GlideAggregate

The GlideAggregate class is an extension of GlideRecord and works in a similar way. The difference is that GlideRecord tends to give you database objects whereas GlideAggregate deals in counts and numbers.

We'll take a quick look at how GlideAggregate works:

var counter = new GlideAggregate('incident');
counter.addAggregate('COUNT');
counter.query();
if (counter.next()) {
    var noOfIncidents = counter.getAggregate('COUNT');
}

This first example will give us the number of incidents in the database and place it in the noOfIncidents field. We can add addQuery lines in exactly the same way we would for GlideRecord if we wanted to reduce the number of incident records we returned.

As well as COUNT, we can also use SUM, MAX, MIN, and AVG to get the total sum, maximum number, minimum number, and average, respectively.

I don't find GlideAggregate used that regularly, but it is an efficient way to count records.