You can create variables that derive unique values from existing data fields, which you can apply locally in the resource you’re working on to make monitoring and correlation more specific to particular scenarios.
In addition to these local variables, there is a global variable resource, which makes it possible to define a variable once, then re-use it in multiple places wherever conditions can be expressed (active channels, rules, filters, data monitors, and queries), and wherever fields can be selected (CCE, field sets).
Global variables are centralized and reusable, which make them an essential building block for user correlation in the Actors feature, and other advanced correlation scenarios.
Once created, global variables appear in the Common Conditions Editor (CCE) as additional fields on the Filters or Conditions tabs, as Group By arguments for data monitors and queries, and in rule conditions and actions. You can add variables to field sets in the Field Set Editor to extend the event and resource schema with values derived from other data fields.
The global variables feature also makes it possible to easily promote local variables defined for a particular resource into a global variable, where it can be re-used in other condition statements.
For details about using the Global Variables feature, see Global Variables.