outer cogroup between Ops and Meetings, then use is null to filter results.